https://psj.gau.ac.ir/ Poultry Science Journal en daily 1 Thu, 01 Jan 2026 00:00:00 +0330 Thu, 01 Jan 2026 00:00:00 +0330 https://psj.gau.ac.ir/article_7358.html To fulfil the substantial demand for broiler chickens from both local consumers and importers, it is imperative to determine the optimal stocking density to maximize production efficiency. A common concern among broiler farmers is the lack of studies evaluating the most suitable stocking densities for commercial practice to enhance broiler production performance. This review examines the impacts of different stocking densities on the production performance, carcass traits, and meat quality of broiler chickens. The review followed the PRISMA Statement to ensure a comprehensive approach. The Scopus, ScienceDirect, and Google Scholar electronic databases were searched for literature published between 2012 and 2021 to capture a comprehensive and up-to-date decade of research, ensuring a robust dataset that reflects recent advancements, methodologies, and findings in the field. Generally, broilers raised in a closed house system at a high stocking density (15 birds/m²) exhibited a better feed conversion ratio compared to those at a lower stocking density (10 birds/m²). However, broilers raised at lower stocking densities generally yielded heavier carcasses (including carcass weight, hot carcass weight, wing, thigh, ribcage, breast muscle, liver, and small intestine) compared to those at higher stocking densities. Nevertheless, stocking density did not have a significant impact on meat quality. In conclusion, this review suggests that a stocking density of 15 birds/m² is optimal for broilers in a closed-house system, considering both production efficiency and carcass yield. https://psj.gau.ac.ir/article_7405.html The use of medicinal plants represents a new approach for utilizing phytogenic feed additives to improve production, health, and growth performance in the poultry industry. In this study, the effects of different phytogenic diets on egg production, egg quality and blood parameters in laying hens were investigated. The experimental treatments included the following: (1) a control basal diet (CON); (2) the basal diet+0.15% bioherbal (BHM) mineral supplement; (3) the basal diet+ 1.5% bioherbal (BH); (4) the basal diet+0.15% mineral supplement (M); (5) the basal diet +0.15% bioherbal plus 1.5% mineral supplement (BHPM); and (6) the basal diet + 0.5% bioherbal plus 1.5% BHP. The results showed that egg quality indicators did not significantly differ in response to the addition of the various phytogenic feed additives, whereas the yolk index significantly differed among the treatments only in the first period of study(P<0.05). The findings of this study revealed that the experimental treatments had no significant effect on the hematological parameters of the blood of the birds, whereas they caused significant changes in the means of the biochemical attributes, including triglyceride (TG), cholesterol (CHO), albumin, total protein (TP) and uric acid. The BHP and M treatments caused the highest and lowest triglyceride contents in the blood, respectively (P < 0.05). Adding BH to the diet of birds reduced blood cholesterol levels(P<0.05). The treatment contained BHM trend to increase egg production percent in the whole period of the experiment relative to the control (P < 0.1). The results revealed that the content of immunoglobulin Y reached the highest value in the BHM treatment group at the second immunization, whereas the lowest value was obtained in the BHP diet group(P < 0.05).  These findings show that the use of Bioherbal supplemented by minerals may have some effect on the performance of laying hens that may be significant in stressful conditions. Therefore, the evaluation of these additives in stress conditions is suggested. https://psj.gau.ac.ir/article_7354.html This research investigated the impact of hydrolyzed black cumin seed protein (HBCP) as a potential source of bioactive peptides on the performance of broiler chickens. A total of 560 Ross 308 broiler chicks were randomly assigned to seven distinct dietary groups: Control, 0.05% HBCP, 0.1% HBCP, 0.15% HBCP, 0.2% HBCP, 0.2% Prebiotic and 0.2% Organic Acid. The experiment was conducted over a 42-day period. Birds were fasted for 8 hours before weighing, and feed intake was recorded daily to calculate feed conversion ratios. For microbial and enzyme analyses, two birds per replicate were selected and