Spray-dried whey and skim milk have long been used in nursery diets as sources of high quality protein and lactose (milk sugar). More recently, further processing of these dairy industry byproducts has resulted in deproteinated whey and pure lactose being available at economical prices. Spray-dried plasma is now commonly used as a high quality substitute for the milk protein traditionally supplied in nursery diets using skim milk. Spray-dried blood cells is a product with an extremely high lysine content which has been shown to partially or totally replace fish meal in nursery diets. More recently, we have been questioning whether spray-dried blood cells and lactose could partially or totally replace fish meal in nursery diets.
One hundred and forty four pigs weaned at 17 days were used in a three-seek long trial. The objective was to compare the effects of the partial (50%) or total (100%) substitution of whey by spray-dried blood cells and lactose in Phase 1 (0-21 d post weaning) nursery diets. Pen feed disappearance and individual pig body weight gain, feed disappearance and feed:gain ratios for each weekly period and overall were then calculated. For any weekly period or overall, average daily weight gain and feed disappearance were not different between pigs offered the control diet or the diets in which whey was partially or totally replaced by spray-dried blood cells and lactose. Moreover, the pigs offered the diets in which whey was partially or totally replaced by spray-dried blood cells and lactose had significantly better feed:gain ratios than those pigs fed the control whey diet during the third weekly period and overall. The results of this trial, not only indicate that a combination of spray-dried blood cells and lactose can partially or totally substitute whey in Phase 1 nursery diets, but also showed that the feed conversion efficiency of weanling pigs can be improved.