Effects of Graded Levels of Rice Bran Oil on Laying Performance, Blood Parameters and Egg Yolk Cholesterol in Hy-Line Laying Hens

摘要

This study aimed to determine the effect of different dietary level of rice bran extract (RBO) on the laying performance, egg quality, blood parameter, cholesterol, and fatty acids in yolk of Hy-Line Laying hens. In all, 144 Hy-Line Brown laying hens(29 weeks old) were randomly allocated to one of 4 dietary treatments, with 4 replicates per treatment. A commercial basal diet was used and three additional diets were prepared by supplementing 2.5, 5.0 or 10.0 g/kg of RBO to the basal diet. The experimental diets were fed on an ad libitum basis to the bird during 8 weeks. Hen-day egg production increased (quadratic, p<0.05) with inclusion level of RBO, but feed intake, egg weight, and egg mass were not influenced by inclusion of level of RBO in diet.However, the supplementation of RBO did not have an effect on eggshell strength, eggshell thickness, egg yolk color, and HU during the feeding trial. There were no significant differences in the level of leukocyte. However, heterophil and lymphocytes decreased (quadratic, p<0.0) with inclusion level of RBO. H:L ratio tended to decrease (linear yp=0.08) with inclusion level of RBO. As expected, increasing inclusion level of RBO in diets decreased (linear, /><0.01) the concentrations of total cholesterolin plasma. AST, ALT, glucose, and albumin were not affected by inclusion of RBO in diets. Egg yolk cholesterol increased (linear and quadratic, p<0.05) with inclusion level of RBO in diet. The results of this study indicate that dietary supplementationof RBO improves laying performance and decreased total cholesterol and egg yolk cholesterol levels in laying hens. Therefore, dietary RBO is considered a valuable functional ingredient to improve the performance of birds.