4 minute read
Herd Health
One of the most frustrating conditions to hit our herd sires is testicular degeneration (testicles shrinking up). It often strikes without warning or reason. It causes headaches for both purebred breeders with bulls they have sold, for insurance companies with bulls they have insured, as well as the person using the bull. Let me be very clear, this is always an individual bull problem and one breed does not have any more or less percentage of these. In this herdsire edition, I want to explain it as best as I can and have you realize there are some positive things that come out of at least talking about it.
In this article, I will go over some known causes and what to be observant for. Often we cannot prevent this condition, however, early recognition of warning signs may prevent the economic ramifications it brings.
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The scrotum and its muscular attachments have the ability to expand and contract and in so doing, raise and lower the testicles depending on the ambient temperature and body temperature of the bull. The scrotal temperature is normally lower than body temperature and must be maintained at that for normal sperm production. Anything that alters this greatly will affect normal sperm production and could, over the long-term, lead to testicular degeneration. It is important to note when even a temporary increase in scrotal temperature (say 1°C for 10 days) will affect sperm production for four to five months. Recovery will take a long time, which often times as a producer you do not have.
Any condition which causes increased temperature in the scrotal area must be guarded against. Severe clinical disease, swelling in the area as a result of trauma (stepped on or bunted in the scrotal area) and testicular torsion may all result in degeneration over time. Extremely fat bulls have too much insulation in their scrotum, raising the internal temperature. Charolais, being one of the real growth and yield breeds, have fewer issues with scrotal fat than say some of the British breeds. Frostbite will initially cause the damage freezing brings, but as healing occurs, inflammatory processes set up and these can cause local temperatures to rise. Any stressful event, hot ambient temperature, intimidation by other bulls or a combination of many of these events can lead to testicular degeneration. Most of these conditions may have been long past and may not have even been recognized before testicular degeneration is picked up at semen evaluation time.
The body also has a unique mechanism when it comes to the testicles. Any situation where sperm mixes into the bloodstream causes the equivalent of organ rejection. The bull’s body produces antisperm antibodies, which fight sperm production, causing the testicles to degenerate. This could happen in any traumatic incident or with a testicular torsion. If surgery is necessary to remove a damaged testicle and precautions are not taken the remaining testicle could degenerate as a result of either inflammation or sperm getting into the bull’s blood supply. This very rarely happens but explains why fighting and bunting, especially in the testicular area, can have dire consequences.
There is a huge misconception out there that treating a bull with antibiotics will hurt sperm production. It is far, far worse to leave a medical condition untreated, running the risk of increased body temperature, than it is to quickly treat the condition. Having said that, treatment with anabolic steroids or implanting can have devastating effects on the testicles because of alterations in hormone production. If testicles are seen to be swollen, one of the best treatments is cold water therapy with NSAIDs to quickly bring down the swelling and keep it down, hoping to prevent degeneration as the final outcome.
Degeneration can happen to any bull at any stage in his life. That’s why it’s important to semen evaluate close to the breeding season, in case anything has gone undetected over the winter. Testicles with degeneration will feel a lot softer and will measure much smaller than they did before. Sometimes only one testicle will degenerate, such as from a bunt to only one side of the scrotum. If the other testicle is fully functional you will even see it hypertrophy (get bigger) and it may produce more sperm to compensate for the loss of the other testicle. These bulls will have somewhat reduced capacity but still may be fertile enough to use or collect semen on.
The most obvious clinical signs of degeneration are of course shriveled testicles and the scrotal hair will often grow longer. If you suspect degeneration, or if the testicles are markedly swollen or frostbitten, it is wise to have a semen evaluation performed. As mentioned before, regeneration can take place, but it is a rarer event. Plus, this may take several months and depending on the season of the year, you may not be able to afford the time. Anytime bulls are fighting excessively or you notice even slightly swollen testicles, document it, especially if the bull is insured. The insurance companies will need some form of documentation because ..continued on page 61
