Dietary bacteriophages as an alternative for zinc oxide or organic acids to control diarrhoea and improve the performance of weanling piglets

Abstract

In this study, the antibacterial substances ZnO, organic acids and a bacteriophage cocktail were added to the diet of weanling pigs to evaluate the effects on gut health. Dietary treatments were basal diet without any supplementation (Control) and basal diet either supplemented with 0.34% (2500 ppm) ZnO, 0.20% organic acids or with 0.10% bacteriophage cocktail. Faecal score was decreased in ZnO and bacteriophage cocktail treatments. The total number of ileal anaerobic bacteria, Bifidobacterium spp. and Lactobacillus spp. were higher in ZnO, bacteriophage cocktail and organic acids, while ileal coliforms and caecal Clostridium spp. were decreased in comparison to Control. Faecal coliforms (Day 7 and Day 21) and Clostridium spp. (Day 21 and Day 35) were lower in bacteriophage cocktail. The gain to feed ratio was improved in all supplemented groups. The digestibility of dry matter was increased at the end of the experiment in all supplemented groups, while that of crude protein was increased only at Day 21 in bacteriophage cocktail. Duodenal villus height was increased in ZnO and bacteriophage cocktail. Bacteriophage cocktail also showed a greater villus height in the small intestine. Supplementation of bacteriophage cocktail in weaning pig diets resulted in better growth performance, digestibility and gut development compared to Control, and thus, it can be concluded that its effects are comparable to ZnO or organic acids supplementation.