In the hog kingdom, leanness has been one of the most desired traits. The transformation of dairy cows through technology has been equally profound. UC Davis Professor Juan Medrano, an authority on milk production genes, said a national database tracks the milk output of cows sired by specific males in order to identify the best breeding stock. In the dairy world, technology has also given cows a bigger role in improving the herd. UC Davis animal scientist Gary Anderson explained how embryo transfer allows prize cows to have many more offspring than they would naturally.
Scientists use hormones to stimulate egg production.
Eggs are fertilized by the best available sperm. These well-bred embryos are implanted into surrogate cows. Biotech scientists like UC Davis' Murray fear public concern over bioengineering may halt animal improvements beyond those made possible through artificial insemination or embryo transfer. His experiments take time. He won't know for a year, for instance, whether his gene insertion caused any increase in the milk protein content of his experimental goats.