Length of oestrus, duration of phenomena related to oestrus, and ovulation time in the local fat-tailed Awassi ewe

Abstract

SUMMARYOestrous cycle and phenomena accompanying oestrus were studied in the local fattailed Awassi ewe. By heat detections at 4 h intervals, the average period of oestrous was found to be 35·5 h and the mean duration of the oestrous cycle, 17·5 days. The repeatability of length of oestrus and of cycle length was 0·60 and 0·41, respectively. The appearance of a transparent or cloudy fluid secretion indicated that the ewe was still at least in the first half of the oestrous period, while that of a viscous creamy secretion indicated the approaching end of oestrus as well as the approaching ovulation; the latter events generally coincided. The onset of oestrus was not centred around any particular time of day.