دانشگاه گیلان تحقیقات تولیدات دامی 2252-0872 14 4 2025 12 22 Effect of in ovo injection of Lactobacillus isolates from the gastrointestinal tract of Iranian native poultry on hatchability, immune response, and growth performance in broilers اثر تزریق درون تخم مرغی جدایه های لاکتوباسیلوس از دستگاه گوارش طیور بومی ایران بر قابلیت جوجه درآوری، پاسخ ایمنی و عملکرد رشد جوجه های گوشتی 1 15 9026 10.22124/ar.2025.31136.1909 FA معین قناعت پرست رشتی مرکز تحقیقات ابریشم کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی (AREEO)، رشت، ایران مجید متقی طلب گروه علوم دامی، دانشکده علوم کشاورزی، دانشگاه گیلان مریم رویان پژوهشکده بیوتکنولوژی جانوری، پژوهشگاه بیوتکنولوژی کشاورزی ایران (ABRII)، سازمان تحقیقات، آموزش و ترویج کشاورزی (AREEO)، رشت، ایران رامین صیقلانی پژوهشکده بیوتکنولوژی جانوری، پژوهشگاه بیوتکنولوژی کشاورزی ایران (ABRII)، سازمان تحقیقات، آموزش و ترویج کشاورزی (AREEO)، رشت، ایران Journal Article 2025 07 11 Introduction: Modern industrial poultry production removes the natural relationship between day-old chicks and hens. Consequently, the establishment of gut microbiota largely depends on the bacteria present in the hatchery and barn environment. On the other hand, chicks may be exposed to pathogenic agents while still at the hatchery, during hatching, sex determination, vaccination, and transportation, even before consuming their first feed. Since the initial contact with microbes might involve pathogenic bacteria, introducing beneficial bacteria into the gastrointestinal tract of chicks can help reduce the risk of pathogen settlement. The primary colonization of beneficial microbes is not only crucial for competing against pathogenic bacteria but also plays a significant role in stimulating factors associated with the growth and maturation of the immune system. Additionally, in the agricultural industries, the use of antibiotic growth promoters (AGPs) in animal diets has been reduced or even eliminated due to concerns regarding bacterial antibiotic resistance and antibiotic residues in animal products. As a result, several alternatives to AGPs have appeared in the poultry market. One of the many alternatives that are currently being investigated is the use of probiotics. Probiotics are defined as a “live microbial feed supplement which beneficially affects the host animal by improving its intestinal microbial balance”. Among the probiotics used in poultry, Lactobacillus isolates have been particularly valued for their positive effects on gut health. Furthermore, Lactobacillus naturally dominates the gastrointestinal tract of poultry. The beneficial effects of these bacteria occur through various mechanisms, including competitive exclusion, maintenance of protective intestinal barriers, and immune system enhancement. Probiotics can upregulate the expression of immune-related genes such as cytokines, interferons, and interleukins, which directly or indirectly increase the serum levels of immunoglobulins in response to antigens. Ideally, the best way to avoid the need for drugs is to prevent pathogen proliferation as early as possible. It has been commonly assumed that microbial colonization occurs after hatching in poultry; however, scientific evidence suggests that live bacteria may be present in the intestine in small quantities even before hatching. One favorable method of probiotic administration is the in ovo injection of probiotics into the amniotic sac at the late stage of embryonic development. This approach can facilitate the early establishment of beneficial bacteria in the gastrointestinal tract to create an environment that prevents pathogen colonization. Therefore, the objective of this study was to evaluate in ovo administration as a method for delivering some Lactobacillus isolates derived from the gut microbiota of Iranian native poultry to the intestines of broiler chicks before hatching and assess their effects on hatchability, immune system development, serum metabolites, and growth performance. Materials and methods: To investigate the effect of in ovo injection of Lactobacillus isolates of Iranian native poultry in broilers, on day 18th of incubation, 672 embryonated eggs (Ross 308 strain) were assigned into 24 experimental units, in a completely randomized design with six treatments and four replicates (28 eggs per replicate). The hatched chicks, based on the same division as the in ovo injection stage, were raised for six weeks. Experimental treatments included: 1. In ovo injection of physiological saline (saline 9%; negative control), 2. In ovo injection of physiological saline (saline 9%) and antibiotic growth promoter (avilamycin) in the diet (positive control), 3. In ovo injection of Lactobacillus salivarius isolate Pls2 (MH595986; 105 CFU/egg), 4. In ovo injection of Lactobacillus reuteri isolate Plr6 (MF686483; 105 CFU/egg), 5. In ovo injection of Lactobacillus reuteri isolate Plr4 (MF686463; 105 CFU/egg), and 6. In ovo injection of Lactobacillus reuteri isolate Plr2 (MG547731; 105 CFU/egg). Percent of hatchability was calculated as the percent of healthy hatched chicks from fertile eggs. To evaluate the immune response of the broilers, hemagglutination assay and hemagglutination inhibition methods were separately used to measure the antibody titers against sheep red blood cells (SRBC) and Newcastle disease virus (NDV), respectively, and were expressed as the log2. To measure glucose, triglyceride, and total cholesterol from serum, a spectrophotometric method via liquiform kits was used. Important growth performance metrics, such as body weight gain, feed intake, feed conversion ratio, and European Production Efficiency Factor (EPEF), were evaluated throughout the entire rearing period. Results are reported as means, and differences among treatments were compared using the Tukey test, and significance was determined at P<0.05. Results and discussion: In ovo injection of Lactobacillus, isolates had no negative effect on hatchability (P>0.05). In ovo injection of Lactobacillus isolates and positive control groups showed lower feed conversion ratio compared to the negative control group (P<0.05). The EPEF in the positive control group and in ovo administered Lactobacillus isolates was higher than the negative control group (P<0.05). Among the lactobacilli used, in ovo injection of Plr2 showed similar EPEF to the positive control group (P>0.05). Broiler dietary supplementation of antibiotic growth promoter and in ovo injection of Plr4 and Plr2 