Gorgan University of Agricultural Sciences and Natural Resources Journal of Ruminant Research 2345-4253 14 2 2026 08 23 Effects of Rumen-Protected Methionine on Milk Production Performance, Feed Efficiency, and Economic Parameters in Early Lactation Dairy Cows Under Heat Stress Effects of Rumen-Protected Methionine on Milk Production Performance, Feed Efficiency, and Economic Parameters in Early Lactation Dairy Cows Under Heat Stress 1 14 7801 10.22069/ejrr.2025.23659.2009 FA Sayed Amir Hosseini Rad Department of Animal Science, University college of Agriculture and Natural Resources, University of Tehran, Karaj Farhang Fatehi Assistant Professor, Department of Animal Science, Faculty of Agricultural Science and Engineering, College of Agricultural and Natural Resources, University of Tehran, Karaj, Iran 0000-0003-3262-5841 Kamran Rezayazdi Department of Animal Science, University college of Agriculture and Natural Resources, University of Tehran, Karaj Mostafa Sadeghi Department of Animal Science, University college of Agriculture and Natural Resources, University of Tehran, Karaj Journal Article 2025 05 13 Background and Objective: Heat stress is a fundamental challenge in dairy cattle production in hot regions, particularly during early lactation, causing reduced feed intake, metabolic disorders, and decreased milk production. This stress also disrupts the metabolism of proteins and essential amino acids. Methionine, the limiting essential amino acid in dairy cow diets, plays a key role in protein synthesis, energy metabolism, and metabolic health, but its bioavailability is limited due to ruminal degradation. Under heat stress conditions, the requirement for specific amino acids such as methionine may increase due to metabolic changes and increased need for antioxidants (such as glutathione, in which methionine plays a role in synthesis). However, limited information exists regarding the effects of rumen-protected methionine on the performance of early lactation dairy cows under heat stress. Rumen-protected methionine, which is resistant to microbial degradation in the rumen, can improve milk production, protein percentage, and feed efficiency. Under heat stress conditions, methionine requirements likely increase due to metabolic changes and increased antioxidant needs. This research was conducted to investigate the effect of rumen-protected methionine on milk production performance and economic parameters in early lactation Holstein cows under heat stress.<br />Materials and Methods: This study used 24 lactating Holstein cows (12 cows per treatment) with average days in milk (91 ± 12), milk production (37 ± 3), and parity (2.4 ± 0.1) at the University of Tehran research farm. The present study was conducted using repeated measures designs with 2 experimental treatments including control treatment: basal diet (containing zero levels of rumen-protected methionine) and methionine treatment: basal diet plus methionine (containing 25 grams of rumen-protected methionine per day per lactating cow).<br />Results: Results showed that raw milk production (37 vs. 34.8 liters per day) (P < 0.05) and energy-corrected milk (38.8 vs. 35.8 liters per day) (P < 0.05) were significantly higher for cows receiving rumen-protected methionine compared to the control group. Feed efficiency calculated based on raw milk, fat-corrected milk, and energy-corrected milk was significantly higher in the methionine group. Regarding milk composition, fat percentage (3.42 vs. 3.18 percent) and total milk solids (12.9 vs. 11.1 percent) significantly increased in the methionine-containing treatment. Milk fat yield (1.32 vs. 1.17 kg per day) and total milk solids yield (4.97 vs. 4.10 kg per day) were also significantly higher in the rumen-protected methionine group. Economic parameters showed that milk sales revenue for the methionine treatment compared to the control treatment (13.44 vs. 12.99 US$) was significantly higher (P< 0.02), and income over feed cost for the methionine treatment compared to the control treatment (5.86 vs. 5.33 US$) was also significantly higher (P<0.03). In fact, daily consumption of 50 grams of methionine supplement equivalent to 0.53 US$ per cow generated profit for the farmer.<br />Conclusion: The use of rumen-protected methionine in early lactation dairy cow diets can be considered as an ideal additive in nutritional management of early lactation dairy cows under heat stress due to improved milk production and composition as well as improved economic parameters. Background and Objective: Heat stress is a fundamental challenge in dairy cattle production in hot regions, particularly during early lactation, causing reduced feed intake, metabolic disorders, and decreased milk production. This stress also disrupts the metabolism of proteins and essential amino acids. Methionine, the limiting essential amino acid in dairy cow diets, plays a key role in protein synthesis, energy metabolism, and metabolic health, but its bioavailability is limited due to ruminal degradation. Under heat stress conditions, the requirement for specific amino acids such as methionine may increase due to metabolic changes and increased need for antioxidants (such as glutathione, in which methionine plays a role in synthesis). However, limited information exists regarding the effects of rumen-protected methionine on the performance of early lactation dairy cows under heat stress. Rumen-protected methionine, which is resistant to microbial degradation in the rumen, can improve milk production, protein percentage, and feed efficiency. Under heat stress conditions, methionine requirements likely increase due to metabolic changes and increased antioxidant needs. This research was conducted to investigate the effect of rumen-protected methionine on milk production performance and economic parameters in early lactation Holstein cows under heat stress.<br />Materials and Methods: This study used 24 lactating Holstein cows (12 cows per treatment) with average days in milk (91 ± 12), milk production (37 ± 3), and parity (2.4 ± 0.1) at the University of Tehran research farm. The present study was conducted using repeated measures designs with 2 experimental treatments including control treatment: basal diet (containing zero levels of rumen-protected methionine) and methionine treatment: basal diet plus methionine (containing 25 grams of rumen-protected methionine per day per lactating cow).<br />Results: Results showed that raw milk production (37 vs. 34.8 liters per day) (P < 0.05) and energy-corrected milk (38.8 vs. 35.8 liters per day) (P < 0.05) were significantly higher for cows receiving rumen-protected methionine compared to the control group. Feed efficiency calculated based on raw milk, fat-corrected milk, and energy-corrected milk was significantly higher in the methionine group. Regarding milk composition, fat percentage (3.42 vs. 3.18 percent) and total milk solids (12.9 vs. 11.1 percent) significantly increased in the methionine-containing treatment. Milk fat yield (1.32 vs. 1.17 kg per day) and total milk solids yield (4.97 vs. 4.10 kg per day) were also significantly higher in the rumen-protected methionine group. Economic parameters showed that milk sales revenue for the methionine treatment compared to the control treatment (13.44 vs. 12.99 US$) was significantly higher (P< 0.02), and income over feed cost for the methionine treatment compared to the control treatment (5.86 vs. 5.33 US$) was also significantly higher (P<0.03). In fact, daily consumption of 50 grams of methionine supplement equivalent to 0.53 US$ per cow generated profit for the farmer.<br />Conclusion: The use of rumen-protected methionine in early lactation dairy cow diets can be considered as an ideal additive in nutritional management of early lactation dairy cows under heat stress due to improved milk production and composition as well as improved economic parameters. https://ejrr.gau.ac.ir/article_7801_3097165363050b36fef00d98a1c04b7d.pdf

