https://lst.uk.ac.ir/ Journal of Livestock Science and Technologies en daily 1 Thu, 01 Jul 2027 00:00:00 +0330 Thu, 01 Jul 2027 00:00:00 +0330 https://lst.uk.ac.ir/article_5233.html This study investigated the effects of heat stress and embryonic thermal manipulation (TM) on physiological, biochemical, and heat shock protein 70 (HSP70) gene expression in two broiler strains. A total of 400 fertilized eggs were incubated under either normal (37.8 °C) or thermally manipulated (39.5 °C; embryonic day 7 to 16) conditions. Post-hatch chicks were reared under either normal (25 °C) or heat stress (32 °C; from day 21 onward) conditions. The four experimental groups were defined as follows: Arian strain subjected to embryonic thermal manipulation but not to post-hatch heat stress (ATC); Arian strain without embryonic manipulation but subjected to post-hatch heat stress (ACH); Ross 308 strain subjected to embryonic thermal manipulation but not to post-hatch heat stress (RTC); and Ross 308 strain without embryonic manipulation but subjected to post-hatch heat stress (RCH). Blood parameters, lipid profiles, thyroid hormone (T3) levels, and HSP70 gene expression were analyzed at 42 days of age. Significant differences were observed in red and white blood cell counts, hematocrit, and T3 levels among treatments. RCH exhibited higher cholesterol (157.75±2.21) and LDL levels (59.67±2.88), whereas ATC showed higher T3 levels (8.85±0.32) and spleen weight (0.17±0.02). HSP70 gene expression was highest in RCH. The feed conversion ratio (FCR) was significantly lower in RCH (1.93±0.01). In conclusion, RCH demonstrated superior FCR under heat stress, while ATC modulate the thyroidal activity and immune responses following TM. Thermal manipulation during incubation reduced cholesterol, LDL, and HSP70 levels, enhancing thermotolerance. These findings highlighted the potential of TM to mitigate the heat stress effects, emphasizing the importance of strain-specific strategies for optimizing the broiler performance in heat-stressed environments. https://lst.uk.ac.ir/article_5438.html This experiment was conducted to investigate the effects of two levels of potato plant residues on performance, digestibility, rumination behavior, blood, and rumen parameters in dairy goats. For this purpose, eighteen 3-year old Saanen she goats with an average weight of 38.19±0.84 kg were used. This experiment was conducted in a completely randomized design with 3 treatments, including 0, 50, and 100% replacement of potato plant instead of straw, and 6 replications. The goats were housed in a group pen with free access to water. To evaluate the growth performance, the goats were weighed at the beginning and end of the period, and feed intake was recorded daily. Additionally, blood and ruminal fluid samples were collected on the final day of the experiment. There were no significant differences in eating, chewing, and resting behavior between the treatments, but, rumination behavior increased with consumption of potato plant residues (P<0.05). There were no significant changes (P>0.05) in blood total cholesterol, triglycerides, glucose, total protein, albumin, globulin, creatinine, and the albumin/globulin ratio with increasing the dietary potato plant content. Only blood urea levels showed a significant increase (P<0.05) with higher dietary potato plant content. Using different levels of potato plant residues increased the average daily weight gain, final body weight, feed intake, and improved feed conversion ratio (P=0.0001). Blood concentration of ammonia nitrogen increased significantly with increased consumption of potato plants. Based on the results of this experiment, potato plants can replace up to 100% of straw in goat feed. https://lst.uk.ac.ir/article_5290.html AbstractNative chickens in Iran play a crucial role in food security and rural livelihoods, yet their productivity is lower than that of commercial breeds. Crossbreeding with high-yielding lines has been proposed as a strategy to improve economic traits. This study aimed to evaluate head and neck characteristics in three genetic groups of Marandi, Leghorn, and their crossbreds. A total of 50 hens and 50 cocks from each group were assessed at maturity. Quantitative traits (head circumference, comb height and length, wattle length and width, beak length, and neck length) and qualitative traits (comb type, eye color, earlobe color, and beak color) were recorded. Data were analyzed using a general linear model with Tukey’s test for mean comparison. Results revealed diverse patterns of heterosis, with significant effects of both sex and trait type. Crossbreds showed increased neck and beak length, while comb and wattle size decreased in hens but increased in cocks. Qualitative traits displayed sex-dependent dominance patterns, particularly for eye and earlobe color. These findings highlight the potential of phenotypic traits as indirect indicators of health, physiology, and productivity, providing valuable insights for breeding and management programs aimed at improving native chicken performance. https://lst.uk.ac.ir/article_5449.html In the present study, 15,108 daily records of milk yield (DMY), milk fat percentage (DFP), milk protein percentage (DPP), and milk somatic cell score (DSCS) in the first two lactation periods of the Murciana-Granadina goats, collected from 2017 to 2024 in the southern part of Kerman province of Iran, were used. By applying latent variable modeling technique and confirmatory factor analysis a latent variable of daily milk production performance (DMP) in the first two lactation periods of the Murciano-Granadina goat breed was constructed and evaluated