Master of Science / Department of Animal Sciences and Industry / Joel M. DeRouchey / Five experiments using a total of 4,470 pigs were used to determine the effects of dietary Cu and Zn source and finishing pig space allowance. Experiment 1 evaluated increasing dietary Zn from Zn hydroxychloride or ZnSO₄ for finishing pigs. Increasing dietary Zn up to 100 mg/kg Zn maximized ADG and HCW with the greatest response observed during the last 37 d period when ractopamine was included in the diet. Pigs fed diets with Zn hydroxychloride had greater HCW compared to those fed ZnSO₄. Experiment 2 evaluated increasing dietary Cu from either CuSO₄ or a 50:50 blend of CuSO₄:Cu-AA for finishing pigs. Pigs fed Cu from CuSO₄ alone consumed more feed and tended to have poorer feed efficiency than those fed a 50:50 blend of Cu from CuSO4:Cu-AA. Pigs fed a 50:50 blend of CuSO4:Cu-AA had improved HCW G:F but ADG was unchanged on a live and HCW basis. Experiments 3 and 4 evaluated increasing dietary Cu from tri-basic copper chloride or a Cu-chelate for nursery pigs. In Exp. 3, increasing Cu from Cu-chelate to 150 mg/kg Cu increased ADG and ending BW. Increasing Cu to 150 mg/kg Cu increased ADFI and improved G:F. Pigs fed Cu from Cu-chelate had greater ADG, ADFI and ending BW than those fed Cu from tri-basic copper chloride. In Exp. 4, increasing Cu to 225 mg/kg Cu increased ADG and ending BW. Because ADFI was unchanged, G:F tended to be improved as Cu level increased. There were no differences detected between Cu sources for growth performance. Experiment 5 was conducted to determine the effects of increasing space allowance by pig removal or gate adjustment during the finishing period. Pigs provided 0.91 m² had increased ADG compared with those allowed 0.63 m² with pigs from pens provided increased space intermediate. Pigs provided 0.91 m² had increased ADFI compared with pigs allowed 0.63 m² and those where a pig was removed; however, pigs from pens where the gate was adjusted were intermediate. As pigs grew to the minimum predicted space requirement and were subsequently allowed more space, performance was greater than those initially provided 0.61 m² but less than those allowed 0.91 m².

Master of Science / Department of Animal Sciences and Industry / Joel M. DeRouchey / Five experiments using a total of 4,470 pigs were used to determine the effects of dietary Cu and Zn source and finishing pig space allowance. Experiment 1 evaluated increasing dietary Zn from Zn hydroxychloride or ZnSO4 for finishing pigs. Increasing dietary Zn up to 100 mg/kg Zn maximized ADG and HCW with the greatest response observed during the last 37 d period when ractopamine was included in the diet. Pigs fed diets with Zn hydroxychloride had greater HCW compared to those fed ZnSO4. Experiment 2 evaluated increasing dietary Cu from either CuSO4 or a 50:50 blend of CuSO4:Cu-AA for finishing pigs. Pigs fed Cu from CuSO4 alone consumed more feed and tended to have poorer feed efficiency than those fed a 50:50 blend of Cu from CuSO4:Cu-AA. Pigs fed a 50:50 blend of CuSO4:Cu-AA had improved HCW G:F but ADG was unchanged on a live and HCW basis. Experiments 3 and 4 evaluated increasing dietary Cu from tri-basic copper chloride or a Cu-chelate for nursery pigs. In Exp. 3, increasing Cu from Cu-chelate to 150 mg/kg Cu increased ADG and ending BW. Increasing Cu to 150 mg/kg Cu increased ADFI and improved G:F. Pigs fed Cu from Cu-chelate had greater ADG, ADFI and ending BW than those fed Cu from tri-basic copper chloride. In Exp. 4, increasing Cu to 225 mg/kg Cu increased ADG and ending BW. Because ADFI was unchanged, G:F tended to be improved as Cu level increased. There were no differences detected between Cu sources for growth performance. Experiment 5 was conducted to determine the effects of increasing space allowance by pig removal or gate adjustment during the finishing period. Pigs provided 0.91 m2 had increased ADG compared with those allowed 0.63 m2 with pigs from pens provided increased space intermediate. Pigs provided 0.91 m2 had increased ADFI compared with pigs allowed 0.63 m2 and those where a pig was removed; however, pigs from pens where the gate was adjusted were intermediate. As pigs grew to the minimum predicted space requirement and were subsequently allowed more space, performance was greater than those initially provided 0.61 m2 but less than those allowed 0.91 m2.

