Pre-weaning mortality in pigs in the United Kingdom is estimated to be 11.6% ie the loss of around 2 million piglets every year. If only the cost of piglet production is considered this represents a loss to the industry of approximately £28 million each year. In fact the revenue foregone from finished pigs is much greater (MAFF,1985).

Over 50% of the losses of liveborn piglets occur in the first 48 to 72 hours after birth. Around 75% of mortalities are due to the two, often related causes, overlying by the dam and starvation (English and Morrison, 1984).

Mortality is inversley related to birth weight, small piglets being affected by competition from their larger litter mates and having lower energy reserves. To reduce piglet mortality care must therefore be concentrated, especially on small weakly piglets in the first 48 hours of life.