Are you depending too much on your young bulls? Should you run multiple bulls with a single breeding group? Can your have too many bulls and not enough females?
University of Missouri Extension Regional Livestock Specialist Andy McCorkill said bull-to-female ratios should be taken into consideration when identifying breeding groups in an effort to optimize conception, as well as the bull’s age, pasture and weather conditions, and how “active” a bull is.
“As a general rule, for bulls 12 to 24 months of age, I recommend not to run more than one female per month of age on the bull,” McCorkill said. “On older bulls, it gets to be a matter of how big of gambler you want to be. Size and terrain of your pastures, weather conditions, length of breeding season and the ‘personality,’ so to speak, of the bull all play a role in the decision as well. Some bulls are very efficient in their duties and get the job done without you ever seeing evidence of him breeding a cow, while others will find a cow in heat and stay with her, missing the opportunity to breed one or more others in the herd. Some bulls are lazier than others and just won’t breed as many.”
McCorkill also said produces should reconsider introducing a younger bull into the same breeding group as an older bull.
“Even though the market has softened a bit from last year’s highs, bulls are still worth a lot of money, if you’re trying to buy a good one, so we don’t want to do anything that might get one injured,” he said. “When you turn bulls out together, they are going to establish the ‘pecking order’ and a yearling bull that is not to his mature size is at a big disadvantage to an older bull that is mature in that regard. Some producers I have talked to like to turn a young bull out with older bulls with the thought that if they get whipped they will always be looking out for that bigger bull across the fence and stay at home and not fight. But if you do turn a young bull in with older bulls, there will be a higher risk of getting a young bull injured or possibly killed before you have gotten your money’s worth out of him.”
The use of multiple bulls in a single breeding group can also make it difficult to determine which bull is giving producers the results they want in the breeding season.
“Generally, there will be a dominant bull that will breed most of the herd, as much as 70 percent in some studies done in western states, and whatever is left will get picked up by the rest of the bulls,” McCorkill said. “Running multiple bulls with a herd can sometimes make it difficult to determine which bull a calf is out of and make it difficult to decide how much good a given bull might be doing your herd’s genetic pool.”
He added that producers who run multiple bulls with a herd, try and run bulls that have been together before and get along well with each other.
As the Ozarks enters into the hottest months of the year, McCorkill reminds producers that periods of hot weather can mean that bulls will not be as apt to breed, and producers who opt for a shorter breeding season may not have the results they hoped for.
“If the weather turns hot, particularly on our fescue pastures, fertility issues can arise reducing the likelihood of getting the herd bred,” McCorkill said. “This is one of the reasons many in this area are looking more at fall calving every year; the breeding season is late fall, early winter when the heat is not in the equation. The shorter of breeding season you plan on keeping, the fewer cows a bull can be expected to cover as a rule.”
Prior to putting any bull in a breeding group, it is recommended that producers look closely at scrotal circumference, as well as have a qualified veterinarian perform a Breeding Soundness Exam before use, and use that as a measure of how many cows the bull can cover.
The numbers of bulls utilized by a producer may come down to simple economics.
“In general, the fewer the bulls you think you can get by with in a herd the better off you are from a financial aspect,” McCorkill said. “Extra bulls are eating grass that a cow could be eating. They are also pretty expensive and can tear up a lot of stuff if they get on the fight.”
For the best returns in a breeding season, the utilization of artificial insemination is a way to get more cows breed with fewer bulls, but the practice isn’t for every producer.
“AI is pretty labor intensive and requires gathering the herd and running them through the chute multiple times so good facilities are a must. You can, however, get probably 50 to 60 percent of your cows bred in one day to some of the best bulls available, which will tighten the calving window and hopefully improve the consistency of your calf crop, both great marketing points when it’s time to sell your calves.”
