Nutrient digestibility coefficients of some plant and animal proteins for rohu (Labeo rohita)

Abstract

Apparent protein digestibility (APD), apparent lipid digestibility (ALD) and true protein digestibility (TPD) coefficients of some plant and animal protein were determined for fingerling rohu. The plant protein ingredients were incorporated as the sole source of protein into test diets giving 30% protein. Animal protein ingredients were included in test diets to give a 35% protein level. A protein free diet was used to study the true protein digestion coefficients. Of the plant protein sources tested, soybean meal produced the highest APD (84.06%) and TPD (88.63%) (P < 0.05) and sesame diet the lowest APD (76.16%) and TPD (80.55%) values. Linseed diet had higher (P < 0.05) APD (81.55%) and TPD (86.00%) than that of mustard diet but there were no differences between the ALD value of linseed, sesame and mustard diets. Among the animal proteins tested, both formic and sulphuric acid treated fish silages, silkworm and deoiled silkworm pupae produced significantly better APD and TPD values than those of fish meal. The APD and TPD values of the various animal protein diets varied between 80.23 to 85.21% and 84.18 to 89.08%, respectively. The TPD values for animal proteins showed similar trends as that of plant proteins. In general, ALD values for all the diets tested were higher than those of the APD values. The results of the study indicated that L. rohita may be able to utilize the above mentioned ingredients efficiently.