S.S. Dritz

Kansas State University, Манхэттен, Kansas, United States

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Publications (612)345.12 Total impact


  • No preview · Conference Paper · Feb 2016
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    ABSTRACT: Finishing pigs (n = 320) were used in a 35-day study to determine the effects of ractopamine-HCl (RAC) and supplemental Zinc (Zn) level on loin eye area (LEA) and gene expression. Pens were randomly allotted to the following treatments for the final 35 days on feed: a corn-soybean meal diet (CON), a diet with 10 ppm RAC (RAC+), and RAC diet plus added Zn at 75, 150, or 225 ppm. Sixteen pigs per treatment were randomly selected for collection of serial muscle biopsies and carcass data on day 0, 8, 18, and 32 of the treatment phase. Compared to CON carcasses, RAC+ carcasses had 12.6% larger (P = 0.03) LEA. Carcasses from RAC diets with added Zn had a tendency for increased (quadratic, P < 0.10) LEA compared to the RAC+ carcasses. Compared to RAC+ pigs, relative expression of IGF1 decreased with increasing levels of Zn on day 8 and 18 of treatment, but expression levels were similar on day 32 due to Zn treatments increasing in expression while the RAC+ treatment decreased (Zn quadratic × day quadratic, P = 0.04). A similar trend was detected for the expression of β1-receptor where expression levels in the RAC+ pigs were greater than Zn supplemented pigs on day 8 and 18 of the experiment, but the magnitude of difference between the treatments was reduced on day 32 due to a decrease in expression by RAC+ pigs and an increase in expression by the Zn pigs (Zn quadratic × day quadratic, P = 0.01). The ability of Zn to prolong the expression of these two genes may be responsible for the tendency of Zn to increase LEA in RAC supplemented pigs.
    Full-text · Article · Jan 2016 · Animal Biotechnology
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    ABSTRACT: A total of 255 nursery pigs (PIC 327 × 1050, initially 13.8 lb and 3 d postweaning) were used in a 28-d growth trial to determine the minimum standardized ileal digestible (SID) tryptophan:lysine ratio for 13-to 21-lb pigs. A 2-phase diet series was used with treatment diets fed from d 0 to 14 and a common diet fed from d 14 to 28. The 6 SID tryptophan:lysine ratios were 14.7, 16.5, 18.4, 20.3, 22.1, and 24.0%. Pigs were allotted on d 3 after weaning with 6 or 7 pigs per pen and 7 replications per treatment. Weight and feed disappearance were determined on d 0, 7, 14, 21, and 28 to calculate ADG, ADFI, and F/G. From d 0 to 14, increasing SID tryptophan:lysine ratio improved ADG (linear, P = 0.02) and generated a tendency for improved ADFI and F/G (linear, P = 0.06 and quadratic, P = 0.08, respectively). Although ADG and ADFI were linear, the greatest response was observed at a SID tryptophan:lysine ratio of 20.3%. From d 14 to 28, when the common diet was fed, ADFI increased (linear, P = 0.05) as SID tryptophan:lysine ratio increased in the previous period, but no differences were found in ADG and F/G. For the overall trial (d 0 to 28), ADG and ADFI increased (linear, P = 0.02 and P = 0.03, respectively) with increasing SID tryptophan:lysine ratio, with the greatest response observed at 20.3%. Feed/gain was unaffected by SID tryptophan:lysine ratio. Thus, the optimal SID tryptophan:lysine ratio for 13-to 21-lb nursery pigs in this study appears to be at least 20.3%. This ratio is greater than the minimum ratio currently using in many practical diet formulations in the United States, indicating an importance of tryptophan in diet formulation of low-protein amino acid-fortified diets in the swine industry.
