Automatic oestrus detection system enables monitoring of sexual behaviour in sheep

Abstract An experiment was conducted to observe the oestrous behaviour in ewes through an automated oestrus detection system. Five mature adult Merino male rams, equipped with an electronic detector (Alpha-D), were included with a total of 60 ewes from the same breed. The libido of the males was assessed as the number and frequency of mounts. The accepted mountings by ewes were recorded by an electronic identifier worn by the female. In the first synchronized oestrus (C1), the ewes were exposed to rams wearing an anti-mating apron. In the following spontaneous cycle (C2), all the rams were allowed to mate. In the third cycle (C3) and the fourth cycle (C4), the rams were assumed to detect ewes in oestrus (open ewes). After the exclusion of isolated readings, the mean interval from sponge withdrawal to onset of oestrus was 31 ± 11 h and duration of oestrus in C1–C3 was 22 ± 18, 16 ± 11 and 16 ± 8 h, respectively. The libido differed widely among the rams and cycles number with an average number of mounts per ram in C1–C4, that were 213, 322, 85 and 3 respectively. It is concluded that all the females were correctly detected and the assessed libido of males was repeated.