# Effect of the Interaction Between Dietary Fiber Structure and Apparent Viscosity on the Production Performance of Growing Pigs

## TL;DR

This study shows how the structure and viscosity of dietary fiber affect pig growth, meat quality, and gut health, offering new ways to use high-fiber feeds in pig farming.

## Contribution

The study reveals how fiber structure and viscosity influence lipid metabolism and gut microbiota in pigs, providing a new approach for feed optimization.

## Key findings

- Higher dietary fiber structure and viscosity reduced fat deposition and improved meat tenderness in pigs.
- Increased fiber properties promoted butyrate-producing bacteria and influenced liver lipid metabolism genes.
- These changes lowered serum glucose and cholesterol while increasing glucagon-like peptide-1 in pigs.

## Abstract

Increasing the feeding proportion of unconventional feeds used to replace grain-based feeds in conventional diets has become an important goal for improving the economic efficiency and sustainable production strategies of the pig industry. However, the number of unconventional feeds used is limited due to their high dietary fiber content. How to improve the utilization efficiency of high-fiber feeds and diets in pig production is an urgent issue that needs to be addressed nowadays. This study found that under conditions of relatively high dietary fiber levels, differences in fiber structure and apparent viscosity significantly affect the growth performance, carcass traits, meat quality, and gut microbiota of growing pigs. These findings provide a theoretical basis for the effective utilization and rational combination of agricultural by-products.

To investigate the regulatory effects of dietary fiber structure (β-glucan-to-arabinoxylan ratio, β/AX) and apparent viscosity (AV) on production performance in pigs, this study used a 2 × 3 factorial design, randomly assigning 36 growing pigs (47.2 ± 1.5 kg) to six dietary treatments (two AV levels and three β/AX ratios), and observed the growth performance, carcass traits, meat quality, intestinal microbiota, and liver lipid metabolism. The results showed that increased dietary β/AX and AV reduced subcutaneous fat deposition, improved meat tenderness and the nutrient content of meat, but decreased pig weight gain and dressing percentage. Increased dietary β/AX and AV selectively promoted the relative abundance of butyrate-producing bacteria and the concentration of butyrate in the middle colon, thereby regulating the expression of genes related to hepatic de novo lipid synthesis and oxidation, reducing serum glucose and total cholesterol levels, and increasing plasma glucagon-like peptide-1. These findings reveal the potential mechanism by which the physicochemical properties of dietary fiber mediate lipid metabolism to reduce weight gain and provide new insights for regulating fat deposition in pigs by controlling the structural and physical properties of dietary fiber.