Average Age at First Calving Still Too High
While other areas of the dairy business have made great advances, the average age of heifers at first calving is still stuck at more than 26 months. The 50th percentile of all animals was 26.9 months in 1996. More than a decade later, in 2009, it was 26.7 months, according to CanWest DHI records. In between it ranged from 26.2 in 2002 to 27.0 in 2005 and 2007.
This number has improved on individual farms, but the average has remained unchanged. I believe there are probably two reasons. Heifers are still the forgotten animals on many operations because they are not in plain view every day. Also, too many preventable health issues occur at specific times in early life with heifers getting sick and recovering-resulting in possible future problems-or dying.
There also appears to be no relationship between herd production and heifer-raising measures. This disconnect is puzzling.
Is it possible some producers believe calving heifers older is an advantage? If so, they should rethink their heifer programs. DHI information shows heifers that calve closer to 24 months of age produce more first-lactation milk, and have greater lifetime milk production. Regardless of their age at first calving, cows stay in the herd about the same amount of time.
Graph 1 : Comparison Age at First Calving vs Productive Life
Graph 1, comparing heifers that calved at 23 to 30 months of age, shows this point well. Animals that calved at the younger age produced 2,000 kilograms more milk over their lifetimes. Even though older animals stayed in the herd 45 days longer, they still gave less milk. Even more interesting, animals that calved at 25 months of age and those that gave birth at 30 had only a 15-day difference for time spent in the milking herd.
Graph 2 : Comparison Age at First Calving vs Lifetime Milk
How many heifers calve old? As seen in Graph 2, of the 145,174 animals culled in 2008 and 2009, more than 45 per cent were more than 26 months of age when they first entered the milking herd-and 40,000 animals were 28 months of age or older.
Several organizations have gotten together to find out why. Led by OMAFRA, this group includes CanWest DHI, the University of Guelph and Gencor. They hope to identify roadblocks to getting Ontario herds to calve earlier with healthier, higher producing animals. Among other factors, they will look at whether there is a lack of research in certain areas or other issues that need to be addressed.
Their goal is to raise producer awareness, so heifers gain higher priority. This would improve age at first calving and milk production, resulting in better profitability. The process will:
The cost of raising a heifer to 24 months of age has been estimated at $1,800 to $2,500. Letting them stay on your farm in an unproductive state for two, four or even six months longer costs between $100 and $300 more per animal-in addition to reduced milk production. A 100-cow herd could save $3,500 to $15,000 per year by lowering the first calving age to 24 months.
Stay tuned for more information. Let's make the next 10 years a decade of dramatic improvements in heifer management across our country.
This article first appeared in the Ruminations column of The Milk Producer Magazine, December 2010.
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