Finally, it needs to be emphasised that long-term consequences of more specific, acute environmental influences during specific stages of embryonic, foetal and neonatal calf development remain to be determined. This need for further research extends to consequences of nutrition and growth early in life for subsequent reproductive performance, which has been recently shown to be affected in heifers by nutrition of their dams during late pregnancy (Martin et al., 2007), although neither reproductive or lactational performance were affected by birth weight (Swali and Wathes, 2006).