    Full-text · Article · Oct 2015 · Journal of Animal Science
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    ABSTRACT: Three experiments were conducted to determine the effects of feeder adjustment and diet form on growth performance of nursery (Exp. 1 and 2) and finishing (Exp. 3) pigs. Treatments were arranged as a 2 × 3 factorial with the main effects of feeder adjustment and diet form. The 2 feeder adjustments were a narrow and wide feeder adjustment (minimum gap opening of 1.27 and 2.54 cm, respectively). The 3 diet forms were meal, poor-quality pellets (70% pellets and 30% fines for Exp. 1 and 2 and 50% pellets and 50% fines for Exp. 3), and screened pellets with minimal fines (3 to 10%). In Exp. 1, 210 pigs (initially 11.9 kg BW) were used in a 21-d trial with 7 pigs per pen and 5 pens per treatment. No feeder adjustment × diet form interactions were observed. There were no differences in ADG, ADFI, or G:F due to feeder adjustment. Pigs fed the meal diet had increased ( < 0.05) ADG and ADFI compared with pigs fed the poor-quality or screened pellets. Pigs fed meal or poor-quality pellets had decreased ( < 0.05) G:F compared with pigs fed screened pellets. In Exp. 2, 1,005 nursery pigs (initially 14.1 kg BW) were used in a 28-d trial with 26 to 28 pigs per pen and 6 pens per treatment. Pigs fed from the narrow feeder adjustment had decreased ( < 0.05) ADG and ADFI compared with pigs fed from the wide adjustment with no differences in G:F. Pigs fed the meal diet had decreased ( < 0.05) ADG compared with pigs fed poor-quality or screened pellets. Pigs fed meal or poor-quality pellets had decreased ( < 0.05) G:F compared with pigs fed screened pellets. In Exp. 3, 246 pigs (initially 56.8 kg BW) were used in a 69-d trial with 5 pens per treatment and 6 or 7 pigs per pen. Overall, ADFI decreased ( < 0.05) and G:F increased ( < 0.05) for pigs fed from the narrow adjusted feeders compared with the wide adjustment with no differences in ADG. Overall, pigs fed meal diets tended to have decreased ( < 0.10) ADG and had decreased ( < 0.05) G:F compared with pigs fed screened pellets; ADG and G:F in those fed poor-quality pellets were intermediate. Feeding meal or poor-quality pellets increased ( < 0.05) ADFI compared with pigs fed screened pellets. In conclusion, feeding nursery pigs from a wide feeder gap may increase ADG and ADFI with no negative effects on G:F. For finishing pigs, reducing feeder gap reduced feed disappearance and improved G:F. In all experiments, the greatest G:F improvements from pelleting were observed when the percentage of fines was minimized.
    No preview · Article · Oct 2015 · Journal of Animal Science
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    ABSTRACT: Two experiments were conducted to determine the effects of pelleting, diet type (fat and fiber level), and withdrawal of dietary fiber and fat before marketing on growth performance, carcass yield, and carcass fat iodine value (IV) of finishing pigs. Each experiment used 288 pigs (initially 49.6 and 48.5 kg BW, respectively) with 6 dietary treatments arranged as 2 × 3 factorials. In Exp. 1, main effects were diet form (meal vs. pellet) and diet regimen. Diet regimens were 1) a low-fiber, low-fat (corn-soybean meal) diet from d 0 to 81, 2) a high-fiber, high-fat (30% dried distillers grains with solubles [DDGS] and 19% wheat middlings [midds]) diet from d 0 to 64 followed by the low-fiber, low-fat diet from d 64 to 81 (fiber and fat withdrawal), and 3) the high-fiber, high-fat diet fed from d 0 to 81. Pigs fed pelleted diets had increased ( < 0.05) ADG and G:F compared with those fed meal diets. Pigs fed pelleted diets had increased belly fat IV (2.9 mg/g) compared with those fed meal diets, with a greater increase when fed high-fiber, high-fat diets throughout the entire study (interaction, < 0.05). Pigs fed the low-fiber, low-fat diet throughout had increased ( < 0.001) G:F compared with pigs fed the other 2 treatments. Pigs fed low-fiber, low-fat diets throughout the study or pigs withdrawn from high-fiber, high-fat diets had increased ( < 0.001) carcass yield compared with pigs fed high-fiber, high-fat diets throughout. In Exp. 2, treatment main effects were diet form (meal vs. pellet) and diet type (corn-soybean meal-based control, the control with 30% DDGS and 19% midds, or the control diet with 3% corn oil). The diet containing corn oil was calculated to produce carcass fat IV similar to diets containing DDGS and midds. Overall, pigs fed pelleted diets had increased ( < 0.05) ADG, G:F, and belly fat IV (1.3 mg/g) compared with those fed meal diets. Pigs fed the diets containing DDGS and midds had decreased ( < 0.05) ADG, carcass yield, and HCW compared with pigs fed the control or corn oil diets and decreased ( < 0.001) G:F compared with pigs fed added corn oil. Belly IV was greatest ( < 0.001) for pigs fed diets with DDGS and midds and lowest for pigs fed the control diet, with pigs fed the corn oil diets intermediate. In conclusion, pelleting diets improves pig ADG (approximately 3%) and G:F (approximately 6%); however, a novel finding of this study is that pelleting diets fed to finishing pigs also increases belly fat IV.
