دانشگاه گیلان تحقیقات تولیدات دامی 2252-0872 15 2 2026 06 22 The use of quantile regression to evaluate some lactation curve characteristics of Iranian dairy cows استفاده از رگرسیون کوآنتایل در بررسی برخی خصوصیات منحنی شیردهی گاوهای شیری ایران 1 17 9480 10.22124/ar.2026.31890.1928 FA زینب حسامی زستمی بخش علوم دام، دانشکده کشاورزی، دانشگاه بیرجند سید همایون فرهنگ فر بخش علوم دام، دانشکده کشاورزی، دانشگاه بیرجند مختارعلی عباسی مؤسسه تحقیقات علوم دامی، سازمان تحقیقات، آموزش و ترویج کشاورزی حسین نعیمی پور یونسی بخش علوم دام، دانشکده کشاورزی، دانشگاه بیرجند Journal Article 2025 10 05 Introduction: Over recent decades, numerous mathematical models have been developed to represent the lactation curve of dairy animals. These models are categorized into parametric and non-parametric types, with the three-parameter Wood's gamma incomplete function being extensively utilized for dairy cows. By using the parameters from Wood's model, key lactation characteristics such as peak time, peak yield, and persistency can be determined. These features are considered economic traits, suitable for genetic selection. Previous studies have primarily focused on employing mathematical models to calculate these characteristics based on the average of test day milk records. However, they can also be computed for individual quantiles of test day milk records (TDMR). To our knowledge, no research has yet explored the use of quantile regression for modeling the lactation curve of Iranian dairy cows. Therefore, the primary objective of this study was to assess certain lactation curve characteristics of Iranian dairy cows using the quantile regression technique. Materials and methods: The data for this study were sourced from the Animal Breeding Centre of Iran. Initially, the dataset was merged and refined using SPSS software. The final dataset included TDMR data from 984,690 dairy cows across 579 herds in 26 provinces nationwide. A total of 15,647,867 TDMR records were collected from the first five parities of cows calving between 1995 and 2021. The TDMR was initially analyzed using a fixed linear model tailored to 20 different combinations of parity and calving season. For each combination, the least squares means of TDMR, measured from 4 to 305 days in milk, were applied to Wood’s incomplete gamma function (y=atbe-ct) in a quantile-based approach. This parametric three-parameter model (a, b, c) is extensively used to describe lactation curves. The linearized form of Wood’s model was fitted to these means using the Quantreg procedure in SAS software, estimating parameters across quantiles from 5 to 95 in increments of 5. Based on these parameters, lactation characteristics such as peak time, peak yield, and persistency were calculated across all parity-calving season combinations. Statistical comparisons of the combination means were conducted using SPSS software. Results and discussion: The results of this research indicate that peak time, peak yield, and the persistency of the lactation curve in Iranian dairy cows vary across different quantiles of TDMR, parities, and calving seasons. The findings reveal that peak yield increases with higher TDMR quantiles. Conversely, peak time and persistency are greater in the lower TDMR quantiles compared to the upper ones. Across the TDMR quantiles, the minimum (50.92 days) and maximum (93.36 days) peak times, as well as persistency values (6.64 and 7.37), were observed in cows that calved in autumn and began their first or third lactation period (P<0.05). Regarding peak yield, cows that calved in spring and started their first lactation had a lower mean yield (31.84 kg), while the highest mean yield (40.43 kg) was noted in cows that calved in autumn and began their fourth lactation period (P<0.05). As anticipated, cows in their first parity exhibited greater lactation persistency compared to others. Peak yield was significantly correlated with peak time (-0.9520) and persistency (-0.9516) (P<0.0001), suggesting that cows with lower milk yield at peak time tend to reach their peak later and maintain higher persistency post-peak. Conclusions: The research findings reveal that the peak time, peak yield, and persistency of the lactation curve in Iranian dairy cows differ across the quantiles of test-day milk records. Specifically, peak time and persistency are higher in the lower quantiles compared to the upper ones. Additionally, these lactation characteristics vary across different parities and calving seasons. Based on these results, it is recommended that these variations be considered when using records from various parities for the genetic evaluation of Iranian dairy cows. This consideration is crucial when employing test-day models for genetic analysis of the lactation curve. هدف از پژوهش کنونی، بررسی ویژگی‌های منحنی شیردهی گاوهای شیری ایران با استفاده از رگرسیون کوآنتایل (چندکی) بود. دادههای مورد استفاده شامل 15647867 رکورد روز آزمون شیر بود که از 984690 رأس گاو در 579 گله موجود در 26 استان کشور گردآوری شدند. ابتدا، رکوردهای روز آزمون شیر در ترکیبهای مختلف نوبت زایش–فصل زایش (و مشتمل بر 20 ترکیب) با استفاده از یک مدل خطی تجزیه و تحلیل شدند. سپس، در هر یک از ترکیبات مزبور، میانگین حداقل مربعات رکوردهای روز آزمون شیر در فاصله روزهای 4 تا 305 شیردهی، در تابع خطی شده گامای وود و با روش رگرسیون کوآنتایل، مورد استفاده قرار گرفتند. نتایج نشان داد با بالا رفتن چندکهای رکوردهای روز آزمون شیر، مقدار تولید شیر در اوج شیردهی، افزایش مییابد. زمان رسیدن به اوج شیردهی و میزان تداوم شیردهی در چندکهای پایینی، بزرگتر از چندکهای بالایی رکوردهای روز آزمون شیر بودند. در تمامی چندکها، کمترین و بیشترین میانگین زمان رسیدن به اوج شیردهی (92/50 و 36/93 روز) و میزان تداوم شیردهی (64/6 و 37/7) بهترتیب مربوط به گاوهایی بود که در پاییز زایش داشتند و در دورههای شیردهی سوم یا اول بودند (05/0P<). در رابطه با مقدار تولید شیر در اوج شیردهی، گاوهای زایمان کرده در بهار که دوره اول شیردهی را شروع کرده بودند، کمترین میانگین (84/31 کیلوگرم) و گاوهای زایمان کرده در پاییز که دوره چهارم شیردهی را شروع کرده بودند، بیشترین میانگین (43/40 کیلوگرم) را دارا بودند (05/0P<). با توجه به نتایج تحقیق حاضر، چنانچه قرار باشد در امر ارزیابی ژنتیکی گاوهای شیری ایران برای صفت تولید شیر از اطلاعات دورههای مختلف شیردهی استفاده شود، ضروری خواهد بود تا تغییرات یاد شده در صفات شیردهی، مدنظر قرار گیرند، بهویژه هنگامی که از مدلهای روز آزمون جهت تجزیه ژنتیکی منحنی شیردهی استفاده می شود.

