Effect of benzoic acid supplementation on growth performance and early development of gastrointestinal tract function and immune system in artificially reared suckling piglets

Abstract

The practice of weaning at 21 to 28 days of age in conventional pig production poses a challenge to the digestive tract of piglets. Post-weaning challenges like diarrhea, small intestinal villous atrophy, and decreased feed intake (FI) are a consequence of the abrupt change in diet from sow milk to solid feed. The aim of this study was to investigate the effect of benzoic acid (BA) to artificially reared suckling piglets on growth performance, intestinal morphology and change in gene expression in the small intestine (SI). Twenty-seven one-day-old piglets were included in this study, and randomly allocated between three dietary groups. All three groups received milk replacer (MR) throughout the entire experimental period. One group only received MR (CON), one was supplemented with liquid creep feed (LCF) (MRLF) from day 10, and one was supplemented with LCF with 0.5% BA (BEN) from day 10. Piglets were euthanized and post-mortem examinations conducted on days 28 and 29 of the experiment. Small intestinal tissue samples were collected for analysis of morphological parameters and gene expression. Results displayed no effect on growth performance, however, the feed conversion ratio was higher (p < 0.05) for MRLF compared to CON in P2 (days 10-28) and higher (p < 0.05) in MRLF and BEN compared to CON P1+P2 (days 1-28). A tendency (p < 0.10) to an increased villus height in the proximal part of the SI and increased (p < 0.05) villus width in the medial part of the SI were observed for BEN, when compared to CON and MRLF. Furthermore, pathways related to the immune system and metabolism were enriched (Adj. p < 0.05) by BEN in comparison to CON and MRLF. In conclusion, BA did show some potential to enhance the intestinal integrity in the pre-weaning period, and thereby developing a more robust piglet during the peri‑weaning period.