Studies of Some Ruminal and Blood Metabolites in Sheep Fed Poor Quality Roughage with Supplementation

Abstract

Thirty-two growing Yankasa rams aged 1.5-2 years and having average weight of 13.3kg were used in a 12 week feeding trial to study some ruminal and blood metabolites when poultry litter treated rice straw was fed with supplementation. The diets constitutions were achieved by ensilage method for 21 days after the straw has been chopped to between 3-5 cm. The ensilage was achieved using two different ratios of rice straw to poultry litter; 5:5 and 6:4 designated as PLTRS 1 and PLTRS 2 respectively. The supplements were either maize bran (MB), wheat bran (WB), cotton seed cake (CSC), or a mixture of  either MB or WB with CSC in two different proportions. Results showed significant (p<0.05) differences in daily basal feed intake and digestible crude protein intake across dietary treatments. Dry matter and crude protein digestibility were also influenced significantly (p<0.05) by treatment. Rumen liquor pH (6.38-7.23), rumen ammonia- nitrogen (RAN) (11.14-30.09 mg/100ml) and total volatile fatty acid (TVFA) (8.19-12.21 Mmol/100ml) were significantly (p<0.05) affected by dietary treatments both before and after feeding. The general trend depicted an increase in RAN and TVFA post-feeding across treatments. However, rams on supplement 1 (maize bran, MB; or wheat bran, WB) recorded lower RAN and TVFA values. Blood urea (11.51-17.63 Mmol/l), total blood protein (68.63-73.76g/l) and packed cell volume (30.03-39.90%) increased post-feeding across dietary treatments. The increase in ruminal and blood metabolites observed in this study especially for rams fed either protein or mixture of protein and energy supplement showed that protein and energy supplements are critical in enhancing microbial fermentation and consequently host animal performance.

Keywords: Sheep, Ruminal liquor, microbial fermentation, blood, rice straw, bran