The research is out there and it isn’t new—tightening calving seasons give producers many management and economic benefits. Even so, there are still many producers operating on a year-round calving season. Reining in a calving season can also cause huge management losses if done improperly.
According to Les Anderson, University of Kentucky Extension beef specialist, it will take at least two years for producers to tighten a year-round calving season into a 75-day controlled calving season. He offers eight steps to get a handle on calving season.
- Determine the ideal calving season and a target length. Forage availability and nutrition will be the main factor in whether your herd should be shifted towards a fall or spring calving system.
- Examine the reproductive status of each cow in the herd. When was the last date each cow calved? Record the number of calvings each month. Anderson says if a producer doesn’t keep records, look at pairs to try and determine the calf’s age.
“For example, let’s assume we have 30 cows. Calving dates from fall to spring are as follows: August, no cows calved; September, two calved; October, two calved; November, one calved; December, no cows calved; January, no cows calved; February, three calved; March, nine calved; April, five calved; May, five calved; June, two calved; and July, one just calved,” Anderson explains. “Keep in mind the five cows that calved in the fall
are likely pregnant.”
- Does it make sense to split into two calving seasons? If only five of the 30 cows were closer to a fall calving cycle, Anderson recommends rolling them to spring with the rest of the herd since they would require separate nutrition and bull exposure. “However, half of your herd calved July to December. It is a better economic decision to make these fall-calving cows and the ones that calve from January to June spring-calving cows,” he says.
- Build strong fences. This falls under the category of cow-calf management. If cows are coming into heat at different times and a producer is trying to adjust his breeding season, bull exposure needs to be managed. An electric fence along a regular fence wouldn’t be a bad idea, Anderson says.
- Pull bulls from the herd. “Select the removal date to coincide with about a 120-day season for your spring-calving cows,” he explains. “In our example, we would remove the bull(s) near the end of August. He would stay in the bull pen until May 7 of next year.”
- Preg check females. At least 60 days after bulls are pulled, preg check females and cull any that are open at breeding age.
- Plan replacement heifer breeding season. Anderson recommends replacement heifers are bred 20 to 30 days prior to the final breeding date of the herd. “Most extended calving seasons are the result of failure of young cows to rebreed in a timely fashion. The additional 20 to 30 days enhances the opportunity for these young cows to rebreed next season,” he explains. “So, your replacement heifer breeding season would start around April 10 and these females would begin calving around Jan. 20. I realize that this is a bit early for calving and you might experience 1% to 2% higher calf death loss. Financially, 1% to 2% death loss is easier to swallow than a 25% decrease in pregnancy rate the following year.”
- Repeat for the second year. However, Anderson adds, “Remove the bull the week of July 20. If you have fall and spring calvers, put the bull in for the fall cows around Nov. 20 and remove him around Jan 20.”