https://ar.guilan.ac.ir/article_9480_e6ffb688cddc09f9d0d50db05f7810f1.pdf

دانشگاه گیلان تحقیقات تولیدات دامی 2252-0872 15 2 2026 06 22 Effect of using processed pinto bean straw in the diet on the growth performance of Farahani fattening lambs اثر استفاده از کاه لوبیای چیتی فرآوری شده در جیره بر عملکرد رشد بره های پرواری فراهانی 19 30 9296 10.22124/ar.2025.31459.1914 FA آزاده میرشمس الهی بخش تحقیقات علوم دامی، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان مرکزی، سازمان تحقیقات، آموزش و ترویج کشاورزی، اراک، ایران Journal Article 2025 08 20 Introduction: Livestock nutrition represents a significant portion of the total costs in animal husbandry. To enhance efficiency, identifying inexpensive feed sources is a key strategy. The gap between the demand and supply of feed ingredients has notably widened in recent decades, and livestock producers are facing numerous challenges in obtaining feed resources due to drought and rising prices of conventional feedstuffs. Consequently, there is an increasing need to utilize affordable alternative feed materials in ruminant diets. Processing and effectively using agricultural by-products and residues as feed for ruminants is essential for improving livestock production. Legume straws, particularly bean straw, have gained attention both domestically and internationally as an important and economical source of roughage in ruminant nutrition. With superior nutrient composition compared to cereal straws, legume straws offer greater potential for widespread use in animal diets. In regions where beans are cultivated, the production of bean residues is significant and can fulfill part of the nutritional needs of livestock. Feeding bean straw to ruminants may offer benefits over certain cereal straws, likely due to its higher crude protein content and other valuable nutrients. From a nutritional standpoint, processed legume straws serve as sources of energy and protein in the diets of fattening livestock, helping to reduce feeding costs and improve animal performance. Therefore, this study aimed to evaluate the effects of incorporating processed and unprocessed bean straw into the diets of Farahani lambs on their growth performance and fattening characteristics. Materials and methods: Bean straw was processed with urea by ensiling in plastic covers. For every 100 kg of bean residue, 50 kg of water (50%), 3 kg of chemical urea fertilizer (3%), 1 kg of calcium carbonate (1%), and 100 g of sulfur were added. One month after ensiling, dry matter, ether extract, ash, crude protein, and acid detergent fiber and neutral detergent fiber contents of the processed bean straw were determined. In vitro digestibility of samples was also assessed using the gas test method. Subsequently, at a sheep farm in Arak County, 45 lambs aged 4–5 months with similar average weights were randomly assigned to three experimental groups: 1) wheat straw (control), 2) bean straw, and 3) urea-treated bean straw. The experiment lasted 90 days, during which lambs’ weight gain was measured every 30 days and daily dry matter intake was recorded by collecting feed refusals before morning feeding. Weight gain, feed conversion ratio (FCR) were examined monthly and over the entire fattening period. Data were analyzed using mixed model procedures in SAS software (version 9.1), and treatment means were compared by Duncan’s multiple range test. Results and discussion: The study found that treating bean straw with urea significantly increased its crude protein content by 25.51%, elevating it from 8% in untreated straw to 12.1% in urea-treated straw (P<0.05). Ammoniation effectively reduced both neutral detergent fiber and acid detergent fiber contents (P<0.05). Additionally, urea treatment markedly improved the dry matter and organic matter digestibility of the bean straw compared to untreated samples (P<0.05). Ammoniation also resulted in higher gas production (P<0.05) and enhanced organic matter digestibility by approximately 11%, boosting the metabolizable energy content from 7.29 to 9.1 MJ/kg DM in treated straw (P=0.01). The feeding trial indicated that incorporating bean straw increased daily feed intake compared to the control diet, with urea-treated bean straw further enhancing intake over untreated straw (P=0.03). Furthermore, lambs fed urea-treated bean straw exhibited significantly greater daily weight gain than those in the control and untreated straw groups (P=0.01), along with an improved feed conversion ratio (P=0.01). Economic analysis showed that adding bean straw and urea-treated bean straw to the lambs' diet reduced the feeding cost per kilogram of weight gain compared to the control group. Conclusions: Ammoniating bean by-products with urea is a straightforward and effective method to enhance their nutritional value. This technique significantly increases crude protein content and digestibility, allowing these by-products to replace conventional feeds like alfalfa, corn silage, and various oilseed meals in ruminant diets. As a result, it reduces overall feed costs and lowers meat production expenses. این پروژه بهمنظور بررسی اثر استفاده از کاه لوبیای فرآوری شده در جیره بر صفات رشد و پروار برههای توده فراهانی انجام شد. سیلاژ کاه لوبیا با افزودن 3 درصد اوره تهیه شد. یک ماه بعد از تهیه سیلاژ، میزان ماده خشک، عصاره اتری، خاکستر، پروتئین خام و الیاف نامحلول در شوینده اسیدی و خنثی کاه لوبیای فرآوری شده اندازهگیری شد. گوارش‌پذیری آزمایشگاهی سیلاژها با روش آزمون گاز اندازه‌گیری شد. در مرحله بعد، 45 رأس بره 5-4 ماهه (با میانگین وزن برابر با 29/22 کیلوگرم) به سه گروه تقسیم شده و به جیره‌های آزمایشی اختصاص یافتند. جیره‌های آزمایشی شامل: 1- جیره شاهد، 2- جیره دارای کاه لوبیای فرآوری نشده و 3- جیره دارای کاه لوبیای فرآوری شده با اوره بودند. فرآوری کاه لوبیا با اوره، باعث افزایش پروتئین خام از 8 درصد به 1/12 درصد شد (01/0P<). آمونیاکی کردن کاه لوبیا سبب کاهش مقدار الیاف نامحلول در شوینده خنثی و اسیدی و افزایش گوارشپذیری ماده خشک و ماده آلی آن شد (01/0P<). افزایش وزن روزانه برههای گروه کاه لوبیای فرآوری شده، بیشتر از برههای دو گروه دیگر، و ضریب تبدیل غذایی نیز در برههای گروه کاه لوبیای فرآوری شده، بهبود نشان داد (01/0P<). استفاده از کاه لوبیا و کاه لوبیای فرآوری شده با اوره در جیره غذایی برهها سبب کاهش هزینه تغذیه بهازای هر کیلوگرم اضافه وزن برهها نسبت به برههای گروه شاهد شد. در مجموع، آمونیاکی کردن کاه لوبیا با کود اوره، روشی ساده و مؤثر برای فرآوری و افزایش ارزش غذایی این پسماند است.

