Farm-level factors influencing enteric methane emissions from dairy cattle in smallholder farming systems of Malawi

Smallholder dairy farms are the backbone of the dairy sector in sub-Saharan Africa but face constraints such as feed scarcity and climate effects, making them predominantly low-output systems with high methane emission intensities. A study was conducted in Malawi to determine direct enteric methane ( CH 4 ) concentration values (ppm-m) and to investigate the farm-level variables influencing CH 4 from dairy cattle in smallholder farming systems. Seventy-two smallholder farmers were surveyed across five districts and six milk bulking groups ( MBGs ). Sixty-eight farms and 100 dairy cattle were included for analysis. Farm-level data were collected through intra-household interviews and observations, and daily milk yield was recorded from the farmers. Methane was measured with a Laser Methane Detector directly from the animals. Animal breeds were the Zebu, Holstein Friesian, Jersey and crossbreeds (Zebu × Holstein Friesian; Zebu × Jersey). A Multiple-factor analysis and a linear mixed-effect model were used for analysis. For both methods, the farm-level variables included animal live weight, animal diet, farm manager type, education level, land ownership status of farmer, gender and MBGs. Four datasets were analysed with the linear mixed-effect model. Methane was the dependent variable for the datasets: all animals, cows, heifers. Milk yield was the dependent variable for the lactating cows dataset. The multiple factor analysis accounted for 37.86% of total variance, associating available feed type with farmer’s education, farm manager type and milk bulking group. Average CH 4 was 264.35 ± 10.24 ppm-m. When considering all animals, farm manager type and animal diet emerged as significant on CH 4 ( P = 0.009; P = 0.04), with family-managed farms reporting higher CH 4 than hired-manager farms (284 ± 20.6 vs 231 ± 23.1 ppm-m). The enhanced diet with forage legumes and tree fodder showed lower concentrations than the intermediate diet at 230 ± 26.3 and 275 ± 18.3 ppm-m, respectively. Live weight and farm ownership showed a significant effect ( P < 0.05) on milk yield. Malawian MBGs, farm manager, farmer’s education and land ownership emerged as important farm-level factors influencing the animal diet composition and indirectly affecting CH 4 and milk yield. The findings suggest that farmers’ groups such as MBGs are potential hubs for knowledge transfer on enteric methane mitigation strategies, relevant to smallholder dairy systems in Malawi and sub-Saharan Africa.