Bull Breeding Soundness Evaluation (BSE)

All of our bulls at Bradshaw Cattle Co. are purebred bulls who undergo BSE yearly as well as observation in the pastures. BSE does not test for fertility per say as this can only be proven by the production of offspring each year from fertile cows. It is important to have the test done 45-60 days before turn out.

Mating Ability

This is most often realized not only by few key things a vet can look for in an appointment, but also the producer to watch for social dominance, mounting, the bulls ability to find the cows in heat, and bulls mating patterns. Not only is this determination helped by the BSE, but it also requires the observation in order to correctly classify the ability of the bull.

Libido

Not typically tested in the basic BSE, but producers should watch for this in pastures. If bulls are not mounting, then their libido system is most likely lacking and breeding results will be lacking causing a loss of profit. Libido can also be effected if two bulls in the same paddock are not getting along. Bulls being dominated by another bull are less likely to breed fertile cows as they allow the dominating male to breed.

General Physical Health

Scrotal circumference is associated with the serving capacity of the bull as it is related to the daily sperm output capability of the bull. The minimum circumference differs on the bulls age. The physical health is also important to ensure the bull is healthy enough to adequately breed. Hoof issues can cause pain during mounting or dismounting and therefore leading to lower or no mating rates. Lameness in bulls can come from poor conformation due to poor physical health or thin structure. There are other aspects that effect the bulls health including; teeth so they are capable of eating required nutrition to maintain breeding requirements, eyes clear of lesions, sheath as it can show signs of breeding season issues and body condition to ensure substantial health prior to high physical demands.

Genital Organs

When a bull is being ejaculated, make sure that the penis is fully extended and there is no phimosis (bull unable to get penis out) or paraphimosis (bull cannot get penis in). The elastic tissue near the tip the glans that extends to the prepuce is known as the frenulum. If this elastic tissue is still connected after eight to eleven months old, this is most likely a heritable condition and it should be considered to cull this bull. While erected, the length should also be examined as a short penis will lead to an inability of the bull to breed. Scrotal circumference is associated with sperm production as well as testicular mass and health of testicular tissue. Scrotal circumference should be measured at the widest part of the scrotum. These are only a few genital tests that are completed in a Bull Breeding Soundness Evaluation.

Sperm Production

This is typically evaluated through collecting sperm. The two most common processes to collect sperm is manual stimulation and artificial vagina. To collect using an artificial vagina you use a teaser and mount animal. The bull gets arousal and falsely mounts teaser animal with a collector ready with a false vagina to divert the erect bull. False vaginas use technology including thermal and mechanical stimulation to promote ejaculation. Bulls will need to be comfortable around people in order for them to mount in this kind of setting. Our vet uses manual stimulation to collect our bulls sperm by electronically stimulating the rectum with an anal probe.

Sperm Quality

Parameters & Normal Values

Ejaculate: volume 5 ml (range 1-15 ml)

Concentration: 1200 million/ml (range 300-2500 million/ml)

Total sperm per ejaculate: Typically 4-5 billion

Progressive motility: Greater than 30%

Morphology: Greater than 70% normal

To pass a BSE, a bull must have normal physical requirements as well as meeting minimum scrotal circumference, sperm morphology, and progressive motility. Motility of sperm can show a wide range from sample to sample depending on the handling of the sperm as it must stay at a certain degree or will show irregularities in the sperm samples. There are three classifications as a result of the BSE:

Satisfactory- All criteria requirements met

Deferred- bull did not meet requirements, but the problem is on that could be resolved over time and therefore the bull should be re-evaluated

Unsatisfactory- All criteria requirements are not met and the problem can not be resolved over time