After decades of phenotypic decline in fertility traits as dairy farmers bred cows to make more milk instead, the industry has more recently seen improvements in heifer conception rate (HCR), cow conception rate (CCR), and early first calving (EFC), as well as modest progress in daughter pregnancy rate (DPR). “Overall, I would say we’re making generally favorable progress,” said John Cole during a Dairy Calf and Heifer Association webinar.
This indicates that selection for these specific fertility traits is working, continued the Council on Dairy Cattle Breeding’s (CDCB) chief research and development officer.
Cole explained that HCR and CCR are both based on confirmed pregnancies, specifically, the percentage of inseminated animals that become pregnant at each service. The DPR trait is based on days open. For example, a 1% higher pregnancy rate is correlated to four fewer days open. He recognized that the CDCB trait assumes a 60-day voluntary waiting period, which is shorter than what many farms use today with their more productive cows.
September 30, 2024
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