EFFECTS OF ENERGY AND PROTEIN LEVELS ON FEED INTAKE AND NUTRIENT UTILIZATION BY YANKASA LAMBS

Abstract

TWENTY yearling Yankasa lambs were fed 2 levels of energy (2.4 and 2.9 ME Mcal/kg) and 2 levels of protein (11.3 and 16. 1%) under each energy level for 100 days to study the effects of feed intake, digestibility and nutrient utilization. Groundnut top hay was the basal roughage while maize, wheat bran and cotton seed cake were the energy and protein supplements in different proportions. Hay intake decreased with increase in protein level. Dry matter digestibility significantly (P/0.05) increased with increase in both energy and protein levels. Crude protein digestibility was significantly (P/0.01) affected by protein level but not by energy level. Crude fibre digestibility was depressed in the high-energy-high protein diet. The consumption of nutrients tended to be more on the high energy rations. Nitrogen retention was also significantly (P/0.05) higher on the high energy rations. Liveweight gain was highest in the low energy/high protein group (79.4g/day) and lowest in the low energy/low protein group (56.4g/day). Within each energy level, liveweight gains increased with increase in protein level. Animals fed high energy rations required more protein than those on low energy rations.