[Effect of several factors on the estrogen activity of lucerne]

Investigations were carried out on the estrogen activity of lucerne from various mowings harvested in years of different climate, studying the effect of age and yield of the crop. The observations were made during three successive years on local populations of lucerne grown under nonirrigation conditions. The estrogen activity was determined ny Bikov's biologic method, and the presence of cumestrol and genestein was established through chromatography. It was found that the estrogen activity of lucerne was to a large extent dependent on the intensity of growth. Young plants giving higher yield of green mass and dry matter manifested higher estrogen activity. Highest was the activity of lucerne from the first mowing, gradually decreasing in each of the following mowings. Variations were likewise established in the content of genestein and cumestrol in dependence on the mowing itself and the yield. All samples demonstrated that genestein was present in the first and fourth mowing, while the content of cumestrol varied within a wide range showing no markedly expressed correlations. The activity of the local lucerne populations during the first years of using the crop and the first mowings of green mass was shown to bring about disturbances in the reproduction process of ruminant animals provided lucerne is offered for a long time in greater amounts.