increased total and secondary antibody titer against SRBC compared to the negative control group (P<0.05). The positive control group and in ovo injection of Plr2 showed higher antibody titers against NDV than the negative control group (P<0.05). In ovo injection of Pls2, Plr6, and Plr4 increased serum glucose compared to control groups (P<0.05). In ovo injection of Plr4 decreased the triglyceride concentration of serum compared to the control groups at 42 days of age (P<0.05). In ovo injection of the Lactobacillus isolates reduced the cholesterol concentration of serum in broilers (P<0.05). Conclusions: In general, the injection of Lactobacillus isolates used in this study, particularly Plr4 and Plr2, at the late embryonic stage as appropriate microbial compounds, may improve broiler growth performance without adversely affecting hatchability and by positively influencing the immune response and serum metabolites. برای بررسی اثر تزریق درون تخممرغی جدایههای لاکتوباسیلوس طیور بومی ایران بر قابلیت جوجهدرآوری، پاسخ ایمنی و عملکرد رشد جوجههای گوشتی، در روز 18 دوره جوجهکشی، 672 عدد تخم‌‌مرغ دارای جنین (سویه راس 308) به 24 واحد آزمایشی شامل شش تیمار و چهار تکرار (28 عدد تخممرغ در هر تکرار) در قالب طرح کاملاً تصادفی تقسیم شدند. تیمارهای مرحله پرورش عبارت بودند از جوجههای تفریخ شده از تخممرغهای: 1- تزریق سرم فیزیولوژیک (سالین 9%، شاهد منفی)، 2-تزریق سرم فیزیولوژیک (سالین 9%) بههمراه آنتیبیوتیک محرک رشد (آویلامایسین) در جیره (شاهد مثبت)، 3- تزریق جدایه لاکتوباسیلوس سالیواریوس Pls2، 4- تزریق جدایه لاکتوباسیلوس روتری Plr6، 5- تزریق جدایه لاکتوباسیلوس روتری Plr4و 6- تزریق جدایه لاکتوباسیلوس روتریPlr2. هر یک از جدایهها بهمقدار 105 CFU برای تزریق در هم تخممرغ مورد استفاده قرار گرفت. تزریق جدایههای لاکتوباسیلوسی، اثر منفی بر قابلیت جوجهدرآوری نداشت (05/0<P). تزریق جدایههای لاکتوباسیلوسی موجب کاهش ضریب تبدیل خوراک در مقایسه با گروه شاهد منفی شد (05/0>P). شاخص کارآیی تولید اروپایی در گروه تزریق جدایههای لاکتوباسیلوسی بیشتر از گروه شاهد منفی بود (05/0>P). تزریق Plr4 و Plr2 موجب افزایش عیار آنتیبادی کل اولیه و ثانویه علیه سلولهای گلبول قرمز گوسفندی در مقایسه با گروه شاهد منفی شد (05/0>P). تزریق جدایههای لاکتوباسیلوسی موجب کاهش غلظت کلسترول سرم خون جوجههای گوشتی شد (05/0>P). استنتاج نهایی این است که تزریق لاکتوباسیلوسهای مورد استفاده در این تحقیق بهویژه Plr4 و Plr2، در مراحل انتهایی جنینی بهعنوان ترکیب میکروبی مناسب، بدون اثر منفی بر قابلیت جوجهدرآوری ارزیابی شده و میتوانند از راه اثرگذاری مفید بر پاسخ ایمنی و فراسنجههای خونی موجب بهبود عملکرد جوجههای گوشتی شوند.

https://ar.guilan.ac.ir/article_9026_3e1154fa9f64db947d5a52fc3ff8d781.pdf

دانشگاه گیلان تحقیقات تولیدات دامی 2252-0872 14 4 2025 12 22 Effect of dietary supplementation with sources containing omega-3 and omega-6 fatty acids on the quality and fertility of frozen-thawed sperm of broiler breeder roosters اثر مکمل‌سازی جیره با منابع حاوی اسیدچرب امگا-3 و امگا-6 بر کیفیت و باروری اسپرم منجمد خروس‌های گله مادرگوشتی 17 31 9023 10.22124/ar.2025.30934.1904 FA حسین پاشا زانوسی گروه علوم دامی، موسسه آموزش و ترویج کشاورزی، سازمان تحقیقات ، آموزش و ترویج کشاورزی ، تهران ، ایران حسین منافی ر اثی گروه علوم دامی، موسسه آموزش و ترویج کشاورزی، سازمان تحقیقات ، آموزش و ترویج کشاورزی ، تهران ، ایران Journal Article 2025 06 10 Introduction: One of the major costs in commercial poultry production is the purchase and upkeep of roosters, which are the sires and key contributors to flock fertility. Although roosters make up only about 10 to 15% of the flock, their genetic quality accounts for over 50% of the flock’s fertility. Finding cost-effective solutions, such as artificial insemination, to reduce the expenses associated with acquiring and maintaining breeding roosters is a major concern for producers. Unlike in mammals, artificial insemination is not used in birds because sperm quality and fertility decline after the freezing and thawing processes. Cryopreserving bird semen would allow us to use roosters with superior genetics without their presence. This would reduce genetic defects, lower costs, and help with the global distribution of semen. It would also decrease disease transmission risks, prevent extinction, and create gene banks for better breeds. Despite extensive efforts, developing an effective cryopreservation method for avian sperm remains a challenge. The lower fertility rates observed with cryopreserved poultry sperm, compared to other animals, are a significant hurdle for commercial applications. This difficulty may be related to the unique physiological features of bird sperm. Many hypotheses have been proposed about avian sperm, including the idea that poultry sperm contains a distinctive fatty acid profile, rich in omega-6 fatty acids. Supplementing sperm with essential fatty acids like omega-3 through dietary means has been shown to improve their reproductive performance. The success of cryopreservation heavily relies on maintaining sperm’s biological functions, which are influenced by factors such as extenders, cooling rates, and thawing protocols. Research has focused on optimizing parameters for sperm survival after thawing, including motility, viability, membrane integrity, and structural stability. Despite these efforts, fertility rates above 60% using cryopreserved sperm have not been reached. Studies indicate that providing diets rich in omega-3 fatty acids can enhance various sperm quality parameters and boost fertility. Dietary fats’ type and source affect sperm performance. This is because of their involvement in intricate molecular processes and their role as hormone and signaling pathway precursors, which are crucial for sperm function. Research on fatty acids’ impact on sperm uses fresh samples. Data is lacking on whether dietary supplements containing essential fatty acids can improve cryopreserved and thawed sperm quality. In this study, besides assessing motility and viability, parameters such as plasma membrane integrity, sperm morphology, membrane stability, lipid peroxidation, and DNA fragmentation will be evaluated in the frozen-thawed sperm of broiler breeder roosters. Materials and methods: Thirty-six 42-week-old Ross 308 roosters were randomly allocated to four groups (n=6/group) and housed in individual cages under standard conditions (21-24°C, 75% humidity, 15L:9D photoperiod). Experimental diets included: 1) Control (no oil), 2) 2% flaxseed oil, 3) 2% sesame oil, and 4) 1% flaxseed + 1% sesame oil. All diets were isoenergetic and isonitrogenous, formulated using WUFFDA software. Semen was gathered