University of Guilan Animal Production Research 2252-0872 12 2 2023 08 23 Effect of dietary supplementation of selenium and levothyroxine on performance, carcass characteristics, and thyroid hormone concentration in broiler chickens fed diets containing rapeseed meal Effect of dietary supplementation of selenium and levothyroxine on performance, carcass characteristics, and thyroid hormone concentration in broiler chickens fed diets containing rapeseed meal 1 13 6947 10.22124/ar.2023.23375.1734 FA M. Shiukhi Khotbasera Former MSc Student, Department of Animal Science, Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran H. Darmani Kuhi Associate Professor, Department of Animal Science, Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran A. Ohadi Haeri Assistant Professor, Department of Animal Science, Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran Journal Article 2022 12 03 Introduction: Soybean meal (SBM) is the main protein source in diets for poultry due to its high protein and excellent amino acid quality and profile, in addition to its high availability of amino acids. However, in some countries, other protein sources are available at lower prices and can be included in least-cost formulations instead of SBM. Rapeseed meal (RM) is the second most important oil-producing crop after soybean. Recently, there has been increasing interest in rapeseed production in countries around the world including Iran. Although RM has a good amino acid profile, its crude protein content (36% to 39%) is lower than that of SBM (44% to 48%). Despite higher levels of methionine and cysteine in RM, its lysine content is lower than SBM. The use of RM has been limited by its low available protein and energy contents relative to SBM. The main factor affecting the levels of available crude protein and energy content is the fibrous hull of RM. RM also contains non-starch polysaccharides and glucosinolates. Excessive levels of RM and thus high dietary glucosinolate content could lead to abnormalities in thyroid function activities and consequently a retardation in growth performance. Therefore, the objectives of the current study were to determine the effects of dietary selenium (Se) and levothyroxine (LT) supplementation on performance, carcass characteristics, and thyroid hormone concentration in broiler chickens fed diets containing RM. Materials and methods: This experiment was performed to evaluate the effect of dietary Se and LT supplementation on performance, carcass characteristics, weight of internal organs, and thyroid hormone concentration in broiler chickens of commercial strain Ross 308. The experimental treatments were: 1) diet based on SBM and corn grain (positive control), 2) diet with 10% RM (negative control 1, NG1), 3) diet with 20% RM (negative control 2, NG2), 4) NG1+ 0.3 mg Se/kg diet, 5) NG2+ 0.3 mg Se/kg diet, 6) NG1+ 80 µg LT/kg diet, 7) NG2+ 80 µg LT/kg diet, 8) NG1+ 0.3 mg Se and 80 µg LT/kg diet, and 9) NG2+ 0.3 mg Se and 80 µg LT/kg diet. Nine dietary treatments with four replications and 15 chickens in each replication were allocated to the experimental pens in a completely randomized design. During the experimental period (1 to 42 days), average feed intake, body weight gain, and feed conversion ratio were measured. At day 38, two birds from each pen were selected and blood was taken from their axillary vein for measuring thyroid hormones. At the end of the experiment (day 42), two birds from each replicate were selected, weighed, and slaughtered for carcass and internal organs weight determination. Results and discussion: The results showed that there were no significant differences between the treatments receiving RM and the positive control treatment in terms of growth performance. The percentage of abdominal fat and the relative weight of the internal organs, except the gizzard, were not significant between the dietary treatments. The treatment of 10% RM supplemented with Se and LT had the highest relative weight of the thymus. The treatment with 20% RM had the highest and the treatment with 10% RM + LT and 10% RM + LT and SE had the lowest relative weight of bursa Fabricius. The relative weight of the spleen was not affected by the experimental treatments. The treatment containing 20% RM showed the lowest carcass weight and the positive control treatment had the highest percentage of breast muscle. The use of RM at 20% caused a significant increase in thyroid weight compared to the positive control group (group without RM). The thyroid weight was reduced by SE and LT supplementation to diets containing RM. Rapeseed meal had no significant effect on T4 hormone levels, but treatments supplemented with SE increased and treatments supplemented with LT decreased T3 hormone levels. Also, the level of TSH hormone in the treatments receiving RM was lower than that in the treatments without RM. Chickens receiving RM with SE and LT had the highest levels of antioxidant enzymes of glutathione peroxidase and superoxide dismutase. Conclusions: According to the results of the present experiment, supplementing RM with SE and LT decreased the weight of the thyroid gland and increased the level of antioxidant enzymes, which suggests the positive effects of the use of these compounds in the diet based on RM on the function of the thyroid gland. Introduction: Soybean meal (SBM) is the main protein source in diets for poultry due to its high protein and excellent amino acid quality and profile, in addition to its high availability of amino acids. However, in some countries, other protein sources are available at lower prices and can be included in least-cost formulations instead of SBM. Rapeseed meal (RM) is the second most important oil-producing crop after soybean. Recently, there has been increasing interest in rapeseed production in countries around the world including Iran. Although RM has a good amino acid profile, its crude protein content (36% to 39%) is lower than that of SBM (44% to 48%). Despite higher levels of methionine and cysteine in RM, its lysine content is lower than SBM. The use of RM has been limited by its low available protein and energy contents relative to SBM. The main factor affecting the levels of available crude protein and energy content is the fibrous hull of RM. RM also contains non-starch polysaccharides and glucosinolates. Excessive levels of RM and thus high dietary glucosinolate content could lead to abnormalities in thyroid function activities and consequently a retardation in growth performance. Therefore, the objectives of the current study were to determine the effects of dietary selenium (Se) and levothyroxine (LT) supplementation on performance, carcass characteristics, and thyroid hormone concentration in broiler chickens fed diets containing RM. Materials and methods: This experiment was performed to evaluate the effect of dietary Se and LT supplementation on performance, carcass characteristics, weight of internal organs, and thyroid hormone concentration in broiler chickens of commercial strain Ross 308. The experimental treatments were: 1) diet based on SBM and corn grain (positive control), 2) diet with 10% RM (negative control 1, NG1), 3) diet with 20% RM (negative control 2, NG2), 4) NG1+ 0.3 mg Se/kg diet, 5) NG2+ 0.3 mg Se/kg diet, 6) NG1+ 80 µg LT/kg diet, 7) NG2+ 80 µg LT/kg diet, 8) NG1+ 0.3 mg Se and 80 µg LT/kg diet, and 9) NG2+ 0.3 mg Se and 80 µg LT/kg diet. Nine dietary treatments with four replications and 15 chickens in each replication were allocated to the experimental pens in a completely randomized design. During the experimental period (1 to 42 days), average feed intake, body weight gain, and feed conversion ratio were measured. At day 38, two birds from each pen were selected and blood was taken from their axillary vein for measuring thyroid hormones. At the end of the experiment (day 42), two birds from each replicate were selected, weighed, and slaughtered for carcass and internal organs weight determination. Results and discussion: The results showed that there were no significant differences between the treatments receiving RM and the positive control treatment in terms of growth performance. The percentage of abdominal fat and the relative weight of the internal organs, except the gizzard, were not significant between the dietary treatments. The treatment of 10% RM supplemented with Se and LT had the highest relative weight of the thymus. The treatment with 20% RM had the highest and the treatment with 10% RM + LT and 10% RM + LT and SE had the lowest relative weight of bursa Fabricius. The relative weight of the spleen was not affected by the experimental treatments. The treatment containing 20% RM showed the lowest carcass weight and the positive control treatment had the highest percentage of breast muscle. The use of RM at 20% caused a significant increase in thyroid weight compared to the positive control group (group without RM). The thyroid weight was reduced by SE and LT supplementation to diets containing RM. Rapeseed meal had no significant effect on T4 hormone levels, but treatments supplemented with SE increased and treatments supplemented with LT decreased T3 hormone levels. Also, the level of TSH hormone in the treatments receiving RM was lower than that in the treatments without RM. Chickens receiving RM with SE and LT had the highest levels of antioxidant enzymes of glutathione peroxidase and superoxide dismutase. Conclusions: According to the results of the present experiment, supplementing RM with SE and LT decreased the weight of the thyroid gland and increased the level of antioxidant enzymes, which suggests the positive effects of the use of these compounds in the diet based on RM on the function of the thyroid gland.

