Effect and interaction between wheat bran and zinc oxide on productive performance and intestinal health in post-weaning piglets

Abstract

The inclusion of fibre has been studied as an alternative to antimicrobials in weaning pig diets, while ZnO is used as an effective method to prevent post-weaning diarrhoea. However, it has not been investigated to what extent these two strategies interact with each other. The present study was designed to evaluate the effects of including wheat bran (WB) and ZnO alone or combined in the diet of early-weaning pigs on productive performance and microbial activity in the gastrointestinal tract (trial 1). A total of sixty-four piglets were distributed in a 2 × 2 factorial combination of two levels of WB (0v. 40 g/kg) and ZnO (0v. 3 g/kg) in the diet. The inclusion of ZnO in the diet improved the feed intake and growth of the animals and reduced the incidence of diarrhoea. The inclusion of WB increased SCFA concentrations and decreasedEscherichia colicounts. However, simultaneous incorporation of WB and ZnO increasedE. colicounts. Twoin vitrotrials were also designed to clarify hypotheses derived from thein vivotest: (1) the ability of WB and other fibre sources to bindE. coli in vitro(trial 2) and (2) thein vitrointeractions between WB and ZnO with respect toE. coligrowth (trial 3). We can conclude that incorporation of WB in the diet improved gut health by modulating the activity and composition of the microbial population. The negative interaction between WB and ZnO raises the interest of considering the inclusion of phytase enzymes to reduce the therapeutic levels of ZnO in post-weaning diets.