Effect of protein supplementation and urea treatment on utilization of maize stover

Six Red Maasai sheep were used to investigate the effects of urea treatment and cotton seed cake supplementation of maize stover on intake, digestibility and rumen fermentation parameters. The basal feeds were Rhodes grass (Chloris gayana) hay (H), untreated maize (Zea mays) stover (US) and treated maize stover (TS), each of which was supplemented with 100 g of cotton seed cake (CSC) to make H+CSC, US+CSC and TS+CSC. These were offered over four feeding periods in a completely randomized block design, with periods serving as blocks. Hay and US treatments had similar intakes, digestibility, ruminal fluid volatile fatty acid (VFA) concentrations and pH. Urea treatment of the stover increased the digestibility of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fibre (NDF) and cellulose as well as the rumen ammonia nitrogen (AN) concentration. Cotton seed cake supplementation increased DM, OM and CP digestibility in US from 445 to 614 g/kg, 475 to 633 g/kg and 308 to 604 g/kg, respectively and VFA concentration in the rumen from 31 to 196 mmol/L. Supplementation of treated stover, increased the AN concentration (137 vs. 234 mg/l) rumen in the rumen content with no effect on nutrient digestibility and VFA concentration. The pH of the ruminal content for the diets ranged from 6.83 to 7.12. The trends of rumen AN and VFA for supplemented diets showed a gradual rise to a maximum three hours post-feeding, followed by a decrease in their respective concentrations. It was concluded that urea treatment and CSC supplementation of stover increased its utilization but supplementation of treated stover with CSC was not effective.