دانشگاه گیلان تحقیقات تولیدات دامی 2252-0872 14 3 2025 11 22 Study of genetic similarities and phylogenetic analysis of Iranian dromedary and bactrian camels with seven major species of the Camelidae family based on mitochondrial genome مطالعه شباهت های ژنتیکی و تجزیه و تحلیل تبارشناختی شترهای تک کوهانه و دوکوهانه ایرانی با هفت گونه اصلی موجود در خانواده شترسانان بر اساس ژنوم میتوکندریایی 1 21 8811 10.22124/ar.2025.30642.1895 FA مصطفی هاشمی گروه علوم دامی، دانشکده کشاورزی، دانشگاه بوعلی سینا احمد احمدی گروه علوم دامی، دانشکده کشاورزی، دانشگاه بوعلی سینا پویا زمانی گروه علوم دامی، دانشکده کشاورزی، دانشگاه بوعلی سینا 0000-0002-1051-2259 محمد حسین فردوسی واحد ژنتیک و اصلاح نژاد حیوانات (AGBU)، دانشگاه نیوانگلند، آرمیدال، استرالیا رامین عبدلی مرکز تحقیقات ابریشم کشور، سازمان تحقیقات آموزش و ترویج کشاورزی (AREEO)، گیلان، ایران 0000-0003-0792-1980 Journal Article 2025 05 11 Introduction: Mitochondrial DNA (mtDNA), also referred to as the mitogenome, has emerged as a pivotal tool in evolutionary biology and phylogenetics due to its maternal inheritance, high mutation rate, and lack of recombination. These characteristics make it an ideal molecular marker for tracing lineage divergences and understanding genetic relationships among species. This study leverages complete mitochondrial genome sequences, protein-coding genes (PCG), and single-nucleotide polymorphism (SNP) data to elucidate the genetic similarities and phylogenetic relationships between Iranian dromedary (Camelus dromedarius) and bactrian (Camelus bactrianus) camels and seven major species of the Camelidae family, including wild and domesticated members (including Vicugna vicugna, Lama guanicoe, Vicugna pacos, Lama glama, Camelus ferus, Camelus dromedarius, and Camelus bactrianus). The Iranian dromedary and bactrian camels play a vital role in desert ecosystems and local livelihoods, yet their populations face challenges due to habitat loss and declining traditional pastoralism. The primary objectives of this research were to: 1) compare the complete mitochondrial genomes of Iranian camels with those of other Camelidae species to identify evolutionary divergences and conserved genetic regions, 2) analyze nucleotide and amino acid sequences of 13 protein-coding mitochondrial genes per each mitogenomes to assess functional conservation and divergence, 3) utilize SNP-based genomic data generated based on complete mitogenomes to construct a genomic relationship matrix (GRM) and validate phylogenetic inferences, and 4) resolve the taxonomic classification of Camelidae species and clarify the evolutionary position of Iranian camels within the family. Materials and methods: Complete mitochondrial genomes of seven Camelidae species (Vicugna vicugna, Lama guanicoe, Vicugna pacos, Lama glama, Camelus ferus, Camelus dromedarius, and Camelus bactrianus) and 10 Iranian camel haplotypes (four Camelus dromedary, i.e., Haplotypes 1, 2, 3, and 4, and six Camelus bactrian, i.e., Haplotypes 1, 2, 3, 4, 5, and 6) were retrieved from NCBI. Afterwards, nucleotide and amino acid sequences of 13 PCGs (ATP6, ATP8, COX1, COX2, COX3, ND1, ND2, ND3, ND4, ND5, ND6, ND4L, and CYTB) were extracted for comparative analysis. Also, a total of 3100 SNPs were derived from whole mitogenome alignments, filtered for quality, and used for population genomic analyses. The maximum likelihood (ML) method was applied to whole mitogenome sequences and PCG alignments to reconstruct evolutionary relationships. Nucleotide diversity was calculated for PCGs and mitogenome regions. GRM was generated to quantify pairwise genetic distances. To visualize genetic structuring, heatmap clustering and principal component analysis (PCA) on the SNP dataset, and a level plot of common nucleotides were performed. A heatmap is a data visualization method based on color coding that is widely used to uncover hidden patterns in genomic data. A level plot is a graphical tool for displaying nucleotide similarity or differences between various samples based on SNP data, and is depicted as a color-coded or spectral matrix. Results and discussion: Phylogenetic trees revealed two primary clades: Clade/Claster A: Comprised Vicugna and Lama species (Vicugna vicugna, Lama guanicoe, Vicugna pacos, and Lama glama), forming a distinct group. Clade/Claster B: Included Camelus ferus, Camelus dromedarius, and Camelus bactrianus, with Iranian dromedaries and bactrians forming subclusters closely related to Camelus ferus. Sequence identity between Iranian camels and other species ranged from 82.4% to 100%, with the highest similarity observed among C. dromedarius haplotypes. Analysis of nucleotide and amino acid sequences of all PCGs showed a clustering pattern similar to that of the complete mitochondrial genomes. However, ATP8 exhibited the highest variability, while COX1 was the most conserved, reflecting differential evolutionary pressures. Heatmap, PCA, and level plot analyses of SNP-based nucleotide similarities and GRM data confirmed the results from the complete mtDNA analysis (the separation of Vicugna/Lama and Camelus camelids, with Iranian camels grouping distinctly within the latter), demonstrating that SNPs are an effective tool for phylogenetic and evolutionary studies. SNP-based analyses proved highly congruent with traditional mtDNA methods, validating their utility for high-resolution phylogenetic studies. Conclusions: This study provides a comprehensive genomic framework for understanding the evolutionary history of Camelidae, demonstrating the power of mitochondrial genomics and SNP-based approaches in phylogenetics, as comparative genomic analysis of mtDNA can robustly classify the major species of the Camelidae family and clarify their evolutionary relationships. The results of the present study not only refine the classification of Iranian camels but also offer a foundation for future research on camelid adaptation, domestication, and conservation. توالیهای ژنوم‌ کامل میتوکندریایی هفت گونه اصلی شترسانان شامل Vicugna vicugna، Lama guanicoe، Vicugna pacos، Lama glama، Camelus ferus، Camelus dromedarius، Camelus bactrianus، چهار شتر تک کوهانه و شش شتر دوکوهانه ایرانی همراه با توالیهای ۱۳ ژن رمزگر (PCGs) بهازای هر ژنوم از سایت NCBI استخراج شدند. همچنین، مجموعهای از 3100 چندشکلی تک نوکلئوتیدی (SNP) از توالیهای کامل گونههای مورد بررسی تهیه شد که پس از فیلتراسیون، برای ساخت ماتریس روابط ژنومی مورد استفاده قرار گرفتند. نتایج ترسیم درخت‌های تبارشناختی بر اساس توالی‌های کامل، دو خوشه اصلی همراه با چند زیر خوشه را نشان داد، بهشکلی که گونههای Vicugna vicugna، Lama guanicoe، Vicugna pacos، Lama glama و Camelus ferus، یک شاخه اصلی و باقی گونههای تک کوهانه (Camelus dromedarius) و دوکوهانه (Camelus bactrianus) همراه با Camelus ferus، یک زیر شاخه اصلی دیگر با چند زیر شاخه تشکیل دادند. درصد تشابه ژنتیکی بین هفت گونه اصلی و گونههای ایرانی بین 4/82 تا 100 درصد متغیر بود. توالیهای نوکلئوتیدی و آمینواسیدی ژن‌های رمزگر، خوشه‌بندی مشابه با توالیهای کامل نشان دادند. ژن ATP8، بیشترین و ژن COX1، کمترین تنوع ژنتیکی را داشتند. ترسیم نقشه حرارتی و نمودار PCA مبتنی بر داده‌های SNP و نمودار سطحی شباهتهای نوکلئوتیدی، نتایج مشابهی داشت. یافته‌های این مطالعه نشان داد که مقایسه توالیهای ژنوم میتوکندریایی می‌تواند گونههای اصلی خانواده شترسانان را به‌صورت قوی‌ طبقه‌بندی کند و روابط تکاملی آن‌ها را روشن سازد. این تحقیق، بینش‌های ارزشمندی برای مطالعات آینده در زمینه ژنتیک و تکامل شترسانان فراهم می‌کند.