Master of Science / Department of Animal Sciences and Industry / Robert Goodband / In 6 experiments, a total of 1,802 pigs were used to determine: 1) effects of increasing crystalline amino acids in sorghum- or corn-based diets on nursery or finishing pig growth performance; 2) effects of different Zn sources on nursery pig performance; and 3) effects of different corn oil sources on nursery pig performance. In the first set of experiments, corn or sorghum-based diets were supplemented with increasing levels of synthetic amino acids up to the 5[superscript]th limiting amino acid. For nursery pigs, there were no main or interactive effects (P>0.05) of grain source or added amino acids which suggests that balancing up to the fifth limiting amino acid is possible in both sorghum- and corn-based diets with the use of crystalline amino acids without detrimental effects on nursery pig growth performance. For finishing pigs, balancing to the 5[superscript]th limiting AA using NRC (2012) suggested amino acid ratios in corn- or sorghum-based diets resulted in decreased ADG and G:F and pigs fed corn-based diets had greater G:F and IV than those fed sorghum. The second set of studies compared two new zinc sources to a diet containing pharmacological levels of ZnO on nursery pig growth performance. These studies demonstrated that increasing Zn up to 3,000 ppm Zn increased ADG and ADFI. Lower levels of the new zinc sources did not elicit similar growth performance as the high level of ZnO. The third set of studies compared increasing levels of different sources of corn oil to diets containing soy oil. In the first study, an oil source × level interaction was observed (P<0.05) for ADG, G:F and caloric efficiency; however in the second study that compared a different corn oil source there were no interactions observed. Overall, increasing the level of oil from either corn- or soy-oil improved feed efficiency similar to expectations. However, the data suggests that differences in performance can be observed between different corn oil sources derived from different locations. These studies show the benefits of adding either corn or soybean oil in late-phase nursery diets to improve performance, and cost and availability should dictate which source to use.

Master of Science / Department of Animal Sciences and Industry / Joel M. DeRouchey / Jason C. Woodworth / Two experiments using a total of 720 nursery pigs were used to determine the effects of Elarom SES, in-feed antibiotics, zinc, or copper on nursery pig growth performance and fecal consistency. Two experiments using a total of 1,534 nursery pigs were used to determine the effects of formaldehyde inclusion, lysine level, and synthetic amino acid inclusion on nursery pig performance, amino acid utilization, and gut microbial community. One experiment using a total of 300 nursery pigs were used to determine the effects of chlortetracycline (CTC) or a probiotic inclusion on nursery pig growth performance and antimicrobial susceptibility. Experiment 1 determined the effect of Elarom SES, in-feed antibiotics, or zinc on nursery pig performance and fecal consistency. The addition of Elarom SES or ZnO alone reduced ADG, but G:F was poorest when all three additives were fed in combination. Addition of in-feed antibiotics increased ADG and G:F throughout the study. Experiment 2 determined the effects of Elarom SES or copper inclusion on nursery pig performance and fecal consistency. The addition of Elarom SES or increasing copper did not provide consistent benefits in performance. In both experiments, there were no individual or overall treatment effects or treatment × day interactions observed for fecal consistency. Experiment 3 compared the effects of formaldehyde source and lysine level on nursery pig growth performance. Regardless of source or lys level, the inclusion of formaldehyde in nursery pig diets marginally reduced ADG and resulted in poorer G:F. Experiment 4 compared the effects of formaldehyde and synthetic amino acid inclusion level on nursery pig growth performance, amino acid utilization, and gut microbial community. The inclusion of Sal CURB in diets reduced ADG and ending BW while inclusion decreased ADFI. ADFI response was dependent on synthetic amino acid level in the diet. Sal CURB inclusion in diets reduced total and available lysine, but reduced bacterial microflora in treatment feed. Experiment 5 determined the effects of CTC or a probiotic on nursery pig performance and antimicrobial susceptibility. The addition of CTC to diets improved ADG, ADFI, and ending BW. The addition of Poultry Star improved ADFI and d 14 BW, but benefits did not carry throughout the study.

