Rearing replacement heifer calves is a labour-intensive and expensive component of dairy systems (Drackley 2008). Large numbers of replacement heifers are not meeting target live weights in New Zealand (McNaughton & Lopdell 2012) which has implications for future milk production, fertility and subsequent longevity in the herd (Van Amburgh & Tikofsky 2001). This paper reports results from the second year of a long-term experiment being conducted at Massey University that examines the impact of colostral status and liveweight gain of heifer calves fed different diets on subsequent milk production, fertility and longevity in the herd. Previous work (Cardoso et al. 2015) demonstrated no difference in pre-weaning liveweight gain of calves fed different levels of milk. The calves in that study ate surprisingly little meal. It was surmised that the exposure to frequent shifts onto fresh pasture stimulated intake of pasture, and removed the advantage of feeding calves higher levels of milk and supplementation with meal. Anecdotally, many calves when removed from rearing sheds to pasture are kept on the same paddocks as they are not a high priority for pasture allocation. Therefore, the aim of this experiment was further collection of colostral and Brix data as described by Coleman et al. (2015), and to compare pre-weaning growth rates of calves that are continually offered fresh pasture to those that are set stocked.
Proceedings of the New Zealand Society of Animal Production, 2016, 76 pp. 119 - 121 (3)