Effects of different energy levels on growth performance and nutrient digestibility of pigs reared in different seasons in Korea

Park, J.H., Sureshkumar, S. and Kim, I.H. 2020. Effects of different energy levels on growth performance and nutrient digestibility of pigs reared in different seasons in Korea. Animal Nutrition and Feed Technology, 20: 453–463.

The objective of the current study was to determine the effects of different energy levels and seasons on the growth performance and nutrient digestibility of pigs in Korea. Data were collected from 20 experiments conducted in 2015 to 2017, during the winter period (Dec to next Mar) and summer period (Jun to Sep), with half of them conducted in the summer period and a half in winter. Experiments lasted for 6, 5, and 5 wk for weaning (n=700; BW 7.07±0.12 kg), growing (n=768; BW 27.10±1.65 kg), and finishing pigs (n=768; BW 74.21±0.70 kg), respectively. Animals were fed two energy levels (differed by 150 kcal ME/kg) with soybean oil supplemented at 0 and 3%. There was no effect of different energy levels evident on growth performance in weaning pigs. However, pigs reared during summer period had lower (P < 0.01) average daily feed intake and higher (P<0.01) feed efficiency than those reared in winter. The growing pigs consumed more (P<0.01) feed and grew faster (P<0.01) in winter period than in the summer period. The effect of high energy was shown to increase ADG and FCR, and the increasing effect of the high energy diet was more evident in summer season (interactive effect, P<0.01). The mortality was higher (P<0.01) in summer than in winter period. The apparent total tract digestibility of DM and gross energy were increased (P<0.05) with higher energy. In finishing pigs, ADG was affected by both energy levels and ambient temperature, with the high energy level leading to higher (P<0.01) ADG in summer period than low energy level. Pigs raised in winter period consumed more feed than the summer period. The DM digestibility was higher (P<0.01) in high energy; there was no difference apparent due to season. In conclusion, the ambient temperature could negatively influence the pig growth performance and mortality. Feeding pigs with high energy density diet (by addition of 3% soybean oil) can improve growth performance and nutrient digestibility in growing and finishing phase, and this growth improving effect was much more evident in the summer period. However, gross energy digestibility was not influenced during weaning and finishing phases.