Letters to the editor

Abstract

Abstract Extract Sir:— Zeranol was first licensed for use as a growth promotant in cattle and sheep in the USA in 1969, and subsequently has been licensed and sold in over 50 countries of the world. A vast amount of published material on zeranol's efficacy, particularly in relation to growing and finishing steer cattle, has been documented in the scientific literature during the past 15 years.(2) Bennett, G., Beaumont, W.H. and Brown, P.R.M. 1974. Use of the anabolic agent zeranol (resorcylic acid lactone) as a growth promotor for cattle. Vet. Rec., 94(11): 235–235. [Crossref], [PubMed] , [Google Scholar] (3) Brown, R.G. 1970. An anabolic agent for ruminants. J. Am. Vet. Med. Assoc, 157: 1537–1537. [PubMed], [Web of Science ®] , [Google Scholar] (4) Galbraith, H. and Topps, J.H. 1981. Effect of hormones on the growth and body composition of animals. Commonwealth Bureau of Nutrition, Nutrition Abstracts and Reviews, Series B, 51: 8–8. [Google Scholar] (5) Gartner, R.J.W. and O'Rourke, P.K. 1977. Effects of antibiotics, dried molasses distillers solubles and zeranol in allsorghum grain rations fed to steers. Aust. J. Exp. Agric. and An. Husb., 17(85): 214–222. [Crossref] , [Google Scholar] (6) Geldard, H. and Wellington, J.K.M. 1981. Effect of zeranol on growth rates of steers. Aust. vet. J., 57: 438–438. [Crossref], [PubMed] , [Google Scholar] (7) Hembry, F.G., Bagiey, C.P. and Peterson, F.J. 1975. Effect of zeranol during growing and finishing. J. Anim. Sci., 42: 276–276. [Google Scholar] (10) Moran, J.B. 1972. Effect of zeranol on seasonal growth rates of cattle in a dry monsoonal environment. J. Exp. Agric. and Anlm. Husb., 12: 345–345. [Crossref] , [Google Scholar] (11) Perry, T.W., Stob, M, Huber, D.A. and Peterson, R.C. 1970. Effect of subcutaneous implantation of resorcylic acid lactone on performance of growing and finishing beef cattle. J. Anim. Sci., 31: 789–789. [Crossref] , [Google Scholar] (12) Pryor, W.J. 1973. Implantation of resorcylic acid lactone in cattle and sheep. Aust. vet. J., 49(12): 593–594. [Crossref], [PubMed] , [Google Scholar] (13) Roche, J.F. The use of growth promoters in beef cattle. Proceedings from Conference on The Use, Residues and Toxicology of growth promoters. April91980, Dublin. [Google Scholar] (14) Roche, J.F., Harte, F.J., Joseph, R.L. and Davis, W.D. 1981. The Use of Growth Promoters in Beef Promotion. Proceedings of a workshop at Brussels March 5 and 6 1981 under auspices of Commission of the European Communities Directorate General for Agriculture Division for the Co-ordination of Agricultural Research, [Google Scholar] (15) Roche, J.F., Davis, W.D. and Sheringtori, J. 1978. Effect of trenbolone acetate or resorcylic acid lactone alone or combined on daily liveweight and carcass weight in steers. Irish J. Agric. Res., 17: 7–7. [Google Scholar] (16) Sammons, R. 1980. Effect of subcutaneous implants of zeranol on weight gains of castrated cattle at pasture. Aust. vet. J., 56: 417–417. [Crossref], [PubMed] , [Google Scholar] (17) Sharp, G.D. and Dyer, I.A. 1971. Effect of zeranol on the performance and carcass composition of growing — finishing ruminants. J. Anim. Sci., 33: 865–865. [Crossref] , [Google Scholar] (18) Sharp, G.D. and Dyer, I.A. 1972. Zeranol metabolism in steers. J. Anim. Sci., 34(1): 176–176. [Crossref], [PubMed] , [Google Scholar]