Neonatal mortality represents a major loss of production efficiency for herds throughout the world and despite research and development work spanning many years the losses are still not tolerable either in economic terms or in terms of animal welfare. In the United Kingdom where producers are amongst the very best, the Meat and Livestock Commission estimate that pre-weaning mortality nationally is of the order of 12.8% of all piglets born alive (MLC, 1984).

The causes of death are well documented (Spicer et al 1986) but overlying, starvation, chilling and pathological problems are principal components. Central to all of these factors may be the events occurring within the first hours of a piglets life and those animals which are first born which suckle quickly and effectively have a high probability of survival.

Conversely, those piglets which are later born and which are also smaller than the average for the litter may be at a severe disadvantage because of the competitive environment around the udder of the sow after parturition. Modern hybrid sows also vary widely in their ability to produce colostrum (Varley,1984)