Master of Science / Department of Animal Sciences and Industry / Jim L. Nelssen / Two experiments evaluated the effects of feeding growth promoting alternatives, alone or in combination, on nursery pig performance in comparison to a common feed additive, carbadox. In Exp.1, 288 weaned pigs (Line 600 × 241; DNA, 5.36 kg) were used in a 42-d study. Pigs were allotted to 1 of 9 dietary treatments in pens of 4 at weaning in a randomized complete block design with 8 replications per treatment. Dietary treatments were arranged with a negative control diet with no dietary feed additive, a positive control with added carbadox or 7 treatments including added copper sulfate (CuSO₄; 0 vs. 125 ppm Cu) and added zinc oxide (ZnO; 0 vs. 3,000 ppm Zn from d 0 to 7 and 2,000 ppm Zn from d 7 to 28), essential oils from XTRACT 6930 at 0.91 kg/ton, Safman (yeast cell walls) at 0.23 kg/ton , Biosaf HR (yeast cells) at 0.68 kg/ton. These supplements were fed alone or in combination. From d 0 to 7 experimental diets were a pelleted diet and fed in a meal form from d 7 to 28, followed by a common corn-soybean meal-based diet from d 28 to 42. Essential oil blend (cinnamaldehyde) and yeast had no (P > 0.05) effect on ADG. Feeding carbadox or added trace minerals (Cu and Zn) improved ADG (P < 0.05) of nursery pigs compared to the control. Carryover effects from any of these dietary treatments on subsequent growth performance were not (P > 0.05) different. The use of added trace minerals Cu and Zn alone or in conjunction with either yeast or essential oil blend (cinnamaldehyde) results in ADG and G/F comparable to carbadox. In Exp. 2, 280 weaned pigs (Line 600 × 241; DNA, 5.18 kg) were used in a 35-d study. Pigs were allotted to 1 of 7 dietary treatments in pens of 5 at weaning in a randomized complete block design with 8 replications per treatment. Dietary treatments were arranged with a negative control diet with no dietary feed additive, a positive control with added carbadox or 5 treatments including added copper sulfate (CuSO₄; 0 vs. 125 ppm Cu) and added zinc oxide (ZnO; 0 vs. 3,000 ppm Zn from d 0 to 7 and 2,000 ppm Zn from d 7 to 35), and Victus® LIV (145 or 435 ppm). These supplements were fed alone or in combination (Cu/Zn and 145 ppm Victus® LIV or Cu/Zn and 435 ppm Victus® LIV. Diets were fed in meal form. Feeding carbadox, 145 ppm Victus® LIV or added trace minerals (Cu and Zn) improved ADG (P < 0.05) of nursery pigs compared to the control. In summary, under the conditions of these experiments, pigs fed zinc/copper, 145 ppm Victus® LIV or a combination of these had similar (P > 0.05) growth performance to pigs fed carbadox.

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.