    Full-text · Article · Oct 2015 · Journal of Animal Science
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    ABSTRACT: A total of 210 pigs were used in a 28-d growth study to evaluate the effects of feeding the combination antibiotic neomycin and oxytetracycline (Neo-Terra), different rates of BIOSAF yeast (0.15% or 0.3%), and the combination of Neo-Terra and BIOSAF in nursery diets. Overall, pigs fed the diet containing both Neo-Terra and 0.15% BIOSAF had greater ADG and ADFI than did pigs fed the control diet and pigs fed either concentration of BIOSAF alone (P<0.05). Furthermore, over the entire trial, pigs fed the diet containing both Neo-Terra and BIOSAF also tended to have greater ADG and ADFI than did pigs fed only Neo-Terra (P = 0.15). Pigs fed Neo-Terra had greater ADG and ADFI than did pigs fed the control diet and the diet containing 0.15% BIOSAF, but both ADG and ADFI were similar between pigs fed Neo-Terra and pigs fed 0.3% BIOSAF. Whereas BIOSAF fed alone did not significantly improve growth performance over that of control pigs, pigs fed the diet combining both Neo-Terra and 0.15% BIOSAF had a 16% improvement in ADG, compared with that of pigs fed the control diet, and had a trend for an improvement in ADG, compared with that of pigs fed the diet containing Neo-Terra without added yeast. Thus, in nursery settings where Neo-Terra will be added, addition of 0.15% BIOSAF to diets could enhance growth performance. The overall growth performance of pigs fed 0.3% BIOSAF yeast was intermediate to that of pigs fed the control diet and pigs fed the diet containing Neo-Terra. Additional research will be required to determine definitively if a rate at, or close to, 0.3% BIOSAF can be added to nursery diets to approach growth performance observed with Neo-Terra.
