Heat and conception rate after synchronisation of oestrus with cloprostenol.

The intensity of induced oestrus in heifers on high and low nutritional planes was graded according to the degree of uterine contraction and cervical relaxation and the volume of oestrous mucus, and correlated with the pregnancy rates after insemination. In the heifers on a high nutritional plane, the heat was more intensely expressed and the conception rates were greater than in the poorly fed animals. In both groups the conception rate was lower in treated heifers than in untreated controls but this difference was minimal on a high plane of nutrition.