Master of Science / Department of Animal Sciences and Industry / Joel DeRouchey / Seven experiments using a total of 2,997 nursery and finishing pigs were used to determine the effects of: 1) dietary wheat middlings (midds), dried distillers grains with solubles (DDGS), and NE diet formulation on nursery pig growth performance; 2) corn particle size, complete diet grinding, and diet form on finishing pig growth performance, and carcass characteristics, and 3) particle size, complete diet grinding, and diet form on nursery pig growth. Experiments 1-4 evaluated dietary wheat middlings at levels of up to 20% of the diet for 7 to 23 kg pigs. Increasing dietary midds decreased growth performance but mainly when 10% of more was added. Balancing diets containing 10 or 20% midds on a NE basis had no significant effects on performance compared with not adjusting for NE of the diet. In Exp. 5, the effects of decreasing particle size, complete diet grinding, and diet form were evaluated on finishing pig growth performance, and carcass characteristics. Diet form × portion ground interactions existed for ADG, ADFI, and HCW as grinding the complete diet in meal form was detrimental to performance but advantageous to performance when diets were fed in pelleted form. Reducing the particle size of corn improved G:F and caloric efficiencies. Pelleting the diet improved ADG, G:F, caloric efficiencies, HCW, and loin depth. Experiment 6 evaluated varying particle sizes, diet form, and complete diet grinding on nursery pig growth performance. Pigs fed pelleted diets had improved ADG, G:F, and caloric efficiencies. Fine grinding corn or the complete diet with high by-products diet decreased ADG, ADFI, G:F, and final BW. Experiment 7 evaluated varying particle sizes of corn and DDGS, diet form, and complete diet grinding on nursery pig growth performance. Pigs fed finely ground corn had decreased ADFI when the diet was fed in pellet form and more severe reductions in ADFI when diets were fed in meal form resulting in a diet form × corn particle size interaction. Pigs fed pelleted diets had decreased ADG, ADFI, G:F and final BW, but improved caloric efficiencies. Finely grinding corn decreased ADG, and feeding DDGS decreased ADG, ADFI, and NE caloric efficiency.

<p>Gastrointestinal health in the young pig is a constant challenge for the swine industry. Weaning introduces many stressors such as a new solid diet, being separated from their mother, new pen mates, transportation, and an entirely new environment. Therefore, this dissertation primarily focuses on research aiding the pig immediately post-weaning. In chapter 2, a developmental bacillus direct fed microbial (DFM) was added to nursery pig diets to evaluate its effects on pig growth and health in two 35-d experiments, both randomized complete block designs based on initial BW and sex. Experiment 1 used 376 weaned pigs (17.8 d of age; 5.99±0.18 kg initial BW) allotted to one of four diets. 1) Negative Control (NC; no antibiotics with pharmacological Zn or Cu), 2) NC+DFM 0.275x109 CFU, 3) NC+DFM 0.55x109 CFU, 4) NC+DFM 1.1x109 CFU. Experiment 2 used 420 weaned pigs (20.1 d of age; 6.11±0.34 kg initial BW) allotted to one of four diets: 1) Negative Control (NC; no antibiotics with pharmacological Zn or Cu), 2) NC+DFM 0.55x109 CFU, 3) NC+DFM 1.1x109 CFU, 4) NC+BioPlus 2B 1.1x109 CFU. Experiment 1; during week 1 there were no treatment effects. During week 3 ADFI (P=0.053) quadratically increased while G:F (P=0.028) quadratically decreased as DFM increased in the diet. During d21-35 of experiment 2, ADG (P=0.092) quadratically increased and G:F (P=0.014) quadratically decreased as DFM increased.  Overall, for Experiment 1, ADFI numerically increased (4.3%) with no increase in ADG, resulting in a quadratic decrease in G:F (P=0.010) as the DFM increased in the diet.  For Experiment 2, during week 1, DFM fed pigs tended to have linearly decreased ADFI (P=0.092) and linearly increase G:F (P=0.072). Pigs fed the Bioplus2B bacillus had greater ADFI (P=0.018) than the same dose of the experimental bacillus. During week 2 pigs fed the experimental bacillus at 1.1x109 CFU tended to have improved G:F (P=0.084) than the similar DFM concentration from, the Bioplus 2B. During week 4 ADG tended to linearly (P=0.057) improve with increasing DFM in the diet and the average of all DFMs tended to have improved ADG (P=0.075) over the NC. During week 5 ADFI linearly increased (P=0.029) as DFM increased in the diet and all DFM treatments had greater ADFI (P=0.009) than the NC.  