Gorgan University of Agricultural Sciences and Natural Resources Journal of Ruminant Research 2345-4253 14 2 2026 08 23 The use of organic acids and bacterial additives and their effect on the chemical properties and digestibility of corn silage The use of organic acids and bacterial additives and their effect on the chemical properties and digestibility of corn silage 15 34 7710 10.22069/ejrr.2026.24169.2024 FA Sirous Jalilian ilam university Farshid Fatahnia illam university Mehdi Bahrami-Yekdangi Faculty Member Pirouz Shakeri Asri Mohamad Shamsolahi illam university Ali Tehrani ASRi Marziea Ghadami Kohestani Kimiazym Journal Article 2025 10 14 ABSTRACT<br />Background and objectives: Ensiling high-moisture forages is one of the most effective methods for preserving feed for ruminants animals. Corn forage, due to its high starch content and low buffering capacity, is considered a suitable candidate for silage production. However, excessive moisture during ensiling can promote the growth of undesirable bacteria, increase effluent production, reduce nutritional quality, and contribute to environmental pollution. The use of organic acid and bacterial additives is among the practical strategies to improve the ensiling process, minimize nutrient losses, and enhance the aerobic stability of the final product.<br />Materials and Methods: Experimental silages were 1- corn silage without OA and BA (Con), 2- corn silage contained 1 L/ton fresh forage of OA with 1:6 dilution rate (OA-1), 3- corn silage contained 1 L/ton fresh forage of OA with 1:8 dilution rate (OA-2), 4- corn silage contained Lacobacillus plantarum and Pediococcus acidilactici at 100000 cfu/g fresh forage (BA-1) and 5- corn silage contained Lacobacillus plantarum and Pediococcus acidilactici at 200000 cfu/g fresh forage (BA-2). All silos were opened after 90 d ensiling and their characteristics were assessed. <br />Results: The Con silage gad higher DM and lower crude fat (CF) and starch contents than other silages (P<0.01). Crude protein (CP), NDF and acid detergent fiber (ADF) contents of BA-1 were higher compared to other silages (P<0.01). The Con silage had lower pH and NH3-N content than other silages (P<0.01). The highest acetate and propionate contents were observed in BA-1 and OA-1, respectively (P<0.01). The content of butyrate and lactate were higher in OA-1 silage compared to other silages (P<0.01). Digestibility of DM was higher in OA-1 and BA-2 silages than others (P<0.01). The BA-2 silage had higher NDF digestibility compared to other silages (P<0.01). Effluent production did not influence by OA and BA (P>0.05). The highest fleig point was observed in Con silage (P<0.01). <br />Conclusion: In conclusion, according to these results addition of Lacobacillus plantarum and Pediococcus acidilactici at 200000 cfu/g fresh forgae compared to it at 100000 cfu/g fresh forgae and different levels of OA had better effects on quality and nutrient digestibility of corn silage.<br />Materials and Methods: Experimental silages were 1- corn silage without OA and BA (Con), 2- corn silage contained 1 L/ton fresh forage of OA with 1:6 dilution rate (OA-1), 3- corn silage contained 1 L/ton fresh forage of OA with 1:8 dilution rate (OA-2), 4- corn silage contained Lacobacillus plantarum and Pediococcus acidilactici at 100000 cfu/g fresh forage (BA-1) and 5- corn silage contained Lacobacillus plantarum and Pediococcus acidilactici at 200000 cfu/g fresh forage (BA-2). All silos were opened after 90 d ensiling and their characteristics were assessed. <br />Results: The Con silage gad higher DM and lower crude fat (CF) and starch contents than other silages (P<0.01). Crude protein (CP), NDF and acid detergent fiber (ADF) contents of BA-1 were higher compared to other silages (P<0.01). The Con silage had lower pH and ammonia-N content than other silages (P<0.01). The highest acetate and propionate contents were observed in BA-1 and OA-1, respectively (P<0.01). The content of butyrate and lactate were higher in OA-1 silage compared to other silages (P<0.01). Digestibility of DM was higher in OA-1 and BA-2 silages than others (P<0.01). The BA-2 silage had higher NDF digestibility compared to other silages (P<0.01). <br />Conclusion: In conclusion, according to these results addition of Lacobacillus plantarum and Pediococcus acidilactici at 200000 cfu/g fresh forgae compared to it at 100000 cfu/g fresh forgae and different levels of OA had better effects on quality and nutrient digestibility of corn silage. ABSTRACT<br />Background and objectives: Ensiling high-moisture forages is one of the most effective methods for preserving feed for ruminants animals. Corn forage, due to its high starch content and low buffering capacity, is considered a suitable candidate for silage production. However, excessive moisture during ensiling can promote the growth of undesirable bacteria, increase effluent production, reduce nutritional quality, and contribute to environmental pollution. The use of organic acid and bacterial additives is among the practical strategies to improve the ensiling process, minimize nutrient losses, and enhance the aerobic stability of the final product.<br />Materials and Methods: Experimental silages were 1- corn silage without OA and BA (Con), 2- corn silage contained 1 L/ton fresh forage of OA with 1:6 dilution rate (OA-1), 3- corn silage contained 1 L/ton fresh forage of OA with 1:8 dilution rate (OA-2), 4- corn silage contained Lacobacillus plantarum and Pediococcus acidilactici at 100000 cfu/g fresh forage (BA-1) and 5- corn silage contained Lacobacillus plantarum and Pediococcus acidilactici at 200000 cfu/g fresh forage (BA-2). All silos were opened after 90 d ensiling and their characteristics were assessed. <br />Results: The Con silage gad higher DM and lower crude fat (CF) and starch contents than other silages (P<0.01). Crude protein (CP), NDF and acid detergent fiber (ADF) contents of BA-1 were higher compared to other silages (P<0.01). The Con silage had lower pH and NH3-N content than other silages (P<0.01). The highest acetate and propionate contents were observed in BA-1 and OA-1, respectively (P<0.01). The content of butyrate and lactate were higher in OA-1 silage compared to other silages (P<0.01). Digestibility of DM was higher in OA-1 and BA-2 silages than others (P<0.01). The BA-2 silage had higher NDF digestibility compared to other silages (P<0.01). Effluent production did not influence by OA and BA (P>0.05). The highest fleig point was observed in Con silage (P<0.01). <br />Conclusion: In conclusion, according to these results addition of Lacobacillus plantarum and Pediococcus acidilactici at 200000 cfu/g fresh forgae compared to it at 100000 cfu/g fresh forgae and different levels of OA had better effects on quality and nutrient digestibility of corn silage.<br />Materials and Methods: Experimental silages were 1- corn silage without OA and BA (Con), 2- corn silage contained 1 L/ton fresh forage of OA with 1:6 dilution rate (OA-1), 3- corn silage contained 1 L/ton fresh forage of OA with 1:8 dilution rate (OA-2), 4- corn silage contained Lacobacillus plantarum and Pediococcus acidilactici at 100000 cfu/g fresh forage (BA-1) and 5- corn silage contained Lacobacillus plantarum and Pediococcus acidilactici at 200000 cfu/g fresh forage (BA-2). All silos were opened after 90 d ensiling and their characteristics were assessed. <br />Results: The Con silage gad higher DM and lower crude fat (CF) and starch contents than other silages (P<0.01). Crude protein (CP), NDF and acid detergent fiber (ADF) contents of BA-1 were higher compared to other silages (P<0.01). The Con silage had lower pH and ammonia-N content than other silages (P<0.01). The highest acetate and propionate contents were observed in BA-1 and OA-1, respectively (P<0.01). The content of butyrate and lactate were higher in OA-1 silage compared to other silages (P<0.01). Digestibility of DM was higher in OA-1 and BA-2 silages than others (P<0.01). The BA-2 silage had higher NDF digestibility compared to other silages (P<0.01). <br />Conclusion: In conclusion, according to these results addition of Lacobacillus plantarum and Pediococcus acidilactici at 200000 cfu/g fresh forgae compared to it at 100000 cfu/g fresh forgae and different levels of OA had better effects on quality and nutrient digestibility of corn silage. https://ejrr.gau.ac.ir/article_7710_8a47dfbbb9a8381600a00b297729c7db.pdf