statistically by four goodness of fit measures including standardized root mean square residual (SRMR), root mean square error of approximation (RMSEA), Tucker-Lewis Index (TLI), and comparative fit index (CFI). The values of CFI, TLI, RMSEA, and SRMR, were 0.97, 0.92, 0.05, and 0.02, respectively, implying the suitability of the confirmatory factor model proposed for DMP latent variable in the present study. Standardized factor loadings of the traits used for describing DMP were statistically significant (P < 0.01) values of 0.24, -0.55, -0.54, and -0.37 for DMY, DFP, DPP, and DSCS, respectively. Therefore, it may be concluded that increase in milk yield would increase DMP. On the other hand, increases in milk fat percentage, milk protein percentage, and milk somatic cell score would decrease DMP. For constructing the latent variable of DMP in the Murciano-Granadina goats, emphasis should be on increasing milk quantity and decreasing milk composition traits including milk fat percentage, milk protein percentage, and milk somatic cell score. Pearson’s correlations among the investigated measurable traits were statistically significant (P<0.01), ranging from -0.14 (DMY-DFP and DMY-DSCS) to 0.30 (DFP-DPP). Pearson’s correlations between the DMP latent variable and the measurable milk yield and composition traits were also statistically significant (P<0.01) and were -0.76 (DFP-DMP), -0.75 (DPP-DMP), -0.52 (DSCS-DMP), and 0.33 (DMY-DMP). Overall, the study provides a statistical framework for describing DMP in contexts such as phenotypic evaluations, where a latent construct can capture the concept of milk yield and composition traits more effectively than individual traits alone. https://lst.uk.ac.ir/article_5319.html This research explored the correlation between the chemical composition and asymptotic in vitro gas production (AGP) of diverse agricultural by-products, intending to develop predictive models for AGP using advanced computational methods. The research employed two complementary analytical approaches: artificial neural networks (ANN) and multiple linear regression (MLR), to assess their efficacy in forecasting AGP based on compositional parameters. Two datasets were utilized: a training dataset compiled from previously published literature and a testing dataset comprising experimentally derived chemical profiles and AGP measurements of selected by-products. Following the determination of chemical constituents (e.g., neutral detergent fiber [NDF], acid detergent fiber [ADF], organic matter [OM], and crude protein [CP]) and AGP values, the datasets were merged and subjected to multivariate cluster analysis. This analysis revealed two statistically distinct clusters (A and B), with intra-group similarity thresholds exceeding 80% for Cluster A and 90% for Cluster B. The study focused on Cluster A, which encompassed the selected by-products, for subsequent Pearson correlation and predictive modeling. Key findings included significant inverse relationships between AGP and fiber components (NDF: r=−0.65; ADF: r=−0.72), whereas positive correlations emerged with OM (r=0.58) and CP (r=0.49). Comparative model performance demonstrated ANN’s superiority (r²=0.78, RMSE=5.39) over MLR (r²=0.24, RMSE=18.36), highlighting its potential for accurate AGP prediction in agricultural by-products. https://lst.uk.ac.ir/article_5479.html Sugar beet pulp (BP) is a by-product rich in both non-fibrous carbohydrates and highly digestible neutral detergent fiber. This study evaluated the effects of simultaneously substituting forage (alfalfa hay) and grains (corn and barley) with increasing levels of BP on growth performance, digestibility, chewing behavior, ruminal fermentation, and blood metabolites in fattening lambs. Twenty-six male Lori lambs (body weight= 28.2±3.6 kg) were randomly assigned to one of four iso-nitrogenous and iso-energetic diets in a completely randomized design. Diets included 0% (BP0), 10% (BP10), 20% (BP20), or 30% (BP30) BP, with BP replacing equal proportions of both forage and grains. As BP inclusion increased, the forage-to-concentrate ratio declined from 25:75 to 10:90, dietary neutral detergent fiber (NDF) increased (28.8% to 31.3%), and starch (43.5% to 32.6%) and forage NDF (14.2% to 6.9%) decreased. Increasing BP levels linearly reduced dry matter (DM) intake, while NDF intake remained unchanged. Apparent digestibility of DM and NDF increased linearly, but crude protein digestibility was unaffected. Average daily gain (ADG) tended to decline linearly, whereas feed efficiency showed a quadratic response, peaking at BP10 and BP20. Carcass traits (dressing percentage, tail fat, offal weights), blood metabolites (glucose, urea nitrogen, cholesterol, triglycerides, total protein, β-hydroxybutyrate), urine pH, and ruminal pH were not influenced by treatment. However, ruminal acetate proportion and the acetate-to-propionate ratio increased linearly, while propionate decreased. Total rumination time and rumination per kilogram of DM or NDF intake declined linearly, with the lowest values observed in BP30-fed lambs. In conclusion, moderate inclusion of BP (10–20%) improved fiber digestibility and feed efficiency without compromising health or carcass characteristics, despite a slight reduction in DM intake. Inclusion at 30% may reduce intake and chewing activity, potentially limiting its practical utility at this level. https://lst.uk.ac.ir/article_5323.html Genetic variability is fundamental for the adaptability, health, and long-term sustainability of horse populations. This study sought to provide a comprehensive assessment of genomic diversity, population structure, and selection signatures