During d 21-35 of experiment 2, DFM fed pigs had linearly increased ADG (P=0.04) and ADFI (0.090). All pigs fed DFM had improved ADG (P=0.068) and ADFI (P=0.032) compared to NC fed pigs. Summarizing these two studies, the DFM product had its greatest effect improving gain feed intake and efficiency during late nursery when simplest diets are fed.</p> <p>In chapter 3, Dacitic tuff breccia (DTB) and poultry by-products (PBP) were added to nursery pig diets to evaluate their effects on growth performance and jejunal characteristics in a 35 d experiment. PBP were added as a replacement for fishmeal and was expected to provide an increased immune challenge to the newly weaned pigs. DTB was added as a functional trace element source and was hypothesized to ameliorate some of the negative impacts of PBP on the gut. A randomized complete block design based on BW and sex was used. Newly weaned pigs (N=564, 20.1±1.2 d of age, 6.18±1.13 kg initial BW). allotted to four diets (15 replicates/treatment; 9 or 10 pigs/pen): 1) Control (C; no DTB or PBP), 2) C+DTB (0.5% inclusion), 3) C+PBP (4% chicken by-product meal + 2% feather meal – replacing fishmeal, corn, and synthetic amino acids in the C), 4) C+DTB+PBP. Phase 1-3 were each 7-d and Phase 4 was from d 21-35. One barrow/pen was harvested 11d post-weaning. Jejunal tissue and mucosa were collected for histological measures and gene expression. In week 2, pigs fed DTB tended to increase ADG (323 vs. 303 g/d; P=0.068) and ADFI (376 vs. 356 g/d; P=0.055) compared to pigs not fed DTB and pigs fed PBP tended to have increased ADG (P=0.093). In week 3 pigs fed PBP had reduced ADG (460 vs 483 g/d; P=0.011) and G:F (0.689 vs. 0.723; P<0.001), and there tended to be an interaction for G:F (P=0.083) with DTB improving G:F when fed in combination with PBP but reducing G:F in the control diet.  In week 4, feeding PBP decreased ADG (384 vs 415 g/d; P<0.01) and ADFI (629 vs 666 g/d; P<0.01) compared to pigs fed no PBP.  For Phase 4 (d21-35) pigs fed PBP had decreased ADG (479 vs 497 g/d; P=0.041) and tended to have reduced ADFI (P=0.092) compared to pigs fed no PBP. Overall (d 0-35), there were no significant differences among treatments in pig growth performance.   Pigs fed PBP had increased jejunal expression of interferon-alpha (P=0.041) and interleukin-10 (P=0.037) and tended to have increased expression of claudin-1 (P=0.076).  Pigs fed DTB tended to have decreased jejunal expression of interferon-gamma (P=0.079).  Jejunal gene expression of tumor necrosis factor-alpha and nuclear factor kappa-beta did not differ among treatments. In conclusion, DTB improved nursery pig growth performance early and pigs fed PBP had decreased ADG and feed efficiency late in the nursery period. Feeding PBP had minimal effects on jejunum architecture but increased the gut immune response.</p> <p>Chapter 4 focuses on weaning age in addition to dietary treatments. Changes in weaning age and diet complexity can impact pig growth post-weaning. 432 weanling gilts and barrows (Topigs Duroc Ⅹ (US York X Landrace)) from the same farrowing group were utilized for a 30 or 35 d growth trial to compare early (EW) versus late weaning (LW) and high or low levels of specialty proteins in nursery diets. 216 pigs were EW (18 or 19 d, avg. age=18.4 days, avg. BW=5.96 kg) and 216 pigs were LW 5 days later (24, 25 or 26 d, avg. age=24.6 d, avg. BW=7.50 kg). At weaning pigs were blocked by weaning age, BW, sex and litter, and randomly allotted to 48 pens with 9 pigs/pen. Pigs at each weaning age were fed a High Complexity (HC) or a Low Complexity (LC) diet. The trial was conducted as a 2X2 factorial design: 1) EW+HC; 2) EW+LC; 3) LW+HC; 4) LW+LC. Pigs and feeders were weighed on d 0, 7, 14, 21, 28, and 35 for EW, and on d 0, 7, 14, 21, 28, and 30 for LW.  LW pigs had improved ADG and ADFI from d 0-7, 7-14, 14-21, and the final week of the nursery (P<0.05). G:F decreased for LW pigs from d 21-28 (P<0.01) compared to EW pigs, however for the overall nursery trial LW pigs had increased G:F (P=0.01). LW pigs had increased overall nursery ADG vs EW pigs (452.5 g/d vs 400 g/d; P<0.01). End of nursery BW was greater for LW vs EW pigs (21.70 kg vs 20.74 kg; P=0.001).  