Journal of Animal Production, Print ISSN: 2008-6776., Online ISSN: 2382-994X

Abstract Objective: The honey bee, as one of the most important pollinators in agricultural and natural ecosystems, comprises 10 species belonging to the genus Apis, family Apidae, and order Hymenoptera. One of the most significant species is the European honey bee (Apis mellifera L.), which is now found in most parts of the world. One method for identifying them is through morphometric characteristics, which not only serve as a key tool in their classification but also show a significant correlation with colony performance, efficiency, and adaptation. The aim of this study was to compare the morphometric traits of the native Iranian honey bee (Apis mellifera meda) with the Buckfast hybrid (Apis mellifera buckfast) under the climatic conditions of Gorgan.
Method: The research was conducted at the honey bee breeding farm of Gorgan University of Agricultural Sciences and Natural Resources in July 2025. Six colonies from each genotype were selected, and from each colony 10 worker bees were randomly collected from the entrance of the hive. In total, 120 specimens (60 from each genotype) were anesthetized with ethyl acetate and preserved in 95% ethanol. The target body parts were then dissected and mounted on microscope slides using Canada balsam.Subsequently, 11 traits were measured under the standard Ruttner protocol using a stereomicroscope equipped with a digital camera and image analysis software. These traits included forewing length and width, wing venation angles A4, D7 and G18, cubital index (length of veins a and b in the cubital cell), hind leg components (length of femur, tibia and first tarsal segment), and proboscis length. All data were organized in Microsoft Excel and statistically analyzed in SAS using the t-test and Pearson’s correlation coefficient.
Results: The results showed that the Buckfast breed had significantly greater forewing length and D7 angle than the native Iranian breed (P < 0.05), while no significant differences were observed in the other morphometric traits. Correlation analysis indicated that in the Buckfast breed, significant relationships were mainly confined to within-wing traits. In contrast, in the native Iranian breed, significant positive correlations were observed between wing traits and locomotory traits (hind leg components). These findings suggest a greater structural integration and proportionality between flight and locomotory organs in the native Iranian breed compared with the Buckfast breed.
Conclusion: The results indicated that under the climatic conditions of Gorgan, Buckfast and native bees did not differ significantly in most morphometric traits, and the superiority of the Buckfast breed was limited to forewing length and the D7 angle. Considering the overall morphological similarity between the two breeds, relying solely on these traits is not sufficient to demonstrate the superiority of the Buckfast breed. Therefore, a definitive evaluation requires further studies focusing on functional traits such as productivity, foraging behavior, and resistance to diseases.

Abstract Objective: This study was conducted to evaluate the effects of different dietary levels of bee pollen (BP) on growth performance, immune responses, and serum biochemical parameters of broiler chickens. Considering the increasing interest in natural feed additives as alternatives to antibiotic growth promoters, BP was investigated as a functional ingredient with potential nutritional and physiological benefits.
Methods: A total of 192 broiler chicks were assigned to a completely randomized design with four dietary treatments and four replicates per treatment (12 birds per replicate) for 24 days. The experimental treatments included: 1) control diet (without bee pollen), 2) diet supplemented with three g/kg BP, 3) diet supplemented with six g/kg BP, and 4) diet supplemented with nine g/kg BP. Growth performance was evaluated during the starter (1–10 d), grower (11–24 d), and overall (0–24 d) periods. Immune responses and serum biochemical parameters were assessed at the end of the experiment.
Results: During the starter period, no differences were observed in daily weight gain (BWG), daily feed intake (DFI), and feed efficiency among treatments. During the grower period and the entire experimental period, the BWG of chickens receiving diets containing six and nine g/kg of BP was higher than that of the control group (P < 0.05). However, no differences were observed among treatments in DFI and feed efficiency during these periods. Antibody titers against and Newcastle disease virus and avian influenza virus, as well as the relative weights of the spleen and bursa of Fabricius, were not affected by the treatments. The relative weight of the thymus in chickens receiving six and nine g/kg of BP was higher than that of other chickens (P < 0.05). Serum triglyceride and very low-density lipoprotein levels in birds receiving diets containing nine g/kg of BP were lower than those in control chickens and those receiving three g/kg of bee pollen (P < 0.05). Serum alanine aminotransferase levels in birds receiving three and nine g/kg of BP were lower than those in control chickens (P < 0.05). Furthermore, total antioxidant capacity in the serum of birds receiving BP was higher than that of control chickens (P < 0.05). Creatinine levels (P = 0.057) and lactate dehydrogenase enzyme activity (P = 0.065) tended to decrease in chickens receiving BP.
