Use of oyster shell as calcium supplement. Part 1. Effect on the utilization of gossypol-containing cotton seed cake...

The comparative utilization of cottonseed cake (CSC) diet supplemented with varying levels of oyster shell (0.00, 1.50, 3.00 and 4.50%) as a source of calcium, and groundnut cake (GNC) based diet were evaluated in a feeding trial using 100 day-old HYPECO broiler-chicks. The response criteria included performance, carcass traits and economics of production. The weight gains at the end of the trial were not significantly different. However, feed consumption significantly (P less than 0.5) increased with increasing dietary calcium. Feed consumption was significantly (P less than 0.05) correlated with dietary calcium levels with r = 0.96. Feed efficiency and protein efficiency ratio were significantly (P less than 0.05) better in the GNC diets than CSC based diets in spite of the oyster shell supplementation of the latter. Both nitrogen retention and apparent nitrogen digestibility were not significantly influenced. The percent dressed weight, percent eviscerated weight and the relative weights of the thigh, drumstick, chest, back, head and belly fat were not significantly influenced by the dietary treatment. Only the relative weight of the shank was significantly (P less than 0.05) influenced. The cost-benefit analysis showed that although it was chapter to formulate CSC diets, profits were identical with GNC diets when fed to the chicks. It was suggested that CSC could be a good substitute for GNC because of the ready availability of the former. Dietary calcium of up to 1.82% was beneficial in the utilization of the CSC.