https://ar.guilan.ac.ir/article_9296_25c6feff3e25a94fd84d146ab0f8f1ca.pdf

دانشگاه گیلان تحقیقات تولیدات دامی 2252-0872 15 2 2026 06 22 The interaction effect of carbohydrase enzyme and phytogenic compound on performance, digestibility, and egg quality characteristics in laying hens fed with reduced energy levels اثر متقابل آنزیم کربوهیدراز و ترکیب فیتوژنیک بر عملکرد، قابلیت هضم و خصوصیات کیفی تخم مرغ در مرغ‌های تخم گذار تغذیه شده با سطح انرژی کاهش یافته 31 43 9024 10.22124/ar.2025.30943.1905 FA احسان صالحی فر گروه مهندسی کشاورزی، واحد مشهد، دانشگاه آزاد اسلامی، مشهد، ایران علی غصبان صخیل گروه مهندسی کشاورزی، واحد مشهد، دانشگاه آزاد اسلامی، مشهد، ایران رضا بهاری کاشانی گروه مهندسی کشاورزی، واحد مشهد، دانشگاه آزاد اسلامی، مشهد، ایران Journal Article 2025 06 11 Introduction: As the cost of high-energy feed ingredients like oils and cereals continues to rise, creating cost-effective poultry diets while maintaining production performance has become increasingly challenging. One approach to tackle this issue is to lower dietary metabolizable energy (ME) levels and offset the reduction by incorporating feed additives such as multi-enzymes and phytogenic compounds. Multi-enzymes enhance nutrient digestibility by breaking down anti-nutritional factors like non-starch polysaccharides, which improves gut function and nutrient absorption. Phytogenic compounds, sourced from herbs and spices, are recognized for their antimicrobial, antioxidant, and digestive stimulant properties. However, their effectiveness in low-energy diets is not yet fully understood. This study aimed to assess the individual and combined impacts of multi-enzymes and a phytogenic compound on the performance, nutrient digestibility, and egg quality of laying hens fed reduced-energy diets. Materials and methods: A total of 320 Hy-Line W-36 laying hens, aged 70 weeks, were randomly assigned to eight dietary treatments using 2×2×2 factorial arrangements in a completely randomized design, with eight replicates of five birds each. The study continued until the hens reached 78 weeks of age. The experimental factors included two levels of dietary metabolizable energy (2800 and 2650 kcal/kg), the inclusion or exclusion of multi-enzyme supplementation (200 g/ton), and the presence or absence of a standardized phytogenic compound (0.02%). The eight dietary treatments were as follows: (1) control diet (2800 kcal/kg), (2) control diet with enzyme, (3) control diet with phytogenic compound, (4) control diet with both enzyme and phytogenic compound, (5) reduced-energy diet (2650 kcal/kg), (6) reduced-energy diet with enzyme, (7) reduced-energy diet with phytogenic compound, and (8) reduced-energy diet with both enzyme and phytogenic compound. Data were collected on feed intake, egg production, egg weight, feed conversion ratio, mortality, nutrient digestibility (using acid-insoluble ash marker), and egg quality traits, including yolk color, shell strength, and Haugh unit. Results and discussion: Hens on the control diet (2800 kcal/kg) demonstrated significantly superior (P<0.05) performance in egg production, egg weight, egg mass, and feed conversion ratio compared to those on a reduced-energy diet (2650 kcal/kg). However, supplementing the reduced-energy diet with multi-enzymes and phytogenic compounds markedly enhanced these parameters. Notably, hens receiving both enzyme and phytogenic compound supplements with the reduced-energy diet achieved production performance comparable to the control group, indicating that these additives effectively offset the lower energy content. Digestibility studies revealed that supplementation with enzymes and phytogenic compounds, whether alone or combined, significantly improved (P<0.05) the digestibility of dry matter, crude protein, crude fiber, and metabolizable energy, especially in reduced-energy diets. This improvement likely resulted from enhanced enzyme-substrate interactions, better gut morphology, and improved microbial balance in the gastrointestinal tract. Egg quality also benefited from the supplements. Phytogenic compounds enhanced yolk color through their natural carotenoid content, while enzyme supplementation improved eggshell strength, likely by increasing calcium absorption. A significant three-way interaction among energy level, enzyme, and phytogenic compound was observed for various traits, including egg production, egg mass, feed conversion ratio, and yolk pigmentation, underscoring a synergistic effect of these dietary components. Conclusions: Reducing dietary energy from 2800 to 2650 kcal/kg adversely affected the performance, nutrient digestibility, and egg quality of laying hens. However, adding multi-enzymes and phytogenic compounds helped counteract these negative effects. The combination of these additives was especially effective in improving performance, digestibility, and egg quality in hens on reduced-energy diets. This makes the additives a viable strategy for cost-effective and sustainable poultry production. These findings highlight the potential of integrating enzyme-phytogenic mixtures into layer diets with lower metabolizable energy to maintain optimal productivity without sacrificing economic efficiency. بهمنظور بررسی اثر متقابل مولتی‌آنزیم و ترکیب فیتوژنیک‌ بر عملکرد، قابلیت هضم مواد مغذی و خصوصیات کمّی و