https://ar.guilan.ac.ir/article_8811_31eed69b93480df6c28e63e09bc41339.pdf

دانشگاه گیلان تحقیقات تولیدات دامی 2252-0872 14 3 2025 11 22 Study of STAT5B gene polymorphism and its association with production traits in Fars native fowl بررسی چندشکلی ژن STAT5B و ارتباط آن با صفات تولیدی در مرغ بومی فارس 23 32 8882 10.22124/ar.2025.29364.1870 FA حامد خراتی کوپایی بخش علوم دامی، دانشکده کشاورزی، دانشگاه شیراز محمد دادپسند بخش علوم دامی، دانشکده کشاورزی، دانشگاه شیراز Journal Article 2024 12 24 Introduction: Genetic resources are one of the most valuable assets of any country. Due to adaptation to specific environmental conditions, Iranian indigenous chickens exhibit remarkable genetic diversity. Identifying and characterizing the genetic makeup of native chicken breeds can facilitate the development of effective conservation and breeding programs. Polygenic traits such as growth and reproduction are economically important in the poultry industry. Single-nucleotide polymorphism (SNP) association studies explore the relationship between genetic variants and traits by targeting genes involved in physiological pathways. Signal transducers and activators of transcription (STAT) proteins are a family of cytoplasmic proteins critical in the signal transduction pathways of multiple cytokines and peptide hormones. Several functional polymorphisms in the STAT5B gene have been reported in chickens. Previous studies demonstrated the pivotal roles of STAT5A and STAT5B in physiological processes linked to growth hormone and prolactin in mice. Members of the STAT protein family are involved in growth and reproduction. Identifying genetic markers in candidate genes and their association with economically important traits can optimize breeding programs through marker-assisted selection (MAS). The main goal of this study was to investigate the SNP (G4533815A/G-250A) polymorphism in the STAT5B gene and its association with production traits in Fars native fowl. Materials and methods: Blood samples were randomly collected from 313 native chickens at the Native Chicken Breeding Farm in Fars Province (Shamsabad station). DNA was extracted using the salting-out protocol and evaluated through 2% agarose gel electrophoresis and nanodrop analysis. A 554 bp fragment of the STAT5B gene containing the SNP (G4533815A/G-250A) was amplified using the following primers: F: 5'-CCATCCCTTCCTGGTGCAGT-3' and R: 5'-ACTGCTGCCATTTCCCTTTG-3' with annealing temperature at 60°C. Genotyping was performed using the MspI restriction enzyme at 37°C for 3 hours. Allelic and genotypic frequencies, Hardy-Weinberg equilibrium (HWE), polymorphism information content (PIC), and genetic parameters were calculated using PopGene3.2 software. The distribution of phenotypic data was not normal; therefore, nonparametric statistics were used to analyze the data. The association between the STAT5B gene polymorphism and production traits (egg number [EN], age at first egg [AFE], egg weight at 84 weeks [EW84], and body weight at 12 weeks [BW12]) was analyzed using the Mann-Whitney test in the Minitab program (version 18). Gene networks associated with the STAT5B gene in Gallus gallus domesticus were visualized using the STRING web tool (version 12). Results and discussion: SNP genotyping identified three genotypes: AA (128 individuals, uncut fragment- no mutation), AG (174 individuals, heterozygote, 554/477 and 77 base pairs fragments- one mutant allele), and GG (11 individuals, 477, and 77 base pairs fragments- two mutant alleles). The frequencies of the A and G alleles were 0.69 and 0.31, respectively. The chi-square test (ꭓ² = 31.47) indicated that the population deviated significantly from HWE (P<0.01). This deviation can be attributed to selection intensity and mating systems. The Mann-Whitney test revealed a significant difference in AFE between genotypes AA/GG (W= 191.50) and GG/GA (W= 354.50). The GG genotype had a lower median AFE (142 days) compared to AA (150 days) and AG (147 days). Previous studies have demonstrated that hormones, cytokines, and their receptors regulate growth, reproduction, immunity, and metabolism in animals. The chicken’s STAT5B gene has been implicated in sexual maturation via ovary development regulation. Protein interaction network analysis also revealed that STAT5B interacts with proteins related to growth, immunity, and reproduction, reinforcing its importance in controlling production and economic traits. Conclusions: The results of the present study showed that there is a significant association between the SNP (G4533815A/G-250A) polymorphism of the STAT5B gene and age at first egg, but no significant association was reported with other traits. The main reason for the difference between the provided results and other investigations can be attributed to the statistical method used and the different genetic potential of the populations. Identification of beneficial mutations and genetic pathways affecting reproductive traits, such as AFE in chickens, can be used to select the desired allele in the population to achieve appropriate performance. Identification of candidate genes affecting economic traits can be used in MAS breeding programs. The findings provide an applied strategy to improve Fars native chicken through breeding programs. ژن‌های STAT کدکننده‌ مجموعه‌ای از پروتئین‌های درگیر در مسیرهای انتقال پیام سیتوکین‌ها و هورمون‌های پپتیدی هستند و چندین چندشکلی عملکردی از آنها در طیور گزارش شده است. هدف این پژوهش، بررسی چندشکلی ژن STAT5B برای (G4533815A/G-250A) SNP و ارتباط آن با صفات وزن بدن در 12 هفتگی، وزن تخممرغ در 84 هفتگی، شمار تخم‌مرغ و سن اولین تخم‌گذاری در مرغ بومی فارس بود. تعداد 313 قطعه مرغ ایستگاه اصلاح نژاد مرغ بومی با روش PCR-RFLP تعیین ژنوتیپ‌ شدند. بر این اساس، 128، 174 و 11 فرد بهترتیب دارای ژنوتیپ‌های AA (بدون جهش)،AG (یک آلل جهش‌یافته) و GG (دو آلل جهش‌یافته) بودند. فراوانی آلل A وG بهترتیب 69/0 و 31/0 برآورد شد. آزمون کای مربع، انحراف جمعیت مورد مطالعه از تعادل هاردی-وینبرگ را نشان داد (01/0>P). اختلاف میانه ژنوتیپ AA با ژنوتیپ‌های GG و AG برای سن نخستین تخم‌گذاری بر اساس آزمون من-ویتنی، معنی‌دار بود (05/0>P). ژنوتیپ GG، میانه سن نخستین تخم‌گذاری کمتری (142 روز) در مقایسه با دو ژنوتیپ AA (150 روز) و AG (147 روز) داشت. بررسی شبکه برهمکنش پروتئین‌ها نشان داد که پروتئین STAT5B در مرغ با مجموعه‌ای از پروتئین‌های مربوط به رشد، سیستم ایمنی و تولیدمثلی در ارتباط است که نشان‌دهنده نقش کلیدی این ژن در کنترل صفات اقتصادی است. یافتههای این پژوهش، دیدگاهی را برای بررسی بیشتر ارتباط بین چندشکلی‌های ژن STAT5B و صفتهای مهم اقتصادی و همچنین، کاربرد نشانگرهای ژنتیکی در بهنژادی طیور ارایه می‌دهد.

