Observation on Reproductive Efficiency in Dairy Cows 1. Average Number of Days from Parturition to Conception |
Chung Ho Jo1, Mahn Joong Yong1, ChuI Woo Lee2 |
1Department of Veterinary Medicine, The City College of Seoul 2Korea-German Dairy Farm |
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) |
조충호1, 용만중1, 이철우2 |
1서울산업대학 수의학과 2한독낙농시범목장 |
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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. |
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