Abstract

A telephone survey of 400 randomly selected sheep farmers was undertaken to determine the incidence of ram, cryptorchid, and wether lambs in the New Zealand lamb flock in 2000. Respondents were asked why they choose to produce rams, cryptorchids or wethers and how willing they would be to change. The percentage (+/-5%) of male lambs left entire and made cryptorchids was similar at 39% and 41% respectively with the remaining 20% wethers. The primary reasons why farmers produced cryptorchids was to achieve good lamb growth rates and lean carcasses without having fertile male lambs. Published research reports support the perception of leanness relative to wether lambs but indicate that carcass weights are similar to those of ram and wether lambs and that some cryptorchids may be fertile. Secondary reasons given for producing cryptorchids were that they were cleaner and easier managed than ram lambs. Although the production of cryptorchids has declined in recent years, 71% of the farmers who currently produce them have a preference for this method and indicated unwillingness to change from this practice.

IS, Tarbotton, AR Bray, and JA Wilson

Proceedings of the New Zealand Society of Animal Production, Volume 62, Palmerston North, 334-336, 2002