کیفی تخم‌مرغ در مرغ‌های تخم‌گذار، تعداد 320 قطعه مرغ تخم‌گذار در قالب طرح کاملاً تصادفی در آزمایش فاکتوریل به هشت تیمار، چهار تکرار و 10 مرغ در هر تکرار از سن 70 تا 78 هفتگی اختصاص داده شدند. تیمارهای آزمایشی عبارت بودند از: 1) جیره پایه، 2) جیره پایه + 200 گرم در تن خوراک آنزیم، 3) جیره پایه + 02/0 درصد ترکیب فیتوژنیک، 4) جیره پایه + 02/0 درصد ترکیب فیتوژنیک + 200 گرم در تن خوراک آنزیم، 5) جیره با انرژی کاهش یافته، 6) جیره با انرژی کاهش یافته + 200 گرم در تن خوراک آنزیم، 7) جیره با انرژی کاهش یافته + 02/0 درصد ترکیب فیتوژنیک و 8) جیره با انرژی کاهش یافته + 200 گرم در تن خوراک آنزیم + 02/0 درصد ترکیب فیتوژنیک. نتایج این تحقیق نشان داد که مرغ‌های دریافتکننده جیره دارای انرژی توصیه شده همراه با دو ترکیب گیاهی و آنزیم، بیشترین درصد تولید، وزن تخم‌مرغ، توده تخم‌مرغ، درصد زرده تخم‌مرغ، رنگ زرده تخم‌مرغ، انرژی قابل سوخت و ساز، پروتئین خام و الیاف خام جیره و کمترین میزان خوراک مصرفی را نسبت به سایر تیمارهای آزمایشی داشتند و مرغ‌های تخمگذار دریافتکننده جیره با انرژی کاهش یافته، کمترین میزان این فراسنجه‌ها را داشتند. افزودن هر دو ترکیب افزودنی منجر به بهبود عملکرد و خصوصیات تخم‌مرغ مرغ‌های تخمگذار دریافتکننده جیره با انرژی کاهش یافته شد، بهطوری که تفاوت معنی‌داری با گروه شاهد نداشت. بهطور کلی، افزودن مولتی‌آنزیم و ترکیب فیتوژنیک به جیره‌های کم انرژی منجر به افزایش قابلیت استفاده از جیره‌ها و قابلیت رقابت با جیره‌های با انرژی قابل سوخت و ساز بالاتر شد.

https://ar.guilan.ac.ir/article_9024_8053c7740c9dad1280d999a5c4e6b831.pdf

دانشگاه گیلان تحقیقات تولیدات دامی 2252-0872 15 2 2026 06 22 Impact of betaine and choline supplementation on productivity, egg quality, blood parameters, and antioxidant levels in laying hens fed low-methionine diets اثر افزودن بتائین و کولین به جیره های با سطوح پایین تر متیونین بر صفات تولیدی، کیفیت تخم مرغ، شاخص های خونی و صفات پاداکسندگی خون مرغ های تخم گذار 45 61 9328 10.22124/ar.2025.31893.1929 FA امیر جوادی فر گروه علوم دامی، دانشکده کشاورزی، دانشگاه بیرجند سیدجواد حسینی واشان گروه علوم دامی، دانشکده کشاورزی، دانشگاه بیرجند احمد حسن آبادی گروه علوم دامی، دانشکده کشاورزی، دانشگاه فردوسی مشهد هادی سریر گروه علوم دامی، دانشکده کشاورزی، دانشگاه بیرجند Journal Article 2025 10 06 Introduction: Methionine is an essential amino acid that plays a vital role in many physiological processes in birds. In birds fed corn-soybean diets, it is the first limiting amino acid. The amount of methionine in a bird's diet should be appropriate for its age, production requirements, and physiological needs. An imbalanced amino acid composition in a bird's diet can lead to increased feed costs, reduced protein intake, and a greater environmental impact, all of which affect the sustainability of poultry production. A methionine deficiency can result in reductions in body weight, egg production, egg weight, and egg mass in laying hens. However, certain reactions can be partially compensated for by methyl donor compounds such as choline and betaine, which can act as partial substitutes for methionine. Choline is a precursor of betaine and a beta-hydroxy trimethylammonium hydroxide compound. Its metabolic functions are well-defined and include cell structure formation, liver fat regulation, inhibition of lipolysis, production of acetylcholine, and provision of methyl groups. Betaine, also known as trimethylglycine, is an organic compound obtained from sugar beet molasses. It is also synthesized in the body from choline and plays a role in providing methyl groups and regulating osmotic pressure in all vertebrates. In poultry, it is estimated that betaine can provide up to 25% of the required choline. To date, few studies have examined the combined impact of choline and betaine supplementation on reducing the methionine requirements of poultry, particularly laying quails. Given the economic viability of using betaine and choline in poultry feed and the limited information available on laying hens, a study was conducted to determine the effect of betaine and choline supplementation at reduced levels of methionine on egg production and quality traits, blood indices, and blood and egg antioxidant properties in Bovans strain laying hens. Materials and methods: In this experiment, 315 laying hens of the Bovans strain were arranged in a completely randomized design using a 3×3 factorial arrangement, including three levels of methionine (80%, 90%, and 100%) and three supplements (no supplement, 0.15% betaine, and 0.15% choline), with nine treatments, seven replications, and five hens for each replication. Following a 10-day adaptation period, the birds were randomly assigned to experimental units. The birds were fed the dietary treatments over two 28-day periods. On the last two days of each period, four eggs from each replication were collected to evaluate egg quality traits including the egg shape index, specific weight, Haugh unit, yolk height, yolk color index, the relative weight of the yolk, the albumen and the eggshell, and the eggshell thickness. Blood samples were taken from two birds in each replicate at the end of the experimental period to determine biochemical indices. The data were analyzed using the GLM procedure of SAS software. Results and discussion: The results revealed a significant interaction between the treatments. Birds fed diets containing 100% methionine had the lowest feed conversion ratio (P<0.05) and the highest egg mass