THE GENETIC STRATEGY TO IMPROVE SUSTAINABILITY Chuck Sattler, vice president of genetic programs, Select Sires Inc.
The U.S. dairy industry has made remarkable environmental progress over time and has a tremendous story to tell about sustainability and doing more with less. When comparing 2017 to 2007, U.S. producers needed 25.2% fewer cows, 17.3% less feed, 20.8% less land and 34.1% less water to produce one ton of energy-corrected milk. A lot of this progress is due to steady rates of genetic improvement and the capability of making more milk per cow.
Measuring sustainability and environmental impact can be complicated. However, the basic principle is quite straightforward. Improved efficiency can be achieved in four ways:
Making more product Making product faster Using fewer animals Using fewer inputs
When thinking about sustainability, our minds often skip directly to improving production and improving feed efficiency. While improved milk and component yield of our cows is a big part of the industry’s success story, this was possible because selection programs did not just focus on improving production traits but also included traits needed by cows to sustain increased production over multiple lactations. The recent addition of PTAs for Feed Saved and Residual Feed Intake (RFI) provide new tools and new opportunities to further reduce a cow’s environmental footprint. However, we should recognize these tools are a work in progress and currently have low accuracy. Improvement from these tools will initially be small as the industry works to gather more individual cow feed intake data. It’s easy to see how production traits and feed efficiency help herds harvest more product or harvest the same amount of product with fewer inputs. The principles of harvesting more from each animal can be extended to traits like health and fertility to highlight their role in improving sustainability. Cow fertility Selecting for improved cow fertility using traits like Daughter Pregnancy Rate (DPR) or Cow Conception Rate (CCR) prepares herds to have a higher percentage of cows in peak lactation, a lower percentage of stale cows and fewer reproductive failures that require forced culling. These fertility traits allow us to produce more product and do it with fewer animals since fewer replacement heifers are needed.
Health traits A similar argument can be made for genetic improvement of health traits. Mastitis resistance is the leading candidate because of its prevalence, but this also applies to metabolic disease and respiratory disease. Improved resistance to these health events means fewer unproductive cows in the sick pen and fewer cows dying. Once again, emphasis on these traits require fewer replacement heifers to achieve similar production yields. Calf and heifer management Calf health and Heifer Conception Rate (HCR) traits are also important contributors to improved sustainability. Emphasis on calf health will translate to higher heifer completion rates, meaning a lower percentage of the herd is non-producing heifers and a larger percentage of calves can be allocated for beef production. More beef calves can help produce more product and add revenue sources to dairy operations. Being mindful to HCR will ensure that healthy, fertile heifers reach the milking string at younger ages and help make product faster. Reducing death loss and reproductive failures in heifers will lessen the inputs needed for heifer raising. The bottom line The dairy industry has a rich history as being responsible stewards of the environment. It is as important for us to share this story as it is to continue to build on these gains. To meet the demands of a growing population, genetic improvement needs to emphasize a broad range of traits including improved fertility and disease resistance. To ensure your genetic strategy aligns with sustainability goals, talk with your Select Sires representative today. u REFERENCES Capper, J. L., R. A. Cady. 2020. The effects of improved performance in the U.S. dairy cattle industry on environmental impacts between 2007 and 2017. J. Animal Science 98:1-14.
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