The experiment was carried out on 160 exotic gilts 20 kg body weight, from that 80 gilts of Yorkshire x Landrace (YL) and 80 gilts of Landrace x Yorkshire (LY) were assigned according to a completely randomized design (CRD), with 5 nutrient levels of experimental diets (high level: 110 percent and 105 percent of NRC (1998) energy con~ent, protein and acid amine (lysine, methionine+cystine, threonine)
medium level: 100 percent of NRC(1998) and low level: 90 and 95 percent of NRC(1998), for a totalS treatments (4 pigs/cage x 5 treatments x 4 replications). The results revealed that the growth rate and reproductive performance of exotic gilts of two breeds have the same, and the tendency to increase in nutrient density of the diet from low to high. However, they were reduced with high level 110 percent of NRC (1998) nutrient level. The gilts were fed with 105 percent of NRC (1998) nutrient level achieved the highest of the growth rate and reproductive performance. Demand for metabolism energy in the diet (90 percent OM) of LY and YL gilts in the period from 20 kg to 50 kg
from 51 to 90 kg and 91 kg to the first mating in ad libitum conditions was 4,425 kcal/kg feed. Demand for crude protein and digestible amino acids (lysine, methionine + cystine, threonine) in the diet (90 percent OM) for gilts of Landrace and Yorkshire in a libitum feeding conditions during the period from 20 kg to 50 kg were18 percent
0.78 percent
0.46 percent
0.49, from 51 kg to 90 kg were17 percent
0.74 percent
0.44 percent
0.48 percent, and from 91 to first mating were 15 percent
0.57 percent
0.39 percent
0.46 percent, respectively.