https://lst.uk.ac.ir/ Journal of Livestock Science and Technologies en daily 1 Sun, 01 Feb 2026 00:00:00 +0330 Sun, 01 Feb 2026 00:00:00 +0330 https://lst.uk.ac.ir/article_4951.html Perinatal kid loss in the early and later stages of production is a major problem in goat breeding. This study investigates the associated risk factors of stillbirth and dystocia in the Murciano-Granadina goat breed under an intensive production system in the semi-arid tropical region of southern Iran. Data were collected from 2017 to 2024 on a private dairy farm in Ghale-Ganj city, the southern area of Kerman Province, Iran. Data included information from 8,349 kidding records across the first three parities. A multivariate logistic regression model was used to evaluate the influences of independent variables, including kidding year, kidding season, parity, birth type of kid born, sex of kid born, birth weight of kid born, gestation length of doe, and age of doe at kidding. The average incidence rates of stillbirth and dystocia across the first three parities were 2.73% and 3.90%, respectively. The obtained results revealed that stillbirth was significantly influenced by kidding year, sex of the kid born, gestation length of doe, and age of doe at kidding, whereas dystocia was significantly associated with kidding year and sex of the kid born. These findings can inform better management and breeding strategies to reduce perinatal losses and improve reproductive performance in Murciano-Granadina goats raised under intensive conditions. 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_4954.html This study aimed to develop a mathematical function for the performance of a goat production system for meat production, based on zootechnical and economic indicators. Data on the technical and economic parameters used in the models were obtained from the goat herd control file database, which covered the years 2013 to 2017. Descriptive statistics were performed using PROC UNIVARIATE, while multiple linear regression models were developed using PROC GLMSELECT. Multiple linear regression analysis showed an adjusted coefficient of determination, indicating that the variables mortality rate, calving interval, weaning rate, and reproductive efficiency explained 95 percent of the variations in total goat weight at weaning. The results indicated that total weight of offspring at birth and weaning, mortality rate, reproductive efficiency, and gross income affect the system's profitability and can be used as decision-making criteria in meat goat farming. Furthermore, feed costs and rainfall also influenced the predicted variables, highlighting the importance of integrating climatic and economic factors in herd management. The multiple linear regression equations developed in this study are a useful and accessible tool for ruminant technicians and producers, allowing simulations and analyses of different production and economic scenarios, contributing to strategic planning and the development of the meat goat production system. 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_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_4956.html Genetic selection in dairy cattle can be enhanced by identifying the candidate genes and variants associated with economic traits. This study examined the productive and reproductive characteristics of Holstein cattle based on the genotypes of the pyruvate carboxylase (PC) gene. A total of 50 cows, aged three to five years, was included in the study, with identical feeding and maintenance protocols applied to all animals. All cows completed a lactation period of 305 days. The genotype and allele frequencies were determined through genotyping. Sequencing analysis of 816 bp amplicons detected two single-nucleotide polymorphisms (SNPs), rs42195003 and rs110476776. The association analysis of the two SNPs was not significantly associated with lactation period, dry period, milk composition, and reproductive performance (P>0.05). In contrast, the highest milk production (4305.63±222.01 kg), was associated with the CT genotype of the PC (rs110476776) polymorphism. The results revealed that the SNP rs110476776 in the PC gene was associated with total milk production in Holstein cows. This study may provide valuable insights into the role of the analyzed gene in the functional traits of dairy cattle; however, it is essential to validate the results by researching larger populations and different breeds of cattle. https://lst.uk.ac.ir/article_4992.html Estimating the genetic parameters for growth traits is a crucial step before designing breeding programs to enhance the productivity in local chicken breeds. The current study estimated the genetic parameters of two local chicken lines selected for meat production (Normally Feathered, CE1, and naked-neck, CE3) and tracked the changes in these parameters over three generations of selection. Heritability estimates for the hatch weight were moderate, ranging between 0.30 and 0.31. Lower estimates ranged from 0.28 to 0.33, and were obtained for BW2 and BW4, respectively. The genetic correlations were moderate to high, and varied from 0.43 (BW12 and BW18) to 0.88 (initial BW and BW2) in the seventh generation of selection. The values in the eighth generation had the same trend and varied from 0.41 (initial BW and BW18) to 0.86 (BW2 and BW4). Similar values were obtained for body weight gain (BWG) and growth rate (GR) traits, where the highest genetic correlation (0.86) was between BWG (0-6) and GR (0-6) in the seventh and ninth generations, respectively, and the lowest was 0.62 that found between BWG (6-12) and GR (12-18) in the eighth generation. However, the highest phenotypic correlation (0.71) was also obtained between BWG (0-6) and GR (0-6) in the eighth generation, and the lowest value (0.42) was obtained between BWG (6-12) and GR (12-18) in the ninth generation of selection. The results suggested that there is enough genetic variation for further improvement in body weight at the juvenile stage. 