Effects of Dietary Calcium, Phosphorus, Biotin, and Fat on the Performance and Nutrient Utilization of Meat Chickens

The effects of different dietary levels of calcium (Ca), available phosphorus (AP), biotin, fat and different types of fat on 5-to 19-day growth performance, liver biotin concentration, and nutrient utilization of meat chickens were investigated in two experiments. A high Ca diet (25.4 vs. 12.2 g/kg) reduced growth and feed efficiency of meat chickens, while a high Ca and AP diet (25.7 & 11.9 g vs. 12.2 & 5.2 g) caused further depression in performance. Neither 125 ug biotin/kg diet nor 4% tallow, 4% vegetable oil or a mixture of 2% vegetable oil and 2% tallow appeared to completely overcome the growth depression caused by a high Ca diet. The addition of 125 ug/kg biotin in combination with 4% vegetable oil or a mixture of 2% vegetable oil and 2% tallow, appeared to completely overcome the growth depressing effect of a high Ca diet but not of a high Ca and high phosphorus diet. It was concluded that the addition of biotin and vegetable oil to high Ca diets was successful in preventing growth depressio