Sexual behavior of subordinate, but not dominant, rams increases following observed sexual activity

Sexual performance of rams does not improve after observing hetero-sexual behavior of other rams, as happens in bucks and bulls. This lack of effect might be masked by the positive and negative effects that sexual stimulation could have on dominant or subordinate rams, given that important differences have been found within both categories. Thus, the objective of the present experiment was to determine if rams’ sexual behavior is modified differently in dominant (DOM) and subordinated (SUB) rams after observing the sexual behavior of each other. The dominance relationship of nine dyads of Corriedale rams was determined using a food competition test. Next, each ram was tested in two different situations; a control test (CT), and a test in which the other ram was joined with two estrous ewes in the contiguous pen (visual sexual stimulation test; VSST). Estrous ewes were placed in one pen, and each ram was located first 20 min in the contiguous pen. Then, the ram was moved into the pen with the estrous ewes, staying there for other 20 min. During the CT the ewes remained alone the first 20 min. During the VSST the other ram of the dyad was in the pen with the ewes, but it was taken out before introducing the tested ram. There were no differences in the frequency of any behavior during the 20 first min between DOM or SUB rams. The DOM rams did not modify any behavior according to the type of test. On the other hand, SUB rams increased the number of ejaculations and the ejaculation efficiency (P = 0.04 and 0.03, respectively) when tested after viewing the DOM rams, and tended (P = 0.058) to achieve their 1st ejaculation earlier in VSST test. It was concluded that while visual pre-stimulation of a SUB ram courting and mating estrous ewes had no effect on DOM rams’ sexual behavior, the observation of a DOM ram, enhanced mating behavior of SUB rams. This expands the concept that DOM and SUB rams respond with different strategies to visual stimulation.