Abstract
Reducing greenhouse gas (GHG) emissions from livestock is a crucial step towards mitigating the impact of climate change and improving environmental sustainability in agriculture. This study aimed to evaluate the effects of Yucca schidigera extract, chitosan, and chitosan nanoparticles as feed additives on in vitro GHG emissions and fermentation profiles in ruminal fluid from bulls. Total gas, CH(4), CO, and H(2)S emissions (up to 48 h), rumen fermentation profiles, and CH(4) conversion efficiency were measured using standard protocols. The experiments involved supplementing 0.25, 0.5, and 1 mL/g dry matter (DM) of additives in different forages (alfalfa hay, corn silage, and oats hay). The chemical composition of forage showed suitable levels of DM, ash, crude protein, acid detergent fiber, neutral detergent fiber, lignin, and metabolizable energy. The addition of these supplements increased asymptotic gas production across all forages while simultaneously reducing CH(4), CO, and H(2)S emissions, though the extent of reduction varied depending on forage type. Moreover, the treatments improved fermentation profiles, including pH and dry matter digestibility, and significantly influenced CH(4) conversion efficiency (CH(4):ME, CH(4):OM, and CH(4):SCFA; P < 0.05). These results underscore the potential of Y. schidigera extract, chitosan, and chitosan nanoparticles as effective strategies for mitigating GHG emissions from ruminants given these promising in vitro findings. Further in vivo studies are recommended to validate their efficacy under real-world conditions, which could pave the way for practical applications in the field.