Abstract
Extract
Sir:- It is well documented in the literature that bulls grow 10–20% faster and have a higher efficiency of feed conversion than steers.(3)(4)(5) New Zealand's beef production could well be increased markedly if more dairy and traditional beef calves are fattened as bulls. The secondary sex characteristics (behaviour problems) of bulls fattened is one of the main reasons why bull beef production is not practised extensively. Under feedlot conditions, zeranol (marketed under trademark RALGRO*) was shown to reduce riding when bulls were implanted every 100 days, from birth.(2)