across 14 horse breeds, encompassing five indigenous Iranian breeds (Iranian Arabian-Asil, Turkmen, Caspian, Kurdish, Dareshuri) as well as nine international breeds (Thoroughbred, Quarter Horse, Belgian, Arabian, Welsh Pony, Standardbred, Icelandic, Lusitano, Morgan), based on ultra-high-density SNP array data. Following quality control and imputation, we analyzed the combined dataset of 1.57 million SNPs across 438 individuals to assess within- and between-breed genetic diversity, population structure, and signatures of selection. Observed heterozygosity (Hₒ) ranged from 0.1727 (Thoroughbred) to 0.2068 (Welsh), with Iranian breeds generally demonstrating lower allelic richness and effective number of alleles. Pairwise FST and private allele analyses revealed moderate genetic differentiation, with Thoroughbred and Icelandic being the most divergent, while Iranian breeds revealed high shared ancestry. Population history assessments via Tajima’s D and Garza–Williamson M-ratio highlighted varying degrees of past bottlenecks, most evident in Dareshuri and Kurdish populations. Population structure analyses (PCA and PCoA) showed well-defined breed clusters, highlighting both geographic origin and selective breeding history. HapFLK analysis detected 83 candidate genes under selection, associated with neural development, immune response, coat color and traits related to performance or reproduction. These findings emphasize the combined effects of historical selection, demographic events, and breed management on the genomic architecture of horse populations. The results provide applicable information for conservation strategies and breeding programs aimed at maintaining genetic diversity while preserving breed-specific traits, particularly in endangered Iranian and intensively selected international breeds. https://lst.uk.ac.ir/article_5483.html The present study evaluated the effects of Pistacia atlantica Subsp. Kurdica gum essential oil (PAKEO) on nutrient disappearance, volatile fatty acid (VFA) profile and rumen microbial population using a rumen simulation technique (RUSITEC). Treated vessels were supplied with 0.0 (as control diet), 150 µL/L of PAKEO (EO150) and 300 (EO300) µL/L of PAKEO (two vessels per treatment). Experiments were performed in two runs consisting of a 7-day adaptation followed by an 8-day sampling period per run. The sampling period started on the day after administration of the first treatment. For measurement of nutrient disappearance, samples were collected on the initial (days 8 and 9) and final stages (days 14 and 15) of the period. On day 15, samples for the VFA and microbial population (at 4 h after morning vessels feeding) were collected from the vessel contents. Results showed that the addition of PAKEO at 150 µL/L resulted in an increase (P<0.05) in the disappearance of dry matter, organic matter, and crude protein in basal diet. Neutral detergent fiber disappearance increased (P<0.05) with the addition of 150 and 300 µL/L of PAKEO. Total VFA concentration increased (P<0.05) by 300 µL/L PAKEO supplementation. Addition of PAKEO at 300 µL/L resulted in a lower molar proportion of propionate and a higher acetate: propionate ratio compared with the control (P<0.05). However, the molar proportions of acetate, butyrate, valerate, and isovalerate were not affected by PAKEO supplementation. The relative abundance of total bacteria increased (by 10%, P<0.05) with the addition of PAKEO. Compared to the control, PAKEO supplementation at 150 µL/L sharply decreased (P<0.05) the relative abundance of methanogens. Treatment with PAKEO decreased (P<0.05) the relative abundance of major cellulolytic bacteria (i.e., Ruminococcus albus, R. flavefaciens, and Fibrobacter succinogenes). Total number of protozoa, Entodinium and Ophryoscolex species also decreased (P<0.05) by PAKEO treatment. These findings suggested that PAKEO has the potential as a feed additive to improve rumen microbial fermentation. https://lst.uk.ac.ir/article_5351.html This study evaluated the effects of emulsified oil (EO) and lysophospholipid (LPL) supplementation on early-lactating Holstein cows under heat stress. Fifteen multiparous Holstein cows were assigned to a completely randomized design for 70 days with three dietary treatments: 1) a basal diet containing (dry matter basis; DM) 1.52% pure fat powder (PFP; control); 2) the basal diet supplemented with 0.15% LPL (partially replacing PFP); and 3) the basal diet supplemented with 1.52% EO (completely replacing 1.52% PFP). Dry matter intake and milk yield were recorded daily. Milk and blood samples were collected at the end of the experiment. The average temperature-humidity index (THI) during the study was 71. Dietary treatments did not significantly affect DM intake or average milk yield (P>0.05). Milk fat yield was significantly greater in the EO group compared with the LPL and PFP groups (P<0.05). Supplementation with EO increased milk yield during weeks 2, 3, and 6 relative to PFP (P<0.05). Cows receiving EO exhibited lower proportions of C16:0 and higher proportions of C18:1, C18:2, and C18:3 fatty acids (P<0.05). Plasma glucose concentrations were elevated in cows fed EO compared with the other treatments (P<0.05), whereas cholesterol concentrations were reduced by both EO and LPL compared with PFP (P<0.05). Emulsified oil supplementation significantly decreased plasma low-density lipoprotein (LDL), β-hydroxybutyric acid (BHBA), and non-esterified fatty acids (NEFA) levels relative to PFP (P<0.05), while plasma albumin concentrations were higher in the LPL and PFP groups than in EO (P<0.05). In addition, EO supplementation significantly reduced plasma