Conclusion: Based on the results of this study, the addition of BP to the diet of broiler chickens, particularly at the level of nine g/kg, improved growth performance, relative thymus weight, lipid metabolism indices, liver enzyme activity, and serum antioxidant capacity. Therefore, the use of this level of BP as a natural and functional additive in the diet of broiler chickens is recommended.

Abstract Objective: This study was conducted to investigate the effect of palm oil, camelina oil, and whole camelina seeds on performance, nutrient digestibility, feeding behavior, and fecal score in fattening lambs.
Method: Thirty-two male lambs (mean age 3.5 months and initial weight 23.89 ± 0.48 kg) were fattened in a completely randomized design with 4 treatments and 8 replicates for 84 days. The treatments included: 1- basal diet without oil supplement (control), 2- basal diet containing 1.5% palm oil, 3- basal diet containing 1.5% camelina oil, and 4- basal diet containing 5% camelina seed. Lambs were housed individually with ad libitum fresh water. Body weight was recorded every 28 days and daily feed intake was measured. Nutrient digestibility was assessed using acid‑insoluble ash (AIA) as an internal marker during the final two weeks. Feeding behavior was observed over 24 h by instantaneous sampling every 5 min, and time spent eating, ruminating, and resting was calculated. Fecal consistency was scored weekly on a 1–5 visual scale. Data were analyzed with the General Linear Model (GLM) in SAS 9.4 and means compared by Duncan’s test (α = 0.05). All procedures followed the university’s animal‑care guidelines.
Results: Results showed that although feed intake decreased in oil-supplemented treatments (P < 0.001), yet daily weight gain and feed conversion ratio were not affected by treatments (P > 0.05). Average daily feed intake was ~12 % lower in the oil groups compared with control, while average daily gain (ADG) remained around 185 g day⁻¹ across all treatments. The digestibility of dry matter, organic matter, crude protein, and neutral detergent fiber (NDF) in treatments containing palm oil and camelina oil was significantly (P < 0.05) lower than that of the camelina seed treatment, while crude fat digestibility increased in these treatments. Lambs fed camelina seed had the longest time spent eating, ruminating, and chewing during the day (P < 0.001). Fecal score at the end of the period in treatments containing camelina (oil and seed) was significantly higher (softer) than in the palm oil and control treatments, indicating looser stools. No clinical signs of digestive disturbance were observed.
Conclusions: In general, the use of camelina seed, due to the protective effect of the seed coat on the rumen environment, led to the preservation of nutrient digestibility and improved rumination behavior, and also affected fecal consistency. The physical form of fat supply (seed vs. free oil) is a key factor in its effect on digestive processes in fattening lambs Incorporating camelina seed can increase diet energy density while maintaining fiber utilization—a practical strategy for lamb producers. Future work should test higher seed inclusion levels and assess long‑term effects on carcass composition, especially omega‑3 fatty‑acid enrichment.

Abstract Objective: Increasing feed costs and the shortage of conventional forage resources highlight the utilization of unconventional and readily available feed sources, such as green space tree leaves, as a practical strategy in ruminant nutrition. This study was conducted to evaluate the effects of substituting a portion of dietary forage with different levels of plane tree (Platanus orientalis) leaves on feed intake, productive performance, nutrient digestibility, blood biochemical parameters, and the antioxidant system status in Saanen dairy goats.