euthanized, with intestinal samples collected under sterile conditions. Serum samples were taken on day 42 to assess liver enzyme concentrations, and immune response was measured using a sheep red blood cell assay. The results indicated that including 0.1%, 0.15%, and 0.2% HBCP in the broiler diets significantly improved body weight gain and feed conversion ratio throughout the rearing period. Additionally, the inclusion of 0.2% prebiotic and organic acid in the diet notably increased body weight and decreased feed conversion ratio compared to the control group (P<0.05). These dietary interventions had a positive effect on the intestinal microbiota, decreasing Escherichia coli counts while boosting Lactobacillus populations (P<0.05). Additionally, supplementation with HBCP, prebiotics, and organic acids improved immune function, as indicated by elevated antibody titers and enhanced liver enzyme activity. (P<0.05). In conclusion, the study showed that bioactive peptides derived from black cumin hydrolysate had effects similar to those of prebiotics and organic acids, improving both productive traits and immune status in broilers at comparable dosage levels. https://psj.gau.ac.ir/article_7355.html Ascites syndrome is a multifactorial disease in poultry, associated with high mortality and significant economic losses. Genomic studies have identified UTS2B gene as a candidate gene associated with ascites syndrome in poultry. Therefore, this study employed an in-silico approach to explore the structural and functional characteristics of the UTS2B protein and its potential link to ascites. The amino-acid sequence of UTS2B protein was retrieved from the NCBI database and subjected to analyze through ProtParam, ProtScale, NetPhos, NetNGlyc, LocTree3, and SignalP tools to determine its sequence features and physicochemical properties. Secondary and tertiary structures were predicted using I-TASSER, AlphaFold, and trRosetta, with structural quality validated by PROCHECK (Ramachandran plot analysis) and ERRAT scores. Promoter analysis was performed using MEME Suite, TOMTOM, and GOMo to identify regulatory motifs. The UTS2B protein exhibited a theoretical isoelectric point of 5.67, an instability index of 42.33, and an average hydrophilicity coefficient of -0.199, indicating a hydrophilic and moderately unstable nature. It contains 17 phosphorylation sites and 4 N-glycosylation sites, suggesting post-translational modifications that impact extracellular activity in peptide signalling pathways. Secondary structure analysis revealed a predominance of alpha helices and random loops. Among the predicted 3D models, the trRosetta structure achieved the highest quality, with 92.4% of residues in favorable regions of the Ramachandran plot and an ERRAT score of 85.6. Protein network analysis indicated that UTS2B may interact with proteins involved in pathways associated with calcium ion binding and cellular stress responses, both of which play a critical role in the pathophysiology of ascites. Promoter analysis identified regulatory motifs potentially linked to ion transport and inflammation, providing further insights into gene regulation. The findings suggest that UTS2B may play a role in calcium ion signalling and peptide-mediated extracellular pathways, contributing to ascites syndrome. This study presented critical bioinformatics insights into the UTS2B protein, providing foundational knowledge for future research aimed at understanding its role in ascites syndrome.  https://psj.gau.ac.ir/article_7356.html This study integrates clustering and network analyses to identify performance-based groups and their connections to phenotypes, providing insights to zoptimize local chicken breeding programs in Cameroon. A total of 113 Birds were grouped based on growth patterns between 16 and 22 weeks, assessed using total weight gain (TWG) and leg circumference gain (LCG). Repeated measures and Welch ANOVA were used to test performance differences, while Generalized Least Squares (GLS) ANCOVA identified growth predictors. Although phenotypic diversity was observed, TWG and LCG did not differ significantly across phenotypes (p > 0.05), whereas final body weight (BW) and leg circumference (LC) at 22 weeks did (p<0.01). Cluster analysis identified four distinct performance cluster groups independent of phenotype, with significant divergence in performance. Birds in Clusters 3 and 4 consistently outperformed (p<0.001) their counterparts in the other Clusters 1 and 