Abstract

Exposure of ewe lambs (also known as hoggets or yearlings) to vasectomised rams (teasing) has increased breeding activity early in the breeding period in some but not all studies (Hudgens et al. 1987; Kemp et al. 1991; Ungerfled 2007; Cave et al. 2012; Kenyon et al. 2012, 2014). Additional effects reported include increased overall pregnancy rates and number of foetuses per ewe lamb (Kenyon et al. 2014). It would be of benefit if the cause of the variation among studies in the ewe lamb response to teasing could be identified. In mature ewes, nutrition has been reported to influence the teasing response when it is used to advance the breeding season (Scaramuzzi & Martin, 2008). Therefore, the present study aimed to test the hypothesis that ewe lambs offered an unrestricted level of pastoral nutrition would have an enhanced response to teasing.

PR, Kenyon, C Viñoles, and ST Morris

Proceedings of the New Zealand Society of Animal Production, Volume 74, Napier, 76-78, 2014