Effect of Rumen Degradable Nitrogen Supplementation on In Vitro Digestibility and Performance of Lambs Fed Sorghum Stover as Basal Diet

Supplementation of rumen degradable nitrogen (RDN) in the form of cotton seed cake, ground nut cake, rice bran, guinea grass, para grass, Luecaena leucocephala and Gliricidia sepium top fodder at four rumen degradable nitrogen (RDN) levels viz., 0,15,22 and 30 g RDN/kg digestible organic matter (DOM) on in vitro organic matter (IVOMD) and neutral detergent fibre digestibility (TVNDFD) of sorghum stover was studied. Supplementation of RDN in the form of Leucaena top fodder, ground nut cake and rice bran significantly (P< 0.05) increased the IVOMD (%) of sorghum stover at 15, 22 and 30 g RDN/kg DOM. No effect was observed with guinea grass and para grass. Further, the IVOMD (%) was significantly (P<0.01) increased as the rate of supplementation of RDN increased from 15 to 30 g. A similar trend was observed with IVNDFD digestibility. Based on the in vitro digestibility results, a growth trial for 90 days was conducted on twenty four lambs (4 months fed) 10.26 BW with sorghum stover (control) and supplemented with rice bran, ground nut cake and Leucaena ttp fodder. Supplementation of rice bran, groundnut cake and Leucaena top fodder at 1.0% of body weight of lambs significantly (P<0.05) increased average daily gain (ADG). Overall, the studies indicated that supplementation of RDN has beneficial effects on digestibility of cereal crop residues like sorghum stover and thus improved the performance of growing lambs in terms of ADG.