Method: The experiment was carried out using 18 multiparous Saanen goats (average milk yield 1.75 ± 0.72 kg/day and lactation days 52.7 ± 13.4) in a completely randomized design with three treatments and six replicates over a period of 56 days (14 days of adaptation and 42 days of the main experimental period). The experimental diets were as follows: 1- control (basal diet without plane leaves), 2- replacement of 20% of forage with plane leaves, and 3- replacement of 40% of forage with plane leaves, all of which were formulated to be isonitrogenous and isocaloric. Throughout the experimental period, dry matter intake and milk yield were recorded daily. Milk samples were collected for composition analysis, blood samples were taken to assess biochemical parameters (glucose, total cholesterol, lipids, and liver enzymes) and oxidative status indicators (total antioxidant capacity and malondialdehyde), and fecal and feed samples were gathered to determine apparent nutrient digestibility. The collected data were analyzed using the MIXED procedure of the SAS software.
Results: Replacing 20% of the dietary forage with plane leaves resulted in a significant increase in dry matter intake, daily milk yield, and 4% fat-corrected milk in Saanen goats compared to both the control group and the 40% replacement group (P < 0.05). Although the percentages of milk fat and total milk solids decreased in goats receiving plane leaves in their diet (P < 0.05), the daily yield (g/day) of protein, fat, non-fat solids, and total milk solids in goats from the 20% replacement group was significantly higher than in the other groups (P < 0.05). Feed conversion ratio and body weight changes were not affected by the experimental treatments. No significant differences were observed among treatments regarding the apparent digestibility of dry matter, crude protein, organic matter, and acid detergent fiber. However, replacing 40% of the conventional dietary forage with plane tree leaves led to a significant decrease in the digestibility of neutral detergent fiber and a significant increase in the digestibility of ether extract (P < 0.05). Regarding blood parameters, triglyceride concentration was higher in the 20% replacement group, while low-density lipoprotein concentration was significantly higher in the 40% replacement group compared to the other treatments (P < 0.05). Liver enzyme activities, including aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase, were not influenced by the dietary treatments. However, serum malondialdehyde concentration in the 40% plane leaf replacement group showed a tendency to decrease (P = 0.086).
Conclusion: In conclusion, the findings of this study indicate that plane tree leaves can serve as an alternative feed source, replacing up to 20% of the conventional forage in the diet of Saanen dairy goats. This level of substitution, while improving feed intake and productive performance, does not exert significant adverse effects on liver health, nutrient digestibility, or the antioxidant status of the animals. Higher substitution levels (40%) may be associated with a reduction in milk fat percentage, possibly due to the presence of secondary compounds. Therefore, the optimal utilization of this feed resource necessitates adherence to an appropriate substitution level.

Abstract Abstract
Objective: This experiment was conducted to investigate and compare the effects of probiotic supplements containing Bacillus subtilis and Enterococcus faecium on growth performance, intestinal morphology, and gastrointestinal microbial population of Arian strain broiler chickens. Given the benefits of adding probiotic supplements to the diet, a more detailed understanding of the mechanisms of action and comparative effects of these two probiotics can lead to targeted diet adjustment to improve feed efficiency, body weight gain, and reduce disease incidence in Arian strain broiler chickens.
Method: In this study, 500 mixed-sex Arian broiler chicks were utilized in a Completely Randomized Design (CRD) consisting of five experimental treatments and five replicates, with 20 chicks per replicate, from day 1 to 42 of age. The experimental treatments were as follows: (1) Control (corn-soybean meal-based diet without additives); (2) Control + Lincomycin antibiotic (500 mg/kg diet); (3) Control + Probiotic Supplement A (1 g/kg diet containing Bacillus subtilis and Bacillus licheniformis); (4) Control + Probiotic Supplement B (1 g/kg diet containing Lactobacillus spp. and Enterococcus faecium); and (5) Probiotic Supplement C (1 g/kg diet containing Saccharomyces cerevisiae yeast). The 42-day rearing period was conducted in three phases using diets formulated according to the Arian breed nutritional guidelines. On day 38, blood serum biochemical parameters were analyzed. On day 42, jejunal histological indices, including villus height, villus width, crypt depth, villus-to-crypt ratio, and absorptive surface area, were measured. Total bacterial count, lactic acid bacteria (LAB), Escherichia coli, and coliform populations in the feces were determined using the drop plate method.
