The influence of oestradiol, and of synthetic substitutes for the natural hormones such as stilboestrol and hexoestrol, on growth and fattening in livestock has been investigated by many workers. In particular the emphasis given to work at Iowa State College (Burroughs et al., 1955), led to a very rapid and widespread adoption of the technique of oral administration to fattening beef animals in the U.S.A., and to a resurgence of interest in techniques of administration in other countries. Workers in Great Britain have investigated the results of administration of oestrogens, both orally and by implantation, in beef cattle, sheep, pigs and poultry.
Prediction of achievement of Iowa State College engineering students having transferred from other institutions