Gorgan University of Agricultural Sciences and Natural Resources Journal of Ruminant Research 2345-4253 14 2 2026 08 23 The effect of vitamin and mineral supplementation injection in late pregnancy on performance and inflammatory indices of Dalagh ewes The effect of vitamin and mineral supplementation injection in late pregnancy on performance and inflammatory indices of Dalagh ewes 35 53 7711 10.22069/ejrr.2025.24229.2026 FA Hossein Emrani 1 Corresponding Author, Assistant professor, Biotechnology Research Department , Animal Science Research Institute of Iran, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran. E mail: h.emrani@areeo.ac.ir Mohammad Asadi Dept. animal sciences Gholamali Halako 3 Animal Science Research Department, Golestan Agriculture and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization, Gorgan, Iran Email: flowermino@gmail.com Ayda Teymouri 4Department of Animal Science, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran. E mail: teymouriayda2000@gmail.com Journal Article 2025 10 31 The transition period in ewes, which usually lasts three weeks before and three weeks after parturition, is one of the most critical physiological stages during the reproductive cycle. During this period, the ewes undergo extensive metabolic and hormonal changes that are necessary to prepare the body for parturition and the onset of lactation. Late pregnancy is associated with reduced feed intake and increased energy requirements due to rapid fetal growth and mammary gland development. This mismatch between energy intake and requirements leads to negative energy balance (NEB), which results in the mobilization of body fat stores and an increase in the concentration of non-esterified fatty acids (NEFA) and beta-hydroxybutyrate (BHBA) in the blood. These changes predispose to the development of ketosis, fatty liver, and preeclampsia in ewes. Negative energy balance also increases the production of reactive oxygen species (ROS) and oxidative stress, which weakens the immune system and increases the risk of inflammation and metabolic and infectious diseases. As a result, colostrum quality, first milk production and lamb growth are affected. In these conditions, vitamins and minerals, especially those with antioxidant properties, play an important role in reducing oxidative stress and maintaining immune health. Adequate and balanced supply of these micronutrients during the transition period improves the immune response, reduces the incidence of metabolic disorders and increases production performance. Therefore, targeted nutrition rich in antioxidants during the transition period is crucial for the health and productivity of ewes. <br />Materials and Methods: The present study was conducted to investigate the effect of vitamin and mineral supplementation injection in late pregnancy on performance, digestibility, milk production, and inflammatory indices of Dalagh ewes. The study used 40 Dalagh ewes with a mean weight of 42 ± 3.7 kg, which were divided into four treatments and ten replications in a completely randomized design in late pregnancy. The experimental treatments included: 1) control group (no vitamin and mineral supplementation injection), 2) ewes receiving injectable vitamin supplementation, 3) ewes receiving injectable mineral supplementation, and 4) ewes receiving simultaneously injectable vitamin and mineral supplementation. To determine the amount of dry matter consumed daily, the after-feed was collected and weighed before the new feed was fed. The amount of milk production and composition were measured and recorded. To measure the digestibility of the ewes, fecal and feed samples were collected in the last five days of the experiment to determine the digestibility of dry matter, organic matter, crude protein, ether extract and neutral detergent insoluble fiber. To measure inflammatory indices and blood antioxidant status,<br />Results: The results of the effect of mineral and vitamin injection in late pregnancy showed that minerals and vitamins improved the final weight and feed consumption of ewes after calving, and the highest feed consumption was for ewes injected with minerals and vitamins simultaneously (P<0.05). Also, minerals and vitamins improved the digestibility of dry matter and neutral detergent insoluble fiber in ewes (P<0.05). On the other hand, minerals and vitamins had no effect on the amount of milk production, protein, fat, and lactose in ewes. On the other hand, mineral and vitamin injection reduced BHBA, NEFA, ROS, and OSI and increased SAC in ewes at all three times (P<0.05). The greatest improvement in NEFA at all times, ROS before calving and on the day of calving, and SAC and OSI before calving were related to ewes receiving minerals and vitamins simultaneously.<br />Conclusion: Considering the improvement in weight performance, digestibility, and inflammatory markers of ewes, simultaneous injection of minerals and vitamins is recommended for ewes in late pregnancy. The transition period in ewes, which usually lasts three weeks before and three weeks after parturition, is one of the most critical physiological stages during the reproductive cycle. During this period, the ewes undergo extensive metabolic and hormonal changes that are necessary to prepare the body for parturition and the onset of lactation. Late pregnancy is associated with reduced feed intake and increased energy requirements due to rapid fetal growth and mammary gland development. This mismatch between energy intake and requirements leads to negative energy balance (NEB), which results in the mobilization of body fat stores and an increase in the concentration of non-esterified fatty acids (NEFA) and beta-hydroxybutyrate (BHBA) in the blood. These changes predispose to the development of ketosis, fatty liver, and preeclampsia in ewes. Negative energy balance also increases the production of reactive oxygen species (ROS) and oxidative stress, which weakens the immune system and increases the risk of inflammation and metabolic and infectious diseases. As a result, colostrum quality, first milk production and lamb growth are affected. In these conditions, vitamins and minerals, especially those with antioxidant properties, play an important role in reducing oxidative stress and maintaining immune health. Adequate and balanced supply of these micronutrients during the transition period improves the immune response, reduces the incidence of metabolic disorders and increases production performance. Therefore, targeted nutrition rich in antioxidants during the transition period is crucial for the health and productivity of ewes. <br />Materials and Methods: The present study was conducted to investigate the effect of vitamin and mineral supplementation injection in late pregnancy on performance, digestibility, milk production, and inflammatory indices of Dalagh ewes. The study used 40 Dalagh ewes with a mean weight of 42 ± 3.7 kg, which were divided into four treatments and ten replications in a completely randomized design in late pregnancy. The experimental treatments included: 1) control group (no vitamin and mineral supplementation injection), 2) ewes receiving injectable vitamin supplementation, 3) ewes receiving injectable mineral supplementation, and 4) ewes receiving simultaneously injectable vitamin and mineral supplementation. To determine the amount of dry matter consumed daily, the after-feed was collected and weighed before the new feed was fed. The amount of milk production and composition were measured and recorded. To measure the digestibility of the ewes, fecal and feed samples were collected in the last five days of the experiment to determine the digestibility of dry matter, organic matter, crude protein, ether extract and neutral detergent insoluble fiber. To measure inflammatory indices and blood antioxidant status,<br />Results: The results of the effect of mineral and vitamin injection in late pregnancy showed that minerals and vitamins improved the final weight and feed consumption of ewes after calving, and the highest feed consumption was for ewes injected with minerals and vitamins simultaneously (P<0.05). Also, minerals and vitamins improved the digestibility of dry matter and neutral detergent insoluble fiber in ewes (P<0.05). On the other hand, minerals and vitamins had no effect on the amount of milk production, protein, fat, and lactose in ewes. On the other hand, mineral and vitamin injection reduced BHBA, NEFA, ROS, and OSI and increased SAC in ewes at all three times (P<0.05). The greatest improvement in NEFA at all times, ROS before calving and on the day of calving, and SAC and OSI before calving were related to ewes receiving minerals and vitamins simultaneously.<br />Conclusion: Considering the improvement in weight performance, digestibility, and inflammatory markers of ewes, simultaneous injection of minerals and vitamins is recommended for ewes in late pregnancy. https://ejrr.gau.ac.ir/article_7711_491774046b8f5bb3bd18fc14a2038442.pdf

