DAIRY RESEARCH DAIRY RESEARCH
HOW COW LONGEVITY AND WELFARE IMPROVE HERD MANAGEMENT OVER THE LONG RUN By Gabriel M. Dallago, Elsa Vasseur, Valérie Bélanger and Shelley Crabtree CONTRIBUTORS
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nimal welfare is an important part of herd management, but what does the industry know about the relationships between welfare, herd performance and economics? Using Quebec data, researchers identified five herd profiles with various levels of welfare—from poor to good. The profile with the best overall welfare status also had the highest longevity, profitability and productivity. Dairy cow longevity is a key aspect of achieving a sustainable dairy industry. As a result, longevity is one of the major components of the Industrial Research Chair in Sustainable Life of Dairy Cattle and research conducted by Gabriel M. Dallago, PhD candidate at McGill University. The longer the cows remain productive in a herd, the more profitable the herd will be since cows only become profitable after the third lactation. This is when revenue from milk sales breaks even with all the costs associated with the rearing period (Pellerin et al., 2014). Mature cows in their third lactation or greater also
produce more milk, resulting in more revenue compared with younger animals (Dallago et al., 2021). In addition, when cows are culled earlier than expected, it is often because of health and welfare issues. Therefore, improving cow longevity means improving cow welfare and vice versa. Established by Novalait and its partners at McGill University in Quebec, the Industrial Research Chair in Sustainable Life of Dairy Cattle is headed by researcher Elsa Vasseur. The research team focuses on cow longevity in relation to cow profitability and welfare. Chair partners include Dairy Farmers of Canada, Lactanet and the Natural Sciences and Engineering Research Council of Canada.
CURRENT LONGEVITY STATUS
which measures the length of time between first calving and culling or death, was estimated using yearly official statistical publications from high milk-producing countries (Figure 1). New Zealand was the only country where longevity increased. Meanwhile, no change was observed in the United States, Germany and the Netherlands, and longevity decreased in the remaining six countries, including Canada. Once scientific evidence confirmed dairy cow longevity has decreased, the focus of the analysis shifted toward early life conditions potentially associated with longevity. Identifying those early life conditions could help improve the current situation by providing guidance on how to increase longevity.
Increasing dairy cow longevity has been identified as a problem in the industry. However, longevity status is not always consistently reported by dairy herd improvement agencies or national databases. As a result, researchers focused on developing a standard methodology to estimate longevity in different countries to allow them to analyze the status and trends over time and make a fair comparison between countries. The longevity metric length of productive life,
Figure 1: Linear trend of longevity, measured by the length of productive life (year), in 10 high milk-producing countries as estimated using statistical models
GABRIEL M. DALLAGO is a PhD student in 32
NOVEMBER 2021 | MILKPRODUCER
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