2, showing superior TWG and LCG while sexual dimorphism was in favour of males (p < 0.05). Cluster 4 exhibited the highest final BW, whereas Cluster 3 had the greatest total weight gain, indicating a distinct tendency for early and late-stage growth, which could be strategically zoptimized for selective crossbreeding to combine their complementary traits. Network analysis indicates historical gene flow and possible heterozygosity within the population, with Normal and Feathered shank phenotypes potentially serving as genetic bridges for performance traits, while the distinct peripheral positioning of Feathered leg and Naked neck, linked only to Clusters 1 and 2, suggests genetic distinctiveness. GLS-ANCOVA confirmed Cluster 3 and 4, as the most significant predictors of TWG (p<0.001), alongside sex (p<0.05) and LCG (p<0.05). Integrating cluster and network analysis can enhance sustainable breeding strategies in low-input systems, balancing growth efficiency with genetic diversity. Breeders and policymakers are encouraged to adopt systematic performance recording practices and promote cross-cluster crossbreeding within local flocks. https://psj.gau.ac.ir/article_7406.html The type of fiber utilized in broiler diets at different ages has not been extensively studied, and the data supporting this theory are rare. A total of 160 hatched Ross 308 male broiler chicks were randomly distributed among four dietary groups, each with four replicates and ten chicks per replicate. The treatment groups were as follows: basal diet without any additives until the finisher period (Control); diet containing 3% rice hull (RH) in the grower period and 3% sugar beet pulp (SBP) in the finisher period (RG-SF); diet containing 3% SBP in the grower period and 3% RH in the finisher period (SG-RF); and diet containing 1.5% RH and 1.5% SBP in the grower and finisher periods (RS-GF). The findings indicated a significant improvement in the feed conversion ratio of broilers in the RG-SF group from days 11 to 24, as well as in body weight gain in the RG-SF and RS-GF groups from days 11 to 42 (P < 0.05). The proventriculus and gizzard percentage in the SG-RF group increased at 24 and 42 days of age, respectively (P < 0.05). At 42 days of age, the greatest percentage of thigh and intestinal weights was observed in the RG-SF group (P < 0.05). The small intestinal relative length decreased at 24 and 42 days of age in the RS-GF group compared to the control group (P < 0.05). In conclusion, our results showed that the 3% RH and 3% SBP in broiler diets at grower and finisher periods, respectively (RG-SF group), and supplementation with 1.5% RH and 1.5% SBP in both grower and finisher periods (RS-GF group) could improve broiler performance. https://psj.gau.ac.ir/article_7407.html The use of alternative feed additives, such as prebiotics, probiotics, or their combination (synbiotics), can help control pathogens and enhance the physiological performance of poultry. This study evaluated the effects of dietary probiotic and prebiotic supplementation on productive performance, egg quality, blood parameters, gut morphology, carcass traits, and cecal microflora in Japanese laying quails. A total of 196 laying quails, 22 weeks old, were randomly assigned to seven dietary treatments with seven replicates of four birds each for 56 days: basal control diet (C), 1% whey powder (W), whey powder + 1% dried mealworm (WM), whey powder + Lactobacillus plantarum (WB), whey powder + commercial probiotic (100 g/ton) (WP), mealworm + Lactobacillus plantarum + whey powder (MBW), and mealworm + commercial probiotic + whey powder (MPW). Egg production, feed conversion ratio, and most egg quality traits were not significantly affected by dietary treatments (P > 0.05). Feed intake was significantly reduced in the W, WB, MBW, and MPW groups compared with the control (P < 0.05). Gut morphology was significantly altered, with supplemented diets generally increasing duodenal villus length, villus width, and villus-to-crypt ratio compared with the control (P < 0.05). Whey supplementation increased serum protein, phosphorus, and triglyceride levels, whereas combining whey with probiotics and prebiotics mitigated the rise in triglycerides (P < 0.05). No significant differences were observed in carcass yield, internal organ weights, or cecal Lactobacillus and Escherichia coli counts (P > 0.05). In conclusion, dietary supplementation with prebiotic and probiotic sources, whether administered individually