Effect of Tithonia diversifolia (Hemsl.) A. Gray intake on in vivo methane (CH4) emission and milk production in dual-purpose cows in the Colombian Amazonian piedmont

The inclusion of Tithonia diversifolia in pasture-based diets is a promising alternative to increase bovine productivity, due to its chemical composition and wide adaptation, but there are few in vivo studies to determine its effect on methane yield and animal production in grazing systems. The objective of this study was to determine the effects of the T. diversifolia inclusion in a basal diet of Brachiaria humidicola on methane (CH4) emissions by enteric fermentation, and on milk yield and quality in dual-purpose cows. The polytunnel technique was used for the determination of methane yield and two diets were evaluated (Diet 1: Brachiaria humidicola 100%; Diet 2: T. diversifolia 15% + B. humidicola 85% dry matter basis) in the moderate rainy and rainy seasons using a cross-over experimental design; milk production was measured by daily milk weighing, and milk quality was determined using a LACTOSCAN analyzer. The inclusion of T. diversifolia did not increase the dry matter intake (P = 0.369), but increased the intake of crude protein and minerals, and reduced fiber intake, resulting in the increased yield of milk and its components in the moderate rainy season (P = 0.012). The inclusion of T. diversifolia reduced the absolute CH4 emissions (P = 0.016), Ym and emission intensity (per unit of fat, protein and kilogram fat and protein corrected milk yields) both in the moderate rainy and rainy seasons (P < 0.05). We conclude that the inclusion of T. diversifolia in the forage feed base in the humid tropics such as the Amazon piedmont can be used as a tool to both mitigate enteric CH4 emissions and to increase animal productivity and hence reduce emissions intensity, and thus reduce pressure on the agricultural frontier in critical areas such as the Amazon. Lay Summary Due to the need to identify alternatives to reduce climate change, ways of producing in cattle systems that reduce the generation of greenhouse gases must be known and evaluated. Livestock systems are an important source of greenhouse gases; this study found that the use of a shrub (Tithonia diversifolia) in cattle systems under grazing reduces methane emissions and improves animal production (milk yield and solids). The results found can favor the efficiency of cattle systems and make them more sustainable in a key area such as the Amazon. This work reports for the first time the mitigation of methane (CH4) under in vivo conditions and in an area with high conflict in land use such as the Amazon piedmont. The inclusion of T. diversifoliacan be included in low-quality diets of grazing cattle to reduce enteric methane emissions. The use of T. diversifoliain grazing systems increases milk production in medium-production cows, and thus it can be an alternative to reduce pressure on the agricultural frontier in critical areas such as the Amazon.