Oestrous behaviour of the ewe and the influence of treatment with progestagen.

Abstract

Summary. Polled Dorset Horn ewes at a progestagen-synchronized oestrus (six ewes) or at a normal oestrus (six ewes) were teased for a 10-min period at 4-hr intervals by a series of different rams. The frequency of nudging, kicking, Flehmen posture, mounting and service by the ram, and of squatting, active soliciting, tail fanning and looking over shoulders by the ewe were recorded. The mean duration of oestrus±S.E. was 48·0±2·1 hr for the ewes at a normal oestrus and 51·3±3·5 hr for ewes at a progestagen-synchronized oestrus. In the 24-hr period before the onset of oestrus, the frequencies of nudging, Flehmen and squatting were greater when the ewes were treated with progestagen. During oestrus, progestagen treatment produced no major differences in the manifestation of behaviour and some components were of a consistent pattern. At the second of five proportionately equal stages of oestrus, there was a reduction in nudging, Flehmen and squatting which corresponded to an increase in the frequency of tail fanning, looking over shoulders and active soliciting.