using abdominal massage on days 1, 20, 40, and 60. It was immediately diluted (1:20) in Lake’s extender, which had 5% glycerol, and held at 5°C for 2 hours. Afterward, it was frozen in 0.25 mL straws with liquid nitrogen vapor before being stored at -196°C. Thawing was performed in 4°C water for three minutes. Motility was assessed using computer-assisted sperm analysis (CASA). Viability was determined by eosin-nigrosine staining. Membrane integrity was measured with the hypo-osmotic swelling test (HOST). Lipid peroxidation (MDA) was measured using the thiobarbituric acid assay. Morphology was evaluated by phase-contrast microscopy. For fertility trials, pooled semen from each group was used to inseminate 20 hens/group (250 μL containing 300×10⁶ sperm). They gathered the eggs for five days after insemination, placed them in the incubator, and candled them on day 10 to determine their fertility. The data obtained from this experiment were statistically analyzed using the GLM procedure in SAS software. The comparison of means was conducted using the Tukey test at P<0.05. Results and discussion: Flaxseed oil (2% of diet) or a mix of flaxseed and sesame oil (1:1 ratio) improved total motility, progressive motility, sperm lipid peroxidation, membrane integrity, sperm viability, and fertility. These results were superior to control and sesame oil treatments (P<0.05). Fertility rates were significantly higher in the flaxseed (80%) and mixed oil (79%) groups compared to the control (60%, P<0.05), though hatchability did not differ significantly. The findings show that dietary flaxseed oil or its combination with sesame oil significantly enhances frozen-thaw sperm quality in broiler breeders. The improvements in motility, membrane integrity, and oxidative stability likely result from increased incorporation of omega-3 fatty acids (particularly DHA) into sperm membranes, improving fluidity and cryoresistance. The antioxidant properties of omega-3s may also mitigate freeze-thaw-induced lipid peroxidation. Conclusions: The study suggests that adding 2% flaxseed oil or a 1:1 flaxseed-sesame mixture to rooster diets can improve frozen-thawed semen quality and fertility in commercial poultry. Future research should optimize fatty acid ratios and evaluate long-term reproductive performance. The protocol provides a practical approach to reducing male maintenance costs while enabling global semen distribution in breeding programs. هدف از انجام این پژوهش، بررسی تاثیر منابع خوراکی حاوی اسیدهای چرب امگا-۳ و امگا-۶ (کتان و کنجد) بر فراسنجه‌های کیفی، باروری و جوجه‌درآوری اسپرم خروس‌های گله مادر گوشتی پس از انجماد و یخ‌گشایی بود. در این آزمایش از 24 قطعه خروس استفاده شد که در قالب طرح کاملاً تصادفی در چهار گروه آزمایشی مورد مطالعه قرار گرفتند. جیره‌های آزمایشی شامل: 1- جیره تجاری (شاهد)، 2- جیره حاوی دو درصد روغن کتان، 3- جیره حاوی دو درصد روغن کنجد و 4- جیره حاوی یک درصد روغن کتان و یک درصد روغن کنجد بودند. پس از دو هفته عادت‌دهی برای اسپرم‌گیری، خروس‌ها بهمدت ۶۰ روز با تیمارهای مختلف خوراک‌دهی شدند. نمونه‌های منی در روزهای ۴۰،۲۰،۱ و ۶۰ آزمایش بهروش ماساژ شکمی از خروس‌ها جمع‌آوری شده و منجمد شدند. فراسنجه‌های کیفی اسپرم شامل جنبایی ‌کل، جنبایی پیشرونده و فراسنجه‌های سرعتی اسپرم، یکپارچگی غشاء، زنده‌مانی، ریختشناسی طبیعی و پراکسیداسیون لیپیدی اسپرم پس از انجماد-ذوب مورد ارزیابی قرار گرفتند. برای بررسی راندمان باروری و جوجه درآوری، مرغ‌های مادر با اسپرم‌های منجمد یخ‌گشایی شده تیمارها در پایان آزمایش تلقیح شدند. نتایج نشان داد که تیمارهای روغن کتان (2 درصد جیره) و یا مخلوط روغن کتان و کنجد (به نسبت 1 به 1) بر فراسنجه‌های جنبایی ‌کل، جنبایی پیشرونده، پراکسیداسیون لیپید اسپرم و یکپارچگی غشای پلاسمایی و زندهمانی اسپرم و همچنین، بر باروری در مقایسه با تیمارهای شاهد و روغن کنجد موثر بوده است. بر اساس نتایج بهدست آمده از این پژوهش، به‌کارگیری روغن کتان و یا مخلوط مساوی روغن کتان و کنجد بهمیزان 2 درصد جیره بهمنظور بهبود کیفیت اسپرم خروس جهت انجماد پیشنهاد ‌می‌شود.

https://ar.guilan.ac.ir/article_9023_3c4df9233dd54577a39057079b8bc1b0.pdf

دانشگاه گیلان تحقیقات تولیدات دامی 2252-0872 14 4 2025 12 22 Effect of ultracentrifuge and ultrasonic treatment of egg yolk before extender supplementation on ram semen quality and fertility outcome after storage at 4°C اثر اولتراسونیک و یا اولتراسانتریفیوژ نمودن زرده تخم‌مرغ قبل از اضافه نمودن آن به رقیق‌کننده، بر کیفیت و قابلیت باروری منی قوچ پس از ذخیره‌سازی در دمای °C4 33 45 8730 10.22124/ar.2025.30074.1888 FA علی مولایی گروه علوم دامی، دانشکده کشاورزی، دانشگاه بوعلی سینا عباس فرح آور گروه علوم دامی، دانشکده کشاورزی، دانشگاه بوعلی سینا مرتضی یاوری گروه علوم درمانگاهی، دانشکده دامپزشکی، دانشگاه بوعلی سینا Journal Article 2025 03 11 Introduction: Egg yolk is an economical option for farm animal semen extenders. However, there are some potential disadvantages and concerns associated with whole egg yolk use as a component in extender media. Preparation of clarified egg yolk by high-speed centrifugation or probe ultrasonic treatment of egg yolk are novel, low-cost, fast, safe, and effective method in providing high-quality extenders for semen preservation. Ultracentrifuge and ultrasonic technology are mechanical methods used for separating and dispersing low-density lipoproteins (LDL), the primary protective component of egg yolk. Each method has its advantages and disadvantages, and as with any novel technique, it is essential to thoroughly evaluate and optimize the ultrasonic technology before using it for extender treatment. Therefore, the purpose of this study was to investigate the effect of ultracentrifuge and ultrasonic treatment of egg yolk before extender supplementation on the ram semen quality and fertility outcome after storage at 4°C for 72 hours. Materials and methods: This study was conducted in a completely randomized block design with three treatments and six replicates. The treatments included: 1) Whole egg yolk (WEY as control), 2) Clarified egg yolk (CEY) prepared by high-speed centrifuge at 25000 g for 60 minutes, and 3) Ultrasonicated egg yolk (SEY) with 50% power (500 W) for 10 minutes. In the breeding season, semen samples of three fertility-proven Mehraban rams (live body weight of 76.37 kg, age of 3-4 years, and BCS of 3.5-4) were collected by artificial vagina once a week, over six consecutive weeks (as an experimental block). Collected ejaculates were passed the minimum quality requirements before dilution. Ejaculates of rams in each week were mixed and divided equally into three parts and diluted up to the concentration of 200×106 