Effect of Dietary Energy on Growth Performance and Fat Deposition of Lantang Growing Pigs

摘要

The pork industry is dedicating to provide fast-growing pigs with high-grade meat; this study aimed to explore the relationship between dietary energy and growth output. Thirty two individually-penned male Lantang pigs (initially weighed 20.21±0.63 kg) were randomly assigned to one of four dietary treatments, with 4 replicates of 2 pigs each. The Digestive Energy (DE) of T (treatment) 1~4 were 9.24, 11.02, 12.66 and 14.29 MJ kg^-1 feed, respectively. Feeding trail was terminated when all pigs within a treatment averaged 60±2 kg b.wt. and all pigs were slaughtered. The feeding time to reach terminal b.wt. were longer in both T1 and T2 in contrast with T3 and T4 (p<0.01). Average daily energy intake increased linearly with dietary energy concentration (p<0.01). Compared with the other three groups, average daily gain (p<0.05) and feed to gain ratio (p<0.05) of T4 were significantly increased and decreased, respectively. Relative contents of major white fat and perinephric fat, as well as adipocyte size of T4 were higher than those of the other groups (p<0.05). These results indicated that increasing dietary energy content improved fat accumulation in Lantang growing pigs possibly through direct deposition of fat in adipocyte. Higher content of dietary energy tend to increase growth rate of the pig, yet the over-deposition of body fat as well as its possible impact on carcass quality and marketing profit need to be further explored.