Extended Data Fig. 3: Spatial data and depiction of main cattle breeds considered in study.

(a) location of study region within Tanzania showing regions and districts used in simulations, (b) improved (Bos taurus x Bos indicus) and (c) local cattle (Bos indicus) breeds considered in model, (d), production systems simulated (MRT = Mixed rainfed tropical, MRH = mixed rainfed humid), (e) dairy breed composition for base year (2018) as % improved cattle for each simulated district. Base year herd genetic compositions are based on the Greening Livestock Survey (GLS 2019). Maps and photographs attributable to authors of this paper.