Author : Magay, Elizabeth J.

Summary : A feeding and slaughter experiment was conducted at the University of the Philippines at Los Banos to determine the protein and energy requirements of native goats at 5-14 kg live weight. Nine rations, consisting of various combinations of three levels each of protein (12, 16, 20 percent crude protein (CP)) and 3 levels of energy (53, 60, 68 total digestible nutrients (TDN)) were used. Dry matter digestibility increased with increasing energy level. Crude protein digestibility was not affected by either protein or energy level while that of ether extract was depressed by higher protein . The digestibility if crude fiber decreased as energy and protein increased. Weanling goats at 5 kg live weight did not survive on a ration containing 12 percent CP and 49 percent TDN. They required 16 percent CP and 59 percent TDN to produce daily gain of at least 25 g. At higher live weights, higher protein and energy levels effected the best gain, but the time lag for the low energy rations to produce similar gain was not as wide as that observed at lower weights. Rumen pH decreased and total volatile fatty acid increased with increasing energy while ammonia nitrogen increased with increasing protein level. Blood urea nitrogen was increased by increasing protein and decreased by increasing energy level. Carcass composition (protein, fat) was constant at all levels of protein and energy. The proportion of fat in the non-carcass components, specifically in the viscera, increased with increasing energy level. Increasing energy level promoted higher and more efficient protein deposition and energy accumulation. It also resulted to higher dressing percentage and heavier weight of lean.