spermatozoa/mL and stored at 4°C for 72 hours. Semen qualitative parameters were evaluated every 24 hours. Sperm viability, membrane integrity, and motility parameters were determined by eosin-nigrosin staining, the hypo-osmotic swelling test (HOST), and computer-assisted sperm analysis (CASA), respectively. In addition, a total of 42 non-pregnant Mehraban ewes, aged 2-4 years, with almost the same body weight and score, were used for the detection of fertility performance. The ewes' estrous cycle was synchronized by flurogestone acetate-loaded sponges and eCG (500 IU), and they were subjected to laparoscopic artificial insemination (LAI) 54 h after sponge removal, and the semen sample of each treatment was deposited into the uterine horns bilaterally. The pregnancy rate was detected by ultrasound scanning on d-45 after LAI. Results and discussion: Semen storage for 72 hours in extenders containing ultrasonic and ultracentrifuged egg yolk (CEY and SEY treatments) significantly showed higher sperm membrane integrity compared to the WEY (P<0.05). Total motility in the CEY treatment (P=0.0807) and progressively motile spermatozoa in the SEY treatment (P=0.0897) tended to increase. Stored semen in the SEY extender showed significantly higher progressively motile spermatozoa compared to the WEY (control), 24 hours after storage (P<0.05). In addition, the amplitude of lateral head displacement (P=0.07) and linearity (P=0.09) tended to increase 24 hours after storage. The highest level of sperm membrane integrity, 48 hours after storage, and the highest viability and total motility, 72 hours after storage, were related to the SEY treatment (P<0.05). The progressive motility (P=0.10) and linear velocity (P=0.07) tended to increase 72 hours after sperm storage in the CEY treatment. Other parameters, as well as the fertility outcome after laparoscopic artificial insemination, were not affected by the treatments. Very few studies have been conducted on the storage of ram semen with a diluent containing ultrasonicated or ultracentrifuged egg yolk at 4°C. Most of the studies reported the effect of a diluent containing ultrasonicated or ultracentrifuged egg yolk after the freeze-thaw process. Consistent with the findings of this study, a study showed that total motility, progressive motility, and membrane integrity of sperm after freeze-thawing of dog sperm in a diluent containing ultrasonicated egg yolk were better preserved than in a diluent containing ultracentrifuged egg yolk. In contrast, another study showed that sperm motility parameters and membrane integrity of pig sperm after freeze-thawing were improved only in a diluent containing centrifuged egg yolk, which is contrary to this finding of this study. Consistent with the findings of this study, it has been shown that freezing of donkey semen in diluents containing ultrasonicated egg yolk with different ultrasonic intensities and durations increased total and progressive motility, curvilinear line velocity, average path velocity, and straight-line velocity after thawing. It could be deduced from our results that during the centrifugation process, some constituents of egg yolk that could be detrimental to sperm cells were pelleted, leaving only LDL molecules in the extender, which had good results in the kinematic parameters. Ultrasonic treatment of egg yolk improves the dispersion of egg yolk components in the extender media, and can improve the extender's ability to protect sperm during chilled semen storage, resulting in increased sperm survival and viability. The sperm plasma membrane is the structure that is mainly injured during semen preservation. The storage temperature at 4°C causes the membrane to move into a gel phase, increasing the loss of lipids that are part of the cell structure, causing a loss in membrane integrity. The results of the present study revealed that ultrasonic and ultracentrifuge treatment of egg yolk were more efficient in maintaining the sperm plasma membrane integrity than the whole egg yolk, probably due to higher surface reactivity and a probable increase in the interaction capacity of egg yolk components due to ultrasonic and ultracentrifuge treatment. In this study, the fertility outcome was not affected by treatments. The reason for this could be related to the artificial insemination method and the time of storage of the inseminated semen. The quality of stored semen decreases over time of storage, but the insemination technique used in this study could compensate for this decline in sperm quality. Conclusions: Ultrasonic and ultracentrifugation processing of egg yolk with a change in its functional characteristics exert a positive effect on membrane integrity and some sperm motility characteristics, and can be used as a suitable approach to improve sperm preservation for artificial insemination. هدف پژوهش حاضر بررسی تأثیر اولتراسونیک و یا اولتراسانتریفیوژ نمودن زرده تخممرغ قبل از اضافه نمودن آن به رقیقکننده بر کیفیت و قابلیت باروری منی قوچ پس از ذخیرهسازی در دمای °C4 بود. تیمارهای آزمایشی شامل زرده کامل تخممرغ (WEY)، زرده اولتراسونیک شده (SEY) و زرده اولتراسانتریفیوژ شده (CEY) بود که در قالب طرح بلوکهای کامل تصادفی با سه تیمار و شش تکرار انجام شد. در فصل تولیدمثلی، منی اخذ شده از سه رأس قوچ نژاد مهربان با هم مخلوط شده و پس از رقیقسازی با رقیقکنندهها، نمونهها در دمای °C4 تا 72 ساعت نگهداری شد. زندهمانی با رنگآمیزی ائوزین-نیگروزین، یکپارچگی غشاء با آزمون تورم هیپواسمتیک و فراسنجههای جنبایی بهوسیله کاسا در هر 24 ساعت ارزیابی شد. همچنین، میشهای همزمانسازی شده با منی تیمارهای مربوطه بهروش لاپاراسکوپی تلقیح شده و میزان آبستنی در 45 روزگی تعیین شد. سلامت غشاء اسپرم در تیمارCEY وSEY بهطور معنیداری نسبت به WEY بیشتر بود (05/0>P). جنبایی کل در تیمار CEY (0807/0=P) و جنبایی پیشرونده در تیمار SEY(0897/0=P) گرایش به افزایش داشت. پس از 24 ساعت، جنبایی پیشرونده در تیمار SEY بهطور معنیداری بیشتر از WEY بود (05/0>P) و دامنه نوسانات حرکت اسپرمها (ALH) و خطی بودن حرکت اسپرمها (LIN) نیز گرایش به افزایش داشت. بیشترین میزان سلامت غشاء اسپرم پس از 48 ساعت و بیشترین میزان زندهمانی و جنبایی کل پس از 72 ساعت، مربوط به تیمار SEY بود (05/0>P). همچنین، پس از 72 ساعت، جنبایی پیشرونده و سرعت حرکت اسپرم روی خط مستقیم (VSL) در تیمار CEY نسبت به تیمار شاهد گرایش به افزایش داشت. میزان باروری تحت تاثیر تیمارها قرار نگرفت. بهطور کلی، عملآوری اولتراسونیک و اولتراسانتریفیوژ زرده تخممرغ با تأثیر مثبت بر سلامت غشاء و برخی ویژگیهای جنبایی اسپرم میتواند بهعنوان راهکاری مناسب جهت بهبود نگهداری اسپرم برای تلقیح مصنوعی گوسفند باشد.