https://ar.guilan.ac.ir/article_6947_d652b6155b843bd536ee45969f0a0320.pdf

University of Guilan Animal Production Research 2252-0872 12 2 2023 08 23 Effect of corn particle size on performance, relative weights of gastrointestinal organs, and small intestine morphology in male Ross 308 broiler chickens Effect of corn particle size on performance, relative weights of gastrointestinal organs, and small intestine morphology in male Ross 308 broiler chickens 15 29 6902 10.22124/ar.2023.23553.1743 FA A. Atrian Ph.D. Student of Animal and Poultry Nutrition, Department of Animal Science, Faculty of Agriculture, University of Kurdistan, Sanandaj, Iran A. Karimi Professor, Department of Animal Science, Faculty of Agriculture, University of Kurdistan, Sanandaj, Iran A. A. Sadeghi Professor, Department of Animal Science, Faculty of Agriculture, University of Kurdistan, Sanandaj, Iran Journal Article 2023 01 02 Introduction: Many studies have been conducted to determine proper corn particle sizes for mash or pelleted diets in broiler chicken’s nutrition, aiming not only to achieve optimum production goals such as higher weight gain and minimum feed conversion ratio but also to reduce milling energy expenditures. However, pelleted and crumbled feed forms are mainly used in intensive poultry production systems in many countries, and mash feed is primarily common in less intensive production systems. Mash feed is less costly and puts less pressure on birds’ metabolic systems to achieve their optimum biological growth potential, which may result in higher welfare and lower metabolic disorders. Therefore, the purpose of this study was to investigate the effects of different proportions of fine and coarse ground corn (3- and 6-mm sieve opening hole size, respectively) on performance, the relative weight of gastrointestinal organs (%), and intestinal morphology in male broiler chickens. Materials and methods: A total of 576 1-day-old male Ross 308 broiler chicks were purchased from a commercial hatchery and raised from 1 to 42 days of age. All birds received identical basal diets from 1 to 11 days of age, but different experimental diets from 12 to 42 d. Experimental diets (12 to 42 days of age) consisted of six corn mixtures prepared by combining different proportions (w/w) of corn ground through sieves with either hole sizes of 3 or 6 mm as 100:0; 80:20; 60:40; 40:60; 20:80 and 0:100 percentage, respectively. The particle size characteristics including geometric mean diameter (GMD) and geometric standard deviation (GSD) of ground corn and finished feed samples were determined. Birds’ body weight was recorded at 12, 24, and 42 days of age as a group basis for the calculation of birds’ bodyweight gain (BWG) during the grower (12-24 d) and finisher (25-42d) periods. The birds’ feed intakes (FI) were also measured during the same period to calculate the feed conversion ratio (FCR) after adjustments were made for the body weights of dead birds, which were recorded daily. on the 21st day of the experiment, two birds from each pen were selected and killed via cervical dislocation. The liver, gizzard, small intestine, caecum, and pancreas of the sampled birds were carefully removed from their abdominal cavity, their weights were recorded carefully, and the relative weights of these parts to the live body weights were calculated and expressed as the percentage of birds live weights. Gizzard acidity was measured on the 21st day of the experiment. Parts from the middle of the jejunum and ileum of slaughtered birds (21 d) were excised and flushed gently with saline solution and immediately placed in a 10% formalin solution. Villus height, villus width, and crypt depth were measured in the laboratory. Results and discussion: Results showed that feeding mash diets with different particle sizes (~775, 835, 910, 1000, 1060, and 1150 µm) had no significant effects on birds’ BWG, FI, and FCR during different growth periods. However, the orthogonal polynomial contrast test showed that the changing of feed particle size from fine (~775 µm) to coarser particles by combining different portions of corn ground with a sieve hole size of 3 mm (~775 µm) and 6 mm (~1150 µm) had linearly deteriorated BWG and FCR from 12 to 24 days of age. The birds’ mortality rate (%) was not influenced by average feed particle size from 12 to 42 days of age. The negative influence of very coarse particle size from 12 to 24 days of age (>1000 µm) in the current experiment is an indicator of birds’ gastrointestinal limits in dealing with coarse particles. The coarse grain particles increase the energy required for the growth and maintenance of the gizzard. The results of the current experiment showed that feed particle size did not significantly affect the relative weights of gastrointestinal sections to body weight at 21 d (P>0.05). However, the relative weight of gizzard to live body weight at 21 d significantly (P<0.001) increased in birds fed diets with higher average particle size (≥775 µm). The results of the orthogonal polynomial contrast test showed that the relative weight of gizzard to live body weight at 21 days of age linearly (P<0.0001) increased by changing the feed particle size from fine to coarser particles. Coarse particles increased the digesta content in the gizzard, which stimulates the development of the gizzard. In addition, the findings of the current experiment indicated that ileum and jejunum morphometry traits such as villus height, crypt depth, villus height to crypt depth, villus tips, and base widths were not influenced by changing the average feed particle size. The pH of gizzard content at 21 days of age was not influenced by the feed particle size. Conclusions: Feed particle size of 775 to 1150 µm in a corn-based mash diet had no significant effect on performance traits or small intestine morphology traits. However, high coarse diets had the potential to deteriorate BWG and FCR at earlier stages of the growth period. Introduction: Many studies have been conducted to determine proper corn particle sizes for mash or pelleted diets in broiler chicken’s nutrition, aiming not only to achieve optimum production goals such as higher weight gain and minimum feed conversion ratio but also to reduce milling energy expenditures. However, pelleted and crumbled feed forms are mainly used in intensive poultry production systems in many countries, and mash feed is primarily common in less intensive production systems. Mash feed is less costly and puts less pressure on birds’ metabolic systems to achieve their optimum biological growth potential, which may result in higher welfare and lower metabolic disorders. Therefore, the purpose of this study was to investigate the effects of different proportions of fine and coarse ground corn (3- and 6-mm sieve opening hole size, respectively) on performance, the relative weight of gastrointestinal organs (%), and intestinal morphology in male broiler chickens. Materials and methods: A total of 576 1-day-old male Ross 308 broiler chicks were purchased from a commercial hatchery and raised from 1 to 42 days of age. All birds received identical basal diets from 1 to 11 days of age, but different experimental diets from 12 to 42 d. Experimental diets (12 to 42 days of age) consisted of six corn mixtures prepared by combining different proportions (w/w) of corn ground through sieves with either hole sizes of 3 or 6 mm as 100:0; 80:20; 60:40; 40:60; 20:80 and 0:100 percentage, respectively. The particle size characteristics including geometric mean diameter (GMD) and geometric standard deviation (GSD) of ground corn and finished feed samples were determined. Birds’ body weight was recorded at 12, 24, and 42 days of age as a group basis for the calculation of birds’ bodyweight gain (BWG) during the grower (12-24 d) and finisher (25-42d) periods. The birds’ feed intakes (FI) were also measured during the same period to calculate the feed conversion ratio (FCR) after adjustments were made for the body weights of dead birds, which were recorded daily. on the 21st day of the experiment, two birds from each pen were selected and killed via cervical dislocation. The liver, gizzard, small intestine, caecum, and pancreas of the sampled birds were carefully removed from their abdominal cavity, their weights were recorded carefully, and the relative weights of these parts to the live body weights were calculated and expressed as the percentage of birds live weights. Gizzard acidity was measured on the 21st day of the experiment. Parts from the middle of the jejunum and ileum of slaughtered birds (21 d) were excised and flushed gently with saline solution and immediately placed in a 10% formalin solution. Villus height, villus width, and crypt depth were measured in the laboratory. Results and discussion: Results showed that feeding mash diets with different particle sizes (~775, 835, 910, 1000, 1060, and 1150 µm) had no significant effects on birds’ BWG, FI, and FCR during different growth periods. However, the orthogonal polynomial contrast test showed that the changing of feed particle size from fine (~775 µm) to coarser particles by combining different portions of corn ground with a sieve hole size of 3 mm (~775 µm) and 6 mm (~1150 µm) had linearly deteriorated BWG and FCR from 12 to 24 days of age. The birds’ mortality rate (%) was not influenced by average feed particle size from 12 to 42 days of age. The negative influence of very coarse particle size from 12 to 24 days of age (>1000 µm) in the current experiment is an indicator of birds’ gastrointestinal limits in dealing with coarse particles. The coarse grain particles increase the energy required for the growth and maintenance of the gizzard. The results of the current experiment showed that feed particle size did not significantly affect the relative weights of gastrointestinal sections to body weight at 21 d (P>0.05). However, the relative weight of gizzard to live body weight at 21 d significantly (P<0.001) increased in birds fed diets with higher average particle size (≥775 µm). The results of the orthogonal polynomial contrast test showed that the relative weight of gizzard to live body weight at 21 days of age linearly (P<0.0001) increased by changing the feed particle size from fine to coarser particles. Coarse particles increased the digesta content in the gizzard, which stimulates the development of the gizzard. In addition, the findings of the current experiment indicated that ileum and jejunum morphometry traits such as villus height, crypt depth, villus height to crypt depth, villus tips, and base widths were not influenced by changing the average feed particle size. The pH of gizzard content at 21 days of age was not influenced by the feed particle size. Conclusions: Feed particle size of 775 to 1150 µm in a corn-based mash diet had no significant effect on performance traits or small intestine morphology traits. However, high coarse diets had the potential to deteriorate BWG and FCR at earlier stages of the growth period.

