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Bull Breeding Soundness Evaluation (BSE)
October, 2010
Courtney Davis - Extension Agent I, Dairy/Water Quality,
Okeechobee County Extension
Once a year all bulls on your operations should have a Bull Breeding Soundness Evaluation. A BSE should be conducted by a veterinarian at least 30 to 60 days before breeding season should start. This will allow time for retesting bulls or time to purchase (a) new bull(s).
A BSE should be consists of four basic steps:
- Visual assessment of feet, legs, eyes, teeth and external genitalia.
- Palpation of accessory sex glands
- Measurement of scrotum and palpation of testis and epididymis
- Collection and microscopic evaluation of semen sample
The physical exam is important, some of the main reasons for a physical exam are as follows:
- Bulls need sound feet and legs to be very mobile to breed as many cows/heifers as possible.
- Eyes should be examined. Bull locate estrous females primarily though visual observation rather than olfactory cues (smell).
- Internal and external genitalia are important because if a bull has an injury or infection he will not breed as well or not all.
Semen evaluation consists of a microscopic examination of the sperm cells for concentration, motility (percent alive) and morphology (percent normal). During semen collection the veterinarian should expose the penis for a visual examination to determine if there are any abnormalities. Studies have shown that bulls that are tested and have satisfactory semen have an increase in pregnancy rate.
Bulls should have a strong libido (sexual desire) to properly perform. Even if a bull has the ability to breed, he can still be infertile if he lacks the desire to mate. Studies have shown that high-serving capacity (high libido) bulls have increased pregnancy rate as well as earlier conception rates. This can result in over $50 more gross income in cows.
There should be anywhere from a 1:25 to 1:60 bull to cow ratio. A ratio of 1:25 would insure that your bull would be able to service the cows properly. This is the normal male-to-female ratio. A young bull (two-year old) should be able to successfully mate with up 60 cows/heifers in a short period of time.
The BSE cannot predict conception rates. Some sound =bulls can have very low conception rates, and some unsatisfactory bulls can have acceptable conception rates. The BSE is used to identify and eliminate unsound breeders rather than to make a prognosis on fertility. This must be understood by sellers and buyers.
Remember that one bull in five will not be a satisfactory potential breeder. A complete BSE is important in all situations, but is even more critical in single-bull cow herds. This examination should be conducted every year at least 30 to 60 days before breeding season to allow adequate time to find a replacement bull if needed.