Breeding soundness exam: Don’t wait until it’s too late

Winter is always a trying time for livestock producers, and cattlemen have told me numerous times they want it to just stay cold to minimize mud issues. Unfortunately, this winter can’t seem to make up its mind. Regardless, winter weather can negatively impact livestock when preparations are not made.

Bulls, and bucks and rams, are typically separated from breeding females. Bulls, in particular, are separated in a pasture with maybe a couple of other bulls. Bitter cold, winds, and frozen ground without bedding can result in a frostbitten scrotum and potential damage to testes.

During normal winter conditions frostbite is not a common problem with breeding bulls. However, some bulls still experience frostbite even with good care and bedding and usually these bulls have large, pendulous scrotums that hang lower and are more exposed to the wind. In cold weather, a bull normally pulls its testicles closer to the body for warmth, but older bulls with pendulous scrotums may be unable to do that.

Evidence of frostbite on the scrotum is usually apparent a few days after freezing. Scrotal inflammation and swelling becomes noticeable and later scabs may appear on the lower portion of the scrotum as healing occurs. The inflammation, which produces heat and swelling, interferes with the cooling and warming mechanism of the testicles. This heat directly affects the sperm that are maturing and stored in the epididymis, which surrounds the testicle at the lower end of the scrotum. The resulting damage may cause temporary or, in more severe cases, permanent sterility in the bull.

Severe frost damage to the testicle and epididymis may cause tissue adhesions, affecting mobility and circulation within the scrotum. If the inflammation and its subsequent repair are severe enough, the testicles maybe be no longer able to move freely with in the scrotum; the bull cannot raise or lower the testicles to maintain the proper temperature for sperm production.

The presence of swelling, inflammation, and scabs may necessitate a breeding soundness exam, or BSE, conducted well in advance of “turning the bulls out.” If conducted early enough, then you may have more time to perform another BSE or secure a replacement bull if your herd bull fails a subsequent BSE.

A BSE consists of three parts:

• A physical exam including the internal and external reproductive structures.

• Determination of scrotal circumference (size is age dependent).

• Collection and evaluation of semen (motility and morphology are assessed).

There is a small percentage of bulls that just will not produce good samples for evaluation and a discussion with the veterinarian performing the BSE collection is needed. However, if a good sample is collected but presents with reduced motility and/or morphology, you will need to determine if you are going to find a replacement bull or submit your herd bull for another BSE. Keep in mind that it will take approximately 75 days for the bull to produce semen (60 days to produce the sperm and 15 days of maturation and transport).

Now consider this — U.S. cattle inventories are at their lowest since the 1950s. Cattlemen have relayed that while bulls can be found, it may take longer to find the right bull that matches your genetic goals. Thus, taking the herd bull in early for a BSE may provide you sufficient time to make decisions about your long-term herd genetic needs.

The breeding soundness evaluation is a useful tool in identifying subfertile bulls. Eliminating bulls with physical problems or reduced fertility from the breeding herd will improve overall reproductive efficiency of the herd.

Teresa L. Steckler is a University of Illinois Extension specialist, commercial agriculture, tsteckle@illinois.edu.