https://ar.guilan.ac.ir/article_8730_8c3fcfe3bd4252bde6965b60c996e746.pdf

دانشگاه گیلان تحقیقات تولیدات دامی 2252-0872 14 4 2025 12 22 Study of differential expression of ovarian duct tissue genes in the follicular phase associated with fertility in the goat using transcriptomics data مطالعه بیان افتراقی ژن‌های بافت مجرای تخمدان در فاز فولیکولی مرتبط با باروری در بز با استفاده از داده‌های ترانسکریپتومی 47 58 9020 10.22124/ar.2025.30377.1892 FA فاطمه اسماعیلی لیما گروه علوم دامی ، دانشکده کشاورزی و منابع طبیعی، دانشگاه تهران حسین مرادی شهربابک گروه علوم دامی ، دانشکده کشاورزی و منابع طبیعی، دانشگاه تهران میلاد غلامی طاحونه گروه علوم دامی ، دانشکده کشاورزی و منابع طبیعی، دانشگاه تهران Journal Article 2025 04 15 Introduction: High fertility of goats is a key economic trait that has a direct impact on production efficiency in the goat industry. Many goat breeds have one or two kids per litter, and as the number of kids per litter increases, the amount of meat, milk, and other related products increases in proportion. The oviduct, as the main route of gamete transmission, plays a key role in mammalian fertility and provides a suitable environment for oocyte maturation, sperm capacitation, fertilization, and early embryo transfer. The follicular phase, which is accompanied by an increase in follicle-stimulating hormone (FSH) levels and the growth of dominant follicles, is of particular importance because it plays an important role in oocyte maturation and fertility. Among the many types of gene expression data, RNA-seq data has a great advantage over other types of data due to its high throughput and inclusion of sequences of transcribed regions and coverage of all these regions. In recent years, computer capabilities have made it possible to analyze this volume of data in a timely and cost-effective manner. One of the advantages of using RNA-seq data is the identification of new genes. The study aimed to identify oviductal genes in two groups of goats, low fertility (birth of one kid) and high fertility (birth of two or more kids), and to analyze the ontology of index genes, metabolic pathways, and molecular processes involved in the foetal stage. Materials and methods: To investigate gene expression patterns in oviduct tissue, RNA-seq data from 12 samples of 3-year-old female Yushang goats sequenced by China Agricultural University using the Illumina NovaSeq 6000 platform were used. The original SRA format files were converted to FASTQ format using SRA Toolkit v2.10.2 software. Data quality was assessed using FastQC v0.11.9 software and its graphical interface in a Java environment. Based on the quality assessment results, if necessary, paired-end data were corrected and cleaned using Trimmomatic v0.39 software. After cleaning, the data were again evaluated for quality with FastQC. To prepare the reference genome for alignment, its indexing was performed using Hisat2 v2.2.1 software, and then, using the same software, the cleaned reads were aligned to the reference genome. The SAM format outputs were converted to BAM format and sorted, indexed, and prepared for the next steps using the Samtools software package. Cufflinks v2.2.1 was used to assemble the transcriptomes, and after independent assembly of each sample, the transcriptome files generated were merged with the Cuffmerge software and converted into a single reference file. Finally, to display the results in the form of graphs and charts, the CummeRbund package was used in the R software environment, and gene ontology and biological pathway analyses related to differentially expressed genes were performed using the GENECARD (https://www.genecards.org) and DAVID (https://david.ncifcrf.gov/) databases. Results and discussion: A total of 69,005 gene identifiers were detected across both groups, from which only those with a |log₂ fold change| ≥ 3 and q-value<0.05 were selected as differentially expressed genes (DEGs), resulting in 22 candidate genes. The highest expression levels were observed in LGALS15, LGALS16, U1, and XLOC_03533. The most prominent gene in terms of expression difference between the two groups was XLOC_019343, which showed greater expression in the low-fertility group but remains uncharacterized in public databases. XLOC_03533 was the most highly expressed gene in the high-fertility group, while LGALS15, LGALS16, and U1 were dominant in the low-fertility group, with the largest expression disparities. These genes are implicated in critical reproductive processes such as endometrial remodeling, embryo implantation, placental formation, and structural and functional adaptations of the reproductive system. Conclusions: 22 genes associated with high and low fertility were identified on the transcriptome of the samples, which played a role in processes such as pregnancy establishment, endometrial remodeling, embryo implantation and placenta formation, regulation of the pH of the fallopian tube for sperm entry, prevention of some placental diseases, pathological inflammatory response, structural and functional adaptation for reproductive processes, and regulation of the gestation period. The results of this study can provide additional information to understand the relationship between effective genes and their pathways on the effect of fertility rate in Yushang goats, which can be generalized to other goat breeds. تخمدان‌ها، اندام‌های تولیدمثلی مهمی در پستانداران ماده هستند که مستقیماً بر چرخه فحلی و توانایی‌های تولیدمثلی تأثیر می‌گذارند. هدف این پژوهش، شناسایی ژن‌های مرتبط با تخمدان در بز نژاد یونشانگ، شامل دو گروه با میزان باروری پایین و باروری بالا و تجزیه هستی‌شناسی ژن‌های شاخص بهمنظور شناسایی مسیرهای متابولیکی و فعالیت‌های مولکولی دخیل در مراحل آبستنی است. در این مطالعه، ترانسکریپتوم توالی mRNA ۱۲ نمونه از بافت مجرای تخمدان بزهای سه‌ساله نژاد بز سیاه یونشانگ از پایگاه اطلاعاتی NCBI استخراج و ذخیره شد. پیش‌پردازش داده‌ها با استفاده از نرم‌افزارهای FastQC و Trimmomatic انجام شد. تجزیه بیان افتراقی ژن‌ها با استفاده از بسته نرم‌افزاری Cufflinks و تجزیه هستی‌شناسی ژن‌ها با کمک پایگاه‌های دادهDAVID وGENECARD صورت گرفت. در نهایت، ۶۹۰۰۵ شناسه ژن روی ترانسکریپتوم دو گروه شناسایی شد، تنها ژن‌هایی با log2 fold change ≥ ±3 و q-value < 0.05 بهعنوان ژن‌های شاخص، انتخاب شدند که شامل ۲۲ ژن بود. بیشترین میزان بیان در ژن‌های LGALS15، LGALS16، U1 و XLOC_03533 مشاهده شد. شاخص‌ترین ژن از نظر میزان بیان در هر دو گروه، شناسه ژن،XLOC_019343 است که در گروه باروری پایین‌تر، بیشتر بیان شده، اما در پایگاه‌های اطلاعاتی فاقد نام اختصاصی است. بیشترین بیان در گروه با باروری بالا مربوط به ژنXLOC_03533 و در گروه با باروری پایین مربوط به ژن‌های LGALS15،LGALS16 وU1 است که بالاترین تفاوت بیان را نیز نشان دادند. این ژن‌ها در فرآیندهایی مانند بازسازی آندومتر، لانه‌گزینی جنین، تشکیل جفت و سازگاری ساختاری و عملکردی مرتبط با فرآیندهای تولیدمثلی نقش دارند.