or in combination, improved specific gut morphological traits and modulated selected blood biochemical parameters without compromising performance or egg quality in laying Japanese quails. https://psj.gau.ac.ir/article_7408.html This study examined the effects of feed restriction and prebiotic supplementation on broiler chickens’ performance, immune response, gut microbiota, and intestinal morphology. A total of 240 one-day-old male Ross 308 broilers were randomly assigned to four treatments: control (C), feed restriction (FR), prebiotic supplementation (P), and a combination of prebiotic supplementation with feed restriction (FR+P). The prebiotic contained mannan-oligosaccharides (MOSs) and beta-glucans at 0.1% of the diet. Feed restriction was set at 80% ad libitum intake during the second week. The findings indicated that prebiotic supplementation increased the feed intake and weight gain, particularly during the early growth phase (p< 0.05). Feed restriction resulted in low daily weight gain and impaired cellular immune response (p< 0.05); however, these detrimental effects were partially mitigated by prebiotic supplementation. The FR+P group treated at 21 days had higher counts of Lactobacillus with lower coliform counts in the cecum (p< 0.05). Moreover, prebiotic supplementation improved intestinal morphology as indicated by an increase in villus height and crypt depth of the duodenum and jejunum with a significant effect in the FR+P and P groups (p< 0.05). The FR+P group recorded the highest villus height of the duodenum at 21 days, whereas the highest jejunal villus height and duodenal crypt depth were observed in the P group at 42 days (p< 0.05). The cell-mediated immunity, as determined by footpad swelling following the injection of PHA, was greatly enhanced in birds fed prebiotics compared to birds with feed restriction alone (p< 0.05). Overall, prebiotics, particularly with feed restriction, enhanced gut health, immune function, and intestinal morphology, suggesting their potential in broiler production. https://psj.gau.ac.ir/article_7409.html Accurate gastrointestinal transit time was essential to the digestibility determination tests. However, the effects of different feedstuffs on intestinal transit time remain unclear. The aim of this study was to investigate the effect of different feedstuffs on the gastrointestinal transit time of 18-wk-old geese. A total of 80 male Magang geese of 18 weeks old were weighed individually and randomly divided into 10 groups with eight geese per group. Ten treatment groups were fed corn, sorghum, wheat, soybean meal, cottonseed meal, rapeseed meal, 25% rice bran and hulls (RBH), 50% RBH, 75% RBH, and 100% RBH, respectively. Fresh excreta samples were collected and weighed from each pen every 6 h during the next 48 h after being tube-fed. Excreta weight increased significantly during the first 24 h after tube-feeding of all feedstuffs (P < 0.05). From 24 to 48 h, no significant changes were observed in excreta weight following tube-feeding of cereal or protein source feedstuffs (P > 0.05). In contrast, birds tube-fed diets containing 25% to 100% RBH showed a progressive increase in excreta weight from 24 to 36 h post–post-tube-feeding, after which excreta output remained stable. No significant changes in TiO₂ recovery were observed in excreta following tube-feeding of cereal or protein source feedstuffs from 24 to 48 h, whereas birds tube-fed diets containing different levels of RBH showed an increase in TiO₂ recovery from 24 to 36 h, which then remained stable. In conclusion, for Magang geese, the optimal gastrointestinal transit time was 24 h for cereal and protein source feedstuffs, in which diets with different fiber contents require a relatively prolonged period of 24-36 h. https://psj.gau.ac.ir/article_7584.html This study evaluated the effects of organic selenium supplementation at different concentrations on laying hen performance, egg quality, and antioxidant status. We hypothesized that increasing levels of organic selenium would improve egg quality, antioxidant capacity, and Se deposition, outperforming inorganic selenium. This study provides novel insights by using a unique yeast strain (PTCC5052) and evaluating nonlinear Se dose–response patterns. A total of 360 Super Nick hens (38 weeks old) were randomly assigned to six groups and fed either a control diet (no selenium), a diet with 0.3 mg/kg Se from an inorganic source, or 0.1, 0.2, 0.3, or 0.4 mg/kg Se from