Deland, M.Ross, R.Abraham, E.Pitchford, W.Neville Jopson,2007-05-142007-05-142001Association for the Advancement of Animal Breeding and Genetics. Proceedings, 2001; 14:333-3360958629919http://hdl.handle.net/2440/29340Hereford cows were mated to semen (total 2438 doses) from seven sire breeds (Angus, Belgian Blue, Hereford, Jersey, Limousin, South Devon and Wagyu). A total of 97 sires were represented over four matings from 1993-1996 with an overall calving rate of 62%. Only 19% received a repeat dose of semen. Year of mating and cow age significantly affected calving rates and gestation lengths. Sire breed differences were not significant. However, a wide range of success rates were noted for individual sires.enCattlesemenoestrus synchronisationcalving ratesgestation lengthConference paper002001197361144Pitchford, W. [0000-0002-5213-3978]