creatine phosphokinase activity compared with PFP (P<0.05). Overall, EO supplementation enhanced milk fat yield, improved milk unsaturated fatty acid profile, and optimized blood metabolites, indicating its potential to support metabolic efficiency and lactational performance in early-lactating Holstein cows under heat stress condition. https://lst.uk.ac.ir/article_5525.html Data-driven herd management is essential for scientific herd management in arid and semi-arid regions; however, traditional counting methods are labor-intensive, time-consuming, and prone to significant human error. This study proposes a drone-based deep learning framework for automated counting and monitoring of camel herds under prevailing desert conditions. Aerial videos were collected from nine camel herds across multiple regions in Iran using unmanned aerial vehicles (UAVs). A dedicated dataset was constructed from extracted video frames and annotated using polygon-based labeling. Two detection strategies were comparatively evaluated, including body-without-head and head-only detection. Object detection models were trained using the YOLOv8 architecture and tested under different training data scales to analyze the effect of dataset size on counting performance. Experimental results showed that head-based detection showed promising robustness under the tested conditions, although a fully controlled comparison with body-based detection would require matched training data. Expanding the training dataset from 100 images (≈900 frames) to 220 images (≈1800 frames) led to substantial improvements in detection stability and counting accuracy. Using the expanded dataset, the proposed system achieved > 98% counting accuracy in multiple real herds, including large groups containing up to 271 camels, with 1 counting error. The trained model was successfully integrated into the Sarebanyar App, enabling automated processing of newly acquired UAV videos and direct storage of results within an operational management workflow. The findings demonstrated that combining the UAV imaging, optimized region-of-interest selection, and diverse real-world training data enables a robust, scalable, and economically efficient solution for intelligent livestock monitoring in harsh desert environments, providing a practical pathway toward AI-driven smart herd management systems. https://lst.uk.ac.ir/article_5364.html To investigate the effect of milk enrichment with vitamin C and copper on dairy calves, 20 newborn calves were used in a completely randomized factorial design with 4 treatments of 5 replication each. Experimental treatments included: 1) control group (without copper and vitamin C supplementation), 2) copper added to milk, 3) vitamin C added to milk and 4) supplementation of milk with copper and vitamin C. Vitamin C and/or copper supplements for each treatment were completely dissolved in milk before feeding. The group receiving vitamin C and copper simultaneously (P<0.05) recorded the best performance in weight on day 63, daily weight gain on days 1-21 and 1-63, and feed intake on days 22-42, 43-63, and 1-63. The highest levels of glucose, triglycerides, LDL, and VLDL, and the lowest level of HDL were observed in the group receiving vitamin C and copper simultaneously (P<0.05). The lowest cortisol and highest insulin levels were observed in the group receiving vitamin C and copper simultaneously (P<0.05). The enrichment of milk with vitamin C, copper, and the combination of vitamin C and copper had no effect on the withers height, hip height, hip width, body length, heart girth and body barrel of the calves. Also, no significant differences were observed between the treatments containing copper and vitamin C and the control group regarding the digestibility of dry matter, organic matter, ether extract, crude protein, neutral detergent fiber, and acid detergent fiber. In general, it is concluded that the simultaneous enrichment of milk with vitamin C and copper during the first two months of calves' lives enhanced growth performance, reduced steress and bolsterd their immune system. https://lst.uk.ac.ir/article_5541.html This research was conducted on 24 roosters in a completely randomized design with 4 treatments (age groups of 5, 6, 7 and 8 months) and 6 replications (roosters) in each treatment. At each sampling time, the roosters were slaughtered, and testicular samples were prepared to simultaneously examine changes in the relative expression of WNT2 and H-PGDS genes, as well as the histological characteristics of the seminiferous tubules. The results showed that the relative expression level of the H-PGDS gene decreased 0.02-fold at 6 months of age compared to 5 months of age and increased 45.54 and 12.69-fold at 7 and 8 months of age respectively, compared to 5 months. While the relative expression of the WNT2 gene increased significantly at 6 (47.77 folds), 7 (71.18 folds), and 8 (88.17 folds) months of age compared to 5 months of age (P≤0.05). In addition, the results of histological examination of the seminiferous tubules showed that the mean diameter of these tubules increased (P≤0.05) at the age of 7 months (405.90 µm and 112.4 µm, respectively) compared to the ages of 5 and 6 months (343.07 µm and 354.74 µm, respectively). Also, the maximum thickness of germinal layer (112.4 µm) was observed at the 7 months of age. Overall, the results showed a coordinated increasing trend in the relative expression of WNT2 and H-PGDS genes and the growth of seminiferous tubules during the puberty period of native roosters. https://lst.uk.ac.ir/article_5570.html Lameness is considered the third leading cause of reduced productivity and economic