Microbial Fermentation Patterns, Diarrhea Incidence, and Performance in Weaned Piglets Fed a Low Protein Diet Supplemented with Probiotics

Abstract

To evaluate the effects of dietary protein levels and probiotic supplementation on microbial intestinal fermentation, diarrhea incidence, and performance in weaned piglets, 162 piglets were randomly assigned to three treatments: high-protein diet (20%), with antibiotics (HPa); high-protein diet (20%), without antibiotics (HP); and low-protein diet, without antibiotics but with probiotics (LPpb). Piglets and feed were weighed weekly to calculate the average daily gain (ADG), average daily feed intake (ADFI), and gain: feed ratio (G:F). Four piglets per treatment were killed on day 21 postweaning to collect ileal and colon digesta for measurement of short-chain fatty acids (SCFAs), branched-chain fatty acids (BCFAs), lactic acid (LA), and ammonia (AM). In the digesta collected from the ileum and colon, piglets fed the HPa diet had the lowest concentration of volatile fatty acids. Additionally, the HP diet produced the highest concentration of BCFAs, while the LPpb diet produced moreacetic, propionic, and butyric acids than the HPa and HP diets. Piglets fed the HP diet had higher incidence and severity of diarrhea than piglets fed LPpb and HPa diets, and similar values were observed between these two groups. The second week postweaning was the most critical for diarrhea measurements; during the second week, animals had higher incidence and severity of diarrhea. Piglets fed the HPa and LPpb diets had similar ADGs, while those fed the HP diet had the poorest ADG. Similar results were observed with ADFI and G:F. A low-protein diet supplemented with probiotics changed the fermentation profile, reducing toxic metabolites, promoting gut health, decreasing the incidence and severity of postweaning diarrhea, and improving the performance of piglets.