Sexual behavior of stallions during in-hand natural service and semen collection: an observation in French studs.

The study conducts an examination of the sexual behavior of 42 stallions during both artificial insemination (AI) and natural service (NS) at French studs. Using observation and measurements such as erection and ejaculation latencies, the number of mounts leading to ejaculation, and overall breeding time, the study provides important reference measures for semen collection.

Methodology

• The researchers studied sexual behavior of 42 stallions from French national and private studs. The behavior was observed in two scenarios: semen collection for artificial insemination, and in-hand natural service.
• Each stallion was observed twice in the same context in order to gather consistent data.
• Erection latency, ejaculation latency, and the number of mounts leading to ejaculation were among the metrics recorded by the researchers.

Findings

• In most cases (6 out of 83 observations), the stallions did not mount without an erection.
• The average time to erection (erection latency) was 89±11 seconds. There was no significant difference between NS and AI scenarios in this regard.
• Most stallions ejaculated after one mount. However, in some cases, it took up to three mounts for ejaculation.
• The average time to ejaculation (ejaculation latency) was 85±15 seconds, with little to no difference between AI and NS scenarios. However, if the first attempt was unsuccessful, the latency greatly increased on the second try.

Implications and Interpretation

• The findings can serve as reference measures for semen collection activities in French studs.
• The lack of significant difference in erection latency between AI and NS scenarios might hint at the similar influence of excitatory inputs from the brain and genital area in both contexts.
• The lack of significant difference in ejaculation latency between AI and NS scenarios suggests that the spinal network controlling ejaculation might operate in a more fixed or rigid pattern, regardless of the method used (AI or NS).