    Full-text · Conference Paper · Sep 2015
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    ABSTRACT: Four experiments were conducted to ascertain the effects of hydrothermal treatment and sodium metabisulfite (SMB) on deoxynivalenol (DON)-contaminated corn dried distillers grains with solubles (DDGS). Experiment 1 evaluated SMB and heat (autoclaving) on high-DON DDGS (20.6 mg/kg). Six levels of SMB were tested: 0.0% (control), 0.5%, 1%, 2.5%, 5%, and 5% with 100 mL/kg distilled water. Autoclaving after 1 h at 121 °C alone elicited a 9.8% reduction in DON, whereas an 82% reduction was achieved when 5% SMB was added before autoclaving. Experiment 2 tested pelleting high-DON DDGS with SMB. Four batches of DDGS (20.5 mg/kg DON) were tested: 0 (control), 1.0, 2.5, and 5.0% SMB. Pelleted samples were collected at conditioning temperatures of 66 and 82 °C and retention times of 30 and 60 s within temperature. Pelleting conditions had no effect on DON levels, but as SMB inclusion increased in pelleted DDGS, DON levels were reduced (quadratic; P < 0.001). Experiments 3 and 4 evaluated pelleting and SMB on nursery pig growth. Both trials were arranged in a 2 × 3 + 1 factorial with 5 replicate pens per treatment. In Exp 3, 987 pigs (13.0 ± 0.2 kg) were used with main effects of (1) diet form: meal or pellet and (2) SMB level: Negative Control (NC), NC + 0.25% SMB, or NC + 0.50% SMB. Negative Control diets were formulated to contain 3 mg/kg DON. Treatment 7 was a Positive Control (P C; < 0.5 mg/kg DON) fed in meal form. Pigs fed high-DON diets had reduced (P < 0.001) ADG and ADFI, but pelleting improved (P < 0.001) ADG and G:F. Adding SMB increased (linear; P < 0.03) ADG and tended to increase (P < 0.10) ADFI. In Exp 4, 1180 pigs (11.1 ± 0.32 kg) were used with main effects of (1) diet form: meal or pellet and (2) DDGS source: PC (< 0.5 mg/kg DON), NC (5 mg/kg DON), or NC + DDGS pelleted and crumbled before mixing into the final diet. In meal form, treatment 7 included 2.5% SMB prior to pelleting DDGS (final diet contained 0.77% SMB). Overall, a 2-way interaction (P < 0.04) was observed within NC diets where pelleting the final diet improved G:F by a greater margin in high-DON diets than when the DDGS was pelleted, crumbled, and re-pelleted. DON reduced (P < 0.002) ADG and ADFI, and pelleting the diet improved (P < 0.01) ADG and G:F. Including SMB prior to pelleting DON-contaminated DDGS increased (P < 0.01) ADG and ADFI. Using SMB combined with thermal processing can mitigate DON effects in diets for nursery pigs.
    Full-text · Article · Sep 2015 · Animal Feed Science and Technology
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    ABSTRACT: Heavy metals, such as copper, are increasingly supplemented in swine diets as an alternative to antibiotics to promote growth. Enterococci, a common gut commensal, acquire plasmid-borne, transferable copper resistance (tcrB) gene-mediated resistance to copper. The plasmid also carried resistance genes to tetracyclines and macrolides. The potential genetic link between copper and antibiotic resistance suggests that copper supplementation may exert a selection pressure for antimicrobial resistance. Therefore, a longitudinal study was conducted to investigate the effects of in-feed copper, chlortetracycline, and tylosin alone or in combination on the selection and co-selection of antimicrobial-resistant enterococci. The study included 240 weaned piglets assigned randomly to 6 dietary treatment groups: control, copper, chlortetracycline, tylosin, copper and chlortetracycline, and copper and tylosin. Feces were collected before (day 0), during (days 7, 14, 21), and after (days 28 and 35) initiating treatment, and enterococcal isolates were obtained from each fecal sample and tested for genotypic and phenotypic resistance to copper and antibiotics. A total of 2592 enterococcal isolates were tested for tcrB by polymerase chain reaction. The overall prevalence of tcrB-positive enterococci was 14.3% (372/2592). Among the tcrB-positive isolates, 331 were Enterococcus faecium and 41 were E. faecalis. All tcrB-positive isolates contained both erm(B) and tet(M) genes. The median minimum inhibitory concentration of copper for tcrB-negative and tcrB-positive enterococci was 6 and 18 mM, respectively. The majority of isolates (95/100) were resistant to multiple antibiotics. In conclusion, supplementing copper or antibiotics alone did not increase copper-resistant enterococci; however, supplementing antibiotics with copper increased the prevalence of the tcrB gene among fecal enterococci of piglets.
