BeefTalk: Calf Growth Observations of May vs. March Calving
NDSU Extension Beef Specialist
Data collected at the Dickinson Research Extension Center show the average daily gain of March- and May-born calves is 2.51 and 2.52 pounds per day, respectively. Interesting!
In an effort to evaluate this change in management, a review was conducted comparing overall performance of the center’s herd for the years 2009, 2010 and 2011(mid-March calving) to the years 2012, 2013 and 2014 (mid-May calving). In the perfect world, the center would have conducted a study with both calving seasons occurring in the same year for several years, but labor, land and facilities do not allow a study of that magnitude.
The next option is a review of the managerial records. This review does not imply a cause and effect; rather, it offers pondering for future efforts. In reality, this sort of review should be conducted on all cattle operations to better guide future directions within individual cattle operations wherever they are located.
CHAPS (Cow Herd Appraisal Performance System) data made available by the North Dakota State University Extension Service, in cooperation with the North Dakota Beef Cattle Improvement Association, show the center’s traditional program: bulls turned out June 1, or thereabouts, for March/April calving in 2009, 2010 and 2011. The average birth date for the third mature cow calving was March 15; the average calving date was March 29.
The calves weighed an average of 86 pounds at birth and gained 2.51 pounds per day (average daily gain, or ADG) on pasture. The average weaning weight was 609 pounds for the steers and 587 pounds for the heifers. The average weaning weight for all calves was 598 pounds, with a frame score of 5. The adjusted 205-day weight averaged 640 pounds.
The center, from a management point of view, was doing very well with March calving. Herd production was very typical of the benchmark values generated for CHAPS: average weaning age is 191 days (center, 205 days), average weaning weight is 558 pounds (center, 598 pounds), average daily gain is 2.49 pounds (center, 2.51 pounds) and adjusted 205-day weight is 623 pounds (center, 640 pounds).
So why change the calving date? The answer is not straightforward, so when a system works from a production point of view, any change needs to be thought through seriously. And in years like this, calving in March looks like a no-brainer. The weather is great, so why not simply enjoy it?
But we still have those nagging questions. Labor, snow or dry, still needs to be present. That means people, dedicated people with the needed skill set to calve cows. The other issue is that of increasing costs. The expense bucket is bulging and the pending fear of fiscal failure is real.
So primarily due to the shortage of labor, the center changed. The center delayed the turnout of the bulls to Aug. 1, or thereabouts, for April/May calving in 2012, 2013 and 2014. The average birth date for the third mature cow calving was May 7, with the average calving date being May 25. The calves weighed an average of 89 pounds at birth and gained 2.52 pounds per day (ADG) on pasture.
No change was made in the weaning date and fall management of the calves. Calves were weaned at an average age of 168 days. Steer calves weighed 537 pounds and heifer calves weighed 487 pounds. The average weaning weight for all calves was 514 pounds, with a frame score of 5. The average adjusted 205-day weight was 639 pounds.
The May-born calves were 37 days younger at weaning, but growth performance was very typical for the growth of the March-born calves. The adjusted 205-day weight for March-born calves was 640 pounds and for the May-born calves was 639 pounds.
The performance of calves on pasture when the center was calving in March-April was very similar to the performance of calves on pasture when calving in May-June. Shifting the calving date to May did not cost the center calf performance on pasture, but it did cost the center 84 pounds per calf in terms of average weaning weight. Delayed calving reduced the opportunity for growth by 37 days. Fall management needs tweaking.
An obvious change that should accompany a change in calving date would be a change in weaning date or fall calf management. This, like the change in bull turnout date, is a complicated question for producers. They need to take potential adverse fall weather, lack of facilities and lack of proper feedstuffs into account.
If the calving date change only shifted labor and expenses to the fall, more thought needs to be put into such a change. But given the experience at the center, those thoughts are certainly worth pursuing.
May you find all your ear tags.