https://ar.guilan.ac.ir/article_9020_320f33511f90ae10db53ac5b47b77681.pdf

دانشگاه گیلان تحقیقات تولیدات دامی 2252-0872 14 4 2025 12 22 Comparative phylogenetic tree reconstruction algorithms based on the BRCA1 gene in different species مقایسه الگوریتم‌های درخت‌تبارزایی روی ژن BRCA1 در گونه‌های مختلف 59 80 9062 10.22124/ar.2025.30337.1890 FA مصطفی قادری‌زفره‌ئی گروه علوم دامی، دانشکده کشاورزی، دانشگاه یاسوج Journal Article 2025 04 13 Introduction: The BRCA1 gene is a pivotal candidate in current research endeavors, specifically drawing significant attention in studies related to bovine mammary tumors and human breast cancer. This gene is recognized for its fundamental biological role, as it encodes a protein that primarily functions as a tumor suppressor. Understanding the intricate evolutionary trajectory and the degrees of conservation or divergence of the BRCA1 gene across various species is of paramount importance. Such an understanding can provide profoundly crucial insights into its underlying functional mechanisms and can offer invaluable comparative perspectives directly relevant to the development and progression of diseases in both human populations and livestock. Considering the substantial and impactful economic consequences that mammary tumors exert on agricultural productivity within cattle farming, alongside the pervasive and persistent challenge posed by breast cancer in human health, a detailed phylogenetic analysis of the BRCA1 gene across a broad and representative spectrum of species becomes an imperative scientific undertaking. This research endeavor specifically aimed to meticulously reconstruct the evolutionary history of the BRCA1 gene across a wide array of selected species. By successfully achieving this, it sought to contribute significantly to a deeper and more comprehensive understanding of its functional preservation across evolutionary time. Moreover, it is intended to explore its potential practical applications, which notably include informing more effective breeding strategies designed to foster disease-resistant livestock and guiding the development of novel diagnostic approaches pertinent to improving human health. Materials and methods: In this computational study, the coding sequence (CDS) region of the BRCA1 gene was precisely extracted from the genomes of 32 mammalian species from the NCBI database. The extracted sequences were then aligned using the BLAST algorithm and MEGA software. To reconstruct the evolutionary relationships, five phylogenetic methods were employed: DNAPARS, Pars, PhyML, Dnaml, and Proml. This comprehensive approach allowed for a multifaceted analysis of the gene's evolutionary history. The current version of Dnaml is faster than its previous iterations. This algorithm accounts for unequal predicted frequencies of the four DNA bases and allows for different predicted frequencies of transitions and transversions, along with various methods for incorporating different rates of interaction at distinct DNA sites. Key assumptions of this algorithm include the independent evolution of each DNA site and different lineages. Proml, optimized for protein data, offers robust statistical inference. Results and discussion: The application of various selected phylogenetic algorithms consistently revealed that all methods clustered closely related species, such as Bos taurus and Ovis aries, into similar phylogenetic groups. This consistent grouping strongly confirms the conserved functional role of BRCA1 in DNA repair and immune regulation. However, significant differences in phylogenetic tree topology were observed. Maximum likelihood methods (PhyML/Dnaml) grouped humans (Homo sapiens) with primates, showing bootstrap values of 65-75%. In contrast, maximum parsimony methods (DNAPARS/Pars) revealed weaker associations for rodents, with bootstrap values of 50-60%. The Proml algorithm, based on Bayesian inference, also showed uncertainty in estimating branch lengths. These differences highlight the sensitivity of the methods to the heterogeneous evolutionary rate of BRCA1 and underscore the necessity of using combined mRNA and protein data to reduce methodological biases. The results showed that most mammals are grouped into closely related clusters; however, even within a single phylogeny, maximum likelihood did not always yield consistent topologies, hinting at complex evolutionary dynamics not fully captured by single gene analyses. Conclusions: The findings of this study not only illuminate the intricate evolutionary history of BRCA1 but also possess practical applications in breeding disease-resistant livestock and in human breast cancer research. Future research should investigate the role of horizontal gene transfer and its influence on BRCA1 evolution. This study ultimately provides a framework for the evolutionary analysis of disease-resistance genes. Given the crucial role of the BRCA1 gene in mammary tumors and breast cancer, the results of this study can provide a better evolutionary perspective across different species and be utilized in diagnostic assays for both humans and livestock. The study consistently showed that in most procedures and algorithms, bovine and ovine species form a very close evolutionary cluster. Therefore, the evolutionary results for one species can be applied to another. The BRCA1 gene, essential for maintaining genomic stability through its role in DNA repair and cell cycle regulation, exhibits a high degree of evolutionary conservation, particularly in the N-terminal RING domain and C-terminal BRCT domains. This was demonstrated in this study, indicating that these vital regions are conserved among various vertebrate species, underscoring their functional importance. ژن BRCA1 بهعنوان یک سرکوبگر تومور در مطالعات ورم پستان گاو و سرطان سینه انسان مورد توجه است. در این پژوهش، توالی CDS این ژن از 32 گونه پستاندار از پایگاه NCBI استخراج شده و با استفاده از الگوریتم BLAST و نرم‌افزار MEGA همردیف‌سازی شد. روابط تکاملی با پنج روش فیلوژنتیک DNAPARS، Pars، PhyML، Dnaml و Proml بازسازی شدند. نتایج نشان داد تمام روش‌ها، گونه‌های نزدیک مانند Bos taurus و Ovis aries را در یک خوشه قرار دادند که حفاظت عملکردی BRCA1 در ترمیم DNA و تنظیم ایمنی را تأیید می‌کند. با این حال، تفاوت‌های معنیداری در توپولوژی درخت‌ها مشاهده شد: روش‌های حداکثر درست‌نمایی (PhyML/Dnaml) با بوت‌استرپ 75-65 درصد، انسان را با نخستی‌سانان گروه‌بندی کردند، در حالی که روش‌های حداکثر صرفه‌جویی (DNAPARS/Pars) با بوت‌استرپ 60-50 درصد، روابط ضعیف‌تری برای جوندگان نشان دادند. الگوریتم بیزی Proml نیز عدم قطعیت در تخمین طول شاخه‌ها را آشکار ساخت. این تفاوت‌ها، حساسیت روش‌ها به نرخ تکاملی ناهمگون BRCA1 را نشان می‌دهد و لزوم استفاده از داده‌های ترکیبی mRNA و پروتئین را برای کاهش سوگیری‌های روش‌شناختی برجسته می‌سازد. یافته‌های این مطالعه نه تنها تاریخچه تکاملی BRCA1 را روشن می‌کند، بلکه کاربردهای عملی در پرورش دام‌های مقاوم به ورم پستان و مطالعات سرطان سینه انسان دارد. پژوهش‌های آینده باید نقش انتقال افقی ژن و تأثیر آن بر تکامل BRCA1 را بررسی کنند. این مطالعه، چارچوبی برای تحلیل تکاملی ژن‌های مقاومت به بیماری ارائه می‌دهد.