at 32–35 weeks of age (P<0.01) compared to those fed diets containing 80% methionine. At 36–39 weeks of age, birds fed a diet containing 100% methionine exhibited the highest egg weight (P<0.01). The yolk color index increased in birds fed 100% methionine with a 0.15% betaine level and 90% methionine with a 0.15% choline level at the end of the first and second periods, respectively (P<0.01). Blood cholesterol and triglyceride concentrations decreased in birds fed the 90% diet without supplementation (P<0.05). Diets containing 100% methionine and a 15% betaine treatment decreased yolk cholesterol concentration (P<0.01). These results suggest that the recommended level of methionine is necessary to maintain egg production and mass. Conclusions: It can be concluded that 100% of the methionine required by laying hens was needed to maximize egg production. However, adding betaine to a low-methionine diet improved egg quality, while choline supplementation improved antioxidant status in the blood and eggs. این آزمایش بهمنظور بررسی اثر افزودن بتائین و کولین در سطوح کاهشی متیونین بر صفات کمّی و کیفی تخممرغ، شاخصهای خونی و صفات پاداکسندگی خون و تخممرغ تخمگذار سویه بونز انجام شد. در این آزمایش از 315 قطعه مرغ تخمگذار سویه بونز در قالب طرح کاملاً تصادفی با آرایش فاکتوریل 3×3 شامل سه سطح متیونین (سطوح 80، 90 و 100 درصد متیونین) و سه مکمل (بدون مکمل، 15/0 درصد بتائین و 15/0 درصد کولین) با نه تیمار، هفت تکرار و پنج قطعه مرغ برای هر تکرار انجام شد. آثار متقابل نشان داد پرندگان در 32 تا 35 هفتگی، در سطح 100 درصد متیونین، کمترین ضریب تبدیل خوراک (05/0P<) و بیشترین گرم توده تخممرغ تولیدی (01/0P<) را در مقایسه با گروه متیونین 80 درصد نشان دادند. در سن 36 تا 39 هفتگی، بیشترین وزن تخممرغ تولیدی مربوط به سطح 100 درصد متیونین (01/0P<) بود. بیشترین میانگین شاخص رنگ زرده در پایان دوره اول و دوم (01/0P<) بهترتیب مربوط به سطح 100 درصد متیونین و 15/0 درصد بتائین و سطح 90 درصد متیونین و 15/0 درصد کولین بود. کمترین غلظت کلسترول و تریگلیسرید خون در سطح 90 درصد بدون مکمل مشاهده شد (05/0P<). کمترین غلظت کلسترول زرده در تیمار سطح 100 درصد متیونین و 15 درصد بتائین مشاهده شد (01/0P<). با توجه به اینکه بتائین و کولین هر دو از گروههای دهنده متیل هستند و متیونین نیز در حضور این دو مکمل عملکرد بهتری را نشان داد، میتوان نتیجه گرفت که مکمل بتائین با جیره کم متیونین، بدون هیچ تأثیر منفی بر بهرهوری عملکرد تخمگذاری، باعث بهبود کیفیت تخممرغ و کولین باعث کاهش کلسترول خون و پایداری اکسیداتیو تخممرغ می شود.

https://ar.guilan.ac.ir/article_9328_7553d1ba312388c48d76f3372c4a47f1.pdf

دانشگاه گیلان تحقیقات تولیدات دامی 2252-0872 15 2 2026 06 22 Effects of physical feed form of the diets on growth performance, intestinal microflora and morphology, and litter quality in broiler chickens اثر شکل فیزیکی خوراک بر عملکرد رشد، فلور میکروبی و ریخت‌شناسی روده و کیفیت بستر در جوجه‌های گوشتی 63 76 9100 10.22124/ar.2025.29869.1884 FA مصطفی نوید طالمی گروه علوم دامی، دانشکده علوم کشاورزی، دانشگاه گیلان حسن درمانی کوهی گروه علوم دامی، دانشکده علوم کشاورزی، دانشگاه گیلان عباس صفری گروه علوم دامی، دانشکده علوم کشاورزی، دانشگاه گیلان شبنم شاهنگیان گروه علوم دامی، دانشکده علوم کشاورزی، دانشگاه گیلان Journal Article 2025 02 19 Introduction: In recent years, the poultry industry has encountered several challenges. One critical yet often overlooked issue is the relationship between feed texture and litter quality, which significantly impacts locomotive problems and carcass quality. Nutritional factors such as energy and protein levels, minerals, feed texture, and dietary restrictions play a crucial role in influencing litter moisture, litter quality, carcass characteristics, and the condition of bird feet. Litter serves as a conducive environment for microbial growth and ammonia production. Effective management of litter moisture and ammonia emissions is vital for disease prevention and enhancing air quality in poultry houses. Ammonia production is a major concern in enclosed poultry systems, originating from the microbial breakdown of uric acid in excreta. The emission rate of ammonia gas from poultry litter is influenced by pH, moisture content, temperature, ventilation, ammonia and uric acid levels in excreta, litter type, stocking density, and bird age. Different feed processing methods and structural changes impact bird performance, intestinal microbial diversity, intestinal health, digestion, intestinal content viscosity, enzyme activity, and pH levels. In the first week post-hatching, the small intestine experiences rapid growth, with increased villi height and crypt depth, enhancing nutrient digestion and absorption. This growth is accompanied by the stabilization of gut microbiota. The balance between pathogenic and non-pathogenic bacteria is crucial in determining disease occurrence. The type, structure, quality, and quantity of diet significantly influence intestinal cell growth, nutrient utilization, and bacterial species composition, particularly at the digestive system's end. Over 640 microbiota species in the digestive system contribute to digestive health and microflora balance. Research indicates that the ileum's microbial profile in broiler chickens affects intestinal performance and, subsequently, nutrient digestion and absorption. This study aimed to explore the effects of different feed textures (mash, crumble, pellet, and extruded) on intestinal histology, microbiota, and litter