losses in dairy herds, after reproductive disorders and mastitis. The objective of this study was to quantify the economic impact of lameness and determine the optimal herd life and replacement strategy for dairy cows with different production levels using a bio economic optimization model. This study was conducted using data collected from several large industrial dairy farms in Ardabil Province, Iran. A systems analysis approach was employed to decompose the dairy herd economic system into its income and cost components. Subsequently, a bio economic model was developed and simulated using mathematical modeling techniques, and optimization was performed using the Compecon toolbox in MATLAB. Dairy cows were classified according to production level into low-, medium-, and high-producing groups and according to lameness status into healthy, subclinical, and clinical lameness categories. An objective function was defined to maximize the present value of net income generated by a cow and its replacement heifer. The results showed that healthy cows were predominantly represented in the low-producing group, cows with subclinical lameness were more common in the medium-producing group, and cows with clinical lameness were primarily found among high-producing cows. Lameness reduced milk production by 0.16, 0.57, and 0.88 kg per cow per day in low-, medium-, and high-producing cows, respectively. Corresponding cumulative milk yield losses over the study period were estimated at 45, 84, and 66 kg per cow. According to the model results, the present value in the low-producing group increased until the fourth calving and declined thereafter. In contrast, although present value generally decreased with increasing parity in the medium- and high-producing groups, retaining cows remained economically optimal up to the seventh and eighth calving, respectively. The optimal culling and replacement decisions were similar across different lameness statuses within each production level. Furthermore, future economic value was influenced by age, production level, and stage of lactation. The average optimal herd life was estimated to be 4.69 years. Based on this value, the annual replacement rate was calculated at 21.32%, using the inverse of the optimal herd life. https://lst.uk.ac.ir/article_5377.html This study aimed to quantify a latent variable for body size (BS) in cattle by using six morphometric traits, including body height at withers (HW), body length (BL), hip width (HpW), chest depth (CD), shoulder width (SW), and chest width (CW). The statistical measures for goodness of fit, including comparative fit index (CFI), Tucker-Lewis Index (TLI), and standardized root mean square residual (SRMR), were 0.94, 0.91, and 0.05, respectively, and appropriately indicate the adequacy of the confirmatory factor model proposed for the latent variable of BS. The standardized factor loadings of HW, BL, HpW, CD, SW, and CW for describing BS were 0.83, 0.76, 0.82, 0.89, 0.80, and 0.40, respectively, and statistically significant (P<0.01), implying that the observed variables were appropriate indicators of the corresponding BS latent trait. All correlations among morphometric traits were positive and statistically significant (P<0.01), ranging from 0.26 (CW-SW) to 0.77 (HW-CD). The correlations between the BS latent trait and the considered morphometric traits were also positive and statistically significant (P<0.01); ranged from 0.42 (CW-BS) to 0.93 (CD-BS). It was concluded that the proposed confirmatory factor analysis model showed adequate fit indices for constructing the BS latent trait, implying that the proposed framework adequately captures the underlying relationships among the observed variables. Overall, the study provided a robust framework for applying BS in contexts such as phenotypic evaluations, where a latent construct can capture the complexity of morphometric traits more effectively than individual traits alone. https://lst.uk.ac.ir/article_5384.html This study compared the effects of silage particle size (8 vs. 16 mm) and inoculation with lactic acid bacteria on the nutritional and physiological responses of sheep fed with diets containing corn or foxtail millet silage. Two separate experiments were conducted for 90-day periods arranged as 2×2 factorial experiment within a randomized complete block design. While particle size and inoculation had no significant effect on dry matter (DM), crude protein, or neutral detergent fiber concentrations in corn silage, in millet silage DM content was significantly higher with long particles (395 vs. 350 g/kg DM; P<0.01). Silage pH was significantly affected by particle size in both corn (P<0.05) and millet (P<0.01), with short particles yielding lower pH. Bacterial inoculation further reduced pH only in millet silage (P<0.01). The DM and organic matter (OM) intake were greater with short-particle silages, but digestibility improved only in the sheep fed with short, inoculated millet silage diet (P<0.01). Ruminal pH remained unaffected by two factors in corn silage diets, but in millet silage diets, it was significantly lower at 2 and 4 h post-feeding with short silage particles size diets (P<0.01). Ruminal microbial nitrogen and protein synthesis were higher with short-particle corn silage (P<0.01), whereas millet silage showed a significant particle size×inoculation for these parameters. Chewing behavior also differed; sheep fed on short corn silage chewed longer (P<0.01), while in millet silage, feeding time increased with long particles silage diet and rumination time was longer with short particles (P<0.05). Overall, corn silage responses were driven mainly by physical