Bnutritive value of maize stover harvested at two stages of maturity and mixed with different types and levels of protein supplements

Abstract

Studies were conducted on maize stover harvested at grain milk (MM) or dry (MD) stages and mixed with graded ratios (20, 40, 60, 80%) of protein supplements (PS) including lucerne hay (LH), lespedeza hay (LPZ) and sunflower seed cake (SC). Automated in vitro gas production technique (TVGPT) was used. The degradability (Deg) was higher (P<0.001) in MM than MD (775.9 vs 720 g/kg DM). Also, MM rations had higher (P<0.001) gas production (GP) than MD. Only ST x PS interaction had effect (P<0.001) on the Deg:GP ratio i.e. the partitioning factor (PF), in which MD.LPZ rations had highest values apparently as a result of suppressed GP. The rate of GP from fibre fraction (b,) was increased (P<0.001) by PS although the margins were small across the rations. Supplementation of LPZ increased (P<0.01) lag time, which was highest in MD:LPZ rations. Among the PS, LH and SC had similar but superior nutritive effects relative to LPZ. It is suspected that the presence of tannins in LPZ might be responsible for the poor nutritive attributes observed. The results suggest that supplementation of the stover with at most 40% DM contributed by LH or SC would optimize their utilization. © GSP, India.