EFFECTS OF SOURCE AND LEVEL OF NITROGEN ON THE UTILIZATION OF SORGHUM STOVER BY YANKASA RAMS

Résumé

The effects of cotton seed cake (CSC) or urea in supplying either 12% or 16% crude protein on sorghum stover utilization by Yankasa rams was studied for twelve weeks, using a 2 x 2 factorially designed experiment. Nutrient intake, digestibility, weight gain and feed conversion ratio (FCR) were monitored. In vitro volatile fatty acid (VFA) and ammonia-nitrogen (NH,-N) concentrations were also determined. The result of the study indicated that the source and/or level of nitrogen (or crude protein) significantly (P<0.05) affected crude protein intake (CPI), digestible crude protein intake (DCPI) and in vitro NH,-N concentration. Total feed intake, live weight gain (LWG), FCR and DCPI were significantly (P<0.05) affected by source x level interaction. Acid detergent fibre (A DF) and neutral detergent fibre (NDF) intakes, CP, ADF and NDF digestibilities, digestible ADF and NDF intakes, stover intake and in vitro VFA concentration were not significantly (P>0.05) affected by either main effects of CP source and level or their interaction. The rams on the 16% CSC and 12% urea ration gained more weight and had lower FCR than those on the 12% CSC and 16% urea. The 16% CSC ration gave the best result in terms of sorghum stover supplementation. The 12% urea treatment which also had a good result in terms of weight gain and FCR could also be recommended for use.