https://ar.guilan.ac.ir/article_8882_68dddd962d8a4c139914197915ca24c7.pdf

دانشگاه گیلان تحقیقات تولیدات دامی 2252-0872 14 3 2025 11 22 The investigation of the growth curve of pearl grey guinea fowl with different non-linear models بررسی منحنی رشد مرغ شاخدار خاکستری مرواریدی با مدل های مختلف غیرخطی 33 48 8881 10.22124/ar.2025.30744.1899 FA هادی فرجی آروق گروه پژوهشی شترمرغ، پژوهشکده دام های خاص، پژوهشگاه زابل غلامرضا داشاب گروه علوم دامی، دانشکده کشاورزی، دانشگاه زابل محمد رکوعی گروه علوم دامی، دانشکده کشاورزی، دانشگاه زابل Journal Article 2025 05 22 Introduction: In low-income and marginalized rural communities, poultry species play a vital role as sources of animal protein and household income. The guinea fowl, belonging to the Galliformes order and the Numididae family, is particularly important in these communities. Understanding the growth characteristics and patterns of guinea fowl can be crucial in successfully raising them as a profitable enterprise. This knowledge can help in developing appropriate nutritional and feeding regimens to optimize feed usage and increase profitability. Growth is a complex process that involves physiological and morphological changes from hatching to maturity. It is defined as the increase in body weight and organ size over time and age. This growth can be described using mathematical non-linear models that capture biologically significant parameters. Since growth patterns vary significantly between species and genotypes, it is important to analyze growth for each specific species. While various models have been introduced in different studies to describe the growth curve of different species, research on the growth pattern of guinea fowl is limited. Therefore, this study aimed to evaluate different non-linear models to determine the most suitable model for describing the growth pattern in both male and female pearl grey guinea fowls. Materials and methods: The present study was conducted on pearl grey guinea fowls raised at the Special Domestic Animals Institute, Research Institute of Zabol, Zabol, Iran. A total of 129 one-day-old keets (70 males and 59 females) were obtained from the hatchery and then identified by wing-banded numbers. All keets were individually weighed every week until 28 days of age and then every two weeks until 168 days of age using a sensitive digital electronic weighing scale. After data editing, Gompertz, Richards, Logistic, Weibull, and Lopez models were fitted to describe the growth curve of female and male keets. Four goodness of fit criteria, including mean square error (MSE), Akaike information criterion (AIC), Bayesian information criterion (BIC), and adjusted determination coefficient ( ) were used to compare the studied models and select the best model to describe the growth pattern in both sexes. All models were fitted to the body weight of male and female keets using the nlme package of R software, and model parameters were obtained for both sexes. Results and discussion: Male keets had higher body weight than female keets at all ages. The difference in body weight between the two sexes was not significant until the eighth week (P<0.05), but from 10 to 20 weeks of age, a significant difference was observed (P<0.05). The highest and lowest values for the initial and final weight parameters were related to the logistic model in both sexes. Male keets had a higher maturing index (k), shape parameter (m), age and weight at the inflection point, and absolute growth rate at 1, 12, and 24 weeks of age compared to female keets. Based on goodness-of-fit criteria, the Lopez model was found to be the best model among those studied to describe the growth pattern in male and female keets. When comparing actual body weight with predicted values from the studied models, the Lopez model closely matched the actual values at most ages, indicating that the Lopez model provided a more accurate prediction of body weight in both male and female keets compared to other models. Conclusions: Based on the findings of the present study, the Lopez model was determined to be the best model in describing the growth pattern in female and male keets. Understanding the growth pattern in both sexes can assist in developing nutritional programs to meet nutritional needs at various ages. Overall, additional research is needed to investigate the model parameters and explore the potential of incorporating them into selection programs to attain the desired growth curve. رشد حیوان، یک فرآیند پیچیده و پویایی است که در برگیرنده تغییرات مورفولوژیکی و فیزیولوژیکی بوده و میتواند بهوسیله مدلهای غیرخطی رشد توصیف شود. پژوهش کنونی با هدف تعیین مناسبترین مدل رشد غیرخطی جهت توضیح تغییرات وزن بدن مرغ شاخدار خاکستری مرواریدی در طول زمان انجام شد. بدین منظور از دادههای وزن بدن 129 جوجه مرغ شاخدار خاکستری مرواریدی (70 نر و 59 ماده) استفاده شد که از سن یکروزگی تا 168 روزگی بهصورت انفرادی رکوردبرداری شده بودند. پنج مدل غیرخطی گمپرتز، ریچاردز، لجستیک، ویبول و لوپز بر دادههای وزن بدن برازش شدند و بر اساس چهار معیار نکویی برازش معیار اطلاعات بیزی، معیار اطلاعات آکائیک، میانگین مربعات خطا و ضریب تبیین تصحیح شده ارزیابی شدند. بعد از برازش مدلها، بر اساس فراسنجههای برآورد شده، سن و وزن در نقطه عطف و نرخ رشد مطلق در هفتههای 1، 12 و 24 در دو جنس نر و ماده محاسبه شدند. بر پایه چهار معیار نکویی برازش، مدل لوپز مناسبترین مدل در توصیف منحنی رشد در جوجههای نر و ماده بود. در هر دو جنس، مدل لجستیک وزن ابتدایی را بالاتر و وزن نهایی را پایینتر از حد برآورد نمود. بالاترین مقدار فراسنجهها، بهاستثنای وزن ابتدایی در جوجههای نر و ماده، بهوسیله مدل لوپز بهدست آمد. جوجههای نر، سن و وزن بالاتری در نقطه عطف نسبت به جوجههای ماده داشتند. مقایسه مقادیر پیشبینی شده وزن بدن بهوسیله مدلهای رشد با مقدار واقعی آن نشان داد که مدل لوپز پیشبینی صحیحتری از وزن بدن در دو جنس نر و ماده در مقایسه با مدلهای دیگر داشت. با توجه به نتایج پژوهش کنونی میتوان از مدل رشد لوپز برای مطالعه منحنی رشد در مرغ شاخدار مرواریدی بهمنظور مدیریت تغذیهای و برنامههای اصلاح نژادی جهت تغییر منحنی رشد با صحت بالا استفاده کرد.

