Effects of Two Planes of Nutrition on Performance and Uniformity of Four Strains of Broiler Chicks

Growers of broilers have recommended feeding lower protein feeds in order to reduce feed cost and nitrogen content of litter. However, the impact that very low protein feeds may have on broiler performance has not been thoroughly investigated. Therefore, two planes of nutrition (Standard=NRC-recommended level; or Low=66.1-69.5% as much protein) were fed to each sex of four broiler strains to 8 wk of age. Body weight, feed conversion, mortality, carcass yield, and uniformity were determined. Birds on the Low plane of nutrition had lower body weights, higher feed conversion, decreased carcass yield, and increased abdominal fat pad. In addition, the Low plane of nutrition decreased body weight uniformity and decreased uniformity of parts yield. However, the Low plane of nutrition reduced mortality to 6 wk of age and increased the percentage of dark meat yield. The data indicate that uniformity may be negatively impacted by a lower than NRC plane of nutrition, but careful application of low protein diets along with selection of an appropriate processing age will minimize the negative impact.