Effects of Dietary Fiber and Copper on the Performance and Gut Microbiota of Finishing Pigs

Abstract

This study aimed to investigate the effects of dietary fiber (DF) levels and copper concentrations on the production performance and cecal microbial diversity of finishing pigs. A 2 × 2 factorial experimental design was used, with different levels of dietary fiber (low [23% DF]: L and high [30% DF]: H) and copper concentrations (normal [25 mg/kg]: N and supplemented [45 mg/kg]: S) resulting in four diets (LN, LS, HN, and HS). Forty-eight hybrid barrows (Duroc × Landrace × Yorkshire), with an initial body weight of 76 kg ± 1.5 kg, were randomly assigned to four groups: LN, LS, HN, and HS, with 12 replicates per group and one pig per replicate. There was a 7-day adaptation period followed by a 56-day feeding trial, after which all pigs were slaughtered for sampling. Results indicated that in finishing pigs, the low dietary fiber group exhibited a higher final weight, a higher average daily gain, and a lower feed-to-gain ratio compared to the high fiber group (p p p p p p Firmicutes/Bacteroidetes ratio increased with fiber levels, with a higher relative abundance of Lactobacillus in the LS group. In conclusion, appropriate copper supplementation in diets can mitigate the negative effects of high fiber levels on finishing pig production performance by enhancing nutrient digestibility, fiber-degrading enzyme activity, regulating the microbial community, and its metabolic products.

Keywords

• dietary fiber
• trace element copper
• finishing pigs
• production performance
• colon microflora