https://ar.guilan.ac.ir/article_6902_419a40d5107680508e4dcdbfd27dfdd4.pdf

University of Guilan Animal Production Research 2252-0872 12 2 2023 08 23 Effect of unprotected methionine and choline on feed intake, growth, digestibility, fecal score, blood metabolites, and feeding behavior of suckling calves Effect of unprotected methionine and choline on feed intake, growth, digestibility, fecal score, blood metabolites, and feeding behavior of suckling calves 31 41 7024 10.22124/ar.2023.23543.1742 FA T. Ghoorchi Professor, Department of Animal and Poultry Nutrition, Faculty of Animal Science, Gorgan University of Agricultural Science and Natural Resources, Gorgan, Iran M. Hossein Abadi Former Ph.D. Student, Department of Animal and Poultry Nutrition, Faculty of Animal Science, Gorgan University of Agricultural Science and Natural Resources, Gorgan, Iran A. H. Toghdory Assistant Professor, Department of Animal and Poultry Nutrition, Faculty of Animal Science, Gorgan University of Agricultural Science and Natural Resources, Gorgan, Iran 0000-0002-5198-1940 Journal Article 2023 01 01 Introduction: Choline and methionine are crucial nutrients for livestock as they provide methyl groups. The relationship between these two nutrients is intricate, with varying opinions on their interdependence. Methionine is often a limiting amino acid in dairy diets and its metabolism is linked to that of choline and betaine. Choline as an alternative to methionine, can act as a precursor to phosphatidylcholine, which is important for dairy cows around calving time. Furthermore, choline and betaine impact methionine requirements and methionine can affect choline metabolism. Given that limited study and experimentation have been conducted so far to investigate the effects of unprotected methionine and choline on calves, this research aimed to examine the impact of unprotected methionine and choline on feed intake, growth, digestibility, fecal score, blood metabolites, and feed behavior of pre-weaned calves. The expected hypothesis of the study was the significant effect of utilizing unprotected methionine and choline on feed intake, growth, digestibility, fecal score, blood metabolites, and feeding behavior of pre-weaned calves due to their mono-gastric nature and lack of rumen development. Materials and methods: A total number of 32 Simmental male suckling calves, aged approximately one month old with an initial weight of 44±2.1 kg, were used in this study. The experimental treatments included: 1) a basal diet without choline and methionine (control), 2) the basal diet with three grams of methionine, 3) the basal diet with three grams of choline, and 4) the basal diet with 1.5 grams of methionine and 1.5 grams of choline per head per day. The calves were randomly assigned to the experimental treatments in a completely randomized design with eight replications. The study lasted for 45 days, including a 7-day adaptation period. Blood glucose, cholesterol, triglycerides, and urea nitrogen levels were measured on the last day of the study, four hours after morning feeding, to evaluate the metabolic profile of the animals. Additionally, feed consumption behavior was visually observed for 24 hours on the last day of the study to calculate the animal's rumination, eating, chewing, and resting time. To determine the digestibility of dry matter, samples were collected from feed and feces during the last three days of the experiment using the acid-insoluble ash internal indicator method. Stool consistency was scored for all of the calves as an indicator of animal health. Results and discussion: The inclusion of three grams of methionine in the experimental treatments resulted in a decrease in dry matter intake, and when methionine and choline were added, it increased the daily weight gain of the animals (P<0.05). However, the treatments did not have a significant effect on the feed conversion ratio (P>0.05). The results of other studies showed that the addition of choline did not have a significant effect on the amount of dry matter consumed, daily weight gain, and feed conversion ratio of Holstein bull calves. Consistent with the results of the present study, no improvement was observed in the feed efficiency of steers with the addition of a protected choline supplement, and no effect was observed on dry matter intake. The treatments did not have a significant impact on dry matter digestibility, stool consistency, blood glucose, cholesterol, triglyceride, and urea nitrogen (P>0.05). In agreement with the results of the present study, the digestibility of dry matter and organic matter in steers was not affected by choline. Researchers reported that the use of protected biocholine and methionine did not have a significant effect on the digestibility of dry matter in calves. Also, it was observed that the use of choline did not have a significant effect on the digestibility of dry matter in sheep and pre-weaned calves. Researchers have reported that the use of protected methionine and choline did not have a significant effect on the levels of glucose and triglycerides in the blood of dairy cows before calving. In another study, the urea nitrogen in the blood of dairy cows was not affected by methionine and choline. Additionally, the experimental treatments did not affect feed consumption behavior (P>0.05). Conclusions: Feeding unprotected choline and methionine did not have a significant effect on glucose, cholesterol, triglycerides, blood urea nitrogen, digestibility of dry matter, fecal consistency score, and feeding behavior. However, the use of methionine improved dry matter intake and daily weight gain. Feeding Simmental calves with three grams of methionine per day is recommended to improve dry matter intake and daily weight gain, although it does not significantly affect the feed conversion ratio. Introduction: Choline and methionine are crucial nutrients for livestock as they provide methyl groups. The relationship between these two nutrients is intricate, with varying opinions on their interdependence. Methionine is often a limiting amino acid in dairy diets and its metabolism is linked to that of choline and betaine. Choline as an alternative to methionine, can act as a precursor to phosphatidylcholine, which is important for dairy cows around calving time. Furthermore, choline and betaine impact methionine requirements and methionine can affect choline metabolism. Given that limited study and experimentation have been conducted so far to investigate the effects of unprotected methionine and choline on calves, this research aimed to examine the impact of unprotected methionine and choline on feed intake, growth, digestibility, fecal score, blood metabolites, and feed behavior of pre-weaned calves. The expected hypothesis of the study was the significant effect of utilizing unprotected methionine and choline on feed intake, growth, digestibility, fecal score, blood metabolites, and feeding behavior of pre-weaned calves due to their mono-gastric nature and lack of rumen development. Materials and methods: A total number of 32 Simmental male suckling calves, aged approximately one month old with an initial weight of 44±2.1 kg, were used in this study. The experimental treatments included: 1) a basal diet without choline and methionine (control), 2) the basal diet with three grams of methionine, 3) the basal diet with three grams of choline, and 4) the basal diet with 1.5 grams of methionine and 1.5 grams of choline per head per day. The calves were randomly assigned to the experimental treatments in a completely randomized design with eight replications. The study lasted for 45 days, including a 7-day adaptation period. Blood glucose, cholesterol, triglycerides, and urea nitrogen levels were measured on the last day of the study, four hours after morning feeding, to evaluate the metabolic profile of the animals. Additionally, feed consumption behavior was visually observed for 24 hours on the last day of the study to calculate the animal's rumination, eating, chewing, and resting time. To determine the digestibility of dry matter, samples were collected from feed and feces during the last three days of the experiment using the acid-insoluble ash internal indicator method. Stool consistency was scored for all of the calves as an indicator of animal health. Results and discussion: The inclusion of three grams of methionine in the experimental treatments resulted in a decrease in dry matter intake, and when methionine and choline were added, it increased the daily weight gain of the animals (P<0.05). However, the treatments did not have a significant effect on the feed conversion ratio (P>0.05). The results of other studies showed that the addition of choline did not have a significant effect on the amount of dry matter consumed, daily weight gain, and feed conversion ratio of Holstein bull calves. Consistent with the results of the present study, no improvement was observed in the feed efficiency of steers with the addition of a protected choline supplement, and no effect was observed on dry matter intake. The treatments did not have a significant impact on dry matter digestibility, stool consistency, blood glucose, cholesterol, triglyceride, and urea nitrogen (P>0.05). In agreement with the results of the present study, the digestibility of dry matter and organic matter in steers was not affected by choline. Researchers reported that the use of protected biocholine and methionine did not have a significant effect on the digestibility of dry matter in calves. Also, it was observed that the use of choline did not have a significant effect on the digestibility of dry matter in sheep and pre-weaned calves. Researchers have reported that the use of protected methionine and choline did not have a significant effect on the levels of glucose and triglycerides in the blood of dairy cows before calving. In another study, the urea nitrogen in the blood of dairy cows was not affected by methionine and choline. Additionally, the experimental treatments did not affect feed consumption behavior (P>0.05). Conclusions: Feeding unprotected choline and methionine did not have a significant effect on glucose, cholesterol, triglycerides, blood urea nitrogen, digestibility of dry matter, fecal consistency score, and feeding behavior. However, the use of methionine improved dry matter intake and daily weight gain. Feeding Simmental calves with three grams of methionine per day is recommended to improve dry matter intake and daily weight gain, although it does not significantly affect the feed conversion ratio.