https://ar.guilan.ac.ir/article_8881_997fee5d887e3e107350872d26817554.pdf

دانشگاه گیلان تحقیقات تولیدات دامی 2252-0872 14 3 2025 11 22 Study of the molecular relationship between the jejunum angiogenesis pathway and feed efficiency in Iranian native turkeys بررسی ارتباط مولکولی بین مسیر رگ‌زایی ژژنوم و بازده خوراک در بوقلمون‌های بومی ایران 49 60 8899 10.22124/ar.2025.30674.1897 FA الهام دارنگ گروه علوم دامی، دانشکده علوم کشاورزی، دانشگاه گیلان 0000-0002-6448-4732 سید ضیاءالدین میرحسینی گروه علوم دامی، دانشکده علوم کشاورزی، دانشگاه گیلان شاهرخ قوتی گروه علوم دامی، دانشکده علوم کشاورزی، دانشگاه گیلان مجید خان سفید پژوهشکده تحقیقات کشاورزی ایالت ویکتوریا، مرکز علوم زیستی کشاورزی، 5 رینگ رود، بوندورا، ویکتوریا 3083، استرالیا دانشکده زیست‌شناسی سامانه های کاربردی، دانشگاه لاتروب، بوندورا، ویکتوریا 3083، استرالیا Journal Article 2025 05 15 Introduction: Real-time PCR has become a powerful tool for quantifying nucleic acids and assessing gene expression. Its accuracy and sensitivity have made it indispensable in biological research, allowing for detailed analysis of gene expression changes in response to various stimuli. In the livestock and poultry industry, improving feed efficiency is a key goal in breeding programs due to its significant economic benefits. Defined as the ratio between feed intake and weight gain or production, feed efficiency is influenced by genetic, physiological, nutritional, and environmental factors. Understanding its molecular mechanisms can lead to targeted breeding strategies and the selection of superior genotypes. The intestine is critical for feed utilization efficiency, serving as the main site of nutrient digestion and absorption; its epithelial structure, including villi and microvilli, is essential for effective absorption. Furthermore, a rich vascular network, formed through angiogenesis, is crucial for efficient feed metabolism and nutrient absorption within the intestinal tissue. This study investigated the expression of RHOA, ACTA2, and ENO1 genes in the jejunum of high feed efficiency (HFE) and low feed efficiency (LFE) turkeys. RHOA is involved in angiogenesis. Meanwhile, ACTA2 is essential for maintaining vascular structure and integrity. Additionally, ENO1 provides the adenosine triphosphate (ATP) required for endothelial cell proliferation and migration, processes involved in angiogenesis. The expected higher expression of these genes in HFE turkeys suggests improved intestinal function, energy metabolism, and angiogenesis, contributing to better feed efficiency. This research aimed to lay the groundwork for identifying genetic markers to enhance feed efficiency in turkey, contributing to more sustainable animal protein production. Materials and methods: Samples from native Iranian turkeys were used in this study. A total of 500 male turkey poults were raised under standard production protocols until 20 weeks of age. Subsequently, 75 turkeys were selected and transferred to individual cages to allow for precise monitoring of feed intake and weight gain. Body weight was measured at 20 weeks of age (the initiation of the cage period) and at 24 weeks of age (the termination of the experimental period). The turkeys were then ranked based on their feed conversion ratio (FCR), with FCR ranging from 3.59 to 16.346. Jejunum tissue samples were collected post-slaughter from three turkeys exhibiting HFE and three turkeys exhibiting LFE. The collected tissue samples were immediately stored at -80°C to preserve RNA integrity. Total RNA was extracted from 250 mg of jejunum tissue samples using the RNeasy Midi Kit (Qiagen). The quality and concentration of the extracted RNA were assessed using a spectrophotometer and agarose gel electrophoresis. Primers for the target genes (RHOA, ACTA2, and ENO1) and the reference gene (RPS7) were designed using specialized software. Real-time PCR was performed to quantify the expression levels of the target genes, and gene expression levels were calculated using the Pfaffl method, which normalizes the data to the reference gene. Statistical analyses, including Shapiro-Wilk and Spearman's rank correlation, were performed using GraphPad Prism 8, with significance set at P<0.05. Results and discussion: High-quality RNA was confirmed by spectrophotometry and agarose gel electrophoresis. RPS7 was selected as the stable reference gene, its stability having been confirmed in previous studies. Melting curve analysis confirmed primer specificity and lack of non-specific products. Real-time PCR analysis showed that the expression of all three genes was significantly higher in the HFE group (P<0.05). Specifically, RHOA expression was approximately 7.52 times higher, ACTA2 about 46.17 times higher, and ENO1 around 33.08 times higher in the HFE group compared to the LFE group. Spearman's rank correlation analysis revealed significant positive correlations for ACTA2 and ENO1 with feed efficiency (rs=1, P=0.0028), while RHOA showed a strong positive correlation (rs=0.8) approaching statistical significance (P=0.058). The high correlation between ACTA2 and ENO1 also suggests shared regulatory mechanisms, reinforcing their combined role in feed efficiency. Conclusions: The elevated expression of RHOA, ENO1, and ACTA2 in HFE turkeys enhanced intestinal function, vascular network development, and energy supply, underscoring their importance in nutrient absorption and overall feed efficiency. These findings align with existing evidence in other species and provide a foundation for identifying potential genetic markers and developing nutritional and genetic strategies to improve poultry production efficiency. Further research is necessary to fully elucidate the complex interactions among these genes and other factors contributing to turkey. بهبود بازده خوراک در پرورش بوقلمون از اهمیت اقتصادی بالایی برخوردار است. ژن RHOA با تنظیم اسکلت اکتین و تسهیل مهاجرت سلول‌های اندوتلیال؛ ژنACTA2 با پایداری شبکه عروقی و ژن ENO1با تأمین انرژی در فرآیند رگ‌زایی، نقش کلیدی ایفا میکنند. مطالعه حاضر با هدف بررسی بیان ژن‌های RHOA، ACTA2 و ENO1 در ژژنوم روده بوقلمون‌های نر بومی ایران با بازده خوراک بالا(HFE) و پایین (LFE) انجام شد. نتایج تجزیه و تحلیل Real-time PCR روی نمونه‌هایRNA استخراج شده از بافت ژژنوم سه قطعه بوقلمون از هر گروه نشان داد که بیان هر سه ژن در گروه HFE بهطور معنیداری بالاتر بود (05/0>P). تجزیه همبستگی اسپیرمن، همبستگی‌های مثبت قوی و معنی‌داری برای ژن‌هایACTA2 وENO1 (0028/0=, P1rs =) و همچنین، همبستگی مثبت قوی برای ژن RHOA (8/0rs=) (نزدیک به سطح معنیداری آماری، 058/0P=) با بازده خوراک آشکار کرد. نتایج این پژوهش نشان داد که افزایش بیان ژن‌های RHOA، ACTA2 و ENO1 سبب تقویت رگ‌زایی در روده میشود که این امر، زمینه ساز بهبود جذب مواد مغذی و سوخت و ساز خوراک شده که در نهایت سبب افزایش بازده خوراک در بوقلمون‌های HFE شده ‌است. یافته‌های این پژوهش، زمینه‌ساز شناسایی نشانگرهای ژنتیکی برای بهبود صفت بازده خوراک در بوقلمون هستند.

