Acknowledgement
Supported by : 국제원자력기구(IAEA), 한국과학재단
Studies were conducted in 13 Korean native heifers to determine the puberty based on plasma progesterone profiles and estrus observations. Blood samples for determination of progesterone profiles were collected from jugular vein twice a week from 8 to 24 months of age, and all heifers werce observed for estrous behaviours twice a day. Heifers attained puberty at 11.3 months of age and 188.5kg body weight as determined by progesterone profiles, whereas the first estrous behaviours were observed at 14.2 months of age and 215.4kg body weight. This result indicates that determination of plasma progesterone profiles could be utilized for monitoring the puberty in Korean native heifers, and one or more ovulations occurred before pubertal heifers showed overt estrous behaviours.
Supported by : 국제원자력기구(IAEA), 한국과학재단