quality in broiler chickens. Materials and methods: In this study, 480 one-day-old male Ross 308 broiler chickens, each weighing approximately 36 grams, were used. The chicks were sourced from Navaid Morgh Gilan Company in Rasht, Iran. Before their arrival, experimental diets were prepared and placed in feeding trays, while water was provided using siphon and nipple drinkers. The diets were offered in four physical forms: mash, crumble, pellet, and extruded, formulated to meet the nutrient guidelines for Ross 308. At the experiment's conclusion, the chickens were weighed, and their feed consumption was recorded. Body weight gain (BWG), feed intake (FI), feed conversion ratio (FCR), and mortality rate were calculated at the end of the rearing period. The birds were slaughtered on day 42. To evaluate the impact of feed physical form on intestinal microbial flora, contents from the duodenum, jejunum, and ileum were collected to count Escherichia coli, Lactobacillus, and total coliforms. On days 21 and 42, litter from all pens was examined. Samples were collected from five areas of each pen's litter (four corners and one center sample) and analyzed in the laboratory. For moisture measurement, approximately 50 grams of litter were dried in an oven at 105 °C until a constant weight was achieved, determining moisture content through weight loss. Post-slaughter, samples from the duodenum, jejunum, and ileum were preserved in a 10% formalin solution. After 72 hours of tissue fixation, dehydration was performed using increasing concentrations of ethanol followed by xylene treatment. Samples were then embedded in paraffin and sectioned into 5-6 μm slices, stained with hematoxylin and eosin (H&E). Villus length was measured from top to base, and width was recorded at the midpoint. Crypt depth was measured from the villus base to the end of the mucous layer. The villus length to crypt depth ratio and surface area were calculated, along with the thickness of the lamina propria and muscularis mucosae. Statistical analysis was conducted using SAS software with the GLM procedure in a completely randomized design. Results and discussion: The study results indicated that growth performance was significantly affected by the form of feed (P<0.01). Chicks fed with extruded feed throughout the rearing period demonstrated improved performance compared to other treatments (P<0.05). The highest level of anaerobic bacteria in the litter at 35 days was found in the pellet group (P<0.05). At 21 days, the greatest litter moisture was associated with crumbled feed in the starter diet and pellets in the grower and finisher diets. The lowest weights of the ileum and jejunum were observed in chicks fed extruded feed throughout the rearing period (P<0.05). The maximum villus height in the jejunum was noted with crumbled feed in the starter diet and extruded feed in the grower and finisher diets, as well as with pellets throughout the period. Additionally, using crumbled feed in the starter diet and pellets in the grower diet resulted in the maximum villus width. Conclusions: The study indicated that the physical form of diets significantly influences growth performance, digestive efficiency, nutrient absorption, intestinal histology, litter pH and moisture, and intestinal bacterial populations. Birds fed extruded feed throughout the rearing period achieved the highest BWG. The lowest FCR was observed in chicks that consumed crumbled feed during the starter phase and extruded feed during the grower and finisher phases; however, these differences were not significant compared to birds consistently fed extruded feed. Pellet and extruded diets negatively impacted bedding moisture compared to mash diets, potentially increasing the risk of hock joint burns and lameness in broiler chickens. Therefore, careful attention must be given to litter management, considering the type of feed used. این پژوهش به‌منظور بررسی آثار شکل فیزیکی خوراک (آردی، کرامبل، پلیت و اکسترود) بر عملکرد رشد، فلور میکروبی و ریختشناسی روده و کیفیت بستر با استفاده از 480 قطعه جوجه گوشتی نر سویه راس 308 در قالب طرح کاملاً تصادفی با هشت تیمار و پنج تکرار از سن 1 تا 42 روزگی انجام شد. جوجه‌هایی تغذیه شده با خوراک اکسترود در کل دوره، میانگین وزن بالاتری نسبت به سایر تیمارها داشتند (01/0>P). بیشترین شمار باکتری‌های بی‌هوازی بستر در 35 روزگی مربوط به تیمار با شکل آردی بود (05/0>P). pH بستر در 21روزگی در تیمار با شکل کرامبل در جیره آغازین و اکسترود در جیره رشد و پایانی در بیشترین سطح بود. در 42 روزگی نیز بیشترین مقدار pH بستر در تیمار با شکل اکسترود مشاهده شد. بالاترین سطح رطوبت بستر در 21 روزگی با استفاده از خوراک کرامبل در جیره آغازین و پلت در جیره رشد و پایانی بهدست آمد. کمترین وزن ایلئوم و ژژنوم مربوط به تیمار با شکل اکسترود در کل دوره بود (05/0>P). بیشترین ارتفاع ویلی در ژژنوم با مصرف خوراک کرامبل در جیره آغازین و اکسترود در جیره رشد و پایانی و دان پلت در کل دوره حاصل شد. جیره با شکل کرامبل در جیره آغازین و پلت در جیره رشد، بیشترین عرض ویلی را نشان داد. بیشترین ارتفاع ویلی در ایلئوم مربوط به تیمار اکسترود یا پلت در کل دوره پرورش بود. نتایج نشان داد که شکل فیزیکی جیره‌ها، تأثیر معنیداری بر عملکرد رشد، عملکرد گوارشی، جذب مواد مغذی، بافت‌شناسی قسمت‌های مختلف روده،pH و رطوبت بستر و جمعیت باکتریایی روده دارد. همچنین، توجه به مدیریت بستر جوجه‌ها ضروری است و برای این منظور، نوع خوراک نیز باید مورد توجه قرار گیرد.

