Animal Nutrition and Feed Technology

A study was conducted to observe the effect of feeding canola oil and vitamin A on production performance, blood metabolites and immune response of commercial egg layers. A total of 240 laying hens were distributed into eight treatments each containing three replicates of 10 birds, and fed on diets with 0, 2, 3 and 4% canola oil with either 3,000 or 10,000 IU vitamin A/kg of diet for a period of 12 weeks. During the study, egg production was recorded daily while the feed intake was recorded at weekly intervals. For immune response, blood samples were collected at 0, 14, 28 and 35^th day following revaccination against Newcastle Disease. Blood samples were also collected in the last week of the trial to measure the blood glucose and cholesterol level. The results of the study depicted that the production response of laying hens was not affected by the supplementation of canola oil and vitamin A except for a reduction (P<0.05) in feed intake in the hens on the 3% canola oil diet. The WB was affected negatively (P<0.05) with the increase in dietary canola oil. The serum cholesterol and blood glucose were similar (P>0.05) for the all dietary treatments. However, the antibody titer response to Newcastle Disease vaccination was enhanced (P<0.05) by increasing the supplemental levels of canola oil and vitamin A in the rations. It was concluded from the results that canola oil (4% of diet) and vitamin A (10000 IU/kg of diet) can enhance the immune response of laying hens without affecting laying performance.