Liquid Feeding of Pigs: Implications for Pig and Human Health

Surveillance studies have shown that feeding pigs liquid diets and particularly fermented liquid diets reduces the incidence of Salmonella positive herds. Studies have shown that a concentration of 70 mmol kg lactic acid is bacteriostatic to Salmonella and that concentrations >100 mmol kg are bactericidal. Uncontrolled natural fermentation results in lactic acid concentrations varying between 0 and 140 mmol kg so cannot be relied upon to produce bactericidal levels of lactic acid. However, if selected lactic acid bacteria are used as inoculants and the temperature of the fermentation is controlled (circa 30°C), acid conditions can be produced within 24 h that rapidly and effectively exclude enteropathogens from the diet. FLF has beneficial effects on the gut architecture and significantly reduces coliform numbers in the lower gut. Sows fed FLF, fermented using pig-derived LAB, have reduced numbers of coliforms in their dung. Piglets suckling sows fed FLF have reduced numbers of faecal coliforms and the LAB species used for fermentation can be recovered from the piglets’ faeces. The colostrum from sows fed FLF has increased immunoglobulin concentration and increased mitogenic activity for both lymphocytes and epithelial cells. This suggests that feeding sows FLF could reduce vertical transmission of enteropathogens. Taken together, these results indicate that FLF can reduce the potential for enteropathogen transfer via the food, can beneficially influence the ecophysiology of the gut and can stimulate the pig’s immune system. 1 E-mail: [email protected]