Effects of blood meal, fish meal, soybean meal or casein on growth and body composition in lambs

Abstract

Thirty-two rams of Polish Merino breed, average initial body weight 25 kg (SE ± 0.8 kg) were fed isonitrogenous and isoenergetic diets in which the main sources of protein were blood meal (BM), fish meal (FM), soybean meal (SBM) or casein (C). The highest gains ( P < 0.05) were obtained in lambs fed FM diets (197 g day −1), followed by BM, SBM and C (181 g, 175 g and 114 g day −1, respectively). Lambs supplemented with C were characterised by the highest protein and energy consumption per kilogram body weight (BW) gain. Source of protein did not affect chemical composition of empty BW. The highest values of the k f coefficient were found in lambs fed FM (0.38) and the lowest in those fed C (0.20). Protein deposition was highest ( P < 0.05) in animals fed FM (35.5 g day −1), followed by BM, SBM and C (31.7 g, 30.0 g and 23.7 g day −1, respectively). FM was the optimal source of supplemental protein.