BACKFAT AND CARCASS COMPOSITION OF PIGLETS FED MILK REPLACERS CONTAINING VEGETABLE OIL COMPARED WITH SOW-REARED PIGLETS

The carcass composition of piglets fed artificial milk was compared to sow-reared piglets. The artificial milk diets contained 25%, by weigh t, soybean oil or mixtures of canola and high erucic acid rapeseed oil . Both the total lipid and nitrogen (apparent) digestibility of the ar tificial milk diets was high, even when the dietary oil contained high levels of erucic acid. Sow-reared animals were matched with the pigle ts receiving the artificial milk by sex and live body weight. On both a relative and an absolute basis, the piglets receiving the artificial milk diets had less carcass fat than sow-reared animals. The per cent nitrogen and ash of the carcasses of sow-reared piglets were signific antly reduced compared with piglets eating milk replacer. The fatty-ac id patterns of the backfat of the piglets generally resembled the patt erns of the dietary lipids. Piglets eating vegetable oil diets had lon g-chain polyunsaturated fatty acids in their backfat, even though the oils they were consuming did not.