RECIPIENT MANAGEMENT AND EMBRYO TRANSFER

The recipient is one of the prime determinants of the success of the embryo transfer enterprise and improving recipient quality can produce significant savings in the cost of achieving a pregnancy. The effect of rejecting recipients or failure to achieve a pregnancy on the cost of a pregnancy was estimated by taking UK values of maiden recipients, interest charges, labour, feed, accommodation and drug costs. A period of 6 weeks from inclusion in the recipient pool to embryo transfer with pregnancy diagnosis occurring a further 7 weeks after transfer was assumed. The major changes in cost per pregnancy occur due to shifts in the proportion of those recipients synchronised which are detected in estrus; the proportion of those seen in estrus which are used for transfer; and the proportion of those used for transfer which become pregnant. Keeping two of these factors constant whilst changing the third gives estimates of their relative importance. The effect of an increase in the proportion of those synchronised which are detected in estrus from 85 to 95% is to give a saving of approx. 6% per pregnancy. A change in the proportion of those detected in estrus which are used for transfer from 80 to 90% produces a saving of approx. 7% per pregnancy. An improvement in the pregnancy rate of those used for transfer from 60 to 70% results in the greatest improvement in costs of approx. 14% per pregnancy. There are many factors involved in successful recipient management whose roles are closely related. The effects of genotype, parity, physiological status, health and stress are considered along with the nutritional, physical and climatic environment of the recipient. Further discussion centres on the synchronisation and detection of estrus, and the selection and management of recipients at transfer.