Affiliation: | 1. Meat and Livestock Commission, P. O. Box 44, Queensway House, Bletchley, Milton Keynes MK2 2EF U.K.;2. Agricultural Research Council Research Group on Hormones and Farm Animal Reproduction, University of Nottingham, School of Agriculture, Sutton Bonington, Loughborough, Leicestershire, LE12 5RD U.K. |