Determining the right bull-to-female ratio

There are many aspects to running a cattle operation that require the right balance. The number of females with a herd sire is no exception. If producers turn out a bull with too few females, then there can be potential problems. The same can be said about a herd sire in a pasture with too many females. 

Downfalls of Improper Bull to Female Balance

First, consider if a bull is placed in a field with too few females. Livestock experts state in this scenario once the bull gets his job done, he will lose interest in his home pasture. 

“A lot of bulls after they get those cows bred, they start roaming the fences and eyeing the neighbor cows because they want to go to work,” Bruce Peverley, Nowata and Craig County Extension Educator with Oklahoma State University, said.

Conversely, if a bull is turned out with too many females, he will not be able to successfully get all the females bred. In addition, the strain may take a toll the bull’s physical condition.

Ratio Recommendations

The recommended bull to female ratio relies mostly on the age of the bull. Livestock extension specialists offer guidelines for producers to keep in mind when using a herd sire. “Basically, a cow per month of age is a pretty good recommendation,” Peverley shared.     

 For instance, for a mature bull, one that is four years old or older, producers should expect him to cover 30 to 35 cows a season. However, the ratio decreases with the age of the bull.

Livestock specialists recommend a ratio based on months of age, for younger bulls. For example, if a producer is turning out a 14-month-old bull, it is expected he should breed 14 females during the breeding season. If the bull is 24 months old, it is expected he should cover 24 cows in a breeding season. 

Producers will also want to consider that individual bulls possess different abilities to breed cows. Depending on the climate, environment and season certain bulls can cover more than others. 

Check on Your Investment

Now is a good time to schedule a veterinarian to come out and conduct a physical appraisal on the bulls that will be used for spring breeding season. The breeding soundness exam (BSE) should include an evaluation of the bull to make sure he is physically sound for the task at hand. In addition, the veterinarian should check the bull’s semen to ensure it is viable. 

The physical assessment should include but not be limited to eyes, teeth, testicles, sheath, feet and legs. 

“Actually, of bulls that are evaluated, that physical portion makes more bulls unsatisfactory breeders than the semen does,” Peverley stated. “So, it’s a good practice especially if you are going to be breeding pastures where you only have one bull.”

While the bull is in for the BSE, it’s a good time to get him caught up on vaccinations and deworming. Additionally, assess his body condition. Livestock specialists suggest a body condition score (BCS) of a solid five or ideally a six before he enters the pasture. Once the bull is out with the females, producers will want to check on their investment. 

“It is important to spend time watching to make sure the bulls are physically breeding cows, to make sure they can get that act accomplished, and start helping make a paycheck for the coming year,” Peverley said.  


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