https://ar.guilan.ac.ir/article_9100_41c01bed92692af63c6a453211726b2a.pdf

دانشگاه گیلان تحقیقات تولیدات دامی 2252-0872 15 2 2026 06 22 Effect of different levels of yeast cell wall on performance and cecal microbial population of Japanese quail اثر سطوح مختلف دیواره سلولی مخمر بر عملکرد و جمعیت میکروبی سکوم بلدرچین ژاپنی 77 87 9195 10.22124/ar.2025.31308.1913 FA یوسف سعیدی گروه علوم دامی، دانشکده علوم دامی و صنایع غذایی، دانشگاه علوم کشاورزی و منابع طبیعی خوزستان سمیه سالاری گروه علوم دامی، دانشکده علوم دامی و صنایع غذایی، دانشگاه علوم کشاورزی و منابع طبیعی خوزستان Journal Article 2025 07 31 Introduction: Poultry nutrition constitutes approximately 60 to 70 percent of poultry farming expenses. Consequently, it is crucial to develop cost-effective poultry production using scientific nutritional principles. Yeast and its derivatives are recommended additives in poultry diets to enhance performance. Yeast cell walls, making up 25 percent of the yeast cell's dry weight, not only serve a protective function but also participate in metabolic processes. These cell walls contain mannoproteins, beta-glucan, mannan oligosaccharide, chitin, and N-acetylglucosamine. Notably, beta-glucan, with its helical structure, can absorb mycotoxins, thereby playing a significant role in improving livestock and poultry health by detoxifying their feed. Mannan oligosaccharide has been shown to prevent pathogen colonization in the digestive tract. As prebiotics, oligosaccharides promote the growth of beneficial anaerobic bacteria in the gut, indirectly reducing pathogen populations and enhancing intestinal health. This study aimed to examine the impact of varying levels of yeast cell wall on the performance and blood parameters of Japanese quails. Materials and methods: In this experiment, 360 one-day-old Japanese quails were studied using four levels of yeast cell wall supplementation (0, 0.5, 1, and 1.5 g/kg). The study followed a completely randomized design with 4 treatments and 6 replications each. Throughout the experiment, performance traits such as feed intake, body weight gain, and feed conversion ratio were assessed. At the conclusion of the study, intestinal samples were collected to analyze tissue structure, while cecal contents were sampled to evaluate the microbial population. Blood samples were drawn from the jugular vein, and the serum was stored at −20°C for later analysis of blood parameters, including triglycerides, cholesterol, glucose, HDL, and LDL, as well as serum liver enzymes (AST, ALT, and ALP). These measurements were conducted using Pars Azmoon commercial kits and a Mindray autoanalyzer. Results and discussion: The experiment results indicated that yeast cell wall consumption increased feed intake and enhanced weight gain in birds aged 22 to 35 days and throughout the entire rearing period (P<0.05). Additionally, it lowered the feed conversion ratio during this age range (P<0.05). The yeast cell wall consumption led to an increase in lactobacilli populations and a decrease in Escherichia coli populations in the cecum (P<0.05). Carcass components, such as digestive tract weight, breast and thigh weight, forestomach, gizzard, liver, small intestine length (duodenum, jejunum, ileum), cecum length, blood parameters (triglycerides, cholesterol, glucose, HDL, and LDL), and serum liver enzymes (Alanine Aminotransferase, Alkaline Phosphatase, and Aspartate Aminotransferase) remained unaffected by the treatments (P>0.05). Among the duodenum and jejunum histological characteristics, villus height and the villus height to crypt depth ratio increased with yeast cell wall consumption (P<0.05). The benefits of yeast cell walls are largely attributed to the active immune function due to beta-glucan and mannan oligosaccharides in yeast products. Incorporating yeast products in poultry diets has been shown to boost immunity, balance microbial populations, and promote gastrointestinal health and development. These additives enhance nutrient digestion and absorption, thereby improving growth and overall bird performance. Mannan oligosaccharides in the yeast cell wall effectively bind pathogenic bacteria, exhibiting prebiotic properties. Balancing pathogenic and beneficial bacteria enhances villus length and reduces crypt depth, serving as biomarkers for improved intestinal morphology. Improved intestinal morphology boosts digestive enzyme activity, enhancing digestion. Longer villi signify a more mature epithelium with increased absorptive function due to a larger absorptive area. The development of intestinal morphology reflects the health status of the animal's digestive tract. Greater villus height increases enzyme activity at the villi ends, resulting in improved digestibility. Conclusions: The study results indicated that administering 1 to 1.5 g/kg of yeast cell wall enhanced the microbial population in the cecum and improved the histological features of the duodenum, although it did not affect the birds' overall performance. بهمنظور بررسی تاثیر سطوح مختلف دیواره سلولی مخمر بر صفات عملکردی و فراسنجه‌های خونی بلدرچین ژاپنی، آزمایشی با استفاده از چهار سطح دیواره سلولی مخمر (0، 5/0، 1 و 5/1 گرم در کیلوگرم) و با 360 قطعه بلدرچین ژاپنی یکروزه در قالب طرح کاملاً تصادفی شامل چهار تیمار و شش تکرار انجام شد. نتایج آزمایش نشان داد مصرف دیواره سلولی مخمر سبب افزایش مصرف خوراک و بهبود وزن‌گیری پرندگان در سن 22 تا 35 روزگی و کل دوره پرورش و همچنین، باعث کاهش ضریب تبدیل خوراک در 22 تا 35 روزگی شد (05/0>P). جمعیت لاکتوباسیل‌ها در سکوم تحت تاثیر مصرف دیواره سلولی مخمر افزایش و جمعیت اشریشیاکلی کاهش یافت (05/0>P). ارتفاع پرز و نسبت ارتفاع پرز به عمق کریپت دئودنوم و ژژنوم تحت تاثیر مصرف دیواره سلولی مخمر افزایش یافت (05/0>P). نتایج این پژوهش نشان داد استفاده از سطوح 1 و 5/1 گرم در کیلوگرم دیواره سلولی مخمر باعث بهبود جمعیت میکروبی سکوم، خصوصیات بافتشناسی دئودنوم، افزایش مصرف خوراک و وزنگیری پرندگان در کل دوره پرورش شد.