form, whereas millet silage benefited from the combined optimization of chop length and microbial inoculation. https://lst.uk.ac.ir/article_5631.html AbstractFoot-and-mouth disease (FMD) is a dangerous disease in ruminants that causes severe production reduction in adult livestock and mortality in lambs and calves. In this study, the GSE83514 dataset (samples of nasopharyngeal epithelium from Holstein cattle) was extracted from the GEO database and was analyzed to identify gene network, hub genes and gene clusters underlying foot-and-mouth disease in dairy cows. Before performing any analysis, data quality control and normalization were performed using the online software GEO2R and genes with differential expression between the two treatments of healthy and patient samples at a probability level of P-value < 0.05 and Log Foldchange statistic [-2< LogFC< +2] were identified. We employed CytoNCA and cytoHuba plugins within Cytoscape software for network analysis. The MCL algorithm was used to identify five main clusters in the body of gene network. The results revealed 249 genes with significant expression differences (120 upregulated genes and 129 down-regulated genes). Five main clusters linked to signaling pathways associated with chemokines, tumor necrosis factor-alpha (TNF-α), and suppressor of viral growth were detected in the body of gene network. Ten genes CD9, ICOS, CXCL9, CD2, TTN, PTPRC, CALML5, IRF8, CD40, CXCR5 were identified as the hub genes which closely linked to key pathways involved in FMD infection. These genes were active mainly in hematopoietic system, lymphoid tissue and blood and involved in importance biological process such as immune system process, lymphocyte activation, positive regulation of cytokine production and B cell activation. These genes can be used as genetic markers, making them valuable for increasing genetic resistance to FMD. https://lst.uk.ac.ir/article_5388.html Optimal use of edible plants such as milk thistle (Silybum marianum) as a supplement and for enrichment of the diet to help improve performance and health is a low-risk and acceptable strategy in poultry nutrition, since these herbal plants contain bioactive compounds that can improve animal performance. The present study examined the potential benefits of this strategy for broiler chickens. After analyzing the nutrient and micronutrient composition of the supplement, the experiments were conducted as a completely randomized design including three milk thistle inclusions at levels of 0, 1.5 and 3%, each treatment containing 5 replicates of 10 birds each. Performance data from 1 to 11 days and from 22 to 42 days of age showed that the lowest and best conversion rate at 1.5% dietary level (P<0.05). Significant improvements from milk thistle feeding were detected in blood biochemical and antioxidant status for glucose, cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), atherogenic index, triglycerides, albumin, protein, phosphorus, iron, alanine aminotransferase (ALT), aspartate transaminase (AST), malondialdehyde (MDA), and total antioxidant capacity (TAC). Overall, the results showed that milk thistle feeding was effective in improving blood and meat health status while increasing the performance with the potential to be commercially effective in functional poultry diets. This study demonstrated that the optimum levels of dietary Silybum marianum may create constructive effects on performance, health and meat quality for broiler farmers. https://lst.uk.ac.ir/article_5640.html Nowadays, with the development of arrays containing single-nucleotide polymorphism (SNPs) information for most domestic animal species, genome-wide association studies (GWAS) are some important methods for identifying candidate genomic regions associated with production traits. Therefore, the use of modern approaches, including machine learning methods, especially nonlinear algorithms such as Random Forest (RF), are essential, because these methods are able to reveal complex patterns in genomic data that are often hidden from the view of traditional statistical models. Therefore, this study aimed to identify genes and SNPs affecting body weight traits in Lori-Bakhtiari sheep using RF algorithms. A total of 132 samples of Lori-Bakhtiari sheep were genotyped using Illumina Ovine SNP 50 Bead Chip, containing 51,135 SNP markers. Plink (v 9.1) was used for quality control, where a total of 44,796 SNPs and 122 sheep were retained for downstream analyses. The RF algorithm was used to find significant SNPs associated with weaning weight and 180 days of age’ weight, using the RF package in R (v 4.4.0). The top 50-ranked SNPs were detected based on the RF method. The results indicated 59 candidate genes for weaning weight and 58 candidate genes for weight at 180 days of age. Among the identified candidate genes for weaning weight, the genes including ABL1, INPPL1, and EXOC7, and also for the genes revealed for 180 days of age, ROS1, HCK, and ZFAND4 genes have been identified to be hub genes associated with body weight traits in the current study. Network analysis revealed functional connections among these genes, reinforcing their candidacy for body weight regulation. Notably, the most genes and networks identified in the current study are novel and have not been previously identified by GWAS, underscoring the RF algorithm's effectiveness in discovering novel genetic markers. In conclusion, these findings offer new perspectives on the genetic basis of body weight in sheep and propose targets for enhancing genetic selection in meat-producing breeds. https://lst.uk.ac.ir/article_5671.html Knowledge of the association of single