Comparing effects of feed additives on growth, gut microbiota and cytokine and cytokine regulatory gene expression in weaning piglets

Post-weaning complications in piglets are characterized by heightened susceptibility to infection, diarrhoea, atrophy of small intestine structure and reduction in body weight. The ban on prophylactic antibiotics and environmental concerns with usage of excessive zinc demands for identification of safer alternatives to treat post-weaning complications. Feed additives that maintain homeostasis between the intestinal epithelial layer, intestinal microbes and the local immune cells are of high interest as they have implications in both animal industry and human food industry. Some previous evaluation of feed additives like seaweed extracts, inulin and β-glucan in animal trials have provided us a glimpse of the vast bioactivity potential they hold. Therefore, the objective of this experiment was to compare the effects of supplementing weaning piglet diet with zinc oxide (ZnO), milk hydrolysate (MH), yeast β-glucan (BG) and a combination of MH and BG on growth, gut microbiota and cytokine and cytokine regulatory protein gene expression.

Forty 21 d old weaned piglets (7.3 ± 0.2 kg) were assigned to either: 1) control diet (CD), 2) CD +3.1 g/kg ZnO, 3) CD + 0.25 g/kg MH, 4) CD + 0.25 g/kg BG or 5) CD + 0.25 g/kg MH + 0.25 g/kg BG for 12 days (n=8). Fecal scores per pen were recorded daily and animals were weighed on days 0, 6 and 12. Following sacrifice on day 12, digesta and colonic tissue samples were collected. Tissue samples were used for qPCR analysis while digesta samples were used to enumerate a selected panel of bacterial colonies using 16s rRNA qPCR technology.

The ZnO group and MH+BG treatment group were associated with a similar improvement of growth compared to CD group (P< 0.05). While the BG group was associated with an increase in AEEC strains in gut, MH+BG group was associated with a decrease in abundance of AEEC strains (P< 0.05). Thus, while MH or BG individually were not associated with any major improvement in weaning piglets, a combination of MH+BG improved performance of the piglets similar to ZnO group.

Hence, in this study, addition of milk hydrolysate and yeast β-glucan in feed did not have any major effect on the analysed parameters. However, a combination of milk hydrolysate and yeast β-glucan had an overall positive effect on growth and fecal scores of piglets, similar to what was observed in animals supplemented with zinc oxide.

Disclosure of Interest: None Declared.