    No preview · Article · Aug 2015 · Foodborne Pathogens and Disease
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    ABSTRACT: Two experiments were conducted to estimate the standardized ileal digestible (SID) Trp:Lys ratio requirement for growth performance of nursery pigs. Experimental diets were formulated to ensure that lysine was the second limiting AA throughout the experiments. In Exp. 1 (6 to 10 kg BW), 255 nursery pigs (PIC 327 × 1050, initially 6.3 ± 0.15 kg, mean ± SD) arranged in pens of 6 or 7 pigs were blocked by pen weight and assigned to experimental diets (7 pens/diet) consisting of SID Trp:Lys ratios of 14.7%, 16.5%, 18.4%, 20.3%, 22.1%, and 24.0% for 14 d with 1.30% SID Lys. In Exp. 2 (11 to 20 kg BW), 1,088 pigs (PIC 337 × 1050, initially 11.2 kg ± 1.35 BW, mean ± SD) arranged in pens of 24 to 27 pigs were blocked by average pig weight and assigned to experimental diets (6 pens/diet) consisting of SID Trp:Lys ratios of 14.5%, 16.5%, 18.0%, 19.5%, 21.0%, 22.5%, and 24.5% for 21 d with 30% dried distillers grains with solubles and 0.97% SID Lys. Each experiment was analyzed using general linear mixed models with heterogeneous residual variances. Competing heteroskedastic models included broken-line linear (BLL), broken-line quadratic (BLQ), and quadratic polynomial (QP). For each response, the best-fitting model was selected using Bayesian information criterion. In Exp. 1 (6 to 10 kg BW), increasing SID Trp:Lys ratio linearly increased (P < 0.05) ADG and G:F. For ADG, the best-fitting model was a QP in which the maximum ADG was estimated at 23.9% (95% confidence interval [CI]: [<14.7%, >24.0%]) SID Trp:Lys ratio. For G:F, the best-fitting model was a BLL in which the maximum G:F was estimated at 20.4% (95% CI: [14.3%, 26.5%]) SID Trp:Lys. In Exp. 2 (11 to 20 kg BW), increasing SID Trp:Lys ratio increased (P < 0.05) ADG and G:F in a quadratic manner. For ADG, the best-fitting model was a QP in which the maximum ADG was estimated at 21.2% (95% CI: [20.5%, 21.9%]) SID Trp:Lys. For G:F, BLL and BLQ models had comparable fit and estimated SID Trp:Lys requirements at 16.6% (95% CI: [16.0%, 17.3%]) and 17.1% (95% CI: [16.6%, 17.7%]), respectively. In conclusion, the estimated SID Trp:Lys requirement in Exp. 1 ranged from 20.4% for maximum G:F to 23.9% for maximum ADG, whereas in Exp. 2 it ranged from 16.6% for maximum G:F to 21.2% for maximum ADG. These results suggest that standard NRC (2012) recommendations may underestimate the SID Trp:Lys requirement for nursery pigs from 11 to 20 kg BW.
    No preview · Article · Jul 2015 · Journal of Animal Science

  • No preview · Article · Jun 2015 · The Professional Animal Scientist
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    ABSTRACT: Data from 41 trials with multiple energy levels (285 observations) were used in a meta-analysis to predict growth performance based on dietary NE concentration. Nutrient and energy concentrations in all diets were estimated using the NRC ingredient library. Predictor variables examined for best fit models using Akaike information criteria included linear and quadratic terms of NE, BW, CP, standardized ileal digestible (SID) Lys, crude fiber, NDF, ADF, fat, ash, and their interactions. The initial best fit models included interactions between NE and CP or SID Lys. After removal of the observations that fed SID Lys below the suggested requirement, these terms were no longer significant. Including dietary fat in the model with NE and BW significantly improved the G:F prediction model, indicating that NE may underestimate the influence of fat on G:F. The meta-analysis indicated that, as long as diets are adequate for other nutrients (i.e., Lys), dietary NE is adequate to predict changes in ADG across different dietary ingredients and conditions. The analysis indicates that ADG increases with increasing dietary NE and BW but decreases when BW is above 87 kg. The G:F ratio improves with increasing dietary NE and fat but decreases with increasing BW. The regression equations were then evaluated by comparing the actual and predicted performance of 543 finishing pigs in 2 trials fed 5 dietary treatments, included 3 different levels of NE by adding wheat middlings, soybean hulls, dried distillers grains with solubles (DDGS; 8 to 9% oil), or choice white grease (CWG) to a corn-soybean meal-based diet. Diets were 1) 30% DDGS, 20% wheat middlings, and 4 to 5% soybean hulls (low energy); 2) 20% wheat middlings and 4 to 5% soybean hulls (low energy); 3) a corn-soybean meal diet (medium energy); 4) diet 2 supplemented with 3.7% CWG to equalize the NE level to diet 3 (medium energy); and 5) a corn-soybean meal diet with 3.7% CWG (high energy). Only small differences were observed between predicted and observed values of ADG and G:F except for the low-energy diet containing the greatest fiber content (30% DDGS diet), where ADG and G:F were overpredicted by 3 to 6%. Therefore, the prediction equations provided a good estimation of the growth rate and feed efficiency of growing-finishing pigs fed different levels of dietary NE except for the pigs fed the low-energy diet containing the greatest fiber content.
