Effects of benzoic acid on performance and ecology of gastrointestinal microbiota in weanling piglets

The effects of feeding benzoic acid on weanling pig performance and on the ecology of their gastrointestinal microbiota were evaluated. One hundred and forty-four piglets (4 weeks of age) were used. Half of the piglets were fed a control diet and half were fed the same diet with 0.5% benzoic acid, and their performance was measured for 28 days. At the end of the trial, twelve piglets from each treatment were euthanised and samples of ileal and caecal digesta were collected. The digesta samples were cultured to quantify Lactobacillus spp., Escherichia coli, Enterococcus spp. and Clostridium perfringens and they were also studied by restriction fragment length polymorphism to evaluate the biodiversity degree and the similarity between the profiles of the microbiota. Benzoic acid improved piglets’ performance, and this was associated with a greater ileal microbiota biodiversity.