Landscape analysis of breeding value patterns in Brazilian Montana

The Brazilian livestock industry is a major global producer of beef cattle meat. The country's vast land area contains various biomes and different types of farmers and production systems, ranging from grassland-based to feedlot systems, each with its agricultural practices. Environmental and climatic factors such as solar incidence oscillations, precipitation, and different soils have been found to impact livestock production. Reports indicate that changes in the environment and market demands will require the replacement of breeds and species in production systems within the next 30 years. The Montana Tropical is a composite breed designed for tropical and subtropical beef cattle systems under grazing conditions. This study used data from 571,424 Montana animals born between 1950 and 2019 from 63 farms in 10 Brazilian states to assess the influence of environmental and geo-economic factors on breeding value estimation. The study analyzed traits such as birth, weaning and yearling weights, daily weight gain, scrotal circumference, sheath muscle, height scores, and the Montana selection index. The environmental data was mapped in ArcGIS along with geo-economic information, including soil type, altitude, precipitation, normalized difference vegetation index (NDVI), temperature and humidity index (THI), air temperature, and solar radiation. Socioeconomic data included population density and gross domestic product. The results showed that environmental and geo-economic factors can influence the estimation of breeding values. Breeding values tend to have similar trends in high-altitude regions, medium to high NDVI, especially after weaning, low THI, lower population density, and higher mean air temperature but lower solar radiation. The findings suggest that features not currently included in genetic evaluations, such as environmental and geo-economic factors, can impact the estimation of breeding values of the candidates under selection.