    No preview · Article · Jun 2015 · Journal of Animal Science
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    ABSTRACT: A total of 288 finishing pigs (PIC TR4 × 1050, initially 129.6 lb) were used in a 73-d study to determine the effects of increasing sorghum dried distillers grains with solu-bles (DDGS) in sorghum-or corn-based diets on finishing pig growth performance, carcass characteristics, and fat quality. Pigs were allotted to 1 of 6 dietary treatments in a completely randomized design based on initial pen weight. The dietary treatments included sorghum-based diets with sorghum DDGS included at 0, 15, 30, or 45%; a sorghum-based diet with 30% corn DDGS; and a corn-based diet with 30% corn DDGS. Overall (d 0 to 73), increasing sorghum DDGS from 0 to 45% reduced (linear, P < 0.04) ADG and ADFI. Increasing sorghum DDGS increased (linear, P < 0.01) backfat iodine value (IV), and fat color became less red (a*; linear, P < 0.01) and tended to be less yellow (b*; linear, P < 0.06). No differences were observed in growth perfor-mance among pigs fed corn-or sorghum-based diets with 30% corn DDGS along with similar carcass characteristics, backfat, loin depth, fat-free lean index (FFLI), HCW, carcass yield, and backfat IV. Pigs fed sorghum-based diets with either 30% sorghum or corn DDGS had similar ADG, ADFI, and F/G, as well as similar carcass character-istics; however, pigs fed 30% sorghum DDGS had decreased (P < 0.01) backfat IV and fat color that was more white (L*) and less yellow (b*) in color than pigs fed 30% corn DDGS. We observed similar ADG, ADFI, and F/G, as well as carcass characteristics, for pigs fed corn-or sorghum-based diets with 30% DDGS. Backfat IV was greater in pigs fed increasing DDGS, with a notable increase in pigs fed corn DDGS compared with those fed sorghum DDGS. Feeding sorghum DDGS produces pork fat that is lighter in color and less yellow than those fed corn DDGS, which may have an important role in pork export markets.
    Full-text · Article · Jun 2015 · Journal of Animal Science
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    ABSTRACT: Vaccines consisting of subunit or inactivated bacteria/virus and potent adjuvants are widely used to control and prevent infectious diseases. Because inactivated and subunit antigens are often less antigenic than live microbes, a growing need exists for the development of new and improved vaccine adjuvants that can elicit rapid and long-lasting immunity. Here we describe the development and characterization of a novel oil-in-water emulsion, OW-14. OW-14 contains low-cost plant-based emulsifiers and was added to antigen at a ratio of 1:3 with simple hand mixing. OW-14 was stable for prolonged periods of time at temperatures ranging from 4 to 40°C and could be sterilized by autoclaving. Our results showed that OW-14 adjuvanted inactivated swine influenza viruses (SIV; H3N2 and H1N1) and Mycoplasma hyopneumoniae (M. hyo) vaccines could be safely administered to piglets in two doses, three weeks apart. Injection sites were monitored and no adverse reactions were observed. Vaccinated pigs developed high and prolonged antibody titers to both SIV and M. hyo. Interestingly, antibody titers were either comparable or greater than those produced by commercially available FluSure (SIV) or RespiSure (M. hyo) vaccines. We also found that OW-14 can induce high antibody responses in pigs that were vaccinated with a decreased antigen dose. This study provides direct evidence that we have developed an easy-to-use and low-cost emulsion that can act as a powerful adjuvant in two common types of swine vaccines. Copyright © 2015. Published by Elsevier Ltd.