nucleotide polymorphisms with economically important traits is an important tool for breeding programs in the livestock industry. The aim of the present study was to identify important and influential markers of litter size trait in Zandi sheep using genomic data and random forest method. Significant markers including s59645, OAR14_49049707, s51972, OAR12_19965932, OAR14_40046813, s61144 and OAR2_53988637 were identified by the machine learning method (random forest) for the litter size. The identified markers were associated with new genes including STEAP2, CCNP, RAB11FIP2, GPATCH2, URI1, ROPN1L and SKAP1. Gene ontology study showed that genes discovered by the random forest play roles in key biological functions such as cellular metabolic processes, DNA-templated transcription, biosynthetic process, embryonic skeletal system morphogenesis, embryonic skeletal system development, regulation of gene expression, organ morphogenesis, skeletal system development, and chordate embryonic development. The identified candidate genes provided additional insights into the genetic mechanisms underlying the litter size in Zandi sheep. Furthermore, the important SNP markers identified by the random forest analysis could serve as potential candidates for future functional validation and marker-assisted or genomic selection programs. https://lst.uk.ac.ir/article_5389.html Data consisted of pedigree information and kidding records from 7,541 Murciano-Granadina goats collected between 2018 and 2023, from a commercial dairy farm in Ghale-Ganj City, southern Kerman province, Iran, were used. The functional stayability traits were defined as binary traits and included stayability until 24 months (Stay24), 36 months (Stay36), and 48 months (Stay48) after first kidding. The averages for the functional stayability until 24, 36, and 48 months after first parity were 81%, 52%, and 30%, respectively. Kidding year and milk yield level were statistically significant risk factors for all the investigated stayability traits (P<0.01). Genetic analysis was performed by applying a Bayesian multivariate threshold animal model via Gibbs sampling. Posterior means of heritability estimates ± posterior standard deviation (PSD) were 0.08±0.03, 0.06±0.02, and 0.18±0.06, for Stay24, Stay36, and Stay48, respectively. Posterior means±PSD for genetic correlations among the studied traits were positive estimates of 0.82±0.17 (Stay24-Stay36), 0.74±0.19 (Stay24-Stay48), and 0.68±0.19 (Stay36-Stay48).  The phenotypic correlation estimates were 0.93±0.01, 0.89±0.03, and 0.94±0.01 for Stay24-Stay36, Stay24-Stay48, and Stay36-Stay48, respectively. Given the low heritability estimates, improving environmental conditions and potentially incorporating non-additive genetic effects in future breeding schemes may be more important for enhancing functional stayability of the Murciano-Granadina goat in the flock.  https://lst.uk.ac.ir/article_5391.html The purpose of the present study was to investigate the effect of censoring in the genetic analysis of age at first kidding (AFK) in the Murciano-Granadina goat breed. The dataset included information on first-kidding records collected from 2016 to 2024 from a private dairy farm of the Murciano-Granadina goat breed, in Ghale-Ganj city, located in the southern area of Kerman province, Iran. Five animal models, including linear model (LM), penalty model (PM), modified penalty model (MPM), linear-threshold model (LTM), and modified linear-threshold model (MLTM), were applied for genetic analysis of AFK. The predictive ability of the models was assessed by cross-validation via mean square error of prediction (MSE) and Pearson's correlation coefficient between observed and predicted values (r(y, )). The lowest MSE and highest r(y,y ̂) were obtained under MLTM, indicating the adequacy of MLTM for genetic analysis of AFK, including censored records. The Spearman's rank correlations between predicted breeding values of animals under LM and other censorship handling investigated models for all and 1% top-ranked animals were low and statistically non-significant (p>0.05). By considering the models that contained censoring scenarios, all Spearman's rank correlations among the models were positive and statistically significant (p<0.01), ranging from 0.56 (LTM-MPM) to 0.96 (LTM-MLTM) when all animals were considered and from 0.75 (LTM-MPM) to 0.96 (LTM-MLTM and PM-MLTM) when 1% top-ranked animals were considered. The averages for accuracy of the predicted breeding values of animals were 0.43, 0.49, 0.47, 0.47, and 0.49 under LM, PM, MPM, LTM, and MLTM, respectively, implying that the accuracy of the model under uncensored data is partly lower than the model accuracies under censoring scenarios. Posterior means for heritability estimates of AFK were 0.20±0.03, 0.23±0.02, 0.19±0.02, 0.18±0.03, and 0.18±0.02 under LM, PM, MPM, LTM, and MLTM, respectively. Due to the superiority of MLTM over LM, according to the predictive ability measures, it may be concluded that ignoring censored records under LM results in re-ranking of animals based on the predicted breeding values. Therefore, including censored records by applying MLTM is of crucial importance for genetic evaluation of AFK in the Murciano-Granadina goat breed. https://lst.uk.ac.ir/article_5679.html This study examined the interactive effects of dietary L-carnitine and methionine (Met) supplementation on growth performance, carcass characteristics, serum biochemical parameters, and tibial bone properties in broiler chickens. A total of 144 one-day-old Ross 308 male broiler chicks was distributed among four experimental treatments, with four replicates of nine birds