Interpretive Summary: Impacts of fiber and crude protein on performance and gut microbiota in piglets

By: Anne Kamiya, MS

The prophylactic use of antibiotics and pharmacological zinc were traditionally used to ward off postweaning diarrhea (PWD) in piglets. However, due to antibiotic resistance and strict regulations on the use of zinc and antibiotics in animal feed, other strategies for combatting PWD are needed. Post-weaning diarrhea can be mild or severe with effects ranging from dehydration and reduced growth to death in worst-case scenarios. Therefore, alternative ways to combat PWD are needed. 

In this recent Journal of Animal Science study, researchers investigated how increasing dietary fiber and reducing dietary crude protein (CP) impacted the performance and fecal microbiota of nursery pigs. 

A total of 360 postweaning piglets were fed one of eight diets with either 18 or 21 percent crude protein content and either no fiber or fiber from three different sources (coarse wheat bran, oat hulls, or cellulose) for 24 days. No significant interactions between CP and fiber content on performance were identified, but piglets fed less CP, regardless of fiber content, had decreased average daily gain and decreased gain to feed ratio. Fecal dry matter content increased with reduced CP. There was no impact of fiber on performance. The gut microbiota of piglets fed less CP was also different, with unknown significance. 

Overall, this study suggests that reducing CP in the diets of postweaning piglets by even 3 percent leads to decreased performance. Based on these findings, feeding piglets a diet with reduced CP and increased dietary fiber would likely not mitigate PWD. The authors hypothesized that lower lysine content in low CP diets is what likely reduced piglet performance. Further investigations into how low CP diets supplemented with lysine and dietary fiber might impact the growth performance, gut health and severity of PWD in nursery piglets is a potential area of future study. 

The original article, Effect of fiber source and crude protein level on nursery pig performance and fecal microbial communities, will soon be viewable in the Journal of Animal Science.