    Full-text · Article · Apr 2015 · Vaccine
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    ABSTRACT: Data from existing literature were used to generate equations to predict finishing pig back, belly, and jowl fat iodine values (IV) and an experiment was conducted to evaluate these equations. The final database included 24, 21, and 29 papers for back, belly, and jowl fat IV, respectively. For experiments that changed dietary fatty acid composition, initial (INT) diets were defined as those fed before the change in diet composition and final (FIN) diets were those fed after. The predictor variables tested were divided into 5 groups: 1) diet fat composition (dietary percent C16:1, C18:1, C18:2, C18:3, EFA, unsaturated fatty acids, and IV product) for both INT and FIN diets, 2) day feeding the INT and FIN diets, 3) ME or NE of the INT and FIN diet, 4) live performance criteria (initial BW, final BW, ADG, ADFI, and G:F), and 5) carcass criteria (HCW and backfat thickness). The PROC MIXED procedure of SAS (SAS Inst., Inc., Cary, NC) was used to develop regression equations. Evaluation of models with significant terms was then conducted based on the Bayesian information criterion. The optimum equations to predict back, belly, and jowl fat IV were backfat IV = 84.83 + (6.87 × INT EFA) - (3.90 × FIN EFA) - (0.12 × INT days) - (1.30 × FIN days) - (0.11 × INT EFA × FIN days) + (0.048 × FIN EFA × INT days) + (0.12 × FIN EFA × FIN days) - (0.0060 × FIN NE) + (0.0005 × FIN NE × FIN days) - (0.26 × backfat depth); belly fat IV = 106.16 + (6.21 × INT EFA) - (1.50 × FIN days) - (0.11 × INT EFA × FIN days) - (0.012 × INT NE) + (0.00069 × INT NE × FIN days) - (0.18 × HCW) - (0.25 × backfat depth); and jowl fat IV = 85.50 + (1.08 × INT EFA) + (0.87 × FIN EFA) - (0.014 × INT days) - (0.050 × FIN days) + (0.038 × INT EFA × INT days) + (0.054 × FIN EFA × FIN days) - (0.0066 × INT NE) + (0.071 × INT BW) - (2.19 × ADFI) - (0.29 × backfat depth). Dietary treatments from the evaluation experiment consisted of a corn-soybean meal control diet with no added fat or a 3 × 3 factorial arrangement with main effects of fat source (4% tallow, 4% soybean oil, or a blend of 2% tallow and 2% soybean oil) and feeding duration (d 0 to 42, 42 to 84, or 0 to 84). The back, belly, and jowl fat IV equations tended to overestimate IV when observed IV were less than approximately 65 g/100 g and underestimate belly fat IV when actual IV are greater than approximately 74 g/100 g or when the fat blend was fed from d 0 to 84 or 42 to 84. Overall, with the exceptions noted, the regression equations were an accurate tool for predicting carcass fat quality based on dietary and pig performance factors.
