# 유우(乳牛)의 번식능률(繁殖能率)에 관한 연구(硏究) 1. 분만후(分娩後) 수태시(受胎時)까지의 소요일수(所要日數)

• Published : 1976.10.20

#### Abstract

The survey was carried out to investigate the average number of days from parturition to conception to 349 calving cases out of Holstein cows in total 154 heads observed. The results were as follows: 1. The average number of days from parturition to conception was $97.41{\pm}8.22$ and it's similar during the period from primipara to 4th calving order, and irregular during on and after 5th. 2. The average number of days from parturition to conception in calving month was observed all through the year: the prolongation among on April and July, and the brief duration among on January and March. 3. In the cases under 50 and 150 days after delivery, the distribution showed 53.56% and 83.91%, respectively, and it's about 20% between 70 and 90 days after delivery.