Abstract

Three experiments were conducted to evaluate pet food by-product (PFB) as a component of nursery starter diets and its effects on pig performance. The PFB used in these studies was a pelleted dog food that contained (as-fed basis) 21% CP, 1.25% total lysine, and 8.3% ether extract. In Exp. 1, 288 early-weaned pigs (5.2 kg at 14 d) were used to determine the effects of replacing animal protein and energy sources with PFB at 0, 10, 30, and 50% (as-fed basis) inclusion levels in phase I (d 0 to 7 after weaning) and phase II (d 7 to 21 after weaning) diets. Phase I diets contained 27.5% whey, 18.75% soybean meal, 1.50% lysine, 0.90% Ca, and 0.80% P, with PFB substituted for corn, fat, plasma protein, fish meal, limestone, and dicalcium phosphate. Phase II diets had a constant 10% whey, 1.35% lysine, and PFB was substituted for blood cells, a portion of the soybean meal, and other ingredients as in phase I diets. In phase I, growth performance by pigs fed PFB-containing diets was similar to that of the control diet. In phase II, ADG (linear; P < 0.05 and quadratic, P < 0.005), ADFI (linear and quadratic, P < 0.01), and G:F (quadratic, P < 0.01) were increased with increasing PFB inclusion. In Exp. 2, 80 weaned pigs (6.7 kg at 21 d) were fed a common phase I diet for 1 wk and used to further evaluate the effect of PFB in phase II diets (same as Exp 1; initial BW = 8.1 kg) on growth performance and apparent total tract nutrient digestibility. There were no differences in ADG, ADFI, or G:F across treatments. Dry matter and energy digestibility did not differ among diets; however, digestibilities of CP (P < 0.05) and the essential AA, arginine (P < 0.02), histidine (P < 0.01), lysine (P < 0.001), threonine (P < 0.01), and valine (P < 0.01), were greater as PFB was increased in the diet. In Exp. 3, the performance by pigs (n = 1 70; 5.5 kg; 21 d of age) fed diets with 0 or 30% PFB in both phases I and II was examined. Growth performance was similar in both diets. These studies demonstrate that pet food by-product can effectively be used as a partial replacement for animal protein sources and grain energy sources in the diets of young nursery pigs.