and Internal Prepuce
The penis has already been palpated during the examination of the external prepuce but must be carefully examined and palpated while extended during the collection stage of the BBSE. Problems such as warts, hair rings, lacerations, and persistent frenulum will be discovered at this point. The internal prepuce presents itself for thorough examination during erection, allowing the opportunity to observe lacerations, warts, and fibrotic areas from old injuries that may cause deviations of the penis preventing coitus. The necessity of completely extending the penis at some point of the examination cannot be overemphasized as the previously mentioned conditions will be missed if this is not done. In‐depth coverage of urogenital injuries and their diagnosis, management, and correction are covered in Chapters 15, 18, and 19.
Example of an Examination Protocol
The examination begins with a history and examination at a distance. Evaluate conformation and be certain to record observations and identification of those bulls that have issues. Watching each bull approach the chute is a good time to observe the gait of the bull and overall appearance. Once in the chute, the bull's identification (tag, tattoo, or brand ID), eyes, head, and front claws are observed and observations recorded [6]. From the side of the bull, the testicles are palpated and SC measured (Figure 8.3), the prepuce is palpated for abnormalities, and the hind feet are observed. At this point the scrotal measurement and any observations are recorded. The rear of the bull is then approached and the back, hind legs, and especially the hock joints are observed and/or palpated. Transrectal palpation is then performed, again using a constant sequence. In the pelvic area, the urethralis muscle is followed forward to the seminal vesicles, which are palpated and massaged, the fornix of the seminal vesicles is located, and the ampullae are palpated and massaged, as are the inguinal rings, pelvic lymph nodes, the kidney, and any viscera within reach. The ampullae and the seminal vesicles are then massaged again. The urethralis muscle and the prostate are identified and massaged while progressing toward the anus. In addition to identifying abnormalities or eliciting a painful response, which may indicate a problem, palpation and massage serves to stimulate the bull and facilitate ejaculation (Figure 8.4). Thereafter, the electroejaculator is placed on the standard program and the probe is inserted into the rectum. At this point any observation or abnormalities from palpation are recorded. As erection and protrusion occur, the internal prepuce and the penis are examined by observation and palpation for abnormalities. After microscopic examination of the semen has been done, the bull is then released from the chute. The bull is observed leaving the chute and the chute area for lameness. It is of utmost importance that a standard protocol be developed to ensure that all areas of the physical examination and SC are checked and recorded [2, 5].
Figure 8.3 The correct way to measure SC. The testes are pushed toward the bottom of the scrotum and the scrotal tape is placed at the widest area. The scrotal tape should be pulled tightly.
Figure 8.4 Transrectal palpation to evaluate the internal reproductive tract and prepare the bull for electroejaculation.
Scrotal Circumference
The SC measurement is obtained while doing the general and reproductive examination [6]. It can be obtained from the side or the rear, depending on preference, facilities, and the bull's temperament. After gently forcing both testes to the bottom of the scrotum, the primary considerations are to avoid spreading the testes apart and to ensure sufficient pressure that the top surface of the measuring tape is level with the skin (Figure 8.3). Record the measurement at this point. If the circumference is below the minimum requirement, there is no need to continue the examination. Young bulls or emaciated bulls may receive a deferred classification in some cases. The SFT minimum thresholds [7] for SC are listed below:
30 cm at <15 months
31 cm at >15 to ≤18 months
32 cm at >18 to ≤21 months
33 cm at >21 to ≤24 months
34 cm at >24 months.
References
1 1 AABP. Lameness Committee. AABP Fact Sheet. An approach to corkscrew claw. Ashland, OH: American Association of Bovine Practitioners.
2 2 Koziol, J.H. and Armstrong, C.L. (2018). Society for Theriogenology Manual for Breeding Soundness Examination of Bulls, 2e, 5–70.
3 3 Vermunt, J. and Greenough, P. (1995). Structural characteristics of the bovine claw: horn growth and wear, horn hardness and claw conformation. Br. Vet. J. 151: 157–180.
4 4 Vermunt, J. and Greenough, P. (1996). Hock angles of dairy heifers in two management systems. Br. Vet. J. 152: 237–242.
5 5 Wolfe, D. (2018). Review: abnormalities of the bull – occurrence, diagnosis and treatment of abnormalities of the bull, including structural soundness. Animal 12 (S1): 148–157.
6 6 Alexander, J. (2008). Bull breeding soundness evaluation: a practitioner's perspective. Theriogenology 70: 469–472.
7 7 Chenoweth, P. (1993). A new bull breeding soundness form. Proceedings of the Annual Meeting of the Society for Theriogenology, 63–70. Mathews, AL: Society for Theriogenology.
9 Evaluation of Breeding Soundness: The Spermiogram
Colin W. Palmer
Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
Introduction
The cost of purchasing and maintaining a bull is substantial yet is easily overshadowed when a group of cycling female cattle fail to become pregnant and a complete calf crop is lost. Fortunately, this worst case scenario is a relatively rare occurrence but can have financial implications on a par with any unforeseen natural disaster. Especially in single‐sire breeding systems, this should be reason enough to have a breeding soundness evaluation prior to every breeding season; however, the most costly losses associated with poor fertility are much more insidious. Profit margins in the cow‐calf sector continue to shrink; therefore all producers must look for ways to improve productivity. In well‐managed herds, it is expected that 95% of the breeding females will become pregnant in a 60‐day breeding season, with 65% pregnant during the first 21 days. Anything less than this may be considered subfertility. Most mature beef bulls are expected to successfully mate with at least 25
