COMPARISON OF WATER MELON (CITRULLUS VULGARIS)-SEED MEAL, ACACIA-TORTILIS PODS AND SUNFLOWER-SEED CAKE SUPPLEMENTS IN CENTRAL TANZANIA .1. NUTRITIVE-VALUE AND INFLUENCE ON THE RUMEN ENVIRONMENT

A study was made of the chemical composition and in vitro and in sacco digestibility of water melon (Citrullus vulgaris) seeds, Acacia torti lis pods and sunflower-seed cake and their effect on the rumen environ ment of a steer fed a basal diet of Cenchrus ciliaris hay. Water melon seeds contained 15.5-18.5% crude protein (CP) and 24% ether extract ( EE). Levels of soluble and condensed phenolics were negligible. CP lev el of Acacia seeds (18.6%) was higher than that of the empty pods (9.3 %), the average CP content of the whole pod being 13.4%. Acacia seeds and empty pods had similar levels (41%) of soluble phenolics, while th e level of condensed tannins was higher in the seeds [15 absorbance at 550 nm/g of neutral detergent fibre (abs/g NDF)] than in the empty po ds (7.78 abs/g NDF). Similarly, the Acacia seeds had higher in vitro o rganic matter digestibility (86%) and total rumen degradable nutrients (82%) than the empty pods (60% and 66%, respectively). Rumen NH3-N an d pH levels were not affected by either water melon seed or Acacia pod supplementation. The role of these supplements in cattle farming syst ems in central Tanzania is discussed.