Abstract
BACKGROUND: Reducing the environmental and climatic impact while maintaining high growth performance is an urgent challenge in pig production. Limiting methane emissions from pigs through targeted strategies may help mitigate global methane emissions. Addition of a Bifidobacterium bifidum 1,2-α-L-fucosidase exoglycosidase to pig feed to cleave and release fucose from intestinal mucins into the gut lumen has previously been shown to promote specific beneficial gut bacteria and reduce methanogens. This study aimed to investigate the supplementation of the fucosidase to pig feed as a tool to reduce enteric methane production in pigs while improving growth performance. Four experimental groups were included: a control group (CON) fed Danish standard diets and three groups (Fuc2, Fuc7, Fuc16) fed the same standard diets amended with 100 mg fucosidase per kg feed for 2, 7, or 16 weeks, respectively, starting at weaning. The remaining period (up to 14 weeks), they received the control diets without fucosidase addition. A total of 240 crossbred piglets (weaning age 22 days) from 80 sows were included, and performance, counts of methanogens and methane emission were measured. RESULTS: When comparing all three groups fed with fucosidase together against the CON, a higher ADFI (p = 0.05) was observed in the fucosidase groups during the first two weeks. On day 106, the in vivo methane emission was lower in all three fucosidase groups compared to the CON (p < 0.05) when calculated per kg dry matter intake, and a tendency to reduce methane emission was observed when corrected for body weight (p ≤ 0.10). The in vitro methane production and the number of methanogens were not significantly different in the CON and the fucosidase groups (p >0.05). CONCLUSION: The results suggest that in-feed fucosidase may lead to lower methane emission at later pig production stages, despite neither affecting total methanogenic archaea numbers in the colon nor significantly impacting pig growth performance. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s42523-025-00487-9.