https://ar.guilan.ac.ir/article_8899_0f1f0d87720b55aee3d4a4525bcff6eb.pdf

دانشگاه گیلان تحقیقات تولیدات دامی 2252-0872 14 3 2025 11 22 Influence of adding different levels of kambucha tea to drinking water on performance, small intestine microbial flora and morphology, and serum total oxidant and antioxidant properties of Japanese quail chicks تاثیر افزودن سطوح مختلف چای کامبوچا در آب آشامیدنی بر عملکرد، فلور میکروبی، ریختشناسی روده باریک و خصوصیات اکسیدانی و آنتی اکسیدانی تام سرم در جوجه های بلدرچین ژاپنی 61 75 8767 10.22124/ar.2025.30057.1887 FA علی مهدوی گروه علوم دامی، دانشگاه سمنان امیر امیراحمدی گروه علوم دامی، دانشگاه سمنان سید جواد احمدپناهی گروه علوم پایه، دانشگاه سمنان حمید استاجی گروه پاتوبیولوژی، دانشگاه سمنان سینا محبوب ربانی گروه علوم دامی، دانشگاه سمنان Journal Article 2025 03 08 Introduction: Population growth has turned food security into a major challenge. Poultry meat, as an important source of animal protein, requires innovative strategies to improve health and growth performance. Quail has attracted attention due to its high reproductive efficiency, low rearing costs, and disease resistance. Digestive health plays an important role in improving poultry performance, and gut microbiota balance is a key factor in this process. With the increasing microbial resistance caused by antibiotic use, alternatives such as probiotics, synbiotics, and organic acids have been suggested. Kombucha tea, a fermented beverage containing a variety of beneficial microorganisms, has been proposed as a natural additive in poultry nutrition. This tea, with its probiotic and synbiotic properties, helps regulate the gut microbiota and improves digestive performance. Additionally, its antioxidant, anti-inflammatory, and immune-boosting effects have significant potential in enhancing poultry performance. Its active compounds, including organic acids, polyphenols, vitamins, and antioxidants, play an important role in reducing oxidative stress, improving metabolism, and promoting overall health. Studies have shown that kombucha can be a suitable alternative to oral antibiotics in livestock and poultry, improving growth, immunity, reducing triglycerides, and increasing feed efficiency. It also has positive effects on reducing gut dysbiosis, strengthening the immune system, and improving the microbiota. This research aimed to assess the impact of adding kombucha tea to drinking water on poultry health and performance. It is hypothesized that adding this tea to drinking water could reduce the need for antibiotics and prevent the development of bacterial resistance. Materials and methods: This study was conducted randomly with four groups, five replications, and 10 quails per replicate. The groups included a control group (T1) and three treatments with 5% (T2), 10% (T3), and 15% (T4) fermented kombucha tea. The quail chicks were kept in 20 standard cages with identical environmental conditions and were fed a corn and soybean-based diet according to National Research Council (NRC) 1994 standards. The fermented kombucha tea was prepared by steeping black tea, sugar, apple cider vinegar, and kombucha culture for one week in a warm, dark environment, and was then added to the chicks' drinking water. After one week, the kombucha beverage was ready and stored in the refrigerator. To prepare the housing for the chicks, the room was disinfected, and the temperature was raised to 36°C. The chicks were kept at various temperatures ranging from 36°C to 21°C by the end of the study. Performance was assessed using various indices, including survival rate, feed consumption, weight gain, and feed conversion ratio. Survival rate was evaluated weekly based on the number of deceased chicks. Feed consumption was calculated by measuring the amount of leftover feed. Moreover, the feed conversion ratio was calculated as the ratio of feed intake to weight gain. At the end of the study, samples from the two initial sections of the small intestine (duodenum and jejunum) were collected and fixed in 10% formalin for histological examination. The samples were then placed in alcohol solutions, xylene, and molten paraffin, and sections of 5-6 microns were prepared for staining. Crypt depth and villus length were measured, and the villus-to-crypt ratio was calculated. For microbial flora analysis, DNA was extracted from the cecum of the quail and the presence of microbial genomes, such as Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria, was assessed using PCR. Plasma antioxidant and oxidant capacity were measured using the Erel method. Color changes at specific wavelengths were recorded and analyzed using a spectrophotometer. Data were analyzed using SAS software version 9.2, and descriptive statistics were computed using the Means procedure. For the analysis of variance, general linear models (GLM) were used. The means were compared using Duncan’s multiple range test at the 5% significance level. Results and discussion: The results showed that different kombucha tea treatments significantly affected feed intake across different weeks. The 10% group had the highest feed intake in weeks 1, 2, 3, and 4, while the control group showed the lowest feed intake (P<0.05). Additionally, throughout the entire rearing period, feed intake in the kombucha groups was significantly higher than in the control group (P<0.05). Regarding weight gain, the 10% group showed the best performance, with the highest weight gain in most weeks, including weeks 1 and 4. Concerning the feed conversion ratio, the 15% group had the best feed conversion ratio throughout the entire period, but no significant differences were observed between the groups over the entire period. In terms of mortality, the 15% group had the highest mortality rate, while the 5% group showed the lowest (P<0.05). However, over the entire period, the 5% and 10% groups had the highest survival rates, and the control group had the lowest survival rate. In the intestinal histology evaluation, the 5% and 10% groups