151 Energy Metabolism, Digestive and Absorptive Capacity, and Fecal Microbiome of Nursery Piglets Selected for Feed Efficiency. (21st September 2022) - Wu, Yujia
Abstract: Improving feed efficiency (FE) plays an important role in the economic and environmental sustainability of the swine industry. Genetic selection based on low estimated breeding value for feed conversion ratio (EBV_FCR) can effectively improve FE. This study investigated the growth performance, nutrient and energy digestibility, activity of hydrolyses, expression of nutrient transporters and tight junction proteins, and fecal microbiome of nursery pigs selected for high and low feed efficiency. A total of 128 pigs weaned at 21 + 2 days were selected from parents of low and high EBV_FCR calculated based on phenotypes for FCR during growing-finishing stage. Pigs were fed with corn-soybean meal-based diets in a two-phase feeding program for 4 weeks under similar rearing conditions. The results revealed that there were no differences in average daily feed intake, average body weight gain, FCR, energy, and nutrient digestibility between the two groups. Moreover, enzyme activity kinetics results showed no differences in the maximal activity of alkaline phosphatase, sucrase, maltase, and maltase-glucoamylase between the two groups (p > 0.05). Real-time PCR analyses showed that SGLT1, ASCT2, PepT1, EAAC1, and BoAT1 mRNA abundances were not affected by the pig groups (p > 0.05). There were also no significant differences in claudin-1 and ZO-1 protein abundances on the jejunum membrane between the two pig groups. The two pig groups had similar fecal microbial taxonomic composition and function. However, the microbiota diversity results showed that the high-efficiency pig group has higher species evenness, and there is a trend (p < 0.084) for beta diversity difference, which indicates that high-efficiency pigs might have a more homogenous and healthier gut environment. In conclusion, nursery pigs selected for high and low feed efficiency based on parents EBV_FCR did not differ in growth performance, nutrient digestibility and absorptive capacities, microbiota composition and function.