Effects of a whey protein product and spray-dried animal plasma on growth performance of weanling pigs

Five experiments were conducted to evaluate the effects of a high-protein, whey protein product (WPP; 73% CP, 6.8% lysine, 12.8% fat, and 5% lactose) and spray-dried animal plasma (SDAP) on growth performance of weanling pigs . In all experiments, pigs were fed experimental diets from d 0 to 14 after weaning in a pelleted form and then a common diet in meal form for the rem ainder of the experiment. Dietary treatments were established by substituti ng WPP or SDAP for dried skim milk (Exp. 1) or soybean meal (Exp. 2, 3, 4, and 5) in the control diet. In Exp. 1, we maintained a constant level of la ctose in all diets by adjusting the amount of added crystalline lactose. Th e amount of lactose in diets used in Exp. 2 through 5 varied slightly by th e addition of WPP. In Exp. 1 and 2, 180 weanling pigs (initially 5.8 kg and 19 +/- 1 d of age or 5.5 kg and 17 +/- 1 d of age, respectively) were used . Treatment diets contained SDAP (2.5 and 5%) or WPP (2.7 and 5.4% in Exp.1 , and 2.5 or 5.0% in Exp. 2). In Exp. 1, from d 0 to 7 after weaning, ADG a nd ADFI increased with increasing SDAP (linear, P < .01). No other treatmen t effects were observed during the d 0 to 14 period. In Exp. 2, from d 0 to 14 after weaning, ADG and G:F increased (linear, P < .04) with increasing SDAP or WWP. In Exp. 3, 305 weanling pigs (initially 4.1 kg and 12 +/- 1 d of age) were used. The control diet contained 2.5% SDAP. The experimental d iets were similar to the control diet but contained an additional 2.5 or 5. 0% SDAP or 2.5 or 5.0% WPP. From d 0 to 14 after weaning, ADG, ADFI, and G: F increased (quadratic, P < .05) with increasing SDAP up to 5.0%. Increasin g WPP increased ADG (quadratic, P < .07) and ADFI (linear, P < .09). In Exp . 4 and 5, 329 and 756 weanling pigs (initially 4.1 kg and 12 +/- 1 d of ag e and 5.2 kg and 18 +/- 1 d of age, respectively) were fed diets in which W PP was substituted for 0, 25, 50, 75, and 100% (Exp. 4) or 0, 50, and 100% (Exp. 5) of the SDAP in the control diet. In Exp. 4 and 5, from d O to 14 a fter weaning, pigs fed a 1:1 blend of each protein source had better ADG (q uadratic, P < .04) than those only fed SDAP. In conclusion, WPP can be used in combination with or as a total replacement for SDAP in diets for weanli ng pigs without reducing performance.