https://ar.guilan.ac.ir/article_7024_51a7cc625f510e0cd69c2f51aaf790b2.pdf

University of Guilan Animal Production Research 2252-0872 12 2 2023 08 23 Influence of simultaneous use of immunoglobulin Y, probiotics, and electrolytes on growth performance, health, and diarrhea in Holstein suckling calves Influence of simultaneous use of immunoglobulin Y, probiotics, and electrolytes on growth performance, health, and diarrhea in Holstein suckling calves 43 56 6923 10.22124/ar.2023.23775.1750 FA S. E. Ghorbi Former MSc Student, Department of Animal Science, Faculty of Agriculture, University of Tehran, Karaj, Iran 0000-0002-2198-7460 K. Rezayazdi Professor, Department of Animal Science, Faculty of Agriculture, University of Tehran, Karaj, Iran A. Zareh Shahneh Professor, Department of Animal Science, Faculty of Agriculture, University of Tehran, Karaj, Iran 0000-0001-7781-3315 P. Moslehifar Former MSc Student, Department of Animal Science, Faculty of Agriculture, University of Tehran, Karaj, Iran B. Lor Kalantari Former MSc Student, Department of Animal Science, Faculty of Agriculture, University of Tehran, Karaj, Iran M. Farzi Former MSc Student, Nature Biotechnology Group (Biorun), Karaj, Iran A. Rajabinejad Former MSc Student, Department of Animal Science, Faculty of Agriculture, University of Tehran, Karaj, Iran Mohammad Amin Baradar Former MSc Student, the Barin Dairy Farm, Shahriar, Iran Journal Article 2023 02 04 Introduction: The future of any dairy farm depends on the success of its calf and heifer-raising programs. Regarding the risk of gastrointestinal diseases and the prevalence of diarrhea, suckling calves are among the most sensitive animals in dairy herds. Gastrointestinal diseases are most prevalent in the first two weeks of calves' life and are the reason for 32% of deaths. In addition to short-term economic losses, diarrhea in female calves will delay sexual maturity and reduce milk production performance in the first lactation period. The use of antibiotics to prevent and treat diarrhea in suckling calves is always limited due to antibiotic resistance and some side effects. Research shows that between different anti-diarrhea feed additives, prebiotics and probiotics have the most positive effects in the first weeks of suckling calves' lives. In addition, it has been demonstrated that immunoglobulin Y can be effectively used to inhibit calves' gastrointestinal pathogens such as Escherichia coli and Salmonella species. Also, the use of electrolytes during diarrhea to prevent dehydration in young animals has been known to be positive. However, the synergistic effects of the simultaneous use of the mentioned additives are not clearly defined. Therefore, the present study was conducted to investigate a combination of immunoglobulin Y, probiotics, and electrolytes' effect on growth performance, feed intake, fecal consistency, health status, and blood parameters of Holstein suckling calves. Materials and methods: In this study, 24 suckling Holstein calves from birth to 28 days old were divided into two experimental groups (12 replications in each group) in a completely randomized design. The experimental groups included: 1) the control group (without additive) and 2) the group that received 10 grams per day of an anti-diarrheal feed additive contained 1.2 grams of probiotics with 5×108 cfu/g, 1 g IgY, and 7.8 g electrolytes. All animals had free access to clean water and the ad libitum basal starter feed. The anti-diarrheal additive was dissolved in the calves' morning meal colostrum or milk. Feed intake, growth performance, and Escherichia coli fecal count were measured weekly. Rectal temperature and calves' fecal scores were evaluated daily (according to the method provided by Wisconsin University). Also, at birth, 14 and 28 days, blood samples were taken from the jugular vein. The repeated measurement data were analyzed by the MIXED procedure of the SAS version 9.4 statistical software. The means were reported as LSMEANS, and the significance level was considered as P<0.05. Also, for the statistical analysis of the fecal scores data, the days of each score were counted. Results and discussion: The results showed that the average daily weight gain in the third week in the anti-diarrhea group was significantly higher than the control group (P<0.05). As a result, the live weight of the third and fourth weeks in the anti-diarrhea group was significantly higher than the control group (P<0.05). The starter intake in the anti-diarrhea group was 25% higher in the third week and 12% higher in the whole period than in the control group (P<0.05). Also, the feed conversion rate in the anti-diarrhea group in the second and third weeks was significantly lower than the control group (P<0.05). No significant difference was observed in the blood urea nitrogen, glucose, albumin, cholesterol, and triglyceride concentrations. Also, the anti-diarrheal additive had no significant effect on the count of white blood cells and the percentages of lymphocytes, neutrophils, monocytes, and eosinophils. According to the results, the anti-diarrhea additive had no significant effect on the calves' rectal temperature. The count of fecal Escherichia coli in the anti-diarrhea group was significantly lower than the control group in the first week, the first two weeks, and the whole period (P<0.05). The anti-diarrhea additive led to a significant increase in the number of days with zero scores (improvement of feces consistency) and a significant decrease in scores two and three (reduction of diarrhea prevalence) in calves (P<0.05). The results showed that in the first, second, and third weeks, the number of days with diarrhea significantly decreased in the anti-diarrhea group (P<0.05). In addition, the anti-diarrheal additive led to a significant decrease (58%) in the diarrhea length period. According to the period length and hardness of diarrhea, the cost of treating diarrhea in 28 days was estimated to be 830000 Rials and 470000 Rials in the control and anti-diarrhea groups, respectively. Therefore, the anti-diarrhea additive resulted in a 43% reduction in treatment costs. Conclusions: The results of the present study showed that the supply of an anti-diarrheal additive containing probiotics, immunoglobulin Y, and electrolytes to suckling calves led to a significant increase in growth performance, starter intake, improvement in feed conversion rate, reduction in the count of fecal Escherichia coli, and shortening of the diarrhea duration period. However, this additive did not affect rectal temperature, white blood cell status, and blood parameters such as glucose, cholesterol, triglyceride, albumin, total protein, and blood urea nitrogen. Therefore, the anti-diarrheal additive can reduce the prevalence, duration, and grade of diarrhea and its harmful effects and improve suckling calves' growth performance and health status. Introduction: The future of any dairy farm depends on the success of its calf and heifer-raising programs. Regarding the risk of gastrointestinal diseases and the prevalence of diarrhea, suckling calves are among the most sensitive animals in dairy herds. Gastrointestinal diseases are most prevalent in the first two weeks of calves' life and are the reason for 32% of deaths. In addition to short-term economic losses, diarrhea in female calves will delay sexual maturity and reduce milk production performance in the first lactation period. The use of antibiotics to prevent and treat diarrhea in suckling calves is always limited due to antibiotic resistance and some side effects. Research shows that between different anti-diarrhea feed additives, prebiotics and probiotics have the most positive effects in the first weeks of suckling calves' lives. In addition, it has been demonstrated that immunoglobulin Y can be effectively used to inhibit calves' gastrointestinal pathogens such as Escherichia coli and Salmonella species. Also, the use of electrolytes during diarrhea to prevent dehydration in young animals has been known to be positive. However, the synergistic effects of the simultaneous use of the mentioned additives are not clearly defined. Therefore, the present study was conducted to investigate a combination of immunoglobulin Y, probiotics, and electrolytes' effect on growth performance, feed intake, fecal consistency, health status, and blood parameters of Holstein suckling calves. Materials and methods: In this study, 24 suckling Holstein calves from birth to 28 days old were divided into two experimental groups (12 replications in each group) in a completely randomized design. The experimental groups included: 1) the control group (without additive) and 2) the group that received 10 grams per day of an anti-diarrheal feed additive contained 1.2 grams of probiotics with 5×108 cfu/g, 1 g IgY, and 7.8 g electrolytes. All animals had free access to clean water and the ad libitum basal starter feed. The anti-diarrheal additive was dissolved in the calves' morning meal colostrum or milk. Feed intake, growth performance, and Escherichia coli fecal count were measured weekly. Rectal temperature and calves' fecal scores were evaluated daily (according to the method provided by Wisconsin University). Also, at birth, 14 and 28 days, blood samples were taken from the jugular vein. The repeated measurement data were analyzed by the MIXED procedure of the SAS version 9.4 statistical software. The means were reported as LSMEANS, and the significance level was considered as P<0.05. Also, for the statistical analysis of the fecal scores data, the days of each score were counted. Results and discussion: The results showed that the average daily weight gain in the third week in the anti-diarrhea group was significantly higher than the control group (P<0.05). As a result, the live weight of the third and fourth weeks in the anti-diarrhea group was significantly higher than the control group (P<0.05). The starter intake in the anti-diarrhea group was 25% higher in the third week and 12% higher in the whole period than in the control group (P<0.05). Also, the feed conversion rate in the anti-diarrhea group in the second and third weeks was significantly lower than the control group (P<0.05). No significant difference was observed in the blood urea nitrogen, glucose, albumin, cholesterol, and triglyceride concentrations. Also, the anti-diarrheal additive had no significant effect on the count of white blood cells and the percentages of lymphocytes, neutrophils, monocytes, and eosinophils. According to the results, the anti-diarrhea additive had no significant effect on the calves' rectal temperature. The count of fecal Escherichia coli in the anti-diarrhea group was significantly lower than the control group in the first week, the first two weeks, and the whole period (P<0.05). The anti-diarrhea additive led to a significant increase in the number of days with zero scores (improvement of feces consistency) and a significant decrease in scores two and three (reduction of diarrhea prevalence) in calves (P<0.05). The results showed that in the first, second, and third weeks, the number of days with diarrhea significantly decreased in the anti-diarrhea group (P<0.05). In addition, the anti-diarrheal additive led to a significant decrease (58%) in the diarrhea length period. According to the period length and hardness of diarrhea, the cost of treating diarrhea in 28 days was estimated to be 830000 Rials and 470000 Rials in the control and anti-diarrhea groups, respectively. Therefore, the anti-diarrhea additive resulted in a 43% reduction in treatment costs. Conclusions: The results of the present study showed that the supply of an anti-diarrheal additive containing probiotics, immunoglobulin Y, and electrolytes to suckling calves led to a significant increase in growth performance, starter intake, improvement in feed conversion rate, reduction in the count of fecal Escherichia coli, and shortening of the diarrhea duration period. However, this additive did not affect rectal temperature, white blood cell status, and blood parameters such as glucose, cholesterol, triglyceride, albumin, total protein, and blood urea nitrogen. Therefore, the anti-diarrheal additive can reduce the prevalence, duration, and grade of diarrhea and its harmful effects and improve suckling calves' growth performance and health status.