    No preview · Article · Apr 2015 · Journal of Animal Science

  • No preview · Conference Paper · Mar 2015
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    ABSTRACT: A total of 270 pigs (PIC 327 × 1050, initially 7.1 kg) were used in a 28-d trial to evaluate the effects of increasing levels of a peptone blend on nursery pig performance. The peptone blend is derived from pharmaceutical extraction of chondroitin sulfate from bovine cartilage and then drying on a soybean hull carrier. Each treatment had 8 replicate pens and 6 or 7 pigs per pen. Dietary treatments were: (1) a diet with 1% blood meal and 2% select menhaden fish meal (positive control), (2) a diet with no added specialty protein source (negative control), (3) a diet containing 4% peptone, (4) a diet containing 8% peptone, or (5) a diet containing 12% peptone. Experimental diets were formulated to contain 1.30% SID Lys, and a minimum Val:Lys ratio of 68% without any adjustment for dietary energy content and fed for 14 d. Then a common Phase 2 diet was fed for an additional 14 d to determine carry over effects on growth performance. From d 0 to 14, pigs fed increasing peptone blend had increased (linear, P < 0.001) ADFI but poorer (linear, P < 0.001) G:F. From d 14 to 28, when pigs were fed a common diet, pigs previously fed increasing peptone blend had increased (linear, P = 0.03) ADFI and poorer (linear, P = 0.001) G:F. Overall (d 0 to 28), pigs fed diets with increasing peptone blend for the first 14 d had increased (linear, P < 0.001) ADFI and poorer G:F (linear, P < 0.001) with no differences in ADG (P = 0.87). Pigs fed the positive control diet had increased (P = 0.01) overall ADFI compared with pigs fed negative control diet. Up to 4% of the peptone blend can be used in nursery diets from 7 to 11 kg without negatively impacting growth performance.
    Full-text · Conference Paper · Mar 2015
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    ABSTRACT: Four experiments were conducted to investigate the effects of deoxynivalenol (DON) from naturally contaminated dried distillers grains with solubles (DDGS) and the efficacy of feed additives in nursery pig diets. In Exp. 1, 180 pigs (10.3 ± 0.2 kg BW) were fed 1 of 5 diets for 21 d. Diets were 1) Positive Control (PC; < 0.5 mg/kg DON), 2) Negative Control (NC; 4 mg/kg DON), 3) NC + 0.10% Biofix (Biomin Inc., Herzogenburg, Austria), 4) NC + 0.15% Cel-can (VAST Inc., Mason City, IA) and 0.50% bentonite clay, and 5) NC + 0.25% Defusion Plus (Cargill Animal Nutrition, Minneapolis, MN). Pigs fed the NC diet had poorer ( < 0.01) ADG than those fed the PC. Pigs fed Defusion Plus had improved ( < 0.03) ADG over those fed NC, whereas pigs fed Biofix or Cel-can with bentonite clay had reduced ADG ( < 0.01) compared with those fed PC. In Exp. 2, 340 pigs (11.7 ± 0.1 kg BW) were fed 1 of 8 diets for 21 d. Diets were 1) PC (< 0.5 mg/kg DON), 2) Low NC (1.5 mg/kg DON), 3) Low NC + 0.15% Biofix, 4) Low NC + 0.30% Biofix, 5) High NC (3.0 mg/kg DON), 6) High NC + 0.30% Biofix, 7) High NC + 0.45% Biofix, and 8) Diet 7 with 5% added water. Increasing the DON level reduced (linear; < 0.05) ADG, ADFI, and pig BW, and Biofix did not improve performance. In Exp. 3, 1,008 pigs (12.5 ± 0.3 kg BW) were fed 6 treatments for 24 d. Diets were 1) PC ( < 0.5 mg/kg DON), 2) NC (3 mg/kg DON), 3) NC + 0.25% Defusion, 4) NC + 0.50% Defusion, 5) Diet 3 with supplemental nutrients, and 6) Diet 5, pelleted. Pigs fed the NC had decreased ( < 0.01) ADG and ADFI, but adding Defusion improved (linear; < 0.04) ADG and ADFI over pigs fed NC. Pelleting improved ( < 0.01) both ADG and G:F, resulting in ADG above PC pigs. In Exp. 4, 980 pigs (12.0 ± 0.3 kg BW) were fed 1 of 7 diets in a 28-d trial in a 2 × 3 + 1 factorial arrangement. The 7 treatments were based on 3 diets fed in meal or pellet form: 1) PC (< 0.5 mg/kg DON), 2) NC (3 mg/kg DON), and 3) NC + 0.25% Defusion. Treatment 7 was Diet 3 with supplemental nutrients in pellet form