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_5015.html This study investigated the effects of lysophospholipid (LPL) supplementation at varying inclusion levels on blood parameters, milk production, milk fatty acid composition, and the expression of fat synthesis-related genes in Holstein dairy cows. A total of fifteen cows was randomly assigned to three dietary treatment groups: 1) a control diet with no LPL, 2) the control diet supplemented with 0.1% LPL based on dry matter, and 3) the control diet supplemented with 0.15% LPL based on dry matter. The experimental period consisted of a 14-day adaptation phase, followed by a 21-day data collection phase. The results indicated that the addition of LPL to the diet significantly enhanced the net lactation energy. Furthermore, blood lipid profiles improved with increasing LPL levels, suggesting enhanced lipid metabolism. The fatty acid composition of milk was significantly enriched in the 0.15% LPL group, particularly in terms of beneficial fatty acids. Moreover, the group receiving the higher LPL level showed upregulated expression of key lipogenic genes, including stearoyl-CoA desaturase (SCD) and fatty acid binding protein (FABP). Notably, daily feed intake and milk yield remained unaffected by LPL supplementation. Overall, the findings suggested that LPL inclusion, especially at 0.15% of dry matter, may improve metabolic efficiency and milk quality in early-lactation dairy cows. Further research is recommended to examine the long-term outcomes and economic benefits of LPL supplementation in dairy cows. 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_5047.html Gas production kinetics is considered as one of the key indicators for assessing the nutritional value of feeds; therefore, precise prediction of kinetic parameters can provide reliable estimates of the nutritive value of feedstuffs. The objective of this study was to assess the accuracy of various nonlinear models in predicting ruminal fermentation parameters using the in vitro gas production (IVGP) technique. The fermentation substrates used in this study were agro-industrial by-products, including sugar beet pulp, lemon pulp, tomato pomace, grape pomace, sesame meal, rapeseed meal, bakery waste, and saffron flower waste. Rumen fluid was collected from three adult ruminally-fistulated Mehraban rams, then filtered and buffered. Each of the feed samples (in 3 replicates and 3 separate runs) was incubated with buffered rumen fluid for 144 hours. The gas production data were fitted to five nonlinear models, including Exponential (EXP), Gompertz (GOM), Logistic (LOG), Mitscherling (MCH), and Weibull (WEB). The goodness of fit of these models was evaluated using metrics such as mean square error (MSE), coefficient of determination (R2), residual mean absolute deviation (RMAD), and mean percentage error (MPE). Additionally, the Akaike's information criterion (AIC), Bayesian information criterion (BIC), accuracy factor (AF), run test, and linear regression analysis were employed to assess the accuracy of the models. Based on MSE and R2 statistics, the EXP model demonstrated the lowest accuracy (37.30 and 0.958, respectively), while the MCH (8.15 and 0.991, respectively) and WEB (4.02 and 0.996, respectively) models exhibited the highest accuracy (P<0.05). Additionally, the AIC, BIC, and AF statistics were lowest for the WEB and MCH models, and highest for the EXP model. The results of the run test and linear regression analysis corroborated these findings. Overall, these findings indicated that the WEB model was the most accurate among the evaluated models for predicting the rumen fermentation kinetics, offering a reliable estimate of the nutritional value of new feedstuffs, such as agro-industrial by-products. 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_5048.html Medicinal plants have gained attention as natural alternatives to antibiotic growth promoters in livestock nutrition due to their bioactive compounds. Among these, fennel (Foeniculum vulgare) shows promise, though its role in muscle development remains underexplored. The MYOD1 gene, a key member of the myogenic regulatory factors (MRFs) family, regulates muscle cell differentiation and growth. Increased expression of this gene is associated with enhanced muscle performance. This study examined the impact of fennel supplementation on MYOD1 gene expression in selected muscle tissues. A total of 48 muscle samples were collected from 16 lambs, with 8 animals assigned to each of two experimental groups. From each lamb, three muscle types (shoulder, thigh, and loin) were sampled, resulting in 24 samples per group. Fennel supplementation significantly increased MYOD1 expression in all muscle types (P<0.05), with the highest expression in thigh and the lowest one in shoulder tissue. The results suggested that fennel may positively influence muscle development at the molecular level by upregulating the MYOD1 gene expression although its potential as a natural feed additive to support muscle growth and meat quality in livestock warrants further investigation. Given the MYOD1’s central role in muscle growth regulation, exploring how medicinal plants affect its expression could advance functional livestock nutrition and genetic improvement strategies. Future studies should examine the underlying molecular mechanisms and interactions with other growth-related genes.Keywords: functional nutrition, fennel, muscle development, MYOD1 gene, medicinal plants https://lst.uk.ac.ir/article_5055.html To evaluate the effects of copper (Cu) supplement source on Holstein suckling calves, 40 newborn male calves (mean birth weight: 39.6±2.4 kg) were randomly assigned to a completely randomized design for 70 days. The four experimental treatments consisted of the basal diet (7.89 mg Cu/kg dry matter) supplemented with 10 mg Cu/kg dry matter from different copper sources: Cu-acetate (27% purity), Cu-chloride (36% purity), Cu-sulfate (23% purity), and Cu-tribasic (58% purity). Calf body weight (BW) was measured weekly, while starter intake was recorded daily. Apparent digestibility was assessed using acid-insoluble ash as an internal marker. Blood samples were drawn from the jugular vein at the end of the trial. Final BW, total weight gain, and average daily gain were significantly greater in calves fed Cu-acetate and Cu-sulfate compared to those receiving Cu-chloride and Cu-tribasic (P<0.01). Dry matter digestibility was significantly enhanced in calves fed Cu-acetate compared to the other experimental treatments (P<0.01). Apparent digestibility of ether extract (P<0.01) and acid detergent fiber (P<0.05) was greater in calves fed Cu-acetate than in those fed Cu-chloride or Cu-tribasic. Plasma globulin concentration was significantly greater in calves fed Cu-tribasic compared to those receiving Cu-acetate and Cu-chloride (P<0.05). Plasma cholesterol levels were significantly higher in the Cu-sulfate group than in the other treatments (P<0.05). The concentration of low-density lipoprotein was significantly lower in the Cu-acetate group compared to other treatments (P<0.05). Plasma zinc levels were significantly increased in calves receiving Cu-chloride compared to other groups (P<0.01). Plasma aspartate aminotransferase activity was significantly greater in calves fed Cu-acetate compared to those receiving Cu-chloride or Cu-tribasic (P<0.01). It was concluded that adding 10 mg Cu/kg dry matter to the basal diet through Cu-acetate and Cu-sulfate supplements had a more favorable effect on the growth performance in Holstein suckling calves compared to Cu-chloride and Cu-tribasic salts. 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_5077.html This study aimed to quantitatively evaluate the acid resistance and slow-release properties of two commercial lipid-coated sodium bicarbonate buffers (buffer I and II) designed for equine hindgut supplementation using validated in vitro models. The ability of buffers to resist reacting with acid was evaluated by measuring the gas produced from the incubation of buffers with an acid. Furthermore, the disappearance of the fat coat and the release of sodium bicarbonate were assessed using an in vitro enzymatic digestion method to simulate small intestine digestibility. The results showed that gas production from buffers I and II followed a linear manner. After 30 minutes of incubation in acid, gas production was approximately 16% of that observed in the uncoated. The lipid coating of buffer II was digested to a significantly greater extent than that of buffer I (P<0.001). This consequently led to a significantly greater release of sodium bicarbonate from buffer II (P<0.001). Accordingly, the final buffering capacity of the digesta was significantly higher in the bottle containing buffer II compared to the bottle containing buffer I (P<0.001). In vivo studies involving animals challenged with hindgut acidosis demonstrate the efficacy of equine buffers in supporting gut health. https://lst.uk.ac.ir/article_5174.html Conventional dietary supplements in livestock often face challenges of poor bioavailability and environmental impact, limiting their sustainable use. Nanotechnology-based approaches present innovative solutions by improving nutrient efficiency and enhancing productivity in small ruminant. The present investigation offers a rigorous bibliometric examination of the worldwide scholarly discourse surrounding nanoparticle-mediated nutritional interventions in small ruminant species, particularly sheep and goats. Leveraging a structured analytic framework, this study scrutinized publication data amassed between 2010 and 2025 from the databases Science Direct, Google Scholar, and Dimensions. Data curation and refinement, performed via Publish or Perish and standardized into CSV format, enabled a robust keyword co-occurrence analysis using VOSviewer, thereby ensuring methodological rigor and reproducibility, with acknowledgment that results may be shaped by database scope, English-language bias, and keyword-selection thresholds inherent to co-occurrence mapping. Findings disclose an appreciable escalation in the volume of pertinent literature since 2017, with discernible spikes in scientific productivity concentrated in 2021 and 2023. The bibliometric mapping identified pivotal thematic nodes, namely nanotechnology, nanoparticles, livestock, sheep, digestibility, and bioavailability. Concurrently, emerging research frontiers such as selenium and zinc nanoparticles, rumen physiology, heat stress responses, toxicity, and nano-enabled drug delivery have gained greater visibility in recent scholarly output. Temporal analyses of keyword co-occurrence patterns demonstrated a field-wide evolution, transitioning from foundational inquiries into ruminal fermentation and in vitro digestibility toward sophisticated applications aimed at enhancing feed efficiency, safety, and overall efficacy. Notably, highly cited studies have consistently highlighted the superior bioavailability of nano-form selenium and zinc, which may serve as benchmarks for innovation in the domain. Parallel to these advancements, there is increasing scholarly attention on the assessment of biological safety, metabolic fate, and the ecological ramifications of nanoparticle use in animal nutrition. In summary, emerging evidence highlights that low-dose nano-selenium and nano-zinc can improve rumen function, antioxidant status, and growth in small ruminant, while reducing mineral excretion, when implemented through extension-guided dosing, verified suppliers, and phased farm-scale trials providing practical guidance for farmers and feed producers. 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_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_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_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_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.