Gorgan University of Agricultural Sciences and Natural Resources Journal of Ruminant Research 2345-4253 14 2 2026 08 23 Study of Leptin Gene Expression in Muscle and Liver Tissue of Fattening Lambs under the Influence of Dietary Zinc-Methionine Organic Supplement and Calcium Salt of Flaxseed Oil Study of Leptin Gene Expression in Muscle and Liver Tissue of Fattening Lambs under the Influence of Dietary Zinc-Methionine Organic Supplement and Calcium Salt of Flaxseed Oil 55 70 7712 10.22069/ejrr.2026.24262.2028 FA Mahmood Nazari Department of Animal Sciences, Faculty of Animal Sciences and Food Technology, Khuzestan University of Agriculture and Natural Resources Seiedeh Zahra Badvi Msc student of Animal genetic and Breeding, Faculty of Animal Science and Food Technology, Agricultural sciences and Natural Resources University of Khuzestan ُSepideh Rostami Ph. D graduate of Animal genetic and Breeding, Faculty of Animal Science and Food Technology, Agricultural sciences and Natural Resources University of Khuzestan Journal Article 2025 11 08 Objective: Sheep production, as a fundamental component of the livestock industry, plays a vital role in supplying animal protein worldwide. Growth efficiency and productive performance are key factors determining profitability in this sector. The leptin–melanocortin system (LMS) acts as a major regulatory pathway that governs energy balance, appetite, and body metabolism. The leptin gene, a central element of this system, influences feed intake, energy homeostasis, and lipid metabolism, thereby affecting growth and nutritional status in animals. Recent studies have demonstrated that supplementing diets with unsaturated fatty acid sources such as calcium salts of flaxseed oil can enhance energy utilization and modulate the expression of growth-related genes, ultimately improving animal performance. Moreover, the organic zinc–methionine complex plays a significant role in protein metabolism, enzyme activity, and the regulation of growth and energy-associated hormones, contributing to improved daily weight gain and feed efficiency in ruminants. Therefore, this study aims to evaluate the combined effects of dietary supplementation with calcium salts of flaxseed oil and organic zinc–methionine on leptin gene expression in the liver and muscle tissues of sheep.<br />Method: In this study, forty-four male Arabic lambs aged two to three months were used in a 2×2 factorial experiment arranged in a completely randomized design. The experiment consisted of four dietary treatments with eleven replicates per group: (1) a basal diet without any supplement (control), (2) the basal diet supplemented with 0.083% zinc–methionine (equivalent to 100 mg Zn/kg DM), (3) the basal diet containing 3% calcium salts of flaxseed oil, and (4) the basal diet including both 3% calcium salts of flaxseed oil and 0.083% zinc–methionine. At the end of the 94-day feeding trial, three lambs from each treatment were slaughtered, and liver and muscle samples were collected for leptin gene expression analysis. The collected tissues were immediately frozen in liquid nitrogen and stored at −80°C until further molecular assays. Total RNA extraction and cDNA synthesis were performed according to the manufacturer’s protocols of commercial kits. Leptin gene expression was quantified by the real-time qPCR, with GAPDH used as the reference gene. Relative gene expression levels were calculated using the 2−ΔΔCT method. The obtained data were statistically analyzed using SAS software (version 9.4), and treatment means were compared by the LSD test.<br />Results: The results indicated that dietary supplementation with calcium salts of flaxseed oil significantly downregulated leptin gene expression in the liver (P < 0.01), while no significant effect was observed in muscle tissue (P > 0.05). In contrast, the inclusion of zinc–methionine significantly increased leptin gene expression in both liver and muscle tissues (P < 0.01). Moreover, the combined supplementation of zinc–methionine and calcium salts of flaxseed oil did not cause any significant alteration in leptin gene expression compared with the control group (P > 0.05).<br />Conclusions: The overall findings of this study demonstrate that the type and combination of dietary supplements can markedly influence the genetic regulation of energy metabolism in sheep. The observed downregulation of leptin gene expression following omega-3 fatty acid supplementation, contrasted with its upregulation upon zinc–methionine administration, highlights the critical role of nutritional balance in modulating molecular pathways involved in growth and metabolism. Increasing leptin gene expression with zinc-methionine supplementation may help maintain energy balance and prevent excessive fat storage. At the same time, the calcium salt of flaxseed oil may promote fat storage by reducing leptin levels. The interaction between these two nutritional factors underscores the complexity of dietary regulation at the genetic and physiological levels and emphasizes the need for further investigations at molecular and systemic scales to better elucidate the underlying regulatory mechanisms. Objective: Sheep production, as a fundamental component of the livestock industry, plays a vital role in supplying animal protein worldwide. Growth efficiency and productive performance are key factors determining profitability in this sector. The leptin–melanocortin system (LMS) acts as a major regulatory pathway that governs energy balance, appetite, and body metabolism. The leptin gene, a central element of this system, influences feed intake, energy homeostasis, and lipid metabolism, thereby affecting growth and nutritional status in animals. Recent studies have demonstrated that supplementing diets with unsaturated fatty acid sources such as calcium salts of flaxseed oil can enhance energy utilization and modulate the expression of growth-related genes, ultimately improving animal performance. Moreover, the organic zinc–methionine complex plays a significant role in protein metabolism, enzyme activity, and the regulation of growth and energy-associated hormones, contributing to improved daily weight gain and feed efficiency in ruminants. Therefore, this study aims to evaluate the combined effects of dietary supplementation with calcium salts of flaxseed oil and organic zinc–methionine on leptin gene expression in the liver and muscle tissues of sheep.<br />Method: In this study, forty-four male Arabic lambs aged two to three months were used in a 2×2 factorial experiment arranged in a completely randomized design. The experiment consisted of four dietary treatments with eleven replicates per group: (1) a basal diet without any supplement (control), (2) the basal diet supplemented with 0.083% zinc–methionine (equivalent to 100 mg Zn/kg DM), (3) the basal diet containing 3% calcium salts of flaxseed oil, and (4) the basal diet including both 3% calcium salts of flaxseed oil and 0.083% zinc–methionine. At the end of the 94-day feeding trial, three lambs from each treatment were slaughtered, and liver and muscle samples were collected for leptin gene expression analysis. The collected tissues were immediately frozen in liquid nitrogen and stored at −80°C until further molecular assays. Total RNA extraction and cDNA synthesis were performed according to the manufacturer’s protocols of commercial kits. Leptin gene expression was quantified by the real-time qPCR, with GAPDH used as the reference gene. Relative gene expression levels were calculated using the 2−ΔΔCT method. The obtained data were statistically analyzed using SAS software (version 9.4), and treatment means were compared by the LSD test.<br />Results: The results indicated that dietary supplementation with calcium salts of flaxseed oil significantly downregulated leptin gene expression in the liver (P < 0.01), while no significant effect was observed in muscle tissue (P > 0.05). In contrast, the inclusion of zinc–methionine significantly increased leptin gene expression in both liver and muscle tissues (P < 0.01). Moreover, the combined supplementation of zinc–methionine and calcium salts of flaxseed oil did not cause any significant alteration in leptin gene expression compared with the control group (P > 0.05).<br />Conclusions: The overall findings of this study demonstrate that the type and combination of dietary supplements can markedly influence the genetic regulation of energy metabolism in sheep. The observed downregulation of leptin gene expression following omega-3 fatty acid supplementation, contrasted with its upregulation upon zinc–methionine administration, highlights the critical role of nutritional balance in modulating molecular pathways involved in growth and metabolism. Increasing leptin gene expression with zinc-methionine supplementation may help maintain energy balance and prevent excessive fat storage. At the same time, the calcium salt of flaxseed oil may promote fat storage by reducing leptin levels. The interaction between these two nutritional factors underscores the complexity of dietary regulation at the genetic and physiological levels and emphasizes the need for further investigations at molecular and systemic scales to better elucidate the underlying regulatory mechanisms. https://ejrr.gau.ac.ir/article_7712_3d32ace58adfc34f7e32f872145e6af2.pdf