https://ar.guilan.ac.ir/article_6923_9a7e16dddf47e371237d03d021348fd8.pdf

University of Guilan Animal Production Research 2252-0872 12 2 2023 08 23 Identification of selective signatures associated with gastrointestinal atresia in Holstein calves Identification of selective signatures associated with gastrointestinal atresia in Holstein calves 57 69 6900 10.22124/ar.2023.23703.1748 FA H. Mohammadi Assistant Professor, Department of Animal Sciences, Faculty of Agriculture and Natural Resources, Arak University, Arak, Iran M. Shamsollahi Assistant Professor, Department of Animal Sciences, Faculty of Agriculture, University of Ilam, Ilam, Iran Journal Article 2023 01 25 Introduction: Obstructive gastrointestinal (GI) malformations are one of the most important congenital problems resulting in calf mortality within a few days of birth. The most common site for atresia, after the esophagus, is the jejunum. Jejunum atresia is the congenital absence or complete blockage of a part of the jejunum lumen. Early detection of intestinal obstruction is essential to prevent further complications. Intestinal atresia is an underdiagnosed congenital defect in cattle. It results in complete occlusion of the intestinal lumen and, unless surgically corrected, results in death or euthanasia of the affected calf. There is limited information on the incidence of this condition or risk factors, including predisposing alleles, associated with the defect. Atresia is a well-known congenital defect of the gastrointestinal system in calves and investigations into the etiology of this condition are warranted. Domestication and selection have significantly changed the behavioral and phenotypic traits in modern domestic animals. The selection of animals by humans left detectable signatures on the genome of modern dairy cattle. The identification of these signals can help us to improve the genetic characteristics of economically important traits in goats. Over the last decade, interest in the detection of genes or genomic regions that are targeted by selection has been growing. Identifying signatures of selection can provide valuable insights about the genes or genomic regions that are or have been under selection pressure, which in turn leads to a better understanding of genotype-phenotype relationships. This study aimed to identify the selection signatures using the unbiased theta method associated with gastrointestinal atresia in Holstein dairy calves. Materials and methods: For calves with intestinal atresia, muscle tissue (>1 g) was collected from the Latissimus dorsi muscle postmortem, and submerged in RNA later solution. DNA samples from 91 atresia cases and 377 control animals were genotyped using the Illumina 777K BovineHD beadchip (Illumina Inc). The work described here is a case–control association study. Single nucleotide polymorphism (SNP) missing 5% of data, with MAF of <1% and Hardy–Weinberg equilibrium P-values <10−6 were removed. The genotyping efficiency for samples was also verified, and samples with more than 5% missing data were removed. Grouping was done to infer selection signatures based on FST statistic. The bioinformatics investigations were carried out using the Ensembl database for bovine genes (assembly ARS-UCD1.2), to identify potential candidate genes which already have been reported in/or surrounding genomic regions containing the peak of absolute extreme FST values. The regions corresponding to the upper and lower 0.01% of positive and negative obtained FST scores were considered regions under selection. Genes within a 500-kb span of the start and end of the QTL were identified using Ensembl 108 on the ARS-UCD1.2 bovine genome assembly implemented in biomart. Then, using the PANTHER database, the general biological function of the genes was checked. At this stage, it is assumed that genes that belong to a functional class can be considered as a group of genes that have some specific and common characteristics, and the quantitative trait loci (QTLs) in the selected region were extracted using the Animalgenome database, and the genes were compared with other researches. GeneCards (http://www.genecards.org) and UniProtKB (http://www.uniprot.org) databases were also used to interpret the function of the obtained genes. Results and discussion: with a 99.90 percentile threshold of the obtained theta (θ) values, eight genomic regions on chromosomes 7, 12, 13, 21, 22, 23 (two regions), and 29 in the Holstein calves were identified. Further investigation using bioinformatics tools showed these genomic regions overlapped with the genes (CSF2, SIAH3, TMEM14A, and SKIV2L) associated with embryonic development, small intestine length, apoptosis, and several tumors. The population used in our study is small, owing to the challenge of collecting a substantial amount of blood on calves on commercial herds having received the diagnosis of gastrointestinal atresia and ready to be culled. Diagnosis and culling of gastrointestinal atresia animals are ineffective preventive measures. Further work is required to identify which farm-specific or management risk factors contribute to the incidence of intestinal atresia. Conclusions: The results of this study may provide an important source to facilitate the identification of genomic regions and then, the genes affecting gastrointestinal atresia in claves. However, further studies are warranted to refine the findings using a larger sample size, whole-genome sequencing, and/or high-density genotyping.Materials and Methods: For calves with intestinal atresia, muscle tissue (>1 g) was collected from the Latissimus dorsi muscle postmortem, submerged in RNA later solution. DNA samples from 91 atresia cases and 377 control animals were genotyped using the Illumina 777K BovineHD beadchip (Illumina Inc). The work described here is a case–control association study. SNP missing 5% of data, with MAF of <1% and Hardy–Weinberg equilibrium p-values <10−6 were removed. The genotyping efficiency for samples was also verified, and samples with more than 5% missing data were removed. Grouping was done to infer selection signatures based on FST statistic. The bioinformatics investigations were carried out using the Ensembl database (Cunningham et al., 2022) for bovine genes (assembly ARS-UCD1.2), to identify potential candidate genes which already have been reported in/or surrounding genomic regions containing the peak of absolute extreme FST values. The regions corresponding to the upper and lower 0.01% of positive and negative obtained FST scores were considered as regions under selection. Genes within a 500-kb span of the start and end of the QTL were identified using Ensembl 108 on the ARS-UCD1.2 bovine genome assembly implemented in biomart. Then, using the PANTHER database, the general biological function of the genes was checked. At this stage, it is assumed that genes that belong to a functional class can be considered as a group of genes that have some specific and common characteristics, and the QTLs in the selected region were extracted using the Animalgenome database, and the genes were compared with other researches. GeneCards (http://www.genecards.org) and UniProtKB (http://www.uniprot.org) databases were also used to interpret the function of the obtained genes. Results and Discussion with 99.90 percentile threshold of the obtained Theta (θ) values, eight genomic regions on chromosomes 7, 12, 13, 21, 22, 23 (2 regions), and 29 in Holstein calves breed were identified. Further investigation using bioinformatics tools showed these genomic regions overlapped with the genes (CSF2, SIAH3, TMEM14A, SKIV2L) associated with embryonic development, small intestine length, apoptosis, and several tumours. The population used in our study is small, owing to the challenge of collecting a substantial amount of blood on calves on commercial herds having received the diagnosis of gastrointestinal atresia and ready to be culled. Diagnosis and culling of gastrointestinal atresia animals are ineffective preventive measures. Further work is required to identify which farm-specific or management risk factors contribute to the incidence of intestinal atresia. Conclusions: In conclusion, the results of this study may provide an important source to facilitate the identification of genomic regions and then, the genes affecting gastrointestinal atresia in claves. However, further studies are warranted to refine the findings using a larger sample size, whole-genome sequencing, and/or high density genotyping Introduction: Obstructive gastrointestinal (GI) malformations are one of the most important congenital problems resulting in calf mortality within a few days of birth. The most common site for atresia, after the esophagus, is the jejunum. Jejunum atresia is the congenital absence or complete blockage of a part of the jejunum lumen. Early detection of intestinal obstruction is essential to prevent further complications. Intestinal atresia is an underdiagnosed congenital defect in cattle. It results in complete occlusion of the intestinal lumen and, unless surgically corrected, results in death or euthanasia of the affected calf. There is limited information on the incidence of this condition or risk factors, including predisposing alleles, associated with the defect. Atresia is a well-known congenital defect of the gastrointestinal system in calves and investigations into the etiology of this condition are warranted. Domestication and selection have significantly changed the behavioral and phenotypic traits in modern domestic animals. The selection of animals by humans left detectable signatures on the genome of modern dairy cattle. The identification of these signals can help us to improve the genetic characteristics of economically important traits in goats. Over the last decade, interest in the detection of genes or genomic regions that are targeted by selection has been growing. Identifying signatures of selection can provide valuable insights about the genes or genomic regions that are or have been under selection pressure, which in turn leads to a better understanding of genotype-phenotype