https://ar.guilan.ac.ir/article_9062_29470b1aa35962d24e76659286d20e9a.pdf

دانشگاه گیلان تحقیقات تولیدات دامی 2252-0872 14 4 2025 12 22 Comparison of goodness of fit in lactation curve modeling in Holstein dairy cows مقایسه‌ نکوئی برازش در مدل‌سازی منحنی شیردهی در گاوهای شیری هلشتاین 81 94 8924 10.22124/ar.2025.30723.1898 FA محمد تاجیک خواری گروه علوم دامی، دانشکده علوم دامی و شیلات، دانشگاه علوم کشاورزی و منابع طبیعی ساری محسن قلی زاده گروه علوم دامی، دانشکده علوم دامی و شیلات، دانشگاه علوم کشاورزی و منابع طبیعی ساری غلامرضا پیکانی ماچیانی گروه اقتصاد کشاورزی، پردیس کشاورزی و منابع طبیعی، دانشگاه تهران Journal Article 2025 05 21 Introduction: Lactation curves are essential tools for understanding milk production patterns in dairy cattle, providing critical insights for herd management and genetic improvement. Modeling these curves accurately is vital to predict yield, optimize feeding strategies, and enhance overall productivity. Among the various approaches, non-linear models such as Wood, Wilmink, Dhanoa, Cappio-Borlino, and Cobby & Le Du have been widely used to describe the lactation kinetics in Holstein cattle. However, comparative evaluations of these models' performance under similar conditions remain limited. This study aimed to assess and compare the goodness-of-fit of these five established models to identify the most suitable for characterizing lactation curves in Holstein cows, ensuring more precise and reliable production forecasting. Additionally, the possibility of utilizing the Dynamic Ordinary Least Squares (DOLS) method instead of the traditional nonlinear least squares (LS) approach for the best-fitted model was investigated to explore potential improvements in estimation accuracy. Materials and methods: This study utilized milk production records from a dairy farm in Tehran Province, Iran, under the supervision of the National Animal Breeding Center. The dataset included 1050 test-day records from the first three lactation periods (1st to 3rd), spanning 305 days in milk (DIM). Only cows with a minimum of 10 valid test-day records and lactations exceeding 200 days were considered. Lactation curves were fitted using five non-linear models, Wood, Wilmink, Dhanoa, Cappio-Borlino, and Cobby & Le Du, implemented in R software (packages nlme and minpack.lm). Model performance was assessed using goodness-of-fit criteria, including the coefficient of determination (R²), root mean square error (RMSE), and Akaike Information Criterion (AIC). Upon identifying the best-performing model, the DOLS method was applied to evaluate its potential for improving parameter estimation accuracy. This analysis was conducted using records from the first three lactations of eight Holstein dairy cows. Results and discussion: Comparative analysis of the five non-linear models revealed the Wood model as the most statistically suitable for characterizing Holstein lactation curves. While effective, the Wood model demonstrated limitations under traditional LS estimation, particularly in accurately predicting peak yield magnitude and timing. These shortcomings stemmed from the LS method's sensitivity to initial parameter values and its inability to properly synchronize estimated events with observed farm data. Implementation of the DOLS method substantially enhanced model performance. The DOLS-adapted Wood model showed improved goodness-of-fit metrics and, crucially, provided more biologically accurate estimates of key lactation events, including initial yield, peak timing, and peak magnitude. These estimates closely matched actual farm records, demonstrating superior predictive capability compared to the LS approach. The study confirmed established biological patterns: third-lactation cows exhibited higher initial yields (α parameter) and greater persistence (lower c parameter values) compared to first-lactation animals. These findings align with known metabolic adaptations in mature cows and previous reports of lactation curve dynamics. Visual and statistical comparisons revealed distinct advantages of the DOLS approach. While both methods achieved reasonable goodness-of-fit, the DOLS-generated curve showed better alignment with critical lactation points and lower standard errors, particularly for peak-related parameters. This temporal calibration is essential for practical applications, as even models with high R² values may yield misleading recommendations if event timing is inaccurate. The results substantiate theoretical advantages of DOLS in production function estimation, demonstrating its capacity to generate properly calibrated, differentiable concave functions that faithfully represent biological reality while maintaining statistical rigor. Conclusions: This study demonstrates that the DOLS method offers substantial improvements over traditional nonlinear LS for modeling Holstein lactation curves using Wood’s equation. The DOLS approach effectively addresses critical limitations of conventional nonlinear estimation, particularly its dependence on manual parameter initialization and its tendency for temporal miscalibration. By providing parameter estimates that align more closely with biological reality, DOLS enables superior prediction of key lactation traits, including peak yield and persistence, crucial factors for genetic selection and herd management decisions. The methodological advantages of DOLS extend beyond statistical performance to practical implementation; its ability to estimate marginal productivity within the actual lactation timeline while preserving biological plausibility makes it especially valuable for dairy management applications. These findings suggest that adopting DOLS in breeding programs and farm management systems could enhance both the accuracy and economic outcomes of production decisions. While this research presents a novel application of DOLS to lactation modeling, certain limitations merit consideration. The relatively small sample size, the absence of formal cointegration testing, and unexamined econometric assumptions, such as stationarity and residual independence, highlight the need for validation with larger and more diverse datasets. Future studies should examine DOLS performance across different breeds, management systems, and lactation stages while incorporating appropriate econometric validation procedures. Nevertheless, this work establishes DOLS as a promising alternative to conventional nonlinear approaches, offering both theoretical rigor and practical utility for lactation curve analysis in dairy science. این مطالعه به ارزیابی پنج مدل غیرخطی رایج (وود، وایلمینک، دهنووا، کاپیو-برلینو و کوبی-لیدو) برای برازش منحنی شیردهی در گاوهای هلشتاین پرداخت. داده‌های مورد استفاده شامل 1050 رکورد روزانه تولید شیر طی ۳۰۵ روز از دوره‌های اول تا سوم شیردهی گاوهای یک واحد دامداری در استان تهران، زیر نظارت مرکز اصلاح نژاد دام کشور، بود که تنها گاوهای دارای حداقل ۱۰ رکورد معتبر و دوره شیردهی بیش از ۲۰۰ روز وارد تحلیل شدند. مدل‌های منحنی در نرم‌افزار R و با استفاده از معیارهای برازش R²،RMSE و AIC ارزیابی شدند. نتایج نشان داد مدل وود، بهترین برازش را دارد. سپس، کارآیی روش حداقل مربعات معمولی پویا (DOLS) در تخمین فراسنجههای مدل وود بررسی شد که نسبت به روشهای حداقل مربعات غیرخطی متداول، بهبود قابل توجهی در برآورد دقیق فراسنجههای کلیدی از جمله تولید اولیه شیر، زمان و مقدار اوج تولید و نرخ کاهش پس از اوج نشان داد و انطباق بهتری با رکوردهای روزآزمون گله ایجاد کرد. همچنین، الگوهای زیستی شناخته‌شده‌ای تأیید شد؛ به‌طوری که گاوهای دوره سوم شیردهی در مقایسه با گاوهای دوره اول، تولید اولیه بالاتر و تداوم شیردهی بهتری داشتند. با وجود نتایج امیدوارکننده، محدودیت‌هایی مانند حجم نمونه نسبتاً کوچک، استفاده از داده‌های یک گله و عدم انجام آزمون هم‌انباشتگی، لزوم اعتبارسنجی نتایج در جمعیت‌ها و شرایط مدیریتی مختلف و با نمونه‌های بزرگ‌تر را نشان می‌دهد.