Results: Birds receiving Lincomycin and probiotic supplements A and B exhibited significantly higher live body weight compared to the control group (P>0.05). The effect of experimental treatments on feed intake was not significant. The feed conversion ratio (FCR) was significantly lower in birds fed diets supplemented with either Lincomycin or probiotics than in the control group (P>0.05). Relative ileal length was significantly increased in probiotic-supplemented birds compared to the Lincomycin treatment group (P>0.05). Regarding small intestine morphology, the relative jejunal weight was higher in the Lincomycin group and lower in the group receiving probiotic supplement B (P>0.05). Crypt depth was highest in the Lincomycin-treated birds and lowest in those receiving probiotic supplements A and B (P>0.05). Furthermore, the addition of Lincomycin and probiotic supplement B significantly reduced the total aerobic bacterial count in the small intestine (P>0.05).
Conclusions: The results demonstrated that probiotic supplements containing Bacillus subtilis and Enterococcus faecium improved the growth performance of broiler chickens by enhancing body weight, feed conversion ratio, and intestinal morphological indices. Consequently, these probiotics could serve as effective alternatives to antibiotic growth promoters.

Abstract Abstract
Objective: This study aimed to investigate and evaluate the effects of in-ovo injection of vitamin C, L-glutamine and a combination of Vitamin C and L-glutamine on hatchability traits, growth performance, intestinal development, visceral organ weight, thyroid hormones profiles (T3 , T4) and serum malondialdehyde (MDA) levels of broiler chickens after hatching.
Method: Initially, 800 fertile eggs were obtained from Arbor Acres breeder hens older than 50 weeks of age. On the 18th day of incubation, 600 of these fertile eggs were placed in trays for injection at the site of the sterilizing device, weighing, and uniform distribution. In-ovo injection was performed in five experimental groups. The negative control group received no injection, while the positive control group received 0.5 ml of normal physiological serum. The third group was injected with 6 mg of vitamin C in saline, the fourth group with 6 mg of L-glutamine in saline, and the fifth group with a combination of 6 mg of vitamin C and 6 mg of L-glutamine in saline, each in a volume of 0.5 ml. After hatching, the necessary measurements were made in terms of chick weight, number of healthy chicks hatched, and hatching percentage. Then, all chicks were fed a standard pelleted basal diet during the initial, growth, and final stages.
Results The lowest hatchability rate was observed in the in-ovo Vitamin C injection group (P<0.05). Conversely, the control and in-ovo L-glutamine injection groups exhibited the highest hatchability rates (P<0.05). In-ovo Vitamin C injection resulted in the highest mean hatchling weight, whereas the in-ovo L-glutamine group showed the lowest mean hatchling weight (P<0.05). The combined in-ovo injection of Vitamin C and L-glutamine had no positive effect on hatchability or initial chick weight. Regarding performance, in-ovo injection of Vitamin C, L-glutamine, and their combination did not significantly affect feed intake, body weight gain, or feed conversion ratio (FCR); however, L-glutamine injection improved weight gain and FCR from 1 to 10 days of age (P<0.05). Vitamin C injection significantly decreased carcass, breast, and thigh weights and increased mortality (P<0.05). L-glutamine injection and the combination of Vitamin C and L-glutamine resulted in a relative decrease in thigh weight and a decrease in breast and thigh weights, respectively (P<0.05). The effect of Vitamin C injection on T3 levels at 14 days of age, as well as the effect of experimental groups on malondialdehyde (MDA) levels at 42 days of age, were significant (P<0.05). In-ovo injection of Vitamin C and the combination of Vitamin C and L-glutamine had a negative impact on villus height and the villus height-to-crypt depth ratio in the ileum (P<0.05). However, no significant differences were observed in the morphology of the duodenum and jejunum among the groups compared to the control.
Conclusion: In conclusion, despite the enhancement in initial hatchling weight, in-ovo Vitamin C supplementation proved detrimental, as it significantly reduced hatchability, compromised carcass yield, elevated mortality rates, and adversely affected ileal health. Conversely, in-ovo L-glutamine injection effectively preserved hatchability and optimized early-phase feed conversion, ultimately outperforming the other experimental groups in terms of overall performance.