Yucca schidigera extract in finishing pig diets: impacts on performance, welfare, carcase and meat traits by sex

Context Yucca schidigera extract, rich in saponins and bioactive compounds, gained attention as a phytogenic feed additive for its antimicrobial, antioxidant, and welfare-enhancing effects. Its supplementation has also been linked to lower gas emissions, improved gut health, and potential benefits for meat quality. However, its impact on nitrogen metabolism, carcase traits, and possible sex-specific responses in pigs, especially lean genetic types derived from Pietrain, remains underexplored. Aims This study evaluated the effects of diet supplementation with Yucca schidigera extract on performances, welfare, carcase and meat quality in lean finishing pigs slaughtered at 115 kg average body weight, considering potential sex-related differences. Methods Forty Pietrain crossbred lean pigs were used in a 42-day trial. Animals were homogeneously divided by sex into two experimental groups receiving either a commercial basal diet as control or the same diet supplemented with 300 mg/kg of yucca extract (two pigs per pen, five replicates per diet and sex). The variables measured were growth and feed performance, blood protein and catabolite profiles, behavioural patterns and carcase and meat quality. Key results Yucca supplementation had no significant effect on growth performance or nitrogen mass balance, although females tended to grow more slowly than males. Serum urea levels remained stable in the yucca-supplemented group, while they increased in the control group. Females showed higher albumin, creatinine and cupric reducing antioxidant capacity levels than males. Behavioural patterns were not influenced by diet or sex. Carcase and meat quality were unaffected by yucca extract, although males produced brighter meat with lower protein content. Conclusions Dietary supplementation with Yucca schidigera extract during the fattening phase did not compromise performance, animal welfare or meat quality. However, sex differences in blood protein catabolite profiles and meat quality were evident, possibly reflecting variations in protein metabolism and muscle development. Implications Yucca schidigera extract at 300 mg/kg can be safely included in pig diets with no negative effects on growth, behaviour, nitrogen balance, or carcase and meat quality in lean finishing pigs, independent from sex. Also, variations in the blood protein composition across entire males and females suggest hormonal differences to be evaluated in further studies.