Abstract
This study was conducted to compare the effects of adding sodium butyrate (SB), medium-chain fatty acids (MCFAs), or n-3 polyunsaturated fatty acids (n-3 PUFAs) to the diet of sows during late gestation and lactation on the reproductive performance of sows and the growth performance and intestinal health of suckling piglets. Twenty-four sows (Landrace × Large-White hybrid; third parity; 200 ± 15 kg) were randomly assigned to receive 1 of 4 diets: basal diet (control group), basal diet + 1 g SB/kg (SB group), basal diet + 7.75 g MCFA/kg (MCFA group), or basal diet + 68.2 g n-3 PUFA/kg (n-3 PUFA group). The experiment began on day 85 of gestation and ended day 22 of lactation. Colostrum samples were collected from each sow. After the experiment, blood and tissue samples were collected from 1 randomly selected piglet. The results showed that the weaning-to-estrus interval of sows in the SB, MCFA, and n-3 PUFA groups was shorter than that of sows in the control group (P < 0.05). The incidence of diarrhea in suckling piglets in the SB, MCFA, and n-3 PUFA groups was lower than that of piglets in the control group (P < 0.05). The fat, protein, IgA, IgG, and IgM concentration in colostrum from sows increased following dietary supplementation with SB, MCFA, or n-3 PUFA (P < 0.05). Comparison with the control group, the mRNA expression of claudin-1, zona occludens 1, and interleukin-10 increased in the jejunum mucosa of suckling piglets in the SB, MCFA, and n-3 PUFA groups, while that of TLR4 decreased (P < 0.05). Compared with the control group, the Chao1 and ACE indexes of microbial flora in the colon contents of piglets in the SB, MCFA, and MCFA groups increased (P < 0.05), while the relative abundance of Firmicutes, Actinobacteria, and Synergistetes decreased at the phylum level (P < 0.05). In conclusion, during late pregnancy and lactation, dietary SB supplementation had a greater effect on intestinal health and caused a greater decrease in preweaning mortality of suckling piglets than did dietary MCFA or n-3 PUFA supplementation; dietary MCFA supplementation shortened the weaning-to-estrus interval of sows to a greater extent than did dietary SB or n-3 PUFA supplementation; and dietary n-3 PUFA supplementation increased the fat and protein content in the colostrum to the greatest extent.