Gorgan University of Agricultural Sciences and Natural Resources Journal of Ruminant Research 2345-4253 14 2 2026 08 23 Effects of Different Fat Sources on Performance, Nutrient Digestibility, and Liver Enzymes in Transition Ewes and Blood Metabolites of Their Lambs Effects of Different Fat Sources on Performance, Nutrient Digestibility, and Liver Enzymes in Transition Ewes and Blood Metabolites of Their Lambs 71 88 7713 10.22069/ejrr.2026.24264.2029 FA Babak Kiyarsh PhD Student in Animal Nutrition, Department of Animal Sciences, Faculty of Agriculture, Islamic Azad University, Khorsgan Branch, Isfahan, Iran Amir Davar Foroozandeh Shahraki Department of Animal Scince,,Faculty of Agriculture, Isfahan, Oran, Sayed Ali Tabeidian, Associate Professor, Department of Animal Sciences, Faculty of Agriculture, Islamic Azad University, Khorsgan Branch, Isfahan, Iran Gholamreza Ghalamkari Associate Professor, Animal Physiology, Faculty of Agriculture, Khorsgan Branch, Department of Animal Sciences, Islamic Azad University, Isfahan, Iran Mahshid Defaei Assistant Professor, Department of Biochemistry, Faculty of Biology, Islamic Azad University, Khorsgan Branch, Isfahan, Iran Journal Article 2025 11 09 Background and Objective: The transition period in ewes (3 weeks prepartum to 3 weeks postpartum) is characterized by profound metabolic changes and reduced feed intake, leading to negative energy balance, increased non-esterified fatty acids (NEFA), ketone bodies, and oxidative stress. This condition elevates the risk of ketosis, fatty liver, and impaired immunity. Dietary fat supplementation, as a nutritional strategy, can improve metabolic status by providing a dense energy source and reducing body reserve mobilization; however, its effects on digestion, rumen fermentation, and oxidative stress depend on the type of fat (protected saturated vs. unsaturated). Therefore, the objective of this study was to evaluate the effects of different fat sources on nutrient digestibility, liver enzymes in transition ewes, and selected blood parameters of newborn lambs.<br />Materials and Methods: The experiment was conducted on 60 pregnant ewes (one month before lambing) at the research farm of Islamic Azad University, Khorasgan Branch. Ewes were randomly assigned, based on body weight and expected lambing date, to five treatments (12 replicates) in a completely randomized design: (1) control (no added fat), (2) 3% calcium salts of omega-9 fatty acids, (3) 3% tallow, (4) 3% canola oil, and (5) 3% rumen-protected saturated fatty acid powder. Diets were formulated according to NRC (2007) and offered as TMR from 21 days prepartum to 21 days postpartum. Blood samples (one week before and three weeks after lambing) were collected to determine liver enzymes. Digestibility was estimated using acid-insoluble ash as an internal marker.<br />Results: Supplementation with different fat sources had no significant effect on body weight, dry matter intake, or body condition score of the ewes. Feeding rumen-protected saturated fatty acid powder significantly increased ether extract digestibility compared with canola oil and the control group in both pre- and postpartum periods, and showed higher values than animal fat postpartum (P < 0.05). This treatment also improved acid detergent fiber digestibility compared with animal fat and canola oil before lambing and compared with canola oil after lambing. Neutral detergent fiber digestibility was affected by treatments only postpartum, with higher values in the protected saturated fat group than in the canola oil and omega-9 treatments (P < 0.05), while dry matter and crude protein digestibility did not differ among treatments. Liver enzyme activities were influenced by dietary fat source. ALT and AST levels in ewes fed canola oil and animal fat increased significantly postpartum (P < 0.05), whereas values in ewes receiving calcium salts of omega-9 and protected saturated fat remained within the normal range. ALP activity was also affected in both sampling periods, with the highest values observed in the omega-9 and animal fat groups. The type of dietary fat significantly affected blood parameters of newborn lambs (P < 0.05). Lambs born to ewes fed protected saturated fat and omega-9 fatty acids had higher concentrations of glucose, cholesterol, total protein, and immunoglobulin G compared with the control group. Cholesterol, total protein, and IgG concentrations in these treatments were also higher than in the animal fat group, while albumin concentration did not differ significantly among treatments.<br />Conclusion: Overall, supplementation of transition ewe diets with rumen-protected saturated fatty acid powder improved ether extract digestibility compared with canola oil and the control group and maintained more stable liver enzyme activity postpartum compared with canola oil and animal fat. Although not all traits differed significantly among treatments, these findings suggest that protected saturated fat may contribute to improved digestibility and metabolic status during the transition period compared with some other fat sources. Background and Objective: The transition period in ewes (3 weeks prepartum to 3 weeks postpartum) is characterized by profound metabolic changes and reduced feed intake, leading to negative energy balance, increased non-esterified fatty acids (NEFA), ketone bodies, and oxidative stress. This condition elevates the risk of ketosis, fatty liver, and impaired immunity. Dietary fat supplementation, as a nutritional strategy, can improve metabolic status by providing a dense energy source and reducing body reserve mobilization; however, its effects on digestion, rumen fermentation, and oxidative stress depend on the type of fat (protected saturated vs. unsaturated). Therefore, the objective of this study was to evaluate the effects of different fat sources on nutrient digestibility, liver enzymes in transition ewes, and selected blood parameters of newborn lambs.<br />Materials and Methods: The experiment was conducted on 60 pregnant ewes (one month before lambing) at the research farm of Islamic Azad University, Khorasgan Branch. Ewes were randomly assigned, based on body weight and expected lambing date, to five treatments (12 replicates) in a completely randomized design: (1) control (no added fat), (2) 3% calcium salts of omega-9 fatty acids, (3) 3% tallow, (4) 3% canola oil, and (5) 3% rumen-protected saturated fatty acid powder. Diets were formulated according to NRC (2007) and offered as TMR from 21 days prepartum to 21 days postpartum. Blood samples (one week before and three weeks after lambing) were collected to determine liver enzymes. Digestibility was estimated using acid-insoluble ash as an internal marker.<br />Results: Supplementation with different fat sources had no significant effect on body weight, dry matter intake, or body condition score of the ewes. Feeding rumen-protected saturated fatty acid powder significantly increased ether extract digestibility compared with canola oil and the control group in both pre- and postpartum periods, and showed higher values than animal fat postpartum (P < 0.05). This treatment also improved acid detergent fiber digestibility compared with animal fat and canola oil before lambing and compared with canola oil after lambing. Neutral detergent fiber digestibility was affected by treatments only postpartum, with higher values in the protected saturated fat group than in the canola oil and omega-9 treatments (P < 0.05), while dry matter and crude protein digestibility did not differ among treatments. Liver enzyme activities were influenced by dietary fat source. ALT and AST levels in ewes fed canola oil and animal fat increased significantly postpartum (P < 0.05), whereas values in ewes receiving calcium salts of omega-9 and protected saturated fat remained within the normal range. ALP activity was also affected in both sampling periods, with the highest values observed in the omega-9 and animal fat groups. The type of dietary fat significantly affected blood parameters of newborn lambs (P < 0.05). Lambs born to ewes fed protected saturated fat and omega-9 fatty acids had higher concentrations of glucose, cholesterol, total protein, and immunoglobulin G compared with the control group. Cholesterol, total protein, and IgG concentrations in these treatments were also higher than in the animal fat group, while albumin concentration did not differ significantly among treatments.<br />Conclusion: Overall, supplementation of transition ewe diets with rumen-protected saturated fatty acid powder improved ether extract digestibility compared with canola oil and the control group and maintained more stable liver enzyme activity postpartum compared with canola oil and animal fat. Although not all traits differed significantly among treatments, these findings suggest that protected saturated fat may contribute to improved digestibility and metabolic status during the transition period compared with some other fat sources. https://ejrr.gau.ac.ir/article_7713_ef90a480eda720ca88f0977e3104960f.pdf

