An experiment was conducted to examine the effect of a high environmental temperature on the performance, conformation, and carcass characteristics of pigs and the influence of diet. Thirty-six Three-way crossed castrated male pigs with average initial body weight of 50.4 kg were used in the experiment. The pig were allocated to the following treatments: two environmental temperatures (20 and 30 deg C) X three dietary energy levels (2,980, 3,300 and 3,600 kcal/kg)xthree protein levels (12.8, 15.2 and17.2%). Daily weight gain was tighter (p<0.01) and feed: gam ratio lower (p<0.05) in pigs at 30 deg C than for pigs at 20 deg C. The pigs at 30 deg C were significantly taller with deeper bodies (p<0.05) and significantly longer (p<0.05) both verticallyhorizontally in the planum nasal when kept at 30 deg C. The width of body and the circumference of the neck were greater (p<0.05) at 20 deg C. The lean meat of the loin, middle section, ham, and hind section were significantly greater (p<0.05) in pigs kept at 30 deg C and the belly was significantly heavier. The total unsaturated free fatty acids were significantly higher (p<0.05) in the body fat of pigs kept at 20 deg C than in that of pigs at 30 deg C. The results indicated that when pigs are given very restricted same amounts of feed, they may need less energy to maintain their body temperature under moderately high environmental temperature (30 deg C); consequently, their performance is better than that of pigs under optimum environmental temperature. The results showed very clearly that weight gain of pigs increased with increasing of dietary protein and energy content. The increasing of dietary protein content seemed more significant when content increasing to 17.2% compared with the 12.8 and 15.2% protein content treatments. The increasing of dietary energy content was more significant when content increasing to 3,600 compared with the other low energy content treatments.
關聯:
Asian-Australasian Journal of Animal Sciences, Vol.17 no.2, pp.250-258
