CRUDE PROTEIN REQUIREMENT OF GROWING COCKERELS BY DIET DILUTION TECHNIQUE

Abstract

An improved method called diet dilution technique was used (in place of the orthodox method) to design treatment diets to measure the crude protein (CP) requirement of the growing Isa Brown cockerels during 9 to 13 weeks of age. A 280gkg CP summit diet was serially diluted with an isoenergetic 25.6gkg CP dilution mixture to produce treatment diets containing 120, 140, 160, 180 and 200g/kg CP on as-fed basis with 2600 kcal/kg metabolisable energy content in diets A,B,C,D and E respectively. The diets were fed ad libifi~ittzo a total of 75 birds. Mean daily weight gain and feed conversion ratio (FCR) were improved signitlcantly (P60.05) as dietary CP content increased up to the level sf 180gkg CP diet beyond which there was no significant improvement. This diet (D) supported daily growth rate of about 20g/bird/day and FCR of 4.41. Feed cost per unit of gain on 180 and 200gkg CP diets were the same (ca 10 kobo) and lower than on the rest diets, with the highest feed cost (ca 17 kobo) per unit of gain recorded for diet A. ConcIusively, 180g/Kg CP diet would satisfy the protein reqrairenrcrrt of the growing cockerel for optimal growth rate and FCR and at minimal cost of feeding per unit of gain.