关键词: EP制剂, 莫氏田鼠, 繁殖参数, 不育控制

Abstract:

Objective To test the effect of a contraceptive compound (levonorgestrel-quinestrol, designated EP-1) on reproduction in field populations of Maximowicz's vole (Microtus maximowiczii). Methods In 2004, a field trial was conducted in a guinea grass plot in Baiyinxile pasture, Xilingol league, Inner Mongolia, China. EP-1 was applied at the end of April and the reproductive parameters of field voles were inspected in May to July by monthly line transect census and track surveys. Data were analyzed by independent-samples t test. Results EP-1 strongly inhibited reproduction in female voles in the field. In the EP-1 baited area, the uterine damage rate in adult female voles was 78.9% while their pregnancy rate dropped to 0% in early June. In early July, uterine damage rate remained at a similar high level (76.7%) as that in June; the corresponding pregnancy rate and mean litter size both rose rapidly, but still differed from those in the untreated control area significantly (P<0.05). In early August, the uterine damage rate in female voles fell to 30.0%. Conclusion EP-1 is a safe contraceptive compound for the effective control of reproduction in field M. maximowiczii populations. Its inhibitory effect lasts three months before the vole's reproduction starts to recover.

Key words: EP-1 compound, Microtus maximowiczii, Population reproduction, Fertility control