The EnviroCow index and its impact on the UK dairy industry’s carbon footprint

Abstract

Since 2021, the UK has published the EnviroCow index, derived from genetic evaluations for production traits, calf survival, cow longevity, fertility, and Feed Advantage. The goal of the index is to reduce carbon emissions per kg of product produced, and importantly reflect the lifetime environmental efficiency by incorporating survival traits. The index uses carbon emission equivalents, estimated for the traits in the index based on their feed requirements for a unit change of the trait. Feed intake in turn has been shown to affect enteric methane production. A recent analysis of lifetime efficiency was conducted on approximately 475K females by comparing their EnviroCow genetic index to their phenotypic performance for milk, fat and protein over their lifetimes, age at first calving, number of lactations, mature weight (derived from proxies as liveweight itself is not routinely recorded) and stature (where available). The data showed that each point increase in EnviroCow, on average gave animals that produced 10% less methane per kg milk, through enteric emissions, consumed 10% less feed, while producing 33% higher weight of fat and protein in their lifetime. Genetic trend data estimates that the carbon footprint per kg milk in the UK is predicted to reduce by around 1% each year due to genetic gains achieved in the population.