Applications of embryo transfer in animal breeding

Abstract

Multiple ovulation and embryo transfer (MOET) offers new opportunities for genetic improvement in sheep and cattle breeding. While the techniques are still expensive, their use will mainly be for breed improvement, rather than in commercial production. Improved reproductive rates in females through MOET allow more intense selection, more accurate selection and, of most importance, a shorter generation interval. Each or all of these can contribute to faster rates of genetic change. To exploit the advantages of MOET different breeding systems may be required. Current progeny testing systems can be improved by MOET, but the highest genetic response rates are obtained with nucleus breeding-selection units bred by MOET. Adult MOET (after first breeding) may allow moderate (10–30 percent) gains in genetic response rates. Juvenile MOET (before first breeding) can yield higher (30–100 percent) gains in genetic response rates. Thus effective MOET of juveniles is required to fully exploit the possible advantages of MOET in genetic improvement in practice.