Gorgan University of Agricultural Sciences and Natural Resources Journal of Ruminant Research 2345-4253 14 2 2026 08 23 Comparison of the effect of adding licorice extract (Glycyrrhiza glabra) and nanoliposomal licorice extract to acidotic diets on rumen parameters in vitro Comparison of the effect of adding licorice extract (Glycyrrhiza glabra) and nanoliposomal licorice extract to acidotic diets on rumen parameters in vitro 89 109 7714 10.22069/ejrr.2026.24350.2033 FA Milad Maghsoudi-Parsa Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran Ghader Jalilzadeh Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran Bahram Dalirnaghadeh Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran Ehsan Anasori Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran Behzad Asadnezhad Department of Animal Science, Faculty of Agriculture, University of Urmia, Urmia, Iran Masoud Ahmadnejad Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Razi University, Kermanshah, Iran Journal Article 2025 12 05 Background and Objective:Rumen acidosis is one of the most important nutritional disorders in ruminants, characterized by a decline in ruminal pH, epithelial damage, disruption of fermentative pathways, reduced nutrient absorption, and increased methane emissions. Subacute ruminal acidosis (SARA) is highly prevalent in dairy and feedlot cattle and results in significant economic losses due to reduced milk yield, poor growth performance, veterinary costs, and energy lost through inefficient fermentation. With increasing restrictions on the use of antibiotic feed additives, plant-based additives such as Glycyrrhiza glabra (licorice) have gained attention due to their antimicrobial, anti-inflammatory, and fermentation-modulating properties. However, many plant extracts have limitations such as low solubility, instability, and poor bioavailability. Nanoliposome technology offers a promising strategy to improve stability, controlled release, and bioefficacy of bioactive compounds. This study aimed to evaluate the effects of free and nanoliposome-encapsulated licorice extract on ruminal fermentation parameters, methane production, protozoal population, and pH stabilization under normal and acidosis-induced conditions.<br />Materials and Methods:This in vitro study was conducted using rumen fluid collected from fistulated Holstein bulls. Nanoliposomes were synthesized via thin-film hydration and loaded with standardized commercial licorice extract containing 19–24% glycyrrhizin. A basal diet with a forage-to-concentrate ratio of 70:30 was used, with three treatments: basal diet alone, basal diet plus free licorice extract, and basal diet plus nanoliposome-encapsulated extract. Buffered rumen fluid was incubated at 39 °C under continuous CO₂. Gas production was recorded at multiple intervals up to 120 h. After 24 h of incubation, ruminal pH, protozoal counts, volatile fatty acids (VFA), methane production, digestibility, fermentable organic matter, and metabolizable energy were measured. An acidosis challenge test was performed by adding dextrose to induce rapid fermentation. Data were analyzed using the mixed model procedure of SAS and Tukey’s test for mean comparison.<br />Findings:Nanoliposomes exhibited a uniform spherical morphology with a hydrodynamic diameter of 122.2 nm and a low PDI (0.013), indicating high stability and homogeneity. Both free and nanoliposome licorice extract reduced lag time and increased early-stage fermentation rate, while decreasing gas production during late fermentation (48–120 h). Treatments increased butyrate concentration while decreasing acetate and propionate, resulting in a lower total VFA concentration and reduced methane production. The nanoliposome treatment caused a greater reduction in protozoal population compared with free extract and maintained a significantly higher ruminal pH, particularly under acidosis-induced conditions. Ammonia-nitrogen concentrations and substrate degradability remained within optimal ranges, indicating no adverse effects on overall microbial activity. In the acidosis challenge, nanoliposome licorice extract more effectively prevented severe pH decline and showed superior buffering and stabilization capacity, while supporting adequate microbial fermentation.<br />Conclusion:Encapsulation of licorice extract in nanoliposomes enhanced its functionality in modulating rumen fermentation, reducing methane emission, lowering protozoal counts, and maintaining ruminal pH during acidosis. Controlled release and improved stability of the encapsulated extract provided more sustained biological effects compared with the free form. These findings suggest that nanoliposome-encapsulated licorice extract can serve as an effective natural additive for mitigating SARA, improving nutrient utilization, enhancing environmental sustainability, and potentially reducing reliance on antibiotic feed additives in ruminant nutrition. Background and Objective:Rumen acidosis is one of the most important nutritional disorders in ruminants, characterized by a decline in ruminal pH, epithelial damage, disruption of fermentative pathways, reduced nutrient absorption, and increased methane emissions. Subacute ruminal acidosis (SARA) is highly prevalent in dairy and feedlot cattle and results in significant economic losses due to reduced milk yield, poor growth performance, veterinary costs, and energy lost through inefficient fermentation. With increasing restrictions on the use of antibiotic feed additives, plant-based additives such as Glycyrrhiza glabra (licorice) have gained attention due to their antimicrobial, anti-inflammatory, and fermentation-modulating properties. However, many plant extracts have limitations such as low solubility, instability, and poor bioavailability. Nanoliposome technology offers a promising strategy to improve stability, controlled release, and bioefficacy of bioactive compounds. This study aimed to evaluate the effects of free and nanoliposome-encapsulated licorice extract on ruminal fermentation parameters, methane production, protozoal population, and pH stabilization under normal and acidosis-induced conditions.<br />Materials and Methods:This in vitro study was conducted using rumen fluid collected from fistulated Holstein bulls. Nanoliposomes were synthesized via thin-film hydration and loaded with standardized commercial licorice extract containing 19–24% glycyrrhizin. A basal diet with a forage-to-concentrate ratio of 70:30 was used, with three treatments: basal diet alone, basal diet plus free licorice extract, and basal diet plus nanoliposome-encapsulated extract. Buffered rumen fluid was incubated at 39 °C under continuous CO₂. Gas production was recorded at multiple intervals up to 120 h. After 24 h of incubation, ruminal pH, protozoal counts, volatile fatty acids (VFA), methane production, digestibility, fermentable organic matter, and metabolizable energy were measured. An acidosis challenge test was performed by adding dextrose to induce rapid fermentation. Data were analyzed using the mixed model procedure of SAS and Tukey’s test for mean comparison.<br />Findings:Nanoliposomes exhibited a uniform spherical morphology with a hydrodynamic diameter of 122.2 nm and a low PDI (0.013), indicating high stability and homogeneity. Both free and nanoliposome licorice extract reduced lag time and increased early-stage fermentation rate, while decreasing gas production during late fermentation (48–120 h). Treatments increased butyrate concentration while decreasing acetate and propionate, resulting in a lower total VFA concentration and reduced methane production. The nanoliposome treatment caused a greater reduction in protozoal population compared with free extract and maintained a significantly higher ruminal pH, particularly under acidosis-induced conditions. Ammonia-nitrogen concentrations and substrate degradability remained within optimal ranges, indicating no adverse effects on overall microbial activity. In the acidosis challenge, nanoliposome licorice extract more effectively prevented severe pH decline and showed superior buffering and stabilization capacity, while supporting adequate microbial fermentation.<br />Conclusion:Encapsulation of licorice extract in nanoliposomes enhanced its functionality in modulating rumen fermentation, reducing methane emission, lowering protozoal counts, and maintaining ruminal pH during acidosis. Controlled release and improved stability of the encapsulated extract provided more sustained biological effects compared with the free form. These findings suggest that nanoliposome-encapsulated licorice extract can serve as an effective natural additive for mitigating SARA, improving nutrient utilization, enhancing environmental sustainability, and potentially reducing reliance on antibiotic feed additives in ruminant nutrition. https://ejrr.gau.ac.ir/article_7714_d89e90cf1c67c1e0e359cc3d47126131.pdf

