Substitution of dry Leucaena leucocephala (DLL) leaves for cotton seed cake (CSC) as a protein supplement to urea treated maize stover fed to dairy weaner goats

Twelve males and twelve females weaner goats with mean initial body weight of 12.6±2.6 and receiving ensiled (14 days) chopped maize stover treated with urea (30 g urea in 600 ml of water kg−1 dry matter (DM) maize stover) and a protein supplement containing 30%, 67% and 3% of cotton seed cake (CSC), maize bran (MB) and a mineral mixture, respectively, were randomly allocated to four dietary treatments. These consisted in the replacement of 1/3, 2/3 and 3/3 of CSC and proportional amounts of maize bran by dry Leucaena leucocephala (DLL) to achieve iso-protein diets. Feed intake and growth performance were recorded for 90 days. Nutrients digestibility and nitrogen utilization was also performed on the 12 male goats allocated to treatments. The DM, crude protein (CP) and metabolizable energy (ME) intakes were not significantly (P>0.05) different between treatments and mean daily gains were not significantly (P>0.05) affected by dietary treatment. Digestibility coefficients of DM, organic matter (OM) and CP decreased with increasing levels of leucaena in the diets, but the differences between diets were small. Digestibility coefficients of neutral detergent fibre (NDF) and acid detergent fibre (ADF) were significantly (P<0.05) reduced when CSC was wholly replaced with DLL. The highest efficiency of N utilization (68.97±5.14%) was shown by goats on treatment 3 (T3). It can be concluded that DLL can substitute up to 2/3 of CSC as a protein supplement to goat weaners without reduction in performance.