had similar villus length and villus-to-crypt ratio, with villus length being higher in these groups than in the other groups. Additionally, in the jejunum, the 10% group had the highest villus length and crypt depth (P<0.05), indicating better intestinal health in these groups. In the microbiota analysis, different treatments had different effects on gut bacteria. The 10% group had the highest number of Firmicutes, while the control group showed the highest number of Proteobacteria. Additionally, in the kombucha groups, blood peroxide levels were lower than in the control group, indicating the antioxidant effects of kombucha tea. The results of this study suggest that fermented kombucha tea has a positive effect on the growth performance of quail and can improve feed intake, weight gain, gut health, and reduce oxidative stress. The probiotic and antioxidant properties of kombucha, especially in the 10% and 15% groups, significantly contributed to the health and performance of the quails. Conclusions: This study concluded that adding 10% kombucha solution to water can improve performance traits, economic indices, gut morphology, and microbial flora in quail chicks, making kombucha tea a suitable supplement for industrial quail farming. هدف از این پژوهش، بررسی تأثیر چای کامبوچا به‌عنوان یک افزودنی طبیعی جایگزین آنتی‌بیوتیک‌ها در آب آشامیدنی بر عملکرد، ریخت‌شناسی روده، فلور میکروبی و وضعیت اکسیدانی و آنتی‌اکسیدانی تام سرم بلدرچین‌ها بود. این آزمایش با چهار گروه آزمایشی شامل گروه شاهد، گروههای مکمل‌شده با 5، 10 و 15 درصد چای کامبوچا، پنج تکرار و 10 قطعه بلدرچین در هر تکرار انجام شد. در این مطالعه، شاخص‌های عملکردی شامل درصد ماندگاری، میانگین وزن، مصرف دان و ضریب تبدیل خوراک بررسی شدند. همچنین، ویژگی‌های ریخت‌شناسی روده شامل طول پرز و عمق کریپت در دئودنوم و ژژنوم ارزیابی شدند. ظرفیت اکسیدانی و آنتی‌اکسیداتیو پلاسما با روش ارل اندازه‌گیری شد و نسبت اکسیدان به آنتی‌اکسیدان به‌عنوان شاخص تنش اکسیداتیو تعیین شد. نتایج نشان داد که به‌جز ضریب تبدیل، سایر شاخص‌های عملکردی در گروه‌های دریافت‌کننده چای کامبوچا بهبود معنی‌داری داشتند (05/0>P). در بخش ریختشناسی روده باریک، نتایج نشان داد طول پرز و عمق کریپت در گروههای سهگانه مکمل شده با چای کامبوچا نسبت به گروه شاهد، افزایش یافته است. ترکیب فلور میکروبی بین گروه‌های تیماری و شاهد متفاوت بود و باکتری‌های مفید در گروه‌های دریافت‌کننده چای کامبوچا، افزایش و باکتری‌های مضر، کاهش یافته‌اند. همچنین، نسبت اکسیدان به آنتی‌اکسیدان در گروه‌های تغذیه ‌شده با چای کامبوچا کاهش یافت. به‌طور کلی، مکمل‌سازی جیره با 10 درصد چای کامبوچا دارای بیشترین تأثیر مثبت بر شاخص‌های بررسی ‌شده بود.

https://ar.guilan.ac.ir/article_8767_af339eee285b53dcfb06d80cd30def13.pdf

دانشگاه گیلان تحقیقات تولیدات دامی 2252-0872 14 3 2025 11 22 Effect of adding wood vinegar to drinking water on the growth performance, carcass characteristics, and microflora populations of the small intestine in broiler chickens اثر افزودن سرکه چوب در آب آشامیدنی بر عملکرد رشد، اجزای لاشه و فلور میکروبی روده کوچک جوجه های گوشتی 77 91 8923 10.22124/ar.2025.30756.1900 FA فائزه عبدی نژاد گروه علوم دامی، دانشکده علوم کشاورزی، دانشگاه گیلان اردشیر محیط گروه علوم دامی، دانشکده علوم کشاورزی، دانشگاه گیلان مهرداد محمدی گروه علوم دامی، دانشکده علوم کشاورزی، دانشگاه گیلان محمد مهدی سوهانی گروه بیوتکنولوژی کشاورزی، دانشکده علوم کشاورزی، دانشگاه گیلان Journal Article 2025 05 23 Introduction: Wood vinegar (WV) is a liquid biomaterial produced by the thermo-pyrolysis of wood biomass and defined as a red-brown water-based liquid. It is a natural, non-toxic, safe, low-cost, and universal product suitable for use as an additive in animal feed, as a preventative antibiotic, and as a growth promoter. It has been shown to inhibit bacteria, leading to healthier poultry and higher yields. This study aimed to determine the efficacy of drinking water supplemented with wood vinegar on growth performance, carcass quality, and microbial population parameters of broilers. Materials and methods: A total of 540 one-day-old chicks (Ross-308) were used in a 42-day feeding trial. The experiment was conducted in a completely randomized design with six treatments and six replicates (15 chicks per replicate). The experimental treatments were: 1) negative control (NC, without wood vinegar in drinking water), 2) positive control (PC, commercial acidifier supplemented in drinking water), 3) 1.5 mL wood vinegar in one liter drinking water, 4) 3.5 mL wood vinegar in one liter drinking water, 5) 5.5 mL wood vinegar in one liter drinking water, and 6) 7.5 mL wood vinegar in one liter drinking water. Experimental diets were formulated for three phases: starter (1-10 days old), grower (11-24 days old), and finisher (25-42 days old). During the experimental period, average daily feed intake (ADFI), body weight gain (BWG), and feed conversion ratio (FCR) were measured. At the end of the experiment, two birds were selected from each replicate and slaughtered after weighing, and the weight of the internal organs (breast, thigh, wing, back, heart, liver, abdominal fat, pancreas, bursa of Fabricius, thymus, and Spleen) was measured. On days 21 and 42, two birds from each replicate were slaughtered to collect intestinal digesta and evaluate the intestinal microflora. To this end, dilution was first carried out and then linearly distributed onto the surface of the culture plates. After the incubation period, the bacterial colonies were counted using a colony counter, and the results were expressed as log10 colony-forming units per gram of sample. The MRS agar plates were incubated anaerobically at 39◦C for 24-48 hours, while the MacConkey agar plates were incubated aerobically at 39◦C for the same duration to ensure optimal growth conditions for Enterobacteriaceae. Data were analyzed using the general linear model (GLM) of the SAS program, and treatment means were compared using Tukey's test at P<0.05. Results and discussion: No significant differences in feed intake were observed between the groups during the starter, grower, finisher, and whole periods. It can be concluded that adding wood