Effects of Sow-Piglet Co-Feeding on Post-Weaning Welfare and Jejunal Morphological Development in Suckling Piglets

Under intensive farming conditions, a decline in feed intake after weaning in suckling piglets often results in reduced body weight or diarrhea. We hypothesized that a sow-piglet co-feeding strategy during the suckling period-in which piglets participate in the sow's feeding process and consume both lactating sow feed and creep feed-could alleviate certain aspects of weaning stress. To test this hypothesis, 102 newborn piglets (Large White × Duroc × Min Pig) were selected and divided into a co-feeding group (CF) and a non-co-feeding group (NCF), based on whether they had access to the sow's feed during lactation. The study investigated the effects of the two feeding strategies on piglet growth performance, diarrhea incidence, behavior, and post-weaning immune status, intestinal morphology, and antioxidant capacity. The results showed that the CF group had significantly higher body weight at the end of the nursery period (p < 0.05) and a significantly lower post-weaning observed fecal staining rate (p < 0.05). At 16-17 days post-weaning, piglets in the CF group exhibited a significant increase in feeding behavior (p < 0.05). Compared with the NCF group, the CF group showed highly significant reductions in serum levels of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and interferon-gamma (IFN-γ) (p < 0.01), as well as significantly increased intestinal superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities (p < 0.05) and significantly reduced malondialdehyde (MDA) content (p < 0.05). In terms of intestinal morphology, the CF group had a highly significant increase in the villus-to-crypt ratio in the jejunum (p < 0.01) and a highly significant reduction in crypt depth (p < 0.05), while villus length did not differ significantly between groups (p > 0.05). Overall, in the present study, sow-piglet co-feeding during the suckling period effectively alleviated weaning stress and reduced the incidence of diarrhea. These beneficial effects appear to be associated with reduced inflammatory responses, enhanced antioxidant capacity, and improved intestinal morphology. It should be noted that the relatively late weaning age used in this study likely facilitated the piglets' ability to efficiently utilize solid feed and derive benefits from the co-feeding strategy. Therefore, caution should be exercised when extrapolating these findings to earlier weaning ages, at which the digestive tract is less mature.