There was a weight block by weaning age interaction, EW heavy pigs had lower ADG compared to LW heavy pigs, however when comparing light weight pigs, the EW light pigs had improved ADG compared to LW light weight pigs (P=0.017). EW pigs were lighter at market (approximately d146 of age) compared to LW pigs (120.78 vs 124.16 kg; P=0.014). An interaction between weaning age, nursery diet, and sex (P<0.07) was observed for market weight, EW barrows fed LC diets were lighter at market (120.77 kg) than EW barrows fed HC diets (126.54 kg).  Whereas for LW barrows fed LC had higher market weights (130.04 kg) than LW barrows fed HC diets (127.59 kg). A similar, but non-significant pattern was observed for gilts. Weaning age and feeding pigs the correct diet for their age in the nursery can have a lifelong effect on the pig. </p> <p>In conclusion, feeding a DFM containing bacillus licheniformis did not impact nursery pig growth performance early in the nursery period. From d21-35 ADG and ADFI was improved in both experiments 1 and experiment 2. While the growth results were sporadically improved throughout the nursery period, the DFM’s greatest effect was it ability to improve ADFI. The improvement in the late nursery phase may be due to the need for the DFM to establish itself in the GIT. DTB tended to improve ADG and ADFI in week 2 of the nursery period, however there were no differences for growth overall. PBP reduced ADG in week 3 of the nursery period, as well as reduced ADG and ADFI in week 4 of the nursery. While there were differences in individual weeks of the trial there were no overall differences in growth performance. However, when looking at gene expression in the jejunum at d11 post-weaning, there was an increase in IFN-α and IL-10 in pigs fed PBP. In pigs fed DTB there was a decrease in IFN-γ jejunal gene expression as well. Feeding a high complexity and low complexity diet had no impact on the nursery pigs growth performance, in hindsight the low complexity diet was perhaps not low enough in specialty proteins. When comparing weaning age, pigs weaned later had increased ADG and ADFI from d0-21 post-weaning. For the overall nursery performance, LW pigs had a higher ADG, and ended the nursery period 0.96 kg heavier than the EW pigs. Comparing pigs of similar bodyweight at weaning, EW pigs were 1.5 kg heavier than LW pigs at the end of the nursery period, but the LW pigs were more feed efficient. There was a weight block by weaning interaction in this trial, as the heaviest LW pigs had higher ADG compared to the heaviest EW pigs. However, when looking at the lightest pigs, the EW pigs outperformed the LW pigs. Looking at market weights of each age group, LW pigs were 3.5 kg heavier on average at d146 of age. Although there was not a difference in diet found in the nursery phase, interestingly there were interactions discovered between treatments at market weight. Barrows are more sensitive to nursery diet compared to gilts, as LW barrows fed the low complexity diet performed better than the LW high complexity fed barrows. EW barrows were heavier at market when fed the high complexity diet, compared to EW barrows fed the low complexity diet. This shows that while the diet didn’t appear to have an impact in the nursery, feeding the pig the proper diet for their age has a lifelong impact on the pig.</p>

<p dir="ltr">Maximizing growth performance in swine production, in the face of larger litter sizes and potential milk limitations, is crucial. This thesis explores the impact of various nutritional strategies, including creep feeding, dietary sweeteners, glutamine supplementation, sensory additives, and low crude protein diets on piglet lactation and nursery growth performance. Data in this thesis were analyzed using the GLM procedure in SAS 9.4. In the first study (Chapter 2), fifty-one sows and their litters (17/creep treatment) were used to evaluate the effects of creep feeding and nursery diets on piglet growth. Ten days prior to weaning, litters were assigned to three treatments: control creep feed (CF-CON), CON + garlic-based flavoring (50 ppm Allium XL; CF-ALL-XL), and no creep feed (NO-CF). Post-weaning, 506 pigs were allotted to either control (CON) or