Gorgan University of Agricultural Sciences and Natural Resources Journal of Ruminant Research 2345-4253 14 2 2026 08 23 Effect of a Galactagogue Herbal Supplement on Lactation Performance, Blood Parameters, and Antioxidant Status in Lactating Holstein Cows Effect of a Galactagogue Herbal Supplement on Lactation Performance, Blood Parameters, and Antioxidant Status in Lactating Holstein Cows 111 129 7715 10.22069/ejrr.2026.24371.2035 FA Ali Moazeni Agriculture and Natural Resources Campus, University of Tehran, Karaj. Armin Towhidi Agriculture and Natural Resources Campus, University of Tehran, Karaj. Parisa Nadri Agriculture and Natural Resources Campus, University of Tehran, Karaj. Mehdi Zhandi Agriculture and Natural Resources Campus, University of Tehran, Karaj Abolfazl Zali Agriculture and Natural Resources Campus, University of Tehran, Karaj. Journal Article 2025 12 10 Background and Objective: Galactagogue herbal supplements containing licorice (Glycyrrhiza glabra), fennel (Foeniculum vulgare), and black seed (Nigella sativa) possess antioxidant, antimicrobial, and immune-modulating properties and are commonly used to enhance milk yield, improve milk quality, and alleviate heat stress in lactating cows. The present study was conducted to evaluate the effects of this herbal supplement on milk yield and composition, blood metabolites, and antioxidant status in Holstein dairy cows.<br />Materials and Methods: Sixteen multiparous lactating Holstein cows (third parity or higher) with an average body weight of 620 ± 15 kg were assigned to a completely randomized design and divided into two experimental groups: a control group fed a basal diet and a treatment group fed the basal diet supplemented with 150 g/day of the herbal supplement. The feeding trial lasted 49 days postpartum. Cows were milked at 08:00, 16:00, and 24:00 h, and milk yield was recorded daily. Milk samples were collected at the end of weeks 1 to 7 to determine milk composition. Blood samples were obtained before the morning feeding on days 0, 25, and 49 using EDTA-containing vacutainer tubes. Blood parameters including glucose, triglycerides, total protein, blood urea nitrogen, cholesterol, total bilirubin, direct bilirubin, albumin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) were analyzed. Data were analyzed using a repeated-measures statistical model.<br />Results: Milk yield was significantly higher in the treatment group (40.17 ± 0.403 kg/day) compared with the control group (38.57 ± 0.403 kg/day) (P < 0.001). During the experimental period, 4% fat-corrected milk (P = 0.002), lactose percentage (P = 0.0001), energy-corrected milk (P = 0.007), milk fat yield (P = 0.022), milk protein yield (P < 0.001), and total solids percentage (P = 0.0007) were significantly increased in the treatment group. At the end of the trial, milk protein percentage was significantly higher in the treated cows (2.92 ± 0.157%) than in the control cows (2.63 ± 0.157%), whereas no significant differences were observed for other milk components. The interaction between treatment and time resulted in a significant increase in dry matter intake in the treatment group. Among blood parameters, only the treatment × time interaction for alanine aminotransferase (ALT) was significant (P < 0.01), while other blood metabolites were not affected by the treatment. Furthermore, the herbal supplementation had no significant effect on antioxidant indices, including malondialdehyde, superoxide dismutase, glutathione peroxidase, and total antioxidant capacity. <br />Conclusion :The findings suggest that supplementation with the herbal additive during early lactation, accompanied by increased dry matter intake, may improve milk yield as well as selected milk components, particularly protein yield and percentage, fat yield, lactose percentage, and total solids in Holstein dairy cows. Background and Objective: Galactagogue herbal supplements containing licorice (Glycyrrhiza glabra), fennel (Foeniculum vulgare), and black seed (Nigella sativa) possess antioxidant, antimicrobial, and immune-modulating properties and are commonly used to enhance milk yield, improve milk quality, and alleviate heat stress in lactating cows. The present study was conducted to evaluate the effects of this herbal supplement on milk yield and composition, blood metabolites, and antioxidant status in Holstein dairy cows.<br />Materials and Methods: Sixteen multiparous lactating Holstein cows (third parity or higher) with an average body weight of 620 ± 15 kg were assigned to a completely randomized design and divided into two experimental groups: a control group fed a basal diet and a treatment group fed the basal diet supplemented with 150 g/day of the herbal supplement. The feeding trial lasted 49 days postpartum. Cows were milked at 08:00, 16:00, and 24:00 h, and milk yield was recorded daily. Milk samples were collected at the end of weeks 1 to 7 to determine milk composition. Blood samples were obtained before the morning feeding on days 0, 25, and 49 using EDTA-containing vacutainer tubes. Blood parameters including glucose, triglycerides, total protein, blood urea nitrogen, cholesterol, total bilirubin, direct bilirubin, albumin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) were analyzed. Data were analyzed using a repeated-measures statistical model.<br />Results: Milk yield was significantly higher in the treatment group (40.17 ± 0.403 kg/day) compared with the control group (38.57 ± 0.403 kg/day) (P < 0.001). During the experimental period, 4% fat-corrected milk (P = 0.002), lactose percentage (P = 0.0001), energy-corrected milk (P = 0.007), milk fat yield (P = 0.022), milk protein yield (P < 0.001), and total solids percentage (P = 0.0007) were significantly increased in the treatment group. At the end of the trial, milk protein percentage was significantly higher in the treated cows (2.92 ± 0.157%) than in the control cows (2.63 ± 0.157%), whereas no significant differences were observed for other milk components. The interaction between treatment and time resulted in a significant increase in dry matter intake in the treatment group. Among blood parameters, only the treatment × time interaction for alanine aminotransferase (ALT) was significant (P < 0.01), while other blood metabolites were not affected by the treatment. Furthermore, the herbal supplementation had no significant effect on antioxidant indices, including malondialdehyde, superoxide dismutase, glutathione peroxidase, and total antioxidant capacity. <br />Conclusion :The findings suggest that supplementation with the herbal additive during early lactation, accompanied by increased dry matter intake, may improve milk yield as well as selected milk components, particularly protein yield and percentage, fat yield, lactose percentage, and total solids in Holstein dairy cows. https://ejrr.gau.ac.ir/article_7715_bc4b1a054ad19d5676d4e926388e0584.pdf

