Effect of timing of post-weaning supplementation of soybean oil and exogenous lipase on growth performance, blood biochemical profiles, intestinal morphology and caecal microbial composition in weaning pigs

Abstract

The objective of this experiment was to investigate the effects of dietary supplementation of different levels of soybean oil and exogenous lipase on growth performance, serum biochemical indices and caecal microbial diversity and similarity in weaning pigs. A total of 504 weanling pigs (252 males and 252 females) were randomly assigned to four treatments, with six replicates per treatment and 21 pigs per replicate. Four dietary treatments were arranged in a 2 × 2 factorial arrangement in a completely randomised experiment. The first factor was soybean oil level (2.5% or 5%), and the second factor was lipase level (0 or 200 g/t). In the first 14 days, compared to piglets fed 2.5% soybean oil diets, dietary supplementation of 5% soybean oil improved feed to gain ratio (F/G) (p < .05). On the 14th day, compared to piglets fed 2.5% soybean oil diets, dietary supplementation of 5% soybean oil increased high-density lipoprotein, reduced serum triglycerides and low-density lipoproteins (p < .05). On the 28th day, dietary supplementation of 5% soybean oil increased serum cholesterol and high-density lipoproteins (p < .05). The crypt depth of the duodenum was greater in pigs fed 200 g/t lipase diets compared to those fed non-lipase diets (p < .05). By increasing dietary soybean oil level, bacterial diversity in the caecum was reduced (p < .05). Results from this experiment suggest dietary supplementation of 5% soybean oil could improve growth performance by regulating the glycolipid metabolism and diversity of bacterial in weaning piglets compared to performance on a dietary level of 2.5% soybean oil.