This study evaluated the effects of dietary probiotic Lactococcus lactis on growth performance, frequency of diarrhea, immune responses, and intestinal health of weaned pigs. In a randomized complete block design (block = initial body weight), 48 newly weaned pigs were assigned to two dietary treatments (4 pigs/pen; 6 replicates/treatment; 4-week trial): a basal diet based on corn and soybean meal (CON) and CON supplemented with 0.02% L. lactis (LL). Growth performance, frequency of diarrhea, systemic immune responses and serum biochemical parameters, intestinal morphology, and ileal gene expression of tight junction proteins and inflammatory cytokines were measured. No differences were found in growth performance and serum biochemical parameters between CON and LL. However, the LL group tended to show lower the frequency of diarrhea during the first two weeks after weaning (p = 0.092), hematocrit levels on day 14 (p = 0.093), and serum cortisol concentrations on day 7 (p = 0.096) than the CON group. The LL decreased concentrations of serum tumor necrosis factor-α (TNF-α) on day 7 (p p P = 0.057), and interleukin-1β (IL-1β) on day 14 (p = 0.082) and day 28 (p = 0.070) compared with the CON. Pigs fed LL diet had higher villus area and the number of goblet cells in the small intestine (p p = 0.084) compared with those fed CON diet. Furthermore, the LL upregulated (p L. lactis tended to alleviate post-weaning diarrhea; this may be correlated with improved anti-inflammatory responses, intestinal morphology, and gut barrier functions of weaned pigs.
Kyoung et al. (Mon,) studied this question.