Semen is collected from stags by electro-ejaculation, a procedure that is conducted by professional Artificial Breeding (AB) companies and veterinarians. In some cases it requires the use of sedatives and anaesthetics.
Generally, the farmer’s only involvement is to yard the stags at a scheduled time, and leave the rest to the professionals. Needless-to-say, good facilities are a must for the safety of everybody concerned.
Semen processing is again at the hands of the professionals and is a reasonably complex process. Collection of an ejaculate from a stag does not necessarily mean that good, usable semen will be obtained. AB companies will assess the semen quality once it is processed and judge whether it is suitable for AI based on a set of quality standards.
It is not uncommon for stags to provide poor quality ejaculates early in the breeding season (remember stags are infertile over spring and early summer) generally semen quality will improve approaching the rut and even well after the rut.
Most stag semen is frozen (‘cryopreserved’) and then thawed immediately before insemination. However, some AB companies can offer fresh semen collected within days of the insemination programme. Whilst frozen semen can be successfully preserved for many years, In terms of conception rates to AI, usually ‘fresh is best’. However, many batches of frozen semen have very high AI success.
Other reasons to collect semen
- to check the stag's fertility
- as a back-up option if the stag dies prematurely as an insurance policy
- Post-mortem semen collection
Occasionally valuable stags die during or after the rut. With quick action, it is often possible to remove the testes, store them in a cool box and send them to an AB company for epididymal sperm extraction. The testes need to be processed within 6-8 hours of death. Talk to your nearest AB company to discuss this option should the need arise.
Show me the science
Asher, G.W., Berg, D.K., Evans, G. (2000) Semen collection and AI in deer Asher, G. W., Berg, D.K., Evans, G. (2000) Storage of semen and artificial insemination in deer. Animal Reproduction Science 62: 195-211.