Abstract

Large numbers of replacement heifers are not meeting target live weights in New Zealand (McNaughton & Lopdell 2012; Handcock et al. 2016) which has implications for future milk production, fertility and subsequent longevity in the herd (Van Amburgh & Tikofsky 2001; McNaughton & Lopdell 2013). Undergrown heifers can lead to an overall decline in a herd’s reproductive performance and milk production (McNaughton & Lopdell 2012). McNaughton and Lopdell (2013) reported that for every 1% increase in the percentage of live weight attained, heifers produced approximately 23 litres of extra milk during their first two lactations. As such, heifer growth, particularly post-weaning growth, has been identified as an area requiring greater attention from farmers to improve cow performance. There are established breed liveweight targets as well as liveweight targets based on an individual animals genetic potential and the growth of individual animals and groups can be monitored using programmes such as Livestock Improvement Corporation’s MINDA Weights™ herd-recording software. However, while growth targets are commonly used, in many cases, being ‘on-target’ is based on a mob average, resulting in a proportion of animals below target live weight....

PJ, Back, RE Hickson, NW Sneddon, LW Coleman, and RA Laven

Proceedings of the New Zealand Society of Animal Production, Volume 77, Rotorua, 69-71, 2017