It’s a well-known fact that cows contribute to greenhouse gas (GHG) emissions at a relatively high rate. Their digestive systems break down plant matter and produce methane as a by-product. We also know that cows are an extremely important part of the food chain in a number of ways and are a vital source of income for millions of people. So what if there was an environmentally friendly cow? What would that look like, and how would we even start breeding one?
What makes a cow environmentally friendly?
The highest producing cows in the world can produce over 10,000 litres of milk in a year. On the other end of the scale, in some developing dairy industries, such as those in Ethiopia, Nigeria and Afghanistan, a single cow much produce less than 500 litres in a year. If each cow has a much greater milk yield, then fewer cows are necessary to produce the same volume of milk. While the environmental impact of a single cow might be equivalent, having twenty times fewer cows would have an enormous impact on the carbon hoofprint of the global herd.
The best traits for reducing carbon footprint are:
- High feed conversion ratio
- Fast growing
- High milk yield
- Healthy and resilient cows
How can breeders breed better cows?
Breeding cows for certain traits is an integral part of bovine agriculture. From the original domestication of the ancient cow-like aurochs, there are now over 1000 different breeds of cattle. Breeds like Holsteins and Friesians are known for their milking capacity, whereas other breeds, like Herefords and Angus cattle, are primarily beef breeds.
The main difficulty when breeding cows for particular traits is the problem of trade-offs. Often, breeding for a specific trait, such as fast growth or extremely high milk yield, then has a negative effect on other traits. Fast growing cows might have poor feed conversion, so require huge amounts of food to grow to full size. High milk yield cows can suffer from low fertility and reproductive issues. If producers want to use more environmentally friendly cows, there will inevitably be some difficulties.
How can genetic indexes help cattle breeders?
Genetic indexes have been part of cattle breeding for over 25 years. As Artificial Insemination spread through both the dairy and beef industries, it became much easier to select for specific heritable traits. Semen from top quality bulls is relatively easy to store and to ship, so cows across the world can benefit from good genetic lines. Each sire is given a score based on various factors, such as his performance and the performance of his daughters. Breeders can then choose which sire to use to service their cows to produce the most desirable offspring.
Some genetic indexes are geared towards the milk industry, with traits such as milk fat, yield and protein content taking precedence. Others are geared more towards beef production. Now, there will be indexes to help farmers breed more environmentally friendly cows.
In August of this year, AHDB Dairy will launch EnviroCow. This index ranks cows based on their GHG emissions, with higher scores for cows with small carbon hoofprints. While this may be the first dedicated index of this type, it is unlikely to be the last. As producers move towards reducing carbon, indexes like this will become increasingly important.
Is breeding better cows a perfect solution to greenhouse gas emissions?
Absolutely not! Carbon footprint varies dramatically for cattle across the world. Many factors contribute, from feed availability to climatic conditions. Similarly, some breeds of cattle are not able to thrive in less industrialised or hotter countries without huge economic inputs.
This is only one thread in a matrix of solutions which will help to reduce GHG emissions across the agricultural industry. Changing management styles, feed stuffs, rotating pasture, and many other strategies all have their place. Individual herds and farmers are under different pressures, so solutions to the problem of GHG emissions must reflect that.
