PSXIII-11 A systematic review and meta-analysis of efficacy of exogenous fiber enzymes in modulating growth performances and nutrient digestibility in weanling pigs.

Abstract Dietary fiber is an anti-nutritive factor that reduces nutrient digestibility, profitability and contributes to greenhouse gas emissions in swine production. Exogenous fiber enzymes have been used in the swine industry for over two decades, but their efficacy in modulating growth performance and nutrient digestibility in weanling pigs remains inconsistent. We hypothesized no significant differences in the in vivo efficacy endpoints in responses to exogenous fiber enzyme supplementation. This study conducted a meta-analysis of 35 studies (2003–2024) to examine the effects of exogenous fiber enzyme supplementation on growth performance and nutrient digestibility in weanling pigs fed commercial diets containing oil meals, cereal grains, by-products and co-products. Results showed no differences (P >0.05) between non-enzyme and enzyme-supplemented groups in initial body weight (7.91±0.35 vs. 7.68±0.28 kg) and dietary contents (as-fed) of net energy (2463±63 vs. 2462±63 kcal/kg), crude fat (7.98±2.72 vs. 8.12±2.73%), neutral-detergent fiber (NDF) (12.16±0.77 vs. 13.14±0.85%) and lignin (0.82±0.23 vs. 0.84±0.28%). Supplementation of exogenous fiber enzymes of cellulases and hemi-cellulases in single and/or in combination had no effects (P >0.05) on growth performance indicators of average daily gain, feed intake, and gain-to-feed ratio. Apparent total tract digestibility of dry matter (82.8±0.8 vs. 83.3±0.9%), NDF (53.5±2.3 vs. 55.6±2.5%) and crude fat (69.2±8.8 vs. 70.3±9.3%) remained unchanged (P >0.05). Our meta-analysis results suggest that currently available commercial exogenous fiber enzymes have limited efficacy for improving growth performances and nutrient digestibility in weanling pigs. More efficacious exogenous fiber enzymes or their modifications need to be further developed to improve profitability and sustainability in swine production.