It was demonstrated that nursery pigs fed diets containing irradiated soybean meal had increased ADG, ADFI, and G:F, and pigs fed diets containing irradiated fish meal tended to have improved G:F. Therefore, the objectives of these experiments were to determine the effects of nonirradiated or irradiated spray-dried animal plasma (SDAP) fed in either meal or pellet form, and to evaluate the effects of irradiated protein sources (SDAP, soybean meal, and fish meal) in the diet, fed in either meal or pelleted form, on nursery pig performance.
Two experiments were conducted to evaluate the effects of irradiated ingredients in meal and pelleted diets on nursery pig performance. In Exp. 1, a total of 192 pigs (initial BW, 6.0 kg) were used in a 25-d experiment. Pigs were blocked by BW and randomly allotted in a 2 × 2 factorial arrangement of treatments with main effects of diet form (meal or pellet) and either irradiated (11.92 kGy) or nonirradiated SDAP.
Irradiated SDAP had less total bacterial amounts than nonirradiated SDAP, and pelleted diets also had less bacterial amounts than diets in meal form. However, the complete diets with and without irradiated SDAP had similar bacterial concentrations (P>0.05). There was a diet form × SDAP irradiation interaction (P < 0.05) for ADG from d 0 to 11 and d 0 to 25. Pigs fed irradiated SDAP in meal form had increased ADG compared with pigs fed the nonirradiated meal diet, with no change in ADG of pigs fed pelleted diets. In addition, from d 0 to 11, pigs fed irradiated SDAP or pelleted diets had greater G:F (P < 0.01) compared with pigs fed regular SDAP and meal diets, respectively. In Exp. 2, a total of 350 pigs (initial BW, 4.9 kg) were used in a 22-d experiment to determine the effects of feeding irradiated protein sources (SDAP, soybean meal, fish meal, or all 3) in meal and pellet diets on pig performance. Pigs were blocked by BW and randomly allotted to 1 of 10 treatments consisting of a single diet formulation fed in either meal or pellet form containing either no irradiated protein sources or irradiated SDAP, soybean meal, fish meal, or all 3 irradiated protein sources (10.20 kGy). From d 0 to 11, pigs fed diets containing irradiated protein sources had greater (P < 0.03) G:F compared with pigs fed the control diets, with no difference in ADG or ADFI. From d 0 to 11, and overall (d 0 to 22), pigs fed pellet diets had greater G:F (P < 0.01) compared with pigs fed meal diets, with no difference in ADG and ADFI. Furthermore, pigs fed pelleted diets had increased G:F compared with pigs fed meal diets.
CN Groesbeck, JM DeRouchey, MD Tokach, RD Goodband, SS Dritz, and JL Nelssen. Effects of irradiation of feed ingredients added to meal or pelleted diets on growth performance of weanling pigs. 2009. Journal of Animal Science, 87:3997-4002. doi:10.2527/jas.2008-1156