No abstract

Seven duplicate floor pens with 20 day-old commercial broiler chicks each were fed a practical type broiler diet formulated with guineacornlpalm kernel meal and supplemented with graded levels of biotin (0.00, 0.04, 0.08, 0.12, 0.16, 0.20 and 0.24

A total of 480 day-old broiler chicks were used in two trials conducted to investigate the performance and lipid contents of blood, liver and kidneys of birds when fed varying levels of palm kernel oil (0% and 2%) and biotin (40, 80, 120, 160, 200 and 240 mcg/kg feed) in a 2 x 6 factorial experimental design. The results showed that blood, liver and kidney lipid concentrations were significantly affected by dietary biotin treatments. While total lipid, free fatty acid, triglyceride and cholesterol contents were negatively correlated with dietary biotin level, phospholipid concentrations were positively correlated. Biotin-deficient chicks had significantly higher total lipid, free fatty acid, triglyceride and cholesterol but lower phospholipid contents in their blood and the two organs. Supplementation of the diet with 2% palm kernel oil significantly elevated blood phospholipid concentration, but depressed the accumulation of the other lipid fractions in both organs and the blood of birds. Blood, liver and kidney cholesterol concentrations were not affected by 2% fat supplementation. Observation on the lipid parameters coupled with the results on feed utilisation appeared to suggest that a minimum of 120 mcg of the vitamin per kilogram of diet was required by broiler chicks for optimum performance.

A total of 560 day-old commercial broiler chicks were used in two experiments conducted to investigate the biotin requirement of broilers fed sunflower seed meal (SSM) based diets. Two basal biotin-deficient diets based on dehulled (Experiment 1) and non-dehulled (Experiment 2) SSM were each supplemented with graded levels of biotin so that the rations had 40, 80, 120, 160, 200, 240 and 280 mcg/kg feed. Therefore a total of 14 treatments were tested. Each treatment was given to duplicate floor pens with 20 chicks each for a period of 28 days. Estimation of the live weights, live weight gain, feed intake, blood glucose and free fatty acid concentrations, lipid contents and weights of liver and kidney, and liver pyruvate carboxylase activity and the records of incidence of dermal lesions, fatty liver and kidney syndrome (FLKS) mortality and leg deformities indicated that in the case of dehulled SSM, dietary biotin of of 160 mcg/kg feed was marginal while at least 200 mcg/kg appeared to be needed for optimum performance of the birds. When non-dehulled SSM was incorporated in the diet, 200 mcg biotin/kg feed was found to be the lowest dietary level needed. However, as it seems that better results could be obtained with higher levels, 240 mcg biotin/kg with non-dehulled SSM is being recommended.

A total of 350 day-old commercial broiler chicks were used in a trial aimed at estimating niacin requirement of broilers fed practical ration based on maize - palm kernel meal. The test diet was supplemented with varying levels of racin so that the rations had 15.0, 22.5, 30.0, 37.5, 45.0, 52.5 and 60.0 mg of the vitamin per kg of feed and were fed to 7 duplicate floor pens with 25 chicks each. The treatments were maintained for a period of 42 days. Estimation of live weight gain, feed intake, apparent utilisation of nitrogen, metabolizable energy, calcium and phosphorus and carcass characteristics, and the incidence of dermatitis and leg deformities showed that dietary niacin level of 37.5 mg/kg feed was adequate for achieving good nutrient utilisation, optimising productive performance and for maintaining good health.