flavored (ALL-XL) nursery diets in a 3x2 factorial design with 10 pens/treatment, each containing 7 or 8 pigs. Nursery dietary treatments were fed in phases 1 and 2, followed by common phase 3 and 4 diets. Weekly body weights (BW) and feed intake were recorded to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F). Creep feeding treatment during lactation did not affect litter or piglet BW gain pre-weaning. ALL-XL did not affect total creep feed intake (CON=114 g/pig vs. ALL-XL=110 g/pig). Providing CF-CON or CF-ALL-XL during lactation increased ADFI on d 2, 3, and 4 post-weaning (P<0.013). Pigs fed either CF-CON or CF-ALL-XL increased week 1 nursery ADFI (8.8%; P<0.02), numerically increased ADG (5.2%), and greater d7 BW (P=0.055). Overall (d0-35), pigs fed CF-CON had greater ADG (P<0.05) and ADFI (P<0.05) than CF-ALL-XL with No-CF pigs being intermediate in ADG and greater ADFI (P<0.05) than CF-ALL-XL fed pigs. Final BW (P<0.05) was greater for CF-CON fed pigs than CF-ALL-XL fed pigs with No-CF pigs being intermediate (23.5 kg, 23.0 kg, 23.3 kg, respectively). Nursery dietary flavoring treatment (CON vs ALL-XL) did not affect post-weaning ADG, ADFI, or G:F at any point during the study (P>0.12). In the second study (Chapter 3), fifty-seven sows and their litters were used to test the effects of creep feed and a dietary sweetener (Taktik) on piglet lactation and nursery performance in low lactose diets. Six days prior to weaning, litters were assigned to either control creep feed (CF-CON), control + sweetener (50 ppm Taktik; CF-TAK), or no creep (No-CF). Post-weaning, 550 pigs were assigned to control (CON) or sweetened (Taktik, 50 ppm; TAK) nursery diets in a 3x2 factorial design with 10 nursery pens per treatment, each containing 9 or 10 pigs. There were no significant differences in litter weight, weight gain, or piglet weight during lactation due to CF treatment. However, CF-CON pigs tended to have higher litter feed intake (P=0.060) and ADFI per pig (P=0.059) during lactation. During the first week post-weaning, CF-CON pigs had higher ADFI (P<0.05), ADG (P<0.05), and d7 BW compared to CF-Tak pigs and No-CF pigs. During d 6-14 CF-CON pigs had greater ADG (P<0.05) and ADFI (P<0.05) than CF-Tak pigs and the No-CF pigs tended (P<0.10) to also have greater ADFI than CF-Tak pigs. Overall (d0-34), CF-CON pigs had higher ADG and ADFI compared to CF-Tak pigs (P<0.05) and No-CF pigs tended (P<0.10) to have greater ADG than CF-Tak pigs. There were no significant differences (P>0.15) in ADG, ADFI, or G:F between CON and TAK nursery diet treatments. In the third study (chapter 4), thirty-one sows and their litters were utilized to test the effects creep feed and nursery diets supplemented with or without glutamine on lactation and nursery performance as well as creep feeder type impacts. During lactation there were three dietary treatments: control creep feed (CF-CON), control creep feed + glutamine (0.40%; CF-GLUT), or no creep feed (No-CF). There were two creep feeder types: plastic (PLAST) or stainless steel (SS), that were evenly distributed between the creep feed treatments. Post-weaning 270 pigs were allotted to either control (CON) or control + glutamine (0.40%; GLUT) nursery diets with pigs previously given or not glutamine creep feed continuing to receive similar glutamine treatment in the nursery period and the No-CF pigs being evenly split to CON and GLUT nursery diets. Litter weights and creep feed intake were recorded on d -7 and 0 (weaning). During nursery there were 7 pens/treatment with 6 or 7 pigs/pen, blocked by initial BW within creep treatment. Neither glutamine creep feeding treatments affected litter or piglet weaning weights (P>0.24). Pigs given creep feed during lactation had increased ADFI during the first week post-weaning (P<0.03) but did not result in greater overall nursery growth performance. The inclusion of glutamine in creep feed or nursery diets did not improve growth performance at any point during the study. In the fourth study (chapter 5), 416 weanling pigs were used to test the effects of a sensory feed additive (SA; Luctamax) on control (CON) and low crude protein (LCP) nursery diets in a 2x2 factorial design (CON, CON+SA, LCP, LCP+SA) with 15 replicate pens of 6 or 7 pigs/pen. Decreased dietary CP (4%) was achieved by removing or decreasing