Increased dietary protein (DP) may predispose weanling pigs to health risks and reduced performance due to the negative effects on intestinal health and increased pathogen proliferation. However, since the negative impacts of DP are mostly due to the amount of protein flow into the hindgut, dietary indigestible dietary protein (IDP) content may better explain the potential effects of proteolytic fermentation on nursery pigs compared to DP. Therefore, this meta-analysis reviewed and compared the impact of DP and IDP as 2 independent indexes on the growth performance of weaned pigs from 89 articles using a meta-regression model. Results indicate that the IDP index in diets positively correlates with the increased inclusion of plant-based proteins. Performance simulations based on the DP and IDP index indicate 1) a negative effect on average daily feed intake, and a tendency to negatively impact average daily gain with increasing IDP index, 2) a tendency for increasing DP to impact pigs’ average daily gain and feed efficiency positively. Results emphasize the potential of the IDP index as a better predictor of negative outcomes in newly weaned pigs compared to a DP index.

Read the full article in the Journal of Animal Science.