Assessment of sexual behavior of young rams of Santa Inês breed, with and without prior experience with females

Abstract

The objective of the present work was to determine if prior sexual experience with females in oestrus influences the frequency of events related to sexual behavior and if it is possible to reduce duration of the test period from 10 to 5 min. Nineteen lambs born in 2007 in Espírito Santo State, Brazil, were separated by month of birth into two groups. Those of each group were subjected to a first libido test at 7 mo of age when they had no previous exposure to females since weaning (EXP1). The second test was realized at 11 mo, when the males already had prior experience with females in oestrus (EXP2). Comportments associated with the detection of heat were frequent in both tests, while those associated with courting were more frequent in EXP2. During the first 5 min of observation the behaviors of chasing, smelling, and licking were significantly more frequent than subsequently, while frequency of other characteristics didn’t differ between times of assessment. Body weight and age influenced sexual comportment, older and heavier males tending to mount the female and ejaculate more times. It can be concluded that young rams with prior experience exhibit greater stimulus to complete copulation and that 5 min can be time enough to evaluate their libido.