Effects of coccidiostats and dietary protein on performance and water consumption in broiler chickens

Two, 7-week floor pen experiments were conducted consecutively with male broilers and then female broilers to determine the effects of feeding salinomycin (60 ppm), monensin (99 ppm), or lasalocid (125 ppm) at the following three levels of dietary protein: 1) that which meets National Research Council specifications (NRC, 1977), 2) that level deficient in sulfur amino acids (SAA), or 3) that deficient in protein. Group body weights, feed intake, and water consumption were noted at 28 and 49 days of age with feed efficiency and overall mortalities determined. Reducing SAA resulted in depressed (P less than .05) body weights at 7 weeks in both experiments, whereas deficient protein reduced (P less than .05) growth, feed efficiency, and water consumption. Generally, inclusion of coccidiostats in the diet did not significantly hinder growth or feed efficiency. Feeding of coccidiostats in combination with the low protein diet did not produce additional anorexigenic effects. Although a significant lasalocid SAA-sparing effect was not observed, diet X coccidiostat interactions (P less than .05) were apparent and attributable to an apparent "protein-sparing" effect upon body weight gain when salinomycin was fed in combination with the low protein diet. Lasalocid increased water consumption (P less than .05) relative to monensin in the female broilers.