Veterinary Research Forum

Abstract The present study was conducted to investigate the effect of L-carnitine (LC) supplementation in diets containing different levels of fish oil (FO) on performance, egg quality parameters and egg yolk fatty acids (FAs) profile in aged laying hens. In this study, 432 laying hens (Hy-line-W36, 65 weeks of age) were used allocated in a 3 × 3 factorial design with 6 replications and 8 birds per replication. The experimental treatments included diets containing 3 levels of FO (0, 1.5 and 3% of the diet) and 3 levels of LC (0, 300 and 600 mg/kg of the diet). The results showed that hens treated with 3% FO and 300 and 600 mg LC had the highest egg production rate, egg weight and egg mass, which was significantly higher than the treatments without FO and LC. With increasing usage level of FO to 3% of diet, egg yolk pH decreased significantly (p <0.05), however, yolk pH increased when diet supplemented with 600 mg LC. The percentage of polyunsaturated FAs (PUFA), the ratio of PUFA/saturated FAs (SFA) and the percentage of omega-3 FAs increased significantly with increasing FO usage level in the diet (p <0.05). Therefore, the use of LC in a diet containing FO not only increased egg production performance and egg internal quality (Haugh unit and yolk color) of aged laying hens, but also increased the production and deposition of omega-3 FAs in egg yolk.

Abstract In the recent years, the use of medicinal plants to reduce the effects of mycotoxins in foods and feeds has been considered. This study was conducted to investigate the effects of Aloe vera on performance, serum biochemical parameters and liver histopathology in laying hens fed on aflatoxin B1 (AFB1)-contaminated diet. Seventy-two White Leghorns (Hy-Line W-36) were randomly allocated to four treatments. 1) basal diet (control), 2) control plus 1.00 mg kg^-1 AFB1, 3) control diet plus 1.00 mg kg^-1 AFB1 + 100 ppm Aloe vera powder, and 4) control diet plus 1.00 mg kg^-1 AFB1 + 300 ppm Aloe vera powder. Each treatment consisted of three replicates of 6 birds. Egg weight and Haugh units were not affected by AFB1. Egg production and eggshell thickness were lower for groups fed 1.00 mg kg^-1 AFB1. Egg production, egg weight and eggshell thickness were improved by incorporation of Aleo vera in the AFB1 contaminated feed but were not significant. Chickens fed AFB1 had significantly lower aspartate aminotransferase (AST), alanine aminotransferase (ALT) and uric acid and higher cholesterol than other groups. Aloe vera powder improved levels of cholesterol, uric acid, AST, and ALT. AFB1 also caused histopathological changes in liver tissues, such as vacuolar degeneration, fatty infiltration, and necrosis. The addition of Aloe vera powder to the aflatoxin containing diet reduced the severity of lesions in liver. The data demonstrated the ability of Aloe vera to reduce the adverse effects of AFB1 exposure in laying hens.

Abstract The present study was carried out to determine the effects of fenugreek powder (FP) and extract (FE) on performance, egg quality, blood parameters and immune responses of laying hens. One-hundred and fifty Leghorn laying hens were used in a completely randomized design with five treatments and five replicates for eight weeks. Treatments were various levels of FP and FE including zero (control; T1), 1.00% FP (T2), 2.00% FP (T3), 0.10% FE (T4) and 0.20% FE (T5).The results of this experiment showed that feed intake was increased linearly by the inclusion of FP compared to the control group. Supplementation of laying hens diet with 2.00% FP adversely affected feed conversion ratio (FCR). The FCR was decreased by 0.10% inclusion of FE compared to 0.20%. Egg yolk color was the highest when 1% FP added to laying hens diets compared to the other treatments. Serum metabolites and immune responses of laying hens were not affected significantly by fenugreek supplementation. From the results of the present study, it can be concluded that using 1.00% FP can improve feed intake by supporting FCR. Inclusion of 1.00% FP in laying hens diet enhanced egg yolk color of laying hens in the second production cycle.

Abstract This study was performed to investigate the effects of antibiotic, organic acid, probiotic and prebiotic supplementation on performance, egg shell quality, pH value of gastrointestinal (GI) tract and small intestinal morphology of laying hens. The experiment was a completely randomized design with 160 laying hens strain (W-36) from 32 to 42 weeks of age, with five treatments, four replicates and eight hens in each replicate. The experimental treatments consisted of: 1-basal diet, 2-basal diet + 150 g per ton antibiotic (oxytetracycline), 3-basal diet + 3 kg per ton mixture of organic acids supplementation, 4- basal diet + 50 g per ton probiotic (protoxin) and 5-basal diet + 2 kg per ton prebiotic (mannan oligosaccharide). During the experimental period, performance characteristics were evaluated. At the end of experiment two birds per replicate was sacrificed for small intestinal morphology. The results showed that organic acid and mannan oligosaccharide significantly increased average egg weight. Also feed conversion ratio significantly improved by mannan oligosaccharide. Eggshell quality was not significantly affected by dietary treatments. Regarding gastrointestinal tract characteristics, pH value of different parts of GI tract were significantly affected by dietary treatments. Villi height in duodenum by probiotic and in ileum by mannan oligosaccharide significantly increased. Villi width in duodenum by antibiotic and probiotic and in ileum by mannan oligosaccharide significantly increased. The number of goblet cells in duodenum by addition of antibiotic and in ileum by mannan oligosaccharide significantly increased. It was concluded that the use of organic acids and mannan oligosaccharide could have positive effects on performance of laying hens.