vinegar to drinking water has no significant effect on the feed consumption of broiler chickens. This suggests that wood vinegar does not contribute nutritionally (e.g., by providing energy, protein, vitamins, or minerals) to the diet. Instead, its potential benefits may stem from the general properties of its organic compounds, which could enhance gastrointestinal health and immune function. BWG and FCR in the initial and final periods were not affected by the experimental treatments. During the growth and whole periods, treatment containing 3.5 mL of wood vinegar improved weight gain compared to the negative control treatment (P<0.05). The use of wood vinegar in treatments containing 3.5 and 5.5 mL of wood vinegar increased the bursa of Fabricius weight and decreased abdominal fat without any negative effect on carcass characteristics, breast, and thigh weights (P<0.05). The bursa of Fabricius has an essential role in the poultry immune system. The increased weight of the bursa of Fabricius in wood vinegar-consuming treatments probably indicates an improvement in their immune system. The performance of poultry is significantly influenced by its health and safety status. A weak immune system causes weight loss when exposed to infectious diseases, so the use of immunostimulants can enhance performance by improving immune status. The Lactobacillus population showed a significant increase (P<0.05) compared to the negative control at 21 days of treatment with 3.5 and 5.5 mL of wood vinegar, and at 42 days of treatment with 3.5 and 5.5 mL of wood vinegar, respectively. The count of Colibacillus bacteria exhibited a significant decrease (P<0.05) at 21 days of age in treatments supplemented with 3.5 and 7.5 mL of wood vinegar relative to the negative control group. The use of wood vinegar in poultry drinking water improved microbial population by increasing the number of lactobacilli and reducing the population of Colibacillus bacteria, and improved the growth efficiency of broiler chickens. Conclusions: The results of this study showed that the addition of 3.5 mL of wood vinegar to one liter of drinking water could increase the growth and intestinal microflora of broiler chickens. این تحقیق بهمنظور بررسی اثر سرکه چوب بر عملکرد رشد، فلور میکروبی روده و کیفیت لاشه با تعداد 540 قطعه جوجه گوشتی در قالب طرح کاملاً تصادفی با شش تیمار، شش تکرار و 15 قطعه جوجه در هر تکرار بهمدت 42 روز انجام شد. تیمارها شامل شاهد منفی (بدون سرکه چوب)، شاهد مثبت (اسیدی فایر تجاری) و سایر تیمارها بهترتیب حاوی 5/1، 5/3، 5/5 و 5/7 میلیلیتر سرکه چوب در یک لیتر آب آشامیدنی بودند. خصوصیات عملکردی بهصورت هفتگی و دورهای بررسی شدند. در پایان دوره، وزن اندامهای داخلی دو پرنده از هر تکرار محاسبه شد. بهمنظور بررسی میکروفلور روده، در 21 و 42 روزگی، از محتویات ژژنوم دو قطعه جوجه از هر تکرار، نمونهبرداری شد. در دوره رشد و کل دوره، تیمار حاوی 5/3 میلیلیتر سرکه چوب باعث بهبود افزایش وزن نسبت به تیمار شاهد منفی شد (05/0>P). تیمارهای حاوی 5/3 و 5/5 میلیلیتر سرکه چوب سبب افزایش وزن بورس و کاهش چربی بطنی شدند (05/0>P). تعداد لاکتوباسیلوسها در 21 روزگی در تیمارهای حاوی 5/3 و 5/5 میلیلیتر سرکه چوب و در 42 روزگی در تیمارهای حاوی 5/3، 5/5 و 5/7 میلیلیتر سرکه چوب نسبت به شاهد منفی، افزایش معنیداری یافتند (05/0>P). تعداد باکتریهای کلیباسیل در 21 روزگی در تیمارهای حاوی 5/3 و 5/7 میلیلیتر سرکه چوب نسبت به تیمار شاهد منفی، کاهش معنیداری یافت (05/0>P). در کل، نتایج نشان داد که افزودن 5/3 میلیلیتر سرکه چوب در یک لیتر آب آشامیدنی، ضمن بهبود عملکرد رشد سبب بهبود میکروفلور در جوجههای گوشتی میشود.

https://ar.guilan.ac.ir/article_8923_64964af0c5b96da3759325ceba4a4e70.pdf

دانشگاه گیلان تحقیقات تولیدات دامی 2252-0872 14 3 2025 11 22 Effect of substituting different levels of biuret instead of urea on nutrient intake, growth performance, nutrient digestibility, blood metabolites, and feeding behavior of Afshari fattening lambs اثر جایگزینی اوره با سطوح مختلف بیورت بر مصرف مواد مغذی، عملکرد رشد، گوارش‌پذیری مواد مغذی، متابولیت‌های خونی و رفتار تغذیه‌ای بره‌های افشاری 93 107 8768 10.22124/ar.2025.29746.1881 FA سمیرا نظری گروه علوم دامی، دانشکده کشاورزی، دانشگاه لرستان ایوب عزیزی گروه علوم دامی، دانشکده کشاورزی، دانشگاه لرستان علی کیانی گروه علوم دامی، دانشکده کشاورزی، دانشگاه لرستان مریم اثنی عشری گروه فرآوری تولیدات دامی، موسسه تحقیقات علوم دامی کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران Journal Article 2025 02 02 Introduction: Protein is one of the most expensive nutrients used in ruminant diets and is considered one of the limiting factors in feed intake in ruminants. The various protein sources used in ruminant nutrition include plant protein sources (oilseed meal, including soybean meal, rapeseed meal, etc.), animal protein (including meat meal), marine products (fish meal), and non-protein nitrogen (NPN). However, the apparent shortage of protein sources required by ruminants has become a global problem and has significantly increased production costs. Therefore, finding alternative sources to soybean meal as a standard protein source seems essential. NPN sources are nitrogen-rich compounds that can partially replace real protein in the diet of ruminants and include urea, biuret, thiouret, dicyandiamide, thiourea, hydrazine, and several ammonium salts such as ammonium acetate, ammonium succinate, ammonium carbonate, ammonium bicarbonate, ammonium phosphate, and ammonium lactate. Low supply cost, high nitrogen content, and easy availability are some of the advantages of using NPN sources in ruminant nutrition. Urea is the most widespread source of NPN, which is an organic compound soluble in water and alcohol with the chemical formula CO(NH2)2 and contains 46% nitrogen, which is equivalent to 287.5% crude protein (CP). In Iran, there is a relatively large capacity for urea production and the possibility of making slow-release nitrogenous compounds from it, while, unfortunately, the use of NPN in livestock nutrition has not been given due attention, and these compounds are also imported from abroad in slow-release form. Excessive use of urea in ruminant diets, due to its extremely