Effects of protein content on feed intake and performance of grasscutters fed diets containing forage meal

Abstract

The potential of grasscutters (Thryonomys swinderianus) as a source of animal protein can be exploited with better understanding of its nutrient requirement. This experiment was conducted to determine the protein requirement of growing grasscutters fed formulated diets containing forage meal. Twenty-four growing grasscutters, in groups of four, were randomly allotted to four treatment diets formulated to respectively supply 14, 16, 18 and 20% crude protein (CP). Parameters measured included daily feed intake, daily weight gain (growth rate), final bodyweight, feed conversion ratio and cost-to-gain ratio. Dietary protein significantly (P < 0.05) influenced daily weight gain, as well as the final liveweights of the animals. The mean daily weight gain of the animals fed the 18% CP diet was not significantly (P > 0.05) different from those fed the 20% CP diet (12.8 vs 11.7 g/day), but was significantly higher than animals fed the 16% (6.4 g/day) and 14% (7.0 g/day) CP diets. The mean feed conversion ratios of the animals fed the diets with 18% CP (4.1) was, however, only significantly (P < 0.05) different from animals fed diets with 16% (7.2) and 14% (6.3) CP. Given the overall economic importance of low cost-to-gain ratio, and the profitability of the diets thereof, these results suggest that 18% is the optimum CP level for economically feeding growing grasscutters on formulated diets containing forage meal.