https://ar.guilan.ac.ir/article_9195_d2f3f4b2447e0062d7ea6e2a00ac678b.pdf

دانشگاه گیلان تحقیقات تولیدات دامی 2252-0872 15 2 2026 06 22 Effect of Ferula assa-foetida, Thymus vulgaris, Rheum persicum, Achillea millefolium, and Euphorbia serrata extracts on the control of Varroa mite (Varroa destructor) in honey bee (Apis mellifera L.) colonies اثر عصاره گیاهان آنغوزه، آویشن، ریواس، بوماداران و فرفیون بر کنترل کنه واروآ (Varroa destructor) در کلنی های زنبورعسل (Apis mellifera L.) 89 102 9194 10.22124/ar.2025.31597.1917 FA حدیث گومه گروه گیاه پزشکی، دانشکده کشاورزی، پردیس کشاورزی و منابع طبیعی، دانشگاه رازی 0009-0009-6141-9618 حسنعلی واحدی گروه گیاه پزشکی، دانشکده کشاورزی، پردیس کشاورزی و منابع طبیعی، دانشگاه رازی عطااله رحیمی بخش تحقیقات علوم دامی، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی کردستان، سازمان تحقیقات، آموزش و ترویج کشاورزی، سنندج، ایران Journal Article 2025 09 04 Introduction: Varroa mites are among the most significant parasites affecting honey bee colonies and the global beekeeping industry, causing substantial economic losses. These mites feed on the bees' fat bodies and hemolymph at various developmental stages and also spread pathogenic viruses. The recent use of chemical pesticides has resulted in mite resistance and contamination of hive products. Plant extracts are emerging as viable alternatives to chemical acaricides for controlling Varroa mites. This study aims to explore the acaricidal and insecticidal properties of extracts from Ferula assa-foetida, Thymus vulgaris, Rheum persicum, Achillea millefolium, and Euphorbia serrata against Varroa mites and their host bees in the honey bee colonies under the climatic conditions of Kurdistan province of Iran from 2022 to 2024. Materials and methods: In April and June 2022, plants including F. assa-foetida, T. vulgaris, R. persicum, A. millefolium, and E. serrata were collected from various regions in Kermanshah province and subsequently identified. After removing waste materials, the aerial parts of these plants were dehumidified and dried separately in the shade at room temperature (28°C with 45% relative humidity). Using a shredder, the aerial parts were then crushed into powder. The plant extracts were obtained using a Soxhlet extractor with absolute ethanol as the solvent. Chemical compounds were identified through gas chromatography-mass spectrometry (GC-MS). This study was designed as a factorial experiment (6×2) based on a completely randomized design with 12 treatments and five replications. Before bioassay experiments, the experimental bee colonies were standardized regarding queen age, population (adults and brood), and honey storage. The initial infestation of colonies with Varroa mites was assessed in both adults and brood. Sixty Langstroth colonies were used, each with a sticky white plastic sheet at the bottom. The colonies were treated at sunset with 15 ml of plant extracts at 20% and 40% concentrations when all bees were present. Every five days at 10 am, plastic sheets were removed to count dead bees and mites, after which the sheets were replaced. The acaricidal activity of different plant extract concentrations was evaluated using a well-known and recommended method. The impact of these extracts on the insecticidal activity concerning the population growth rate (adults and brood) was also assessed. Data analysis was performed using the GLM procedure in SAS 9.4, and mean comparisons were conducted using the Tukey method for least significant differences. Results and discussion: The study results indicated that varying concentrations of plant extracts demonstrated favorable acaricidal activity in controlling the Varroa mite. Statistical analysis revealed that a 40% concentration of F. assa-foetida extract had the most significant impact on the mortality rate of Varroa mites in bee colonies, showing a statistically significant difference from other tested concentrations (P<0.01). Additionally, the insecticidal effect on bees showed that none of the extract concentrations resulted in a mortality rate exceeding eight percent in the experimental treatments. GC-MS analysis identified E-1-propenyl sec-butyl disulfide, Z-1-propenyl sec-butyl disulfide, n-propenyl sec-butyl disulfide, Guaiol, and β-pinene as the primary chemical constituents in F. assa-foetida. Conclusions: The findings of this study indicated that the mortality rate of bees exposed to various concentrations of plant extracts did not exceed eight percent in any of the experimental treatments. Consequently, a 40% concentration of F. assa-foetida plant extract is recommended as an effective alternative to synthetic acaricides for controlling Varroa mites in honey bee colonies, owing to its favorable acaricidal properties. پژوهش حاضر بهصورت آزمایش فاکتوریل و در قالب طرح پایه کاملاً تصادفی با 12 تیمار و پنج تکرار با هدف بررسی خواهش کنه کشی و حشره کشی عصاره گیاهان آنغوزه، آویشن، ریواس، بوماداران و فرفیون روی کنه واروآ و میزبان آن در کلنیهای زنبورعسل در شرایط اقلیمی استان کردستان طی سالهای 1402 الی 1404 انجام شد. تیمارها شامل غلظتهای 20 و 40 درصد عصاره گیاهان آنغوزه، آویشن، ریواس، بوماداران و فرفیون و دو تیمار شاهد (یکی به عنوان شاهد مثبت و دیگری شاهد منفی) بودند. در پژوهش حاضر از دستگاه GC-MS برای شناسایی ترکیبات شیمیایی عصاره گیاهان استفاده شد. نتایج نشان داد غلظتهای مختلف عصاره همه گیاهان مورد آزمایش، فعالیت کنه کشی نسبتاً مطلوبی برای کنترل کنه واروآ نشان دادند. براساس نتایج تجزیه های آماری، غلظت 40 درصد عصاره گیاه آنغوزه، بیشترین تأثیر را بر درصد تلفات کنه واروآ در کلنیهای زنبورعسل مورد مطالعه نشان دادند بهطوری که اختلاف آن نسبت به سایر غلظتهای مختلف عصاره گیاهان مورد مطالعه معنی دار بود (01/0>P). تجزیه GC-MS نشان داد که (E) – 1 – پروپنیل sec – بوتیل دی سولفید (38/44 درصد)، (Z) – 1 – پروپنیل sec – بوتیل دی سولفید (37/38 درصد)، n – 1 – پروپنیل sec – بوتیل دی سولفید (54/36 درصد)، گایول (99/20 درصد) و بتا پینن (69/15 درصد) بهترتیب اجزای اصلی عصاره گیاه آنغوزه را تشکیل دادند. بر اساس یافته های پژوهش حاضر، تاثیر غلظتهای مختلف عصاره گیاهان مورد مطالعه بر درصد تلفات زنبورها در هیچ یک از تیمارهای آزمایشی فراتر از هشت درصد نبود. بنابراین، میتوان غلظت 40 درصد عصاره گیاه آنغوزه را بهعلت داشتن تأثیر کنهکشی مطلوب بر کنه ها در مطالعه حاضر به عنوان جایگزین مناسب کنه کشهای سنتتیک برای کنترل کنه واروآ در کلنیهای زنبورعسل پیشنهاد کرد.

https://ar.guilan.ac.ir/article_9194_777d54a09311c4ae09cccb78dea2bb6d.pdf