high solubility in rumen fluid, increases the concentration of blood urea nitrogen (BUN) and causes ammonia poisoning. Slow-release urea production technology with controlled release of nitrogen in the rumen ensures that rumen bacteria have continuous and gradual access to the nitrogen source. To overcome this problem, several slow-release urea products have been developed and evaluated in the past. Another source of slow-release urea is biuret (carbamyl urea, alphanamides) with the chemical formula 2(NH2CONHCONH), which is produced by combining two urea molecules at high temperatures, and as a source of NPN, it has good potential in feeding ruminants. The cost of producing biuret is lower than other slow-release urea sources. Biuret is less soluble in water and is converted to ammonia in the rumen at a much slower rate than urea. Also, biuret is relatively non-toxic compared to urea and does not negatively affect the palatability of the diet. Biuret can be used in ruminant nutrition at much higher levels than urea. Biuret is very safe compared to urea and can be used in beef cattle diets at a dose 20 times higher than the toxic dose of urea. So far, few studies have been conducted on the effects of biuret feeding in ruminants, especially determining the optimal level of biuret in the diet. Therefore, the present study aimed to investigate the effects of replacing different levels of biuret in the diet with urea on nutrient intake, growth performance, nutrient digestibility, and feeding behavior of Afshari fattening lambs. Materials and methods: In this study, 28 Afshari fattening male lambs with an average age of 135±15 days and average live weight of 34±3.49 kg were used in a completely randomized design with four experimental treatments and seven replications. The experimental diets included a control treatment (100% urea on a dry matter (DM) basis) and the inclusion of levels of 34, 67, and 100% biuret based on dietary DM instead of urea. First, the experimental diets were incubated in an in vitro test to determine the concentration of ammonia-N, and then the diets were fed to the experimental animals for 70 days. Results and discussion: Using biuret in the diet did not affect nutrient intake, including DM, organic matter (OM), CP, and neutral detergent fiber (NDF), and feeding behavior traits compared to the control treatment. With increasing the level of biuret in the diet, daily weight gain, total weight gain, and feed conversion ratio improved linearly compared to the control treatment (P<0.05). The improvement in growth performance traits in biuret-fed lambs can be explained by higher feed intake compared to the control (urea only) treatment. One possible reason may be the better efficiency and retention of nitrogen in biuret due to the lower rumen degradation rate compared to urea. The slower release of ammonia from biuret as a source of NPN compared to urea probably makes biuret more efficiently utilized by rumen microorganisms. As the level of biuret increased in the diet, the digestibility of NDF increased linearly compared to the urea-containing treatment (P<0.05), although OM digestibility was not affected by the experimental diets. In the present study, it was expected that the improvement in NDF digestibility with increasing biuret levels in the diet would be accompanied by an increase in nutrient intake, which was not the case. The reason for the increase in fiber digestion with biuret supplementation compared to urea may be due to the greater availability of ammonia to rumen microbes, especially cellulolytic bacteria, as ammonia is known to be the most important source of nitrogen for the growth and proliferation of fiber-digesting bacteria in the rumen. With increasing the amount of dietary biuret, the concentration of blood total protein increased linearly, but the concentration of blood urea nitrogen decreased linearly compared to the treatment containing urea (P<0.05). Conclusions: The results of the present study showed that the use of biuret compared to urea in the diet caused a decrease in ammonia-N content in the rumen and improved growth performance and feed conversion ratio. Therefore, it is recommended to use biuret instead of urea up to the full replacement level in the diet of fattening lambs. هدف از انجام پژوهش حاضر، بررسی اثر جایگزینی سطوح مختلف بیورت بهجای اوره بر مصرف مواد مغذی، عملکرد رشد، گوارش‌پذیری مواد مغذی، متابولیت‌های خونی و رفتار تغذیه‌ای بره‌های پرواری بود. از 28 رأس بره نر پرواری افشاری با میانگین سنی 15±135 روزه و میانگین وزن زنده 49/3±34 کیلوگرم در قالب طرح کاملاً تصادفی با چهار تیمار آزمایشی و هفت تکرار استفاده شد. از چهار جیره آزمایشی شامل جایگزینی سطوح صفر (شاهد)، 34، 67 و 100 درصد ماده خشک بیورت بهجای اوره استفاده شد. ابتدا، جیره‌های آزمایشی در یک آزمون برون‌تنی جهت تعیین غلظت نیتروژن آمونیاکی انکوبه شدند و سپس، جیره‌ها بهمدت 70 روز به دام‌های آزمایشی تغذیه شدند. نتایج آزمایش برون‌تنی نشان داد که با افزایش سطح بیورت در جیره، غلظت نیتروژن آمونیاکی محیط کشت تا زمان 10 ساعت پس از انکوباسیون در مقایسه با تیمار حاوی اوره کاهش نشان داد. استفاده از بیورت در جیره در مقایسه با تیمار شاهد تأثیری بر مصرف مواد مغذی شامل ماده خشک، ماده آلی، پروتئین خام، NDF و صفات رفتار تغذیه‌ای نداشت (05/0<P). با افزایش سطح بیورت در جیره، افزایش وزن روزانه، کل افزایش وزن و ضریب تبدیل غذایی در مقایسه با تیمار شاهد بهطور خطی بهبود یافت (05/0P<). با افزایش سطح بیورت در جیره، گوارش‌پذیری NDF در مقایسه با تیمار حاوی اوره بهطور خطی افزایش یافت (05/0P<)، هرچند گوارش‌پذیری ماده آلی تحت تأثیر جیره‌های آزمایشی قرار نگرفت (05/0<P). با افزایش سطح بیورت در جیره‌، غلظت پروتئین تام خون بهطور خطی افزایش یافت، اما غلظت نیتروژن اوره‌ای خون در مقایسه با تیمار حاوی اوره بهطور خطی کاهش یافت (05/0P<). در کل، نتایج تحقیق حاضر نشان داد کاربرد بیورت در مقایسه با اوره در جیره سبب کاهش غلظت نیتروژن آمونیاکی شکمبه و بهبود عملکرد رشد و ضریب تبدیل غذایی شد. بنابراین، کاربرد بیورت بهجای اوره تا سطح کامل جایگزینی در جیره بره‌های پرواری قابل توصیه است.

https://ar.guilan.ac.ir/article_8768_324d372c9a82256fef4eddf598ed6b39.pdf