https://ar.guilan.ac.ir/article_8924_893a657826c1d23436b0d544dd35cf91.pdf

دانشگاه گیلان تحقیقات تولیدات دامی 2252-0872 14 4 2025 12 22 Effect of feeding inorganic and chelated supplements of trace elements on performance, nutrient digestibility, blood parameters, and fecal score of suckling Holstein calves اثر تغذیه مکمل‌های کیلاته و معدنی عناصر کم‌نیاز بر عملکرد، قابلیت هضم مواد مغذی، فراسنجه‌های خونی و قوام مدفوع گوساله‌های شیرخوار هلشتاین 95 106 9021 10.22124/ar.2025.30644.1896 FA قاسم خادم گروه تغذیه دام و طیور، دانشکده علوم دامی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان تقی قورچی گروه تغذیه دام و طیور، دانشکده علوم دامی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان عبدالحکیم توغدری گروه تغذیه دام و طیور، دانشکده علوم دامی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان 0000-0002-5198-1940 کتایون مهرانی گروه تغذیه دام و طیور، دانشکده علوم دامی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان کامل عموزاده آرائی گروه تغذیه دام و طیور، دانشکده علوم دامی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان Journal Article 2025 05 12 Introduction: Calf rearing is one of the most important and sensitive management programs in livestock farms. Calves are a key factor in profitability; therefore, using appropriate nutritional methods for better growth and health is crucial. One such method is transitioning calves earlier from milk feeding to a dry diet. Faster feeding of the starter diet and the development of rumen villi prepare the calf for the transition period and reduce labor and feeding costs. Early weaning shortens the liquid feeding period. Since calves are susceptible to diarrhea and digestive issues during this phase, reducing their duration can be highly beneficial. However, one of the most important points in the livestock industry is animal nutrition, which is directly related to the growth, health, and mortality of livestock. Therefore, to achieve proper growth and health of livestock to improve production efficiency in animal husbandry, new methods are needed in the livestock nutrition sector. This study was conducted to compare the effect of feeding chelated and mineral forms of trace elements (cobalt, iodine, selenium, zinc, manganese, iron, and copper) on performance, nutrient digestibility, blood parameters, and stool consistency of suckling Holstein calves. Materials and methods: Thirty-six calves with an age of 7±3 days and an initial body weight of 36.2±3.8 kg were divided into three treatments and 12 replications in a completely randomized design. The treatments included: 1. Control group (without mineral supplement), 2. Feeding with two grams of mineral supplement per calf per day, and 3. Feeding with two grams of chelated supplement per calf per day. In the first three days of life, calves received colostrum at a rate of 10% of their body weight. From the fourth day to 60 days of age, they received four liters of milk twice a day (7 am and 7 pm). During the experiment, calves had free access to feed and water. To assess performance, calves were weighed on days 0, 30, and 60 to monitor weight changes. Feed intake and post-feeding were also recorded daily. The increase in feed intake was determined based on the remaining feed of each animal on the following day, so that if the animal left less than 10% of its own feed on three consecutive days, the feed intake was increased. This process continued until the end of the experiment. Feed conversion ratio was obtained from the ratio of the average dry matter intake of each calf to the average daily weight gain during the period. Fecal and feed samples were collected on days 55 to 59 for five days for digestibility tests. To measure blood parameters on day 60 of the study, fasting blood was drawn from the calf's jugular vein before morning feeding using heparinized venoject tubes. To assess the health index of the calves, the appearance of feces was assessed daily during the experiment. The feces score was scored daily for each calf as an indicator of animal health. Results and discussion: According to the results of the present study, adding chelated supplements improved the weight at 30 days, 60 days, weight changes, daily weight gain from 1 to 30 days, and for the entire period (P<0.05). There was no significant difference in body weight at 30 days or daily weight gain (1-30 days) between calves receiving chelated and mineral supplements. Supplementing calf milk with chelated minerals increased total and daily dry matter intake, starter intake, and feed conversion ratio (P<0.05). The results of the present study showed that adding mineral supplements and chelated trace elements to calf milk improved the digestibility of dry matter, organic matter, crude fat, and neutral detergent insoluble fiber (P<0.05). However, no significant difference was observed between calves receiving trace elements. According to the results, adding mineral elements to calf milk increased blood glucose concentration (P<0.05). However, the addition of trace minerals had no significant effect on the concentrations of cholesterol, triglycerides, urea nitrogen, total protein, albumin, and globulin. Serum zinc concentrations in calves receiving mineral supplements were higher than in the other two groups (P<0.05), while this difference was not significant in calves receiving chelated supplements. Calves in the control and chelated supplements groups had the highest (2.30) and lowest (1.86) fecal score among the experimental treatments, respectively (P<0.05). Conclusions: Overall, this study suggests that supplementing milk with chelated minerals, rather than inorganic sources, improves performance traits, enhances stool consistency, and positively influences key physiological parameters in suckling calves. این پژوهش با هدف مقایسه اثر تغذیه شکل‌های کیلاته و معدنی عناصر کم‌مصرف (روی، مس، منگنز، کروم، سلنیوم و کبالت) بر عملکرد، قابلیت هضم مواد مغذی، فراسنجه‌های خونی و قوام مدفوع گوساله‌های شیرخوار هلشتاین انجام شد. بدین منظور، از گوساله‌هایی با سن 3±7 روزگی و وزن بدن اولیه 8/3±2/36 کیلوگرم، در سه تیمار و 12 تکرار در قالب طرح کاملاً تصادفی استفاده شد. تیمارها شامل: 1- شاهد (بدون مکمل مواد معدنی)، ۲- تغذیه با دو گرم مکمل معدنی بهازای هر رأس گوساله در روز و 3- تغذیه با دو گرم مکمل کیلاته بهازای هر رأس گوساله در روز بودند. نتایج نشان داد افزودن مکمل کیلاته موجب بهبود وزن بدن در روزهای ۳۰ و ۶۰ آزمایش، افزایش وزن روزانه در دوره‌ ۱ تا ۳۰ روزگی آزمایش و کل دوره و نیز بهبود عملکرد کلی رشد گوساله‌ها شد (05/0>P). بین گوساله‌های دریافت‌کننده مکمل کیلاته و معدنی از نظر وزن 30 روزگی و افزایش وزن روزانه یک تا 30 روزگی، اختلاف معنی‌داری مشاهده نشد. مکمل کردن شیر گوساله‌ها با مواد معدنی کیلاته سبب افزایش ماده خشک مصرفی کل و روزانه، استارتر مصرفی و ضریب تبدیل خوراک شد (05/0>P). نتایج پژوهش حاضر نشان داد که افزودن مکمل معدنی و کیلاته عناصر کم‌مصرف به شیر گوساله‌ها سبب بهبود قابلیت هضم ماده خشک، ماده آلی، چربی خام و الیاف نامحلول در شوینده خنثی شد (05/0>P). افزودن عناصر معدنی به شیر باعث افزایش غلظت گلوکز خون شد (05/0>P)، در حالی ‌که تأثیر معنی‌داری بر غلظت کلسترول، تری‌گلیسرید، نیتروژن اوره‌ای، پروتئین کل، آلبومین و گلوبولین نداشت. غلظت روی سرم در گروه دریافت‌کننده مکمل معدنی بیشتر از سایر گروه‌ها بود (05/0>P)، در حالی‌ که این اختلاف با گوساله‌های دریافت‌کننده مکمل کیلاته معنی‌دار نبود. گوساله‌های گروه شاهد و مکمل کیلاته، بهترتیب بیشترین (30/2) و کمترین (86/1) نمره قوام مدفوع را بین تیمارهای آزمایشی داشتند (05/0>P). به‌طور کلی، نتایج این مطالعه نشان داد که افزودن مکمل مواد معدنی با منبع کیلاته و غیرآلی به شیر مصرفی میتواند موجب بهبود عملکرد، وضعیت قوام مدفوع و فراسنجههای اندازهگیری شده در گوساله‌های شیرخوار نسبت به گروه شاهد ‌شود.

https://ar.guilan.ac.ir/article_9021_e193a8d91cecefe289dd152c093e0e36.pdf