Master of Science / Department of Animal Sciences and Industry / Jim L. Nelssen / Eight experiments used 1,712 pigs to determine influences of dietary enzymes or specialty proteins on nursery pig performance. Experiments 1 and 2 evaluated the effects of fish meal, fermented soybean meal, or dried porcine solubles on performance. Experiment 1 showed pigs fed dried porcine solubles had improved (P = 0.01) ADG and G:F compared to pigs fed the control diet, and improved (P = 0.03) G:F compared to pigs fed the combination of fermented soybean meal and fish meal. Experiment 2 showed pigs fed increasing fermented soybean meal had improved (quadratic, P = 0.03) G:F. Experiments 3 and 4 evaluated the effects of commercial enzyme addition to diets containing dried distillers grains with solubles (DDGS) on performance. In experiment 3, neither DDGS nor enzyme addition influenced (P > 0.10) ADG and G:F. Experiment 4 found there were no (P > 0.32) enzyme × DDGS source interactions. Corn DDGS did not influence pig performance (P > 0.36). Sorghum DDGS reduced (P = 0.003) G:F, with no difference between sorghum DDGS sources. Adding enzymes to 30% DDGS diets did not improve (P > 0.57) performance. Experiments 5 and 6 evaluated the effects of fish meal (SMFM), spray-dried animal plasma (SDAP), or peptone on performance. In Experiment 5, different specialty proteins had similar (P > 0.10) ADG, ADFI, or G:F. Experiment 6 showed pigs fed 4% Peptone 2 during phase 1 and 2% Peptone 2 during phase 2 had improved (P < 0.05) ADG compared to pigs fed SMFM, and improved (P < 0.05) G:F compared to pigs fed all other diets. Experiments 7 and 8 developed an available P release curve for commercial phytase products. In both experiments, pigs fed increasing inorganic P had improved (linear, P < 0.01) G:F and percentage bone ash. Pigs fed increasing OptiPhos 2000-M, Phyzyme XP, or Ronozyme P had improved (P < 0.001) percentage bone ash. Available P release for up to 1,000 FTU/kg of Escherichia coli-derived phytases can be predicted by the equation (y = -0.000000125x[superscript]2 + 0.000236245x + 0.015482), where x is the phytase level in the diet.

Doctor of Philosophy / Department of Diagnostic Medicine/Pathobiology / Joel M. DeRouchey / Steven S. Dritz / A total of 9,979 pigs were used in 11 experiments to quantify production responses under field conditions in growing pigs to PCV2 vaccination, biofuel co-products and dietary supplemental enzymes. Experiments 1 and 2 were conducted to determine the efficacy of a commercial 2-dose Porcine Circovirus Type 2 (PCV2) vaccine. Growth performance and mortality (P < 0.05) of vaccinated pigs improved compared to non-vaccinated pigs in both experiments with the vaccine causing a greater increase in ADG in vaccinated barrows than vaccinated gilts in Exp. 2. Experiment 3 compared the efficacy of 1-dose and 2-dose commercial PCV2 vaccines, where vaccinated pigs had greater ADG (P < 0.05) than vaccinated pigs regardless of vaccine type. The 2-dose group was heavier (P < 0.05) than the control group while the 1-dose group was intermediate. Therefore, PCV2 vaccines were efficacious under field conditions. Experiments 4, 5, and 6 were conducted to evaluate de-oiled corn dried distillers grains with solubles (dDGS) in grow-finish pigs. In Exp. 4, analyzed CP and AA content were higher, but lysine digestibility and energy content were lower in dDGS than traditional dried distillers grains with solubles (DDGS). In Exp. 5, 0 to 30% dDGS in nursery diets did not affect growth performance (P > 0.52). In Exp. 6, 0 to 30% dDGS reduced (linear; P < 0.01) ADG and ADFI, tended to improve (linear; P > 0.07) G:F, decreased (linear; P < 0.01) carcass yield, and increased (linear; P < 0.01) fat iodine values. Experiment 7 was conducted to determine the AA digestibility and energy concentration of novel high-CP distillers co-products from corn (HPC-DDG) and sorghum (HPS-DDGS). Digestibility of AA was higher for HPC-DDG but lower in HPS-DDGS than traditional DDGS. Both co-products had lower energy than traditional DDGS. Finally, Exp. 8, 9, 10, and 11 were used in a meta-analysis to evaluate supplementary dietary enzymes in pigs. Supplemental enzymes, alone or in combination, did not improve grow-finish pig performance (P > 0.58) regardless of dietary DDGS level. In conclusion, these experiments provide important empirical data to quantify production responses of various interventions and dietary ingredients under actual field conditions.