Sodium butyrate administration improves intestinal development of suckling lambs

This study was conducted to investigate the effects of sodium butyrate (SB) supplementation on growth performance, intestinal barrier functions, and intestinal bacterial communities in sucking lambs. Forty lambs of 7 d old, with an average body weight (BW) of 4.46 ± 0.45 kg, were allocated into the control (CON) or SB group, with each group having five replicate pens (n = 5). Lambs were orally administered SB at 1.8 mL/kg BW in the SB group or the same volume of saline in the CON group. Treatments were administered from 7 to 35 d of age, when one lamb from each replicate was slaughtered to obtain intestinal tissues and contents. The results showed that supplementation with SB tended to increase the BW (P = 0.079) and the starter intake (P = 0.089) of lambs at 35 d of age. The average daily gain of lambs in the SB group was significantly greater than that in the CON group (P < 0.05). The villus height of jejunum in the SB group was markedly higher (P < 0.05) than that in the CON group. In ileum, lambs in the SB group had lower (P < 0.05) crypt depth and greater (P < 0.05) villus-to-crypt ratio than those in the CON group. Compared with the CON group, the mRNA and protein expressions of Claudin-1 and Occludin were increased (P < 0.05) in the SB group. Supplementation with SB decreased the relative abundances of pathogenic bacteria, including Clostridia_UCG-014 (P = 0.094) and Romboutsia (P < 0.05), which were negatively associated with the intestinal barrier function genes (P < 0.05). The relative abundance of Succiniclasticum (P < 0.05) was higher in the SB group, and it was positively correlated with the ratio of villi height to crypt depth in the jejunum (P < 0.05). Compared with the CON group, the function "Metabolism of Cofactors and Vitamins" was increased in the SB group lambs (P < 0.05). In conclusion, SB orally administration during suckling period could improve the small intestine development and growth performance of lambs by inhibiting the harmful bacteria (Clostridia_UCG-014, Romboutsia) colonization, and enhancing intestinal barrier functions.