fish meal and soy concentrate in phases 1 and 2 and reducing soybean meal in phase 3 and adding synthetic amino acids to maintain amino acid ratios (NRC 2012). The SA was included at 0.1% in Phase 1 and 2 diets and 0.05% in Phase 3 diets. During PH1 (d 0-7) pigs receiving the CON diets tended (P=0.065) to have a higher G:F compared to pigs receiving LCP diets. For the remainder of this study there were consistent interactions between dietary CP and SA. When SA was added to the LCP diet ADFI slightly increased but when SA was added to CON diet ADFI decreased and these changes in feed intake often led to similar dietary interactions in ADG. During PH2 (d 7-21), pigs fed CON or LCP+SA diets had higher ADFI (P=0.032) and tended to have a higher ADG (P=0.094) but reduced G:F (P=0.100) compared to pigs fed CON+SA or LCP diets. In PH3 (d 21-36), pigs fed CON or LCP+SA diets had a higher ADG (P=0.027) and ADFI (P=0.011) compared to CON+SA or LCP diets. During PH3 pigs fed LCP diets had higher ADFI (P<0.001) but reduced G:F (P<0.0001) than pigs fed CON diets. Overall (d0-36), pigs fed CON or LCP+SA diets had higher ADFI (P=0.016) and tended to have a higher ADG (P=0.059) but reduced G:F (P=0.067) compared to pigs fed CON+SA or LCP diets. For the entire nursery period, pigs fed CON diets had a higher G:F (P<0.001) compared to pigs fed LCP diets, while LCP pigs tended to have a higher ADFI (P=0.054) compared to CON pigs. Feeding LCP diets during PH2 decreased feed costs/kg of gain but feed cost were increased (P<0.0001) during PH3 when LCP diets were fed compared to CON diets. These studies highlight the potential benefits and limitations of various nutritional strategies in enhancing piglet growth performance. Creep feeding, dietary sweeteners, glutamine supplementation, sensory additives, and low crude protein diets can potentially influence post-weaning performance, but their effectiveness depends on specific conditions and formulations. Further research is needed to optimize these strategies for improved swine production efficiency.</p>

Doctor of Philosophy / Animal Sciences and Industry / Michael D. Tokach / Three experiments using 2,385 pre-weaned pigs, growing pigs, and sows were performed in addition to a meta-analysis and industry survey. Experiment 1 tested the effects of sow vitamin D supplementation from vitamin D₃ (low, medium, or high) or 25OHD₃ (same IU equivalency as the medium level of vitamin D₃) on maternal performance, neonatal pig bone and muscle characteristics, subsequent pre-weaned pig performance and serum 25OHD₃ with only differences in serum 25OHD₃ being impacted. In the second experiment a subsample of pigs weaned from the maternal portion of the study were used in a split-plot design and fed 2 different forms of vitamin D in the nursery and growth performance was evaluated until the pigs reached market weight. Overall, the nursery vitamin D treatments did not impact growth; however, pigs from sows fed the medium level of vitamin D₃ performed better after weaning compared to pigs from sows fed the low or the high level of vitamin D₃, and serum 25OHD₃ was altered based on maternal and nursery vitamin D supplementation. In the third experiment, finishing pigs were initially provided 2 different floor space allowances (0.64 or 0.91 m²) and pigs initially provided 0.64 m² were subject to 1 of 3 marketing strategies which removed the heaviest pigs from the pen in order to provide additional floor space to the pigs remaining in the pen. Overall, pigs initially provided more floor space had improved ADG and ADFI, but increasing the number of marketing events increased ADG of the pigs remaining in the pen following market events. The meta-analysis suggested that a multi-term empirical model using random effects to account for known error and weighted observations to account for heterogeneous experimental designs and replication provided models that best fit the database. Also, the meta-analysis concluded that floor space allowance does influence ADG, ADFI, and G:F and BW of the pig can alter the floor space response. Finally, the vitamin and trace mineral survey suggested that a wide range of supplementation practices are used in the swine industry but most production systems supplement micronutrients above the basal requirement estimates of the animals.