Enteric methane emissions are significant from countries with considerable livestock production, including Brazil. Various strategies exist for the mitigation of greenhouse gas emissions and, in general, the intensification of production systems reduces emissions intensity; that is, emissions of CO₂ equivalents per unit of product (meat or milk). The objective of this trial was to measure CH₄ emissions and animal performance in beef cattle in 4 Brazilian grazing systems with different levels of intensification. The study was conducted at EMBRAPA Southeast Livestock, in São Paulo State, Brazil. Twenty-four Nellore steers were distributed across 4 representative grazing systems: (1) irrigated pasture with high stocking rate (IHS); (2) dryland pasture with high stocking rate (DHS), planted with Panicum maximum; (3) dryland pasture with moderate stocking rate (DMS); and (4) degraded pasture (DP), planted with Brachiaria decumbens. The HIS and DHS systems were composed of 12 paddocks each, and the DMS system consisted of 6 paddocks, all under rotational grazing. The DP system was managed under continuous stocking. Animals were kept in the same grazing systems from weaning until slaughter. Methane measurements were taken during 4 seasons using the SF₆ tracer technique and gases were analyzed by Shimadzu GC 2014. Data were analyzed using the SAS MIXED procedure and averages were compared using the Tukey test and considered significant at P < 0.05. The animals finished in the DP system presented the lowest (P < 0.01) carcass weights (265.5 ± 15.6 kg), whereas those finished in the IHS system presented the highest (328.3 ± 10.2 kg). The average daily methane emissions were similar at 202.7±38.6 g/d, as were emissions per kilogram of live weight at 409.1 ± 59.7 (g of CH₄/kg of live weight). At the end of the experimental period, total methane emissions were similar at 66.9 ± 12.7 kg, whereas carcass gain over the period was significantly lower (P = 0.0234) for the DP group at 73.2 ± 18.0 kg, versus 105.8 ± 25.0 kg in the other intensified systems. The use of technologies that permit increased production favors animal performance, increases carcass production, and dilutes the emissions per kilogram of carcass produced.