ABSTRACT Assessing the effectiveness of grazing management and anti‐methanogenic dietary supplements on tropical pastures is crucial for sustainable livestock production and methane (CH 4 ) mitigation. This study aimed to: (1) compare forage mass, plant part composition, and nutritive value of ‘Mulato II’ hybrid brachiariagrass ( Urochloa spp.) managed under continuous (C) or rotational stocking with lenient (RL) or moderate (RM) defoliation at 20 and 30 cm; and (2) evaluate the effects of these strategies combined with supplementation (Control, Nitrate + elemental sulfur NS, soybean oil SO, corn bran CB, and SO + CB) on fermentation kinetics and CH 4 production. The C20 and RL20 treatments showed superior nutritive value—631 g kg −1 of neutral detergent fibre (NDF), 144 g kg −1 of crude protein (CP), and 591 g kg −1 of NDF degradability (NDFd)—and the highest Partition Factor (PF), but produced more CH 4 (6.3 mL g −1 dNDF). Conversely, RM30 forage had greater NDF (662 g kg −1 DM), less CP (100 g kg −1 DM), and lower NDFd (550 g kg −1 ), resulting in the least methane production (5.5 mL g −1 dNDF). All supplementations reduced CH 4 compared to the control. Additive effects in SO + CB increased NDFd (614 g kg −1 ) and reduced CH 4 by 29.5% without affecting ammonia nitrogen (NH 3 –N). NS had greater NH 3 –N (54 mg dL −1 ) and reduced CH 4 by 93.2% but decreased NDFd (505 g kg −1 ). Optimising forage quality (C20 and RL20) combined with NS or SO + CB provides the best integrated mitigation strategy.
Holschuch et al. (Thu,) studied this question.