Bulls make up half the genetic value of a herd and are worth looking after.
Investing in superior bulls should increase the growth and value of a producer’s calf crop.
There are things producers can do to improve the longevity of their bulls and make them more productive.
Producers can benefit more if they can get more years and/or breed more cows from top genetic bulls.
Stocking density and the bull-to-cow ratio will vary greatly during the breeding season, depending on numerous factors.
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Younger yearlings need to be run with about 15 cows to make sure they are capable. This number won’t burn them out but allows them to grow so that they can be used much heavier as two year olds.
A bull’s capacity will ultimately depend on the pasture’s terrain, size and quality, the ability of the bull to walk and whether some cows were previously artificially inseminated.
Bulls must be evaluated yearly for their probable serving capacity.
The results of the semen evaluation and scrotal measurement will also provide valuable information to help make the final decision.
It has been said that if a cow is serviced by two bulls, it means producers are either running too many bulls or too few cows. It also means the bulls are in close proximity and might fight and injure each other.
Bulls are especially vulnerable to damaging their penises when mounting and breeding cows.
It is best to have a variety of ages when running multiple sire groups. The young yearling bulls will start by breeding cows on the periphery of the herd. The huge size difference between yearlings, two year olds and mature bulls make the pecking order obvious, which generally keeps fighting to a minimum.
Multiple sire herds also mean that others can pull up the slack if one bull goes down.
However, it also means that if the dominant bull has poor semen, it may prevent the others from breeding, which will hinder the conception rate.
Many purebred breeders use single sire herds, but the open cow percentage can be high if the bull develops an undetected problem such as a cut penis or testicles that degenerate.
I know of several cases where bulls had scarred penises from previous cuts and were not semen tested before the breeding season. The result was a 100 percent open rate.
Even purebred herds can run bulls together for cleanup and then do parentage tests on the offspring to determine the exact sire for registration. DNA testing makes this easy to do.
Some commercial breeders are even using parentage tests on calves to help determine which bulls produce the most productive calves.
Calving ease can also be highlighted once parentage is known by looking at the previous year’s records.
It’s a myth that treating breeding bulls with antibiotics damages the sperm. It really is the severity of the ailment coupled with an increased temperature that damages sperm.
The quicker an ailment is treated and a fever prevented, the better.
However, products such as steroids can harm sperm, particularly if used over the long term. Avoid these if possible. As well, any drastic treatment should be overseen by a herd veterinarian.
The bulls should always be found with the cows when checking them in the pasture. If they aren’t, something is wrong.
Look at the prepuce area for signs of swelling, which indicates a problem.
Any lameness, no matter how subtle, can hinder a bull’s breeding performance.
Be especially vigilant when checking feet and legs before breeding season. If hoofs need trimming, get it done.
Some clinics recommend foot rot vaccination for breeding bulls. Avoiding lameness through such preventions goes a long way toward avoiding down time during the breeding season.
The three biggest causes of missed breeding days are injury from fighting, penile injuries and lameness, although not necessarily in that order.
Managing bulls during the off season also deserves attention.
Bulls that aren’t breeding should be kept in as big an area as possible. More room promotes less fighting and more exercise keeping bulls fitter and their feet healthier.
Bulls at two percent body weight daily need only a good forage diet. Providing grain often results in bulls becoming too fat.
Fat bulls lack stamina and the fat in the scrotum insulates the testicle, which results in poor quality, damaged sperm.
Make sure that wintering areas have protection from wind, such as bush or even a portable porosity fence. Herd sires can suffer badly frozen testicles and it can result in permanent sterility.
Standard mineral supplementation is required because bulls need vitamin A for optimal semen production.
Bulls should receive the same vaccinations as the cow herd with the exception of scours vaccinations. An ideal time for vaccination is at semen checking when the bull is restrained. This is just before the breeding season when protection for the cows is paramount.