relationships. This study aimed to identify the selection signatures using the unbiased theta method associated with gastrointestinal atresia in Holstein dairy calves. Materials and methods: For calves with intestinal atresia, muscle tissue (>1 g) was collected from the Latissimus dorsi muscle postmortem, and submerged in RNA later solution. DNA samples from 91 atresia cases and 377 control animals were genotyped using the Illumina 777K BovineHD beadchip (Illumina Inc). The work described here is a case–control association study. Single nucleotide polymorphism (SNP) missing 5% of data, with MAF of <1% and Hardy–Weinberg equilibrium P-values <10−6 were removed. The genotyping efficiency for samples was also verified, and samples with more than 5% missing data were removed. Grouping was done to infer selection signatures based on FST statistic. The bioinformatics investigations were carried out using the Ensembl database for bovine genes (assembly ARS-UCD1.2), to identify potential candidate genes which already have been reported in/or surrounding genomic regions containing the peak of absolute extreme FST values. The regions corresponding to the upper and lower 0.01% of positive and negative obtained FST scores were considered regions under selection. Genes within a 500-kb span of the start and end of the QTL were identified using Ensembl 108 on the ARS-UCD1.2 bovine genome assembly implemented in biomart. Then, using the PANTHER database, the general biological function of the genes was checked. At this stage, it is assumed that genes that belong to a functional class can be considered as a group of genes that have some specific and common characteristics, and the quantitative trait loci (QTLs) in the selected region were extracted using the Animalgenome database, and the genes were compared with other researches. GeneCards (http://www.genecards.org) and UniProtKB (http://www.uniprot.org) databases were also used to interpret the function of the obtained genes. Results and discussion: with a 99.90 percentile threshold of the obtained theta (θ) values, eight genomic regions on chromosomes 7, 12, 13, 21, 22, 23 (two regions), and 29 in the Holstein calves were identified. Further investigation using bioinformatics tools showed these genomic regions overlapped with the genes (CSF2, SIAH3, TMEM14A, and SKIV2L) associated with embryonic development, small intestine length, apoptosis, and several tumors. The population used in our study is small, owing to the challenge of collecting a substantial amount of blood on calves on commercial herds having received the diagnosis of gastrointestinal atresia and ready to be culled. Diagnosis and culling of gastrointestinal atresia animals are ineffective preventive measures. Further work is required to identify which farm-specific or management risk factors contribute to the incidence of intestinal atresia. Conclusions: The results of this study may provide an important source to facilitate the identification of genomic regions and then, the genes affecting gastrointestinal atresia in claves. However, further studies are warranted to refine the findings using a larger sample size, whole-genome sequencing, and/or high-density genotyping.Materials and Methods: For calves with intestinal atresia, muscle tissue (>1 g) was collected from the Latissimus dorsi muscle postmortem, submerged in RNA later solution. DNA samples from 91 atresia cases and 377 control animals were genotyped using the Illumina 777K BovineHD beadchip (Illumina Inc). The work described here is a case–control association study. SNP missing 5% of data, with MAF of <1% and Hardy–Weinberg equilibrium p-values <10−6 were removed. The genotyping efficiency for samples was also verified, and samples with more than 5% missing data were removed. Grouping was done to infer selection signatures based on FST statistic. The bioinformatics investigations were carried out using the Ensembl database (Cunningham et al., 2022) for bovine genes (assembly ARS-UCD1.2), to identify potential candidate genes which already have been reported in/or surrounding genomic regions containing the peak of absolute extreme FST values. The regions corresponding to the upper and lower 0.01% of positive and negative obtained FST scores were considered as regions under selection. Genes within a 500-kb span of the start and end of the QTL were identified using Ensembl 108 on the ARS-UCD1.2 bovine genome assembly implemented in biomart. Then, using the PANTHER database, the general biological function of the genes was checked. At this stage, it is assumed that genes that belong to a functional class can be considered as a group of genes that have some specific and common characteristics, and the QTLs in the selected region were extracted using the Animalgenome database, and the genes were compared with other researches. GeneCards (http://www.genecards.org) and UniProtKB (http://www.uniprot.org) databases were also used to interpret the function of the obtained genes. Results and Discussion with 99.90 percentile threshold of the obtained Theta (θ) values, eight genomic regions on chromosomes 7, 12, 13, 21, 22, 23 (2 regions), and 29 in Holstein calves breed were identified. Further investigation using bioinformatics tools showed these genomic regions overlapped with the genes (CSF2, SIAH3, TMEM14A, SKIV2L) associated with embryonic development, small intestine length, apoptosis, and several tumours. The population used in our study is small, owing to the challenge of collecting a substantial amount of blood on calves on commercial herds having received the diagnosis of gastrointestinal atresia and ready to be culled. Diagnosis and culling of gastrointestinal atresia animals are ineffective preventive measures. Further work is required to identify which farm-specific or management risk factors contribute to the incidence of intestinal atresia. Conclusions: In conclusion, the results of this study may provide an important source to facilitate the identification of genomic regions and then, the genes affecting gastrointestinal atresia in claves. However, further studies are warranted to refine the findings using a larger sample size, whole-genome sequencing, and/or high density genotyping

https://ar.guilan.ac.ir/article_6900_1463516d2d5ab7ecafc60338798ef999.pdf

University of Guilan Animal Production Research 2252-0872 12 2 2023 08 23 A study on the lactation curve characteristics of grade and Iranian purebred Holstein cows with the use of raw, fat-corrected, and energy-corrected milk test day records A study on the lactation curve characteristics of grade and Iranian purebred Holstein cows with the use of raw, fat-corrected, and energy-corrected milk test day records 71 84 6901 10.22124/ar.2023.22771.1718 FA S. H. Farhangfar Professor, Animal Science Department, Agriculture Faculty, University of Birjand, Birjand, Iran M. S. Rashidi Toghroljerdi Former MSc Student, Animal Science Department, Agriculture Faculty, University of Birjand, Birjand, Iran M. B. Montazar Torbati Assistant Professor, Animal Science Department, Agriculture Faculty, University of Birjand, Birjand, Iran M. B. Sayyadnezhad MSc Expert, Animal Breeding Center and Promotion of Animal Products, Karaj, Iran Journal Article 2023 03 26 Introduction: In dairy cattle enterprise, there are several economic traits associated with productive and reproductive performance which milk yield is the main source of income for the herd keeper. Knowledge of lactation is considered a useful tool for management decision-making. Based on this, lactation curve modeling can be utilized as an appropriate guide for planning nutrition programs as well as genetic selection schemes. So far, main research has been focused on using raw (unadjusted) milk test day records to model the shape of the lactation curve by applying a variety of linear and non-linear mathematical models and a few research have been carried out to use adjusted milk test day records in terms of fat and protein percentages. The main objective of the present research was to compare lactation curve parameters of Iranian first-parity dairy cows among three types of milk test day records including raw milk (RM), fat-corrected milk (FCM), and energy-corrected milk (ECM). Materials and methods: The initial data set was provided by the Animal Breeding Center and Promotion of Animal Products of Iran. Editing of the data was carried out by FOXPRO and Excel software based on some criteria such as age at first calving (was set to be in the range of 18-48 months), minimum (3 kg), and maximum (99.9 kg) of RM. There were a minimum of five test day records for each cow during the lactation period. Final data consisted of a total number of 1,902,071 milk test day records belonging to 226,255 first-parity cows (progeny of 5,094 sires and 178,390 dams) distributed in 797 herds and calved during 1996-2015 were utilized. For a mathematical description of the shape of the lactation curve, Wood’s incomplete gamma function was used. The function has three parameters including parameter a (associated with initial milk yield), parameter b (associated with the inclining slope of the lactation), and parameter c (associated with the declining slope of the lactation). Wood's function was fitted to the records of RM, FCM, and ECM of individual cows using SAS software. Based on the estimated parameters, lactation characteristics including peak time (PT), peak yield (PY), and persistency (Per) were subsequently calculated for each cow. Estimated parameters and calculated lactation characteristics were then subjected to a fixed linear model in which the effects of herd, year of calving, the season of calving, age at first calving, genotype group (grade or purebred Holstein), type of milk test day record (RM, FCM or ECM) along with some two-way interactions were included. Results and discussion: The results showed that FCM had the greatest parameter a as compared with RM and ECM (P<0.0001). The greatest magnitude of the parameters b and c were found for RM (P<0.0001). Later PT and higher Per were observed for ECM (P<0.0001), while the highest PY was detected for RM (P<0.0001). For all types of records, minimum and maximum PY were observed for the cows calving in the spring and autumn seasons, respectively. Later PT was observed for ECM in all calving seasons except autumn. As compared to RM and FCM, cows calved in spring and summer had the highest persistency based on ECM while cows calved in autumn and winter were found to have more persistence based upon RM compared with FCM and ECM. The least-square means of peak time (PT) in grade cows were found to be 77.74, 69.5, and 79.85 d for RM, FCM, and ECM, respectively, while the corresponding figures for purebred Holstein cows were 80.27, 72.89, and 83.15 d, respectively. In grade cows, least-square means of peak time (PY) were found to be 32.02, 29.23, and 30.70 kg for RM, FCM, and ECM, respectively, while the corresponding figures for purebred Holstein cows were 32.51, 29.56, and 31.14 kg, respectively. For both purebred Holstein and grade cows, minimum and maximum persistency (Per) were obtained for FCM and ECM, respectively, which were significantly different from each other (P<0.001). For RM, FCM, and ECM, annual change trends of PT were found to be 2.132, 2.306, and 2.293 d, respectively, while the corresponding figures for PY were 0.408, 0.369, and 0.395 kg, respectively, and for Per were 0.037, 0.036, and 0.035, respectively. All trends were statistically significant (P<0.0001). Conclusions: The finding of the present research revealed that purebred Holsteins reach the peak time later than grade cows which is an appropriate characteristic of the lactation curve. Based upon energy-corrected milk yield, peak time as well as persistency was found to be greater than those for raw milk and fat-corrected milk yields. Therefore, the use of energy-corrected milk yield could be suggested to be applied as different experimental nutritional treatments are to be compared in terms of the persistency of the cows. All lactation characteristics of Iranian dairy cows were found to be changed favorably over time. Introduction: In dairy cattle enterprise, there are several economic traits associated with productive and reproductive performance which milk yield is the main source of income for the herd keeper. Knowledge of lactation is considered a useful tool for management decision-making. Based on this, lactation curve modeling can be utilized as an appropriate guide for planning nutrition programs as well as genetic selection schemes. So far, main research has been focused on using raw (unadjusted) milk test day records to model the shape of the lactation curve by applying a variety of linear and non-linear mathematical models and a few research have been carried out to use adjusted milk test day records in terms of fat and protein percentages. The main objective of the present research was to compare lactation curve parameters of Iranian first-parity dairy cows among three types of milk test day records including raw milk (RM), fat-corrected milk (FCM), and energy-corrected milk (ECM). Materials and methods: The initial data set was provided by the Animal Breeding Center and Promotion of Animal Products of Iran. Editing of the data was carried out by FOXPRO and Excel software based on some criteria such as age at first calving (was set to be in the range of 18-48 months), minimum (3 kg), and maximum (99.9 kg) of RM. There were a minimum of five test day records for each cow during the lactation period. Final data consisted of a total number of 1,902,071 milk test day records belonging to 226,255 first-parity cows (progeny of 5,094 sires and 178,390 dams) distributed in 797 herds and calved during 1996-2015 were utilized. For a mathematical description of the shape of the lactation curve, Wood’s incomplete gamma function was used. The function has three parameters including parameter a (associated with initial milk yield), parameter b (associated with the inclining slope of the lactation), and parameter c (associated with the declining slope of the lactation). Wood's function was fitted to the records of RM, FCM, and ECM of individual cows using SAS software. Based on the estimated parameters, lactation characteristics including peak time (PT), peak yield (PY), and persistency (Per) were subsequently calculated for each cow. Estimated parameters and calculated lactation characteristics were then subjected to a fixed linear model in which the effects of herd, year of calving, the season of calving, age at first calving, genotype group (grade or purebred Holstein), type of milk test day record (RM, FCM or ECM) along with some two-way interactions were included. Results and discussion: The results showed that FCM had the greatest parameter a as compared with RM and ECM (P<0.0001). The greatest magnitude of the parameters b and c were found for RM (P<0.0001). Later PT and higher Per were observed for ECM (P<0.0001), while the highest PY was detected for RM (P<0.0001). For all types of records, minimum and maximum PY were observed for the cows calving in the spring and autumn seasons, respectively. Later PT was observed for ECM in all calving seasons except autumn. As compared to RM and FCM, cows calved in spring and summer had the highest persistency based on ECM while cows calved in autumn and winter were found to have more persistence based upon RM compared with FCM and ECM. The least-square means of peak time (PT) in grade cows were found to be 77.74, 69.5, and 79.85 d for RM, FCM, and ECM, respectively, while the corresponding figures for purebred Holstein cows were 80.27, 72.89, and 83.15 d, respectively. In grade cows, least-square means of peak time (PY) were found to be 32.02, 29.23, and 30.70 kg for RM, FCM, and ECM, respectively, while the corresponding figures for purebred Holstein cows were 32.51, 29.56, and 31.14 kg, respectively. For both purebred Holstein and grade cows, minimum and maximum persistency (Per) were obtained for FCM and ECM, respectively, which were significantly different from each other (P<0.001). For RM, FCM, and ECM, annual change trends of PT were found to be 2.132, 2.306, and 2.293 d, respectively, while the corresponding figures for PY were 0.408, 0.369, and 0.395 kg, respectively, and for Per were 0.037, 0.036, and 0.035, respectively. All trends were statistically significant (P<0.0001). Conclusions: The finding of the present research revealed that purebred Holsteins reach the peak time later than grade cows which is an appropriate characteristic of the lactation curve. Based upon energy-corrected milk yield, peak time as well as persistency was found to be greater than those for raw milk and fat-corrected milk yields. Therefore, the use of energy-corrected milk yield could be suggested to be applied as different experimental nutritional treatments are to be compared in terms of the persistency of the cows. All lactation characteristics of Iranian dairy cows were found to be changed favorably over time.

https://ar.guilan.ac.ir/article_6901_a86e8ef2975918d70b9c39a758fb9180.pdf

University of Guilan Animal Production Research 2252-0872 12 2 2023 08 23 Genomic scanning of selection signature in Iranian skin and wool sheep using FST unbiased estimator and hapFLK methods Genomic scanning of selection signature in Iranian skin and wool sheep using FST unbiased estimator and hapFLK methods 85 103 6987 10.22124/ar.2023.22903.1721 FA Z. Patiabadi Ph.D. Student, Department of Animal Science, Faculty of Agriculture, University of Kurdistan, Sanandaj, Iran M. Razmkabir Associate Professor, Department of Animal Science, Faculty of Agriculture, University of Kurdistan, Sanandaj, Iran A. Esmailizadeh Koshkoiyeh Professor, Department of Animal Science, Faculty of Agriculture, Shahid Bahonar University of Kerman, Kerman, Iran M. H. Moradi Associate Professor, Department of Animal Science, Faculty of Agriculture, University of Arak, Arak, Iran A. Rashidi Professor, Department of Animal Science, Faculty of Agriculture, University of Kurdistan, Sanandaj, Iran 0000-0002-7926-3115 Journal Article 2022 09 06 Introduction: The principal aim of the sheep industry worldwide is to produce high-quality meat. In addition to the meat, milk, and wool production are the economic traits in sheep breeding programs. Wool production is one of the most important economic characteristics of sheep with a complex physiological and biochemical process that is influenced by genetics, environment, and nutrition. Almost all Iranian sheep breeds are double-coated and produce carpet wool. Therefore, considering the role of wool on the country's economy, it is necessary to conduct a study to identify the genetic factors affecting this trait. Identifying the genomic regions under selection is effective in understanding the processes involved in the evolution of the genome and also in identifying the genomic regions involved in the emergence of economic traits. Selective signatures in the whole genome can help us to understand the mechanisms of selection and to identify the genomic regions that have been under natural or artificial selection for many years. Since Selective signatures are usually associated with major effect genes and important economic traits, they can provide suitable information sources to improve the performance of selection programs in the future. The objective of this study was to identify the genomic regions that have been under selection in skin and wool sheep breeds. Materials and methods: In the present study, Illumina ovine SNP600K BeadChip genomic arrays of 80 sheep from six breeds were used, three breeds were bred for their skin (Karakul, SiahKabud, and Gray Shiraz) and three breeds were bred for their wool (Sanjabi, Kermani and Baluchi). Unbiased methods of Weir and Cockerham’s FST (Theta) and hapFLK were used to detect the selection signatures. Also, to check the genes and QTLs in the selected regions, the Biomart database, OAR 3.1 version of the sheep genome, was used, and the function of the identified genes was analyzed through a wide search in different databases such as Genecards and OMIM. Finally, the list of genes related to the selected regions was reported. For this purpose, the chromosomal position of