Zeranol and adult steers

Authors: McKenzie JR
Publication: New Zealand Veterinary Journal, Volume 34, Issue 1-2, pp 19, Jan 1986
Publisher: Taylor and Francis

Animal type: Cattle, Livestock, Production animal, Ruminant
Subject Terms: Animal production/wastage, Animal remedies/veterinary medicines, Growth/development, Treatment/therapy
Article class: Correspondence

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Abstract: The growth rate response obtained in yearling steer cattle to zeranol treatment have been extensively documented in New Zealand and overseas literature. I wish to record the result of growth responses in two-year-old steer cattle. Three field trials, with well grown adult steers, were established in three different geographical regions to evaluate the liveweight responses to one implant (36mg) of zeranol. The trial protocol is described below. In early spring 1984, approximately 60 uniform steers were randomised into two groups (treated and control) by weight. All treated animals were implanted subcutaneously with 36mg zeranol at the base of the ear, according to the manufacturer`s recommendations. All animals were grazed together on topdressed developed ryegrass/white clover pastures for the duration of the trial. At the end of the trial (approximately 100 days) the animals were reweighed and the results statistically analysed…

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