Energy and protein metabolism of the Chinese pig

Sixteen Chinese pigs (Meishan breed) from four litter outcome groups with initial weights ranging from 6 to 22 kg BW were used in a 28-d comparative slaughter experiment to determine the utilization of energy for maintenance and growth and the utilization of protein and amino acids (AA) by the Chinese pigs. Pigs were randomly allotted from litter outcome groups to four replicates of four pens each and to four treatments within replicates. A corn-soybean meal basal diet was formulated to provide all the nutrients except energy at twice the recommended levels for 10- to 20-kg pigs. The treatments were the basal diet fed at 3, 4, or 5% of BW. The fourth treatment was the initial slaughter group. As level of feeding increased, ADG increased linearly (P < .01) and gain:feed ratios increased quadratically (P < .06). Increasing the level of feeding had no effect on apparent digestibility coefficients of DM, N, or GE. Fecal N, urinary N, urinary urea N, and N retention increased linearly (P < .01) as feed intake increased. Level of feeding did not affect the DE, ME, or NE concentration in the diet. Metabolizable energy as a percentage of DE averaged 92.7% and was not affected by feeding level. Percentage of ether extract and DM of the empty body increased linearly (P < .01), but percentage of water decreased linearly (P < .01) with the level of feeding. Percentage of CP and ash of the empty body were not affected by the level of feeding (P > .05).(ABSTRACT TRUNCATED AT 250 WORDS)