Abstract
Spray-dried animal plasma (SDAP), mostly of porcine origin, is frequently used as an ingredient of weanling piglets diets in order to improve feed intake and to reduce post-weaning diarrhoea. On the basis of 15 published studies it is concluded that dietary SDAP levels up to 6% increase both average daily gain (ADG) and feed intake (ADFI) in the first 2 weeks after weaning in a dose-dependent fashion. Up to 6% SDAP also reduces feed conversion ratio (FCR). The positive effect of SDAP on ADG and ADFI is much more pronounced in the first than the second week after weaning. There is no positive carry-over effect of SDAP feeding during the period of 2 weeks after weaning on growth performance thereafter. SDAP is an expensive protein source and an economic evaluation should be made before including SDAP in weanling piglets diets. Multiple regression analysis indicated that, apart from SDAP dose, baseline growth rate is an important determinant of the effect of SDAP on ADG, with high baseline growth rate being associated with small effects of SDAP. It should be stressed that SDAP is a non-sterilised product that might spread certain diseases after feeding it to pigs. Porcine plasma has more beneficial effects than bovine plasma. Possible modes of action are discussed. It is suggested that, in addition to improving feed palatability, SDAP reduces post-weaning intestinal disease by preventing attachment of pathogens.