Position Statement: Bull mating ability testing

Policy type: Position statement
Reference: 5e
Status: Current
Ratified: September 2017


The NZVA recognises the diagnostic value of the Mating Ability Test (MAT), but opposes its use unless the testing is carried out in the presence of a veterinarian who is directly responsible for seeing that all animal welfare requirements are met. The NZVA does not support Service Capacity Testing (SCT) of bulls.


Mating Ability Testing is just one aspect of Bull Soundness Evaluation. It is used to assess the mating ability of bulls by observing a bulls ability to successfully serve a restrained mount animal. The test is used to diagnose penile abnormalities, some locomotor and musculoskeletal abnormalities, and can provide an indication of sub-normal libido.

There are three reported surveys that show results of bull breeding soundness evaluations performed by veterinarians in New Zealand beef bulls. Tattersfield et al (2006) showed that 22% of commercial bulls were classified as unsound on the basis of the MAT. Hughes and Oswald (2007) survey results of 2478 commercial beef bulls in the Taihape area revealed that 20.9% of MA bulls are unsound for mating and of these unsound bulls 55% were diagnosed unsound during the MAT. The Wallace (1984) survey of 901 commercial beef bulls in the Gisborne area demonstrated similar results, with19% unsound, of which approximately 65% were diagnosed during the MAT.

The only other means of identifying these bulls would be to observe them in natural mating situation. While this may be feasible for small numbers of bulls it is not feasible on most beef breeding properties in New Zealand. Where MAT tests are not performed unsounds bulls which remain in a breeding herd will lead to inferior calving patterns and higher rates of cull cows due to lower conception rates which results in a significant economic loss to the producer.

Service Capacity Testing (SCT) is an extension of the MAT and is defined by the number of successful serves within a given time frame. It attempts to measure the libido of the bull by ranking them as low, medium, high or very high serving capacity. Some studies have shown a positive correlation between a bull’s performance during a SCT and higher conceptions rates while other studies have failed to repeat these results (Jerebine et al. 2002). Given the lack of conclusive science, the SCT has fallen out of favour with veterinarians. NZVA does not support Service Capacity Testing (SCT) of bulls.

The NZVA acknowledges the reputational risks to the profession associated with veterinarians involvement with MAT. As a profession we are working to find an alternative method with reduced risk of animal welfare compromise for the mount animals.


Animal Welfare Act 1999

Blockey MAdeB. Fertility testing bulls doesn’t cost – it pays. Proceedings of the Society of Sheep & Beef Cattle Veterinarians of the NZVA. 196-203, 1990.

Hughes PL. Serving capacity testing of 2yr old bulls. NZVJ. 39, 35-36, 1991.

Hughes PL. Evaluation of bulls for breeding soundness. Sheep and Beef Cattle Veterinarians Newsletter. 32: 34-44, 2007

Hughes PL and Oswald AWR. A field report on use of a Mating Soundness test in beef bulls. Proceedings of the Society of Sheep & Beef Cattle Veterinarians of the NZVA. 99-108, 2007.

Hughes PL, Wichtel J, Mossman D, and McNeil P.. Report of the bull testing subcommittee, Sheep and Beef Cattle Society, NZVA. Society of Sheep and Beef Cattle Veterinarians Newsletter, 1, 14-28, 1991.

Jerebine BC, Fisher MW, Johnstone PD, Gregory NG. Performance testing of farm animals. A report for the Ministry of Agriculture and Forestry. 2002
Mossman DH. Serving capacity test. NZVJ 31,123-4. 1983.

McDiarmid JJ. Corkscrew penis and other breeding abnormalities in beef bulls. NZVJ 29, 35-36. 1984.

Parkinson TJ and Bruere AN. Evaluation of Bulls for Breeding Soundness. Massey University, Palmerston North. 2007

Tattersfield G, Heuer C, West DM. Bull Soundness Examinations – Current Research and Written Guidelines. Proceedings of the Society of Sheep & Beef Cattle Veterinarians of the NZVA. 123-126, 2006.

Wallace NM. Breeding Soundness of Bulls. Proceedings of the Society of Sheep & Beef Cattle Veterinarians of the NZVA, 107-112, 1984.

Veterinary Council of New Zealand Guide to Professional Conduct