Conception promotion of silent heat dairy cow by means of transplantation of in vitro fertilization of Japanese Black applying score type recipient cow selection method devised for improving embryo transplantation and its economical effect

摘要

For the prupose improvement of dairy farming, the transplantation of in vitro fertilized embryo of Japanese Black cattle (JB IVF-ET) for silent heat dairy cow applying score type method devised for recipient cow selection was carried out. As the result, after introducing the score method, the recipient selection rate increased (p<0.01) to 52.0 percent (198/381) from 44.0 percent (520/1182), and the result of conception rate became 37.4 percent from 33.5 percent. That is, the conception rate of requesting recipiont cow became higher (p<0.05) from 14.7 percent (174/1182) to 19.4 percent (74/381). The relationship between profit of JB IVF-ET (y) and conception rate (x) was y (yen)=136,800x-28,000, and the profit and loss divergence of conception rate (y=0) was 20.5 percent. The profit per head was calculated at 23,100 yen from the conception rate at thes time. From the above findings, it is considered that the utilization of JB IVF-ET to silent heat cow can contribute to the profit improvement of dairy farm.