Gorgan University of Agricultural Sciences and Natural Resources Journal of Ruminant Research 2345-4253 14 2 2026 08 23 Investigation of demographic indicators, breed identity, and production and reproductive performance of indigenous camel herds of Qom province Investigation of demographic indicators, breed identity, and production and reproductive performance of indigenous camel herds of Qom province 131 148 7716 10.22069/ejrr.2026.24409.2037 FA مهدی خجسته کی Animal Science Research Department, Agricultural and Natural Resources Research and Education Center of Qom Province, Agricultural Research, Education and Extension Organization, Qom, Iran. Morteza Keikha Saber Animal Science Research Department, Agricultural and Natural Resources Research and Education Center of Qom Province, Agricultural Research, Education and Extension Organization, Qom, Iran. Morteza Bitaraf Sani Animal Science Research Department, Agricultural and Natural Resources Research and Education Center of Yazd Province, Agricultural Research, Education and Extension Organization, Zazd, Iran. Ali Javanrouh Animal Science Research Institute, Agricultural Research, Education and Extension Organization, Karaj, Iran Nematollah Asadi Animal Science Research Institute, Agricultural Research, Education and Extension Organization, Karaj, Iran 0000-0002-2272-0020 Saber Jelokhni Niaraki Animal Science Research Institute, Agricultural Research, Education and Extension Organization, Karaj, Iran. Mohammad Yeganehparast Animal Science Research Department, Agricultural and Natural Resources Research and Education Center of Qom Province, Agricultural Research, Education and Extension Organization, Qom, Iran Majid Kalantar Neyestanaki Animal Science Research Department, Agricultural and Natural Resources Research and Education Center of Qom Province, Agricultural Research, Education and Extension Organization, Qom, Iran. Fariborz Sadeghi Expert, Nomadic Affairs Department, Qom Province, Qom, Iran Journal Article 2025 12 20 Background and Objective: <br />Conducting ecological studies and breeding capacity assessment on various livestock species, including camels, helps in proper planning and optimal utilization of the genetic capacity of native populations. In Qom province, there are currently approximately 8,000 camels being bred, and this province has a prominent position in the maintenance and breeding of single-humped camels and even dromedaries in the country, and in this respect, it is among the 10 leading provinces in the country. However, no study has been conducted to determine the status of native camel breeding. Therefore, with the aim of identifying and introducing the demographic indicators, racial identity, and production and reproductive performance of the indigenous camel population of Qom province and in order to plan the necessary to increase the production and economic efficiency of camel breeding herds, the present study was conducted in cooperation with the Deputy for Improving Livestock Production and the Nomadic Affairs Department of Qom province.<br />Materials and Methods: <br />The study population included all camel herders in Qom province. Based on the information provided by the Deputy for Improving Livestock Production, 36 herds out of a total of 181 camel herds in different parts of Qom province were visited in person. Herd identity information such as breed type, number of animals, age composition, sex ratio, nutritional management, health management, breeding system, determination of herd purity or non-purity status, as well as direct records of herd production and reproductive performance were collected over a 2-year period (from 2022 to 2024). After initial editing, it was analyzed using the descriptive procedure of SPSS (18) software, and the results were presented in the form of tables, graphs, and selected images along with an analysis of the status of the province's camel herds regarding the indicators under study.<br />Findings: <br />The results showed that all the camel farmers studied use the semi-open or captive method for raising camels and on average the herds spend 28.59±0.8 months of the year in the pasture. The Kolkohi camel is the dominant breed among the camel population of the province with a frequency of 90.07%, and the rest are mixed camels resulting from the crossing of Bactrian camels and Kolkohi or pure Bactrian camels. The herd size has increased from an average of 41.33±65.74 to 89.79±56.35 in the past 10 years, and the camel population in Qom province has more than doubled during this period. The average birth weight, 6-month weight, and 1-year weight of female Kalkohi camels were estimated to be 32.44; 118.14 and 179.28 kg, and for male camles were 38.40, 134.02 and 201.06 kg, respectively. The average daily milk production of camels was estimated to be 2.85±0.66 kg/day and their fleece weight was estimated to be 1.57±0.32 kg/year. The male and female camels’ abundance in the studied herds were 5.78±1.50 and 62.59±10.43% ,respectively. The calving percentage of camel herds was 44.72±8.06% and the interval between two their consecutive calvings was estimated to be 23.66±1.49 months. The frequency of deaths before one year of age and deaths of adult camels was estimated to be 34.90±5.66 and 2.31±1.81 percent, respectively.<br />Conclusion: <br />Low reproductive efficiency of the herd, excessive losses of camel calves, uncontrolled mixing of dromedary camels with Bactrian camels, and lack of pastures to provide camel feed are considered to be the most important challenges of camel husbandry in Qom province. To overcome these problems, firstly, it is recommended that the genetic conservation program of Kalohi camels is planed and then the improving program of reproduction efficiency of camel herds is developed in cooperation of agricultural -jahad organization and camel breeders of Qom province. Background and Objective: <br />Conducting ecological studies and breeding capacity assessment on various livestock species, including camels, helps in proper planning and optimal utilization of the genetic capacity of native populations. In Qom province, there are currently approximately 8,000 camels being bred, and this province has a prominent position in the maintenance and breeding of single-humped camels and even dromedaries in the country, and in this respect, it is among the 10 leading provinces in the country. However, no study has been conducted to determine the status of native camel breeding. Therefore, with the aim of identifying and introducing the demographic indicators, racial identity, and production and reproductive performance of the indigenous camel population of Qom province and in order to plan the necessary to increase the production and economic efficiency of camel breeding herds, the present study was conducted in cooperation with the Deputy for Improving Livestock Production and the Nomadic Affairs Department of Qom province.<br />Materials and Methods: <br />The study population included all camel herders in Qom province. Based on the information provided by the Deputy for Improving Livestock Production, 36 herds out of a total of 181 camel herds in different parts of Qom province were visited in person. Herd identity information such as breed type, number of animals, age composition, sex ratio, nutritional management, health management, breeding system, determination of herd purity or non-purity status, as well as direct records of herd production and reproductive performance were collected over a 2-year period (from 2022 to 2024). After initial editing, it was analyzed using the descriptive procedure of SPSS (18) software, and the results were presented in the form of tables, graphs, and selected images along with an analysis of the status of the province's camel herds regarding the indicators under study.<br />Findings: <br />The results showed that all the camel farmers studied use the semi-open or captive method for raising camels and on average the herds spend 28.59±0.8 months of the year in the pasture. The Kolkohi camel is the dominant breed among the camel population of the province with a frequency of 90.07%, and the rest are mixed camels resulting from the crossing of Bactrian camels and Kolkohi or pure Bactrian camels. The herd size has increased from an average of 41.33±65.74 to 89.79±56.35 in the past 10 years, and the camel population in Qom province has more than doubled during this period. The average birth weight, 6-month weight, and 1-year weight of female Kalkohi camels were estimated to be 32.44; 118.14 and 179.28 kg, and for male camles were 38.40, 134.02 and 201.06 kg, respectively. The average daily milk production of camels was estimated to be 2.85±0.66 kg/day and their fleece weight was estimated to be 1.57±0.32 kg/year. The male and female camels’ abundance in the studied herds were 5.78±1.50 and 62.59±10.43% ,respectively. The calving percentage of camel herds was 44.72±8.06% and the interval between two their consecutive calvings was estimated to be 23.66±1.49 months. The frequency of deaths before one year of age and deaths of adult camels was estimated to be 34.90±5.66 and 2.31±1.81 percent, respectively.<br />Conclusion: <br />Low reproductive efficiency of the herd, excessive losses of camel calves, uncontrolled mixing of dromedary camels with Bactrian camels, and lack of pastures to provide camel feed are considered to be the most important challenges of camel husbandry in Qom province. To overcome these problems, firstly, it is recommended that the genetic conservation program of Kalohi camels is planed and then the improving program of reproduction efficiency of camel herds is developed in cooperation of agricultural -jahad organization and camel breeders of Qom province. https://ejrr.gau.ac.ir/article_7716_00bb84ec6e2d61d91cf7c63127c25000.pdf