each. Dietary treatments included two levels of L-carnitine (0 and 250 mg/kg of diet) and Met (Ross recommendation, 2014) and Met at 20% above Ross recommendation (H-Met), as a 2×2 factorial arrangement. Growth performance parameters, including feed intake (FI), body weight gain (BWG), and feed conversion ratio (FCR), were determined at the end of each rearing phase (d 1–10, 11–25, and 26–42); at d 42, two birds per replicate, nearest to the pen mean body weight, were designated for blood collection, carcass assessment, and tibial bone characterization. The results revealed that L-carnitine supplementation enhanced BWG, relative carcass and breast weights, and tibial dry weight, length, and breaking strength, as well as serum total protein and albumin concentrations, while concurrently reducing FI, FCR, abdominal fat deposition, and serum cholesterol and triglyceride levels (P≤0.05). Birds allocated to the H-Met treatment exhibited the greatest BWG, relative carcass and breast weights, tibial breaking strength, and serum total protein and albumin, alongside the lowest FCR and abdominal fat proportion (P≤0.05). Overall, these findings highlighted the synergistic effects of L-carnitine and H-Met on enhancing metabolic health and production efficiency in broilers. https://lst.uk.ac.ir/article_5392.html This study evaluated the effects of dietary supplementation with probiotic, vitamin C, and organic selenium (selenium-enriched yeast), individually or in combination, on productive performance, eggshell quality, antioxidant status, immune response, and yolk fatty acid profile in laying hens. A total of 180 Bovans hens aged 45 weeks were randomly assigned to five dietary treatments for 12 weeks: (1) Control diet (basal diet supplemented with 0.3 mg/kg inorganic selenium); (2) control diet supplemented with 0.3 g/kg probiotic; (3) control diet supplemented with 0.1 g/kg vitamin C; (4) basal diet supplemented with 0.3 mg/kg organic selenium; and (5) basal diet supplemented with probiotic + vitamin C + organic selenium. Productive traits, including egg production, egg weight, and feed intake, were recorded, and the feed conversion ratio (FCR) was calculated, while blood samples were analyzed for antibody titer against sheep red blood cells (SRBC), antioxidant enzyme activities, and total antioxidant capacity (TAC). Eggshell quality parameters and yolk fatty acid composition were also determined. The results indicated that hens receiving the combination of probiotic, vitamin C, and organic selenium exhibited the lowest FCR and highest egg mass and egg weight compared with most other treatments (P<0.05). Organic selenium improved several aspects of eggshell quality, including shell strength and egg shape index (P<0.05). Vitamin C supplementation increased total antibody titer relative to the probiotic group, although no differences were observed compared with the control group, and IgM and IgG levels remained unchanged. Activities of antioxidant enzymes (catalase, glutathione peroxidase, superoxide dismutase) were not affected by dietary treatments, but TAC was significantly elevated in the combination group (P<0.05). Combined dietary inclusion of probiotic, vitamin C, and organic selenium enhances yolk polyunsaturated fatty acids. In conclusion, concurrent dietary inclusion of probiotic, vitamin C, and organic selenium improved feed efficiency, certain aspects of eggshell quality, total antioxidant capacity, and yolk fatty acid composition in laying hens. These findings suggest that the combined supplementation of these nutrients represents a promising nutritional strategy to enhance productive performance, oxidative stability, and yolk nutritional value, while single additives may produce more limited effects. https://lst.uk.ac.ir/article_5680.html This study evaluated the chemical composition, glycoalkaloids (GA) content, fermentation quality and in vitro digestibility of fresh and ensiled potato haulms (PoH) collected from six agro-climatically diverse locations within Kerman province (Jiroft, Anbarabad, Rudbar, Kahnuj, Faryab, and Manujan). Representative samples were collected from a single commercial field per location, chopped to 3-5 cm, vacuum-sealed in polyethylene silo bags (5 kg), and ensiled for 45 days. The experiment was conducted in a completely randomized design with six treatments (locations) and five replications, and data were analyzed using the GLM procedure of SAS. Location had a large effect on crude protein (CP; P<0.001), acid detergent fiber (ADF; P=0.005), water-soluble carbohydrates (WSC; P=0.05), ash (P<0.01), and GA concentrations (P=0.003) in fresh PoH, with CP varying from 17.8% to 24.0% and GA from 678 to 968 mg/kg dry matter (DM) between locations. During ensiling WSC decreased by 71% (8.20% to 2.38%; P<0.01), nitrate concentration decreased by 58% (0.703% to 0.294%; P<0.01) and total GA content decreased by 43.7% (808 to 455 mg/kg DM; P<0.01) which is the result of acidic hydrolysis and microbial degradation during fermentation. Silage fermentation was characterized by consistently high lactic acid concentrations (63.7-69.2 g/kg DM) and negligible butyric acid (<0.25 g/kg DM) across all locations, indicative of well-preserved, clostridium-free silages. DM digestibility (DMD) decreased from 60.8% to 56.6% and metabolizable energy (ME) from 2.14 to 2.00 Mcal/kg DM (P<0.01) after ensiling. The results suggest that ensiling substantially reduced antinutritional factors while maintaining the overall feeding potential of PoH, although modest reductions in DMD and ME were observed. Thus, the use of potato haulm silage as a suitable ruminant feed in semi-arid areas of Iran is recommended.