The use of a synthetic prostaglandin analogue (cloprostenol) to control parturition in the commercial rabbit

Abstract

ABSTRACTTwo experiments were performed to examine the efficacy of a synthetic prostaglandin analogue, cloprostenol (‘Planate’, ICI) to induce parturition in the rabbit. In experiment 1, does were injected intramuscularly on day 28 of pregnancy with either saline or with 4·38 μg, 8·75 μg, or 17·5 ug cloprostenol; a fifth group comprised untreated controls. Experiment 2 included only the groups treated with 4·38 μg and 17·5μg cloprostenol and untreated controls. In both experiments, cloprostenol injection significantly reduced the length of pregnancy when compared with saline-injected and untreated controls. Of the does treated with cloprostenol, 25 out of 26 kindled between 30 and 60 h after injection, whereas the variation in birth time in untreated and saline-treated groups was much greater (range 26 to 140 h). Litter birth weights tended to be lower in cloprostenol-treated does because of their precocious delivery but this did not appear to reduce pup viability. In both experiments, the proportion of pups dead at birth tended to be higher for does which did not receive cloprostenol (0·22 v. 0·10). Deaths between birth and weaning were similar on all treatments. Conception rate following mating 1 day after parturition appeared to be unaffected by cloprostenol treatment, as was milk yield during the 1st week of lactation.