Physical separation and reduction of contact duration with sexually hyperactive bucks decrease testosterone concentrations and sexual behaviour in bucks in sexual rest

• Published in: Animal (Cambridge, England) England), 2024-06, Vol.18 (6), p.101179, Article 101179
• Main Authors: López-Magaña, N., Tejada, L.M., López-Magaña, D., Hernández, H., Flores, M.J., Vielma, J., Abecia, J.A., Keller, M., Chemineau, P., Delgadillo, J.A.
• Format: Article
• Language: English
• Subjects: Animals; Female; Goats - physiology; Libido; Life Sciences; Male; Male goats; Photoperiod; Photoperiodic treatments; Reproductive seasonality; Seasons; Sexual Behavior, Animal - physiology; Sociosexual interactions; Testosterone - blood; Time Factors
• ISSN: 1751-7311; 1751-732X; 1751-732X
• DOI: 10.1016/j.animal.2024.101179

•Sexually hyperactive bucks stimulate testosterone in males in sexual rest.•Sexually hyperactive bucks also stimulate sexual behaviour in males in sexual rest.•Stimulation occurs in permanent contact with sexually hyperactive bucks.•Separation from hyperactive bucks decreases testosterone and sexual behaviour.•Reduced duration of contact with hyperactive bucks decreases both variables. Sexually hyperactive bucks are more efficient than sexually hypoactive bucks in stimulating testosterone secretion and sexual behaviour in other bucks in seasonal sexual rest by the phenomenon that we called the “buck-to-buck effect”. Here, we determined whether physical separation and reduction of the duration of contact with the sexually hyperactive bucks would modify those parameters in sexually hypoactive bucks exposed to the “buck-to-buck effect”. Bucks were subjected to natural day length throughout the study; this was the sexually hypoactive group. Other bucks were subjected to artificial long days (16 h of light per day) from 15 November to 15 January followed by exposure to natural day length to stimulate their sexual activity during the rest season; this was the sexually hyperactive group. In Experiment 1, we determined testosterone concentrations and sexual behaviour of six sexually hypoactive bucks separated 1.5 m from six sexually hyperactive bucks for 60 days by a metal open work fence, while a control group of six sexually hypoactive bucks was in permanent contact with six sexually hyperactive bucks. In Experiment 2, the duration of contact with sexually hyperactive males was reduced from 31 days (contact group, six bucks) to 10 days (withdraw group, seven bucks). In experiments 1 and 2, there was an effect of time (P