Abstract
The 1st, 2nd and 3rd growing of alfalfa were harvested at full bloom stage and the 4th growing was harvested at vegetative stage. Ethyl ether extract of each alfalfa cutting was added to the estrogen-free basal diet and growth promoting effect on the golden hamster was examined. In this case, the amount of each extract per gram of diet was equivalent to 0.66 gram alfalfa dry matter and estrogenic potencies of these experimental diets were 18.5, 11.2, 2.6 and 5.3μg DES/kg diet, respectively. Each experimental group was formed of five young spayed hamsters and they were fed on one of these experimental diets for 60 days. Body weight gains of the 1st, 2nd, 3rd and 4th cutting group were 46, 25, 34 and 30 percent larger than the control group, and feed efficiencies of these experimental groups were 28, 9, 9 and 5 percent better than that of the control group, respectively. Seasonal variation of estrogenic activity of alfalfa did not agree with that of growth promoting effect on the golden hamster.
