Nutritional evaluation of Senegalia greggii and Prosopis juliflora as browse supplements for sheep

This studywas conducted to evaluatethe influence of leavesof two shrubs on digestion and nitrogen retention by sheep. Twelve rumen-fistulated castrated male sheep (Pelibuey x Rambouillet) of 42.2±1.3 kg live weight were randomly assigned to three diets (four sheep/diet): diet 1 containing 77% of Cynodon plectostachyus straw and 23% Medicago sativa hay, diet 2 containing 70.7% C. plectostachyus straw and 26.3% Senegalia greggii leaves, and diet 3 containing 76.3% C. plectostachyus straw and 14.3% Prosopis juliflora leaves. Medicago sativa hay was used as control feed of good nutritional quality. The intakes of dry matter and the fiber components of sheep were not significantly different between sheep fed the diets containing the M. sativa hay or S. greggii leaves, but both were significantly higher than sheep fed the P. juliflora leaves. The in vivo digestibility coefficients of dry matter and the fiber components were not different (P>0.05) between sheep fed the all diets; however, the digestibility of CP was higher (P<0.05) for sheep fed the M. sativa diet compared with sheep on other diets. The N intake was similar (P>0.05) between sheep fed diets containing M. sativa hay or S. greggii leaves, but both were higher than sheep containing P. juliflora leaves. A similar pattern as N intake was registered in fecal and urine N excretions. The N balance was higher (P<0.05) and positive in sheep fed the M. sativa hay diet followed by S. greggii and sheep on P. juliflora were lowest and negative. Senegalia greggii leaves may have potential as an economical supplementary feed for sheep fed diets based on roughages.