According to a search on the web, the oldest cow that ever lived was Big Bertha, she was born in Ireland, produced 39 calves and lived for 48 years and 9 months — pretty impressive! And you must have noticed that I mentioned not just how many years she lived, but also how much she produced. So, yes, longevity in cows is linked to how long the cows live and how much milk they produce.
Good genetics is probably part of Big Bertha’s long life but longevity in dairy cows is also influenced by nutrition, health, management and culling decisions. Herd performance indicators such as milk yield, somatic cell count, fertility, calving interval and technical efficiency are also related to cow longevity and can affect the economic and environmental sustainability of dairy farms.
Differences in longevity in dairy cows exist between farms and continents. The average productive lifespan varies from less than 3 years in the United States to at least 4.5 years in some European countries. In the Netherlands, the average age of culled cows was reported to be 5.87 years. No doubt that longevity in cows is an important topic for dairy producers, as well as for animal welfare (by reducing replacement costs, improving genetic potential), environmental concerns (by mitigating environmental impact) and farm profitability.
So often in the news today, dairy production is criticized as being a major contributor to emissions of greenhouse gases. In general, increasing the longevity of dairy cows can reduce their carbon footprint per unit of product, as they can produce more milk over their lifetime with a lower replacement rate and fewer emissions from raising heifers.
Methane is the biggest greenhouse gas and is responsible for about 50% of emissions, so practices such as milking healthy cows for as long as possible (at least four lactations), having a good replacement rate and appropriate calving interval will help lower the footprint.
Nitrous oxide is the next biggest greenhouse gas on a dairy farm, accounting for about 30% of emissions. It comes from fertilizers and slurry. Thus, spreading on pasture/crop at the correct time and following requirements based on a soil analysis is beneficial.
Concentrates contribute approximately 10% of greenhouse gas emissions. Carbon dioxide, with sources like electricity and fuel use, completes the rest of the emissions.
The implementation of some strategies for dairy methane reduction such as alternative manure management, methane capture and utilization (digesters) and enteric methane reduction (with, for example, the use of enteric feed additives) is a reality for many dairy farmers already.
Even knowing that Big Bertha is unique, research has shown that increasing the length of the productive life of dairy cows, selecting for heat tolerance and reducing emissions directly may reduce the climate impact and improve the profitability of dairy production.
Please let us know if you are interested in knowing more about management practices and receiving information on how to improve the longevity of cows from your farm by contacting dacosta.2@osu.edu.