an organic source derived from Saccharomyces cerevisiae PTCC5052—a unique yeast strain. Over 10 weeks, egg production, feed conversion ratio, egg quality, and Se deposition in eggs were assessed. Production performance was not significantly affected by selenium supplementation. However, hens receiving 0.3 and 0.4 mg/kg of organic Se showed significantly thicker eggshells and higher egg selenium content (p < 0.05). Antioxidant enzyme activities (glutathione peroxidase, superoxide dismutase) were significantly enhanced in organic Se groups, while malondialdehyde levels were reduced (p < 0.05). The strongest antioxidant capacity was observed at 0.1–0.2 mg/kg Se, suggesting a nonlinear dose–response pattern. Serum protein, uric acid, AST, and ALT remained unchanged. These results demonstrate that organic selenium from S. cerevisiae PTCC5052 improves egg quality and antioxidant capacity without affecting production performance, highlighting the importance of selenium source and dose–response dynamics. https://psj.gau.ac.ir/article_7585.html Feed form affects the physiology of the gastrointestinal tract of pullets, but the optimum time of pelleted diet feeding during the rearing period should be determined to achieve optimum performance. This experiment evaluated the effects of feed form (mash or pelleted) on pullets' productive performance when fed during different rearing periods. Five treatments included: feeding a mash diet from hatching to 14 wk (MA14), feeding a pelleted diet from hatching and shifting to the mash diet at the end of the 4th (PE4), 8th (PE8), and 12th (PE12) wk, and feeding a pelleted diet from hatching to the 14th wk (PE14). Results showed that the average daily feed intake (ADFI) and average daily gain (ADG) increased linearly with increasing pelleted feeding time from 0 to 14 weeks (p < 0.01). Pullets shifted from a pelleted to a mash diet at any age had a poorer overall FCR than those fed either diet continuously (p< 0.05). The gizzard weight was linearly decreased by increasing the pelleted diet feeding time from 0 to 14 wk (p<0.01). The jejunal absorptive surface area was lower (p<0.01) in pullets fed PE4, PE8, and PE12 diets than in those fed the MA14 diet. In examining the relative weights of internal organs, tibia bone quality, and feather score, no significant differences were observed among the experimental treatments. The results showed that feeding pullets a pelleted diet throughout the rearing period increased ADFI and ADG but led to poor gizzard development. However, pullets that shifted from a pelleted to a mash diet at 4, 8, and 12 wk of age had a well-developed gizzard compared to those fed a pelleted diet continuously. https://psj.gau.ac.ir/article_7582.html The aim of the research was to determine the impact of an in Ovo injection of ascorbic acid and creatine pyruvate in the amnion of viable eggs on day 17 of incubation through evaluation of hatchability percentage as well as antioxidant status (Reduced glutathione (GSH) and Malondialdehyde (MDA)) and creatine kinase in pectoral muscles, blood glucose level and histopathology of liver and intestine. After the non-fertilized eggs were removed, 180 eggs that were to hatch were divided into three groups of 60. The first group was the control group, which did not receive any treatment; the positive control group received 0.6 ml of physiological saline; and the treated group received an injection of a mixture of ascorbic acid and creatine pyruvate (12 mg of creatine pyruvate and 3 mg of pure ascorbic acid were dissolved in 0.6 ml of saline). The results indicated that the treated group showed a significant increase in chick weight, hatchability percentages, creatine kinase, GSH activities in pectoral muscle tissue and blood glucose level when compared with the control and positive control groups. Moreover, the treated group showed a significant decrease in MDA concentrations in pectoral muscle tissue when compared with the control and positive control groups at P < 0.05. Furthermore, the intestinal villi of the treated group exhibited increased villus length and width as well as enhanced muscle size relative to the control and positive control, whereas there was a notable reduction in hepatocyte cellular vacuolation in the treated group when compared with the control and positive control. These results imply that the incubation of viable chicken eggs can be optimized through the administration of ascorbic acid and creatine pyruvate injections