SNPs with high numerical values of theta and hapFLK, as well as the 250 kbp region around these markers, were further investigated. Then, the DAVID database online search was used to investigate the biological and functional processes of genes and to study the ontology. Finally, Cytoscape software was used to determine gene networks. Then, DAVID database online search was used to investigate the biological and functional processes of genes and to study the ontology. سپس از جستجوی آنلاین پایگاه داده DAVID برای بررسی فرآیندهای بیولوژیکی و عملکردی ژن ها و مطالعه هستی شناسی استفاده شد. Then, to investigate the biological and functional processes of genes and to study the ontology, DAVID database was used to search online. سپس برای بررسی فرآیندهای بیولوژیکی و عملکردی ژن ها و مطالعه هستی شناسی از پایگاه داده DAVID برای جستجوی آنلاین استفاده شد. Can't load full results Try again Retrying... Results and discussion: The results of the Theta analysis revealed 26 genomic regions on 1, 2, 6, 19, and 24 chromosomes, and the results of hapFLK revealed seven genomic regions on 6 and 19 chromosomes. Bioinformatics analysis demonstrated that some of these genomic regions overlapped with known genes related to pigment traits and characteristics of wool (KIT on chr 6, MITF on chr 19, IGSF10 on chr 1, PDGFRA on chr 6), muscles (MICALL2 on chr 24), vasodilation and immune response (P2RY on chr 1) and cancer (MIR339 on chr 24, ELFN1 on chr 24, MAD1L1 on chr 24, GPR87 on chr 1). The investigation of reported QTLs showed that these regions are related to QTLs of important economic traits, including traits related to meat, carcass, milk, body weight, bone density, and the total number of lambs born. Also, the analysis of Gene Ontology and Enriched pathway terms in regions under positive selection were related to the pathways involved in the differentiation of melanocytes and pigments, differentiation of stem cells, cellular processes, development of the immune system, blood system, reproductive and cellular processes. The results of the gene networks with the information obtained from Theta and hapFLK statistics showed that the genes identified were significantly active in the development and morphogenesis networks of the embryonic digestive tract, the networks related to pigment and melanocyte differentiation, and the networks related to Purine and G protein. However, to identify the exact function of the identified genes and QTLs, it is recommended to carry out more investigations. نتایج شبکه‌های ژنی با اطلاعات به‌دست‌آمده از آمار تتا و hapFLK نشان داد که ژن‌های شناسایی‌شده به‌طور معنی‌داری در شبکه‌های رشد و مورفوژنز دستگاه گوارش جنینی، شبکه‌های مربوط به تمایز رنگدانه و ملانوسیت و شبکه‌های مربوط به The results of the gene networks with the information obtained from theta and hapFLK statistics showed that the genes identified were significantly in the development and morphogenesis networks of the embryonic digestive system, the networks related to the differentiation of pigment and melanocytes and the networks related to نتایج شبکه‌های ژنی با اطلاعات به‌دست‌آمده از آمار تتا و hapFLK نشان داد که ژن‌های شناسایی‌شده به‌طور معنی‌داری در شبکه‌های رشد و مورفوژنز دستگاه گوارش جنینی، شبکه‌های مربوط به تمایز رنگدانه‌ها و ملانوسیت‌ها و شبکه‌های مربوط به Can't load full results Try again Retrying... Conclusions: The results of the present study and the identified genomic regions can play an important role in the study of the effect of the selection on population differentiation in two sheep breeds that bred for skin and sheep production. Subsequently, this would direct us to identify the genomic regions associated with traits that differentiate these groups. However, these areas need to be confirmed in other independent studies with more samples. In general, the data of this research can be used in research related to genomic selection, design of mating systems, and additional reviews and evaluations to improve skin and wool production in sheep. Introduction: The principal aim of the sheep industry worldwide is to produce high-quality meat. In addition to the meat, milk, and wool production are the economic traits in sheep breeding programs. Wool production is one of the most important economic characteristics of sheep with a complex physiological and biochemical process that is influenced by genetics, environment, and nutrition. Almost all Iranian sheep breeds are double-coated and produce carpet wool. Therefore, considering the role of wool on the country's economy, it is necessary to conduct a study to identify the genetic factors affecting this trait. Identifying the genomic regions under selection is effective in understanding the processes involved in the evolution of the genome and also in identifying the genomic regions involved in the emergence of economic traits. Selective signatures in the whole genome can help us to understand the mechanisms of selection and to identify the genomic regions that have been under natural or artificial selection for many years. Since Selective signatures are usually associated with major effect genes and important economic traits, they can provide suitable information sources to improve the performance of selection programs in the future. The objective of this study was to identify the genomic regions that have been under selection in skin and wool sheep breeds. Materials and methods: In the present study, Illumina ovine SNP600K BeadChip genomic arrays of 80 sheep from six breeds were used, three breeds were bred for their skin (Karakul, SiahKabud, and Gray Shiraz) and three breeds were bred for their wool (Sanjabi, Kermani and Baluchi). Unbiased methods of Weir and Cockerham’s FST (Theta) and hapFLK were used to detect the selection signatures. Also, to check the genes and QTLs in the selected regions, the Biomart database, OAR 3.1 version of the sheep genome, was used, and the function of the identified genes was analyzed through a wide search in different databases such as Genecards and OMIM. Finally, the list of genes related to the selected regions was reported. For this purpose, the chromosomal position of SNPs with high numerical values of theta and hapFLK, as well as the 250 kbp region around these markers, were further investigated. Then, the DAVID database online search was used to investigate the biological and functional processes of genes and to study the ontology. Finally, Cytoscape software was used to determine gene networks. Then, DAVID database online search was used to investigate the biological and functional processes of genes and to study the ontology. سپس از جستجوی آنلاین پایگاه داده DAVID برای بررسی فرآیندهای بیولوژیکی و عملکردی ژن ها و مطالعه هستی شناسی استفاده شد. Then, to investigate the biological and functional processes of genes and to study the ontology, DAVID database was used to search online. سپس برای بررسی فرآیندهای بیولوژیکی و عملکردی ژن ها و مطالعه هستی شناسی از پایگاه داده DAVID برای جستجوی آنلاین استفاده شد. Can't load full results Try again Retrying... Results and discussion: The results of the Theta analysis revealed 26 genomic regions on 1, 2, 6, 19, and 24 chromosomes, and the results of hapFLK revealed seven genomic regions on 6 and 19 chromosomes. Bioinformatics analysis demonstrated that some of these genomic regions overlapped with known genes related to pigment traits and characteristics of wool (KIT on chr 6, MITF on chr 19, IGSF10 on chr 1, PDGFRA on chr 6), muscles (MICALL2 on chr 24), vasodilation and immune response (P2RY on chr 1) and cancer (MIR339 on chr 24, ELFN1 on chr 24, MAD1L1 on chr 24, GPR87 on chr 1). The investigation of reported QTLs showed that these regions are related to QTLs of important economic traits, including traits related to meat, carcass, milk, body weight, bone density, and the total number of lambs born. Also, the analysis of Gene Ontology and Enriched pathway terms in regions under positive selection were related to the pathways involved in the differentiation of melanocytes and pigments, differentiation of stem cells, cellular processes, development of the immune system, blood system, reproductive and cellular processes. The results of the gene networks with the information obtained from Theta and hapFLK statistics showed that the genes identified were significantly active in the development and morphogenesis networks of the embryonic digestive tract, the networks related to pigment and melanocyte differentiation, and the networks related to Purine and G protein. However, to identify the exact function of the identified genes and QTLs, it is recommended to carry out more investigations. نتایج شبکه‌های ژنی با اطلاعات به‌دست‌آمده از آمار تتا و hapFLK نشان داد که ژن‌های شناسایی‌شده به‌طور معنی‌داری در شبکه‌های رشد و مورفوژنز دستگاه گوارش جنینی، شبکه‌های مربوط به تمایز رنگدانه و ملانوسیت و شبکه‌های مربوط به The results of the gene networks with the information obtained from theta and hapFLK statistics showed that the genes identified were significantly in the development and morphogenesis networks of the embryonic digestive system, the networks related to the differentiation of pigment and melanocytes and the networks related to نتایج شبکه‌های ژنی با اطلاعات به‌دست‌آمده از آمار تتا و hapFLK نشان داد که ژن‌های شناسایی‌شده به‌طور معنی‌داری در شبکه‌های رشد و مورفوژنز دستگاه گوارش جنینی، شبکه‌های مربوط به تمایز رنگدانه‌ها و ملانوسیت‌ها و شبکه‌های مربوط به Can't load full results Try again Retrying... Conclusions: The results of the present study and the identified genomic regions can play an important role in the study of the effect of the selection on population differentiation in two sheep breeds that bred for skin and sheep production. Subsequently, this would direct us to identify the genomic regions associated with traits that differentiate these groups. However, these areas need to be confirmed in other independent studies with more samples. In general, the data of this research can be used in research related to genomic selection, design of mating systems, and additional reviews and evaluations to improve skin and wool production in sheep.

https://ar.guilan.ac.ir/article_6987_bea850d9411d6e59815814b960c5bc1d.pdf