Veterinary Research Forum

Abstract This study aimed to examine the effects of varying levels of L-carnitine and omega-3 and omega-9 fatty acids on performance, blood parameters, and testicular histomorphometry in fattening male Moghani lambs. Thirty-five five-month-old male Moghani lambs (27 ± 600 kg) were individually housed and randomly assigned to five dietary treatments. Diets included a control and four diets containing 3% calcium salts of omega-3 or omega-9 fatty acids with 100 or 200 mg/kg DMI of L-carnitine. Lambs were fed for 75 days to evaluate growth performance, nutrient digestibility, blood metabolites, carcass traits, and testicular histomorphometry.The results indicated significant effects on daily weight gain during the second month, average weight gain in the second month, and feed conversion ratio in the third month (P<0.05). However, glucose, total cholesterol, LDL cholesterol, triglycerides, blood urea nitrogen, and HDL cholesterol levels on day 30, as well as triglyceride levels on day 60, were not significantly influenced by dietary treatments. Blood urea nitrogen and HDL cholesterol levels, along with total protein, were significantly affected on day 60, with dietary treatments having a marked influence (P<0.05). Liver enzyme activities, including aspartate aminotransferase (AST) and alanine aminotransferase (ALT), were significantly affected during the first 30 days of the study (P<0.05), while alkaline phosphatase (ALP) activity remained unaffected over the 30 and 60-day periods. Testicular histomorphometry showed significant effects of dietary treatments on spermatogenesis index, seminiferous tubule diameter, and Leydig cell count (P<0.05).

Abstract Nutritional interventions play a pivotal role in sustaining egg production performance and improving egg quality parameters in aged laying hens. 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 and allocated in a 3 × 3 factorial design with six replications and eight birds per replication. The experimental treatments included diets containing three levels of FO (0.00, 1.50 and 3.00% of the diet) and three levels of LC (0.00, 300, and 600 mg kg^-1 of the diet). The results showed that hens treated with 3.00% 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 3.00% of diet, egg yolk pH was significantly decreased, however, yolk pH was increased when diet was supplemented with 600 mg LC. The percentage of polyunsaturated FAs, the ratio of polyunsaturated FA/saturated FAs and the percentage of omega-3 FAs were increased significantly with increasing FO usage level in the diet. Overall, these findings suggested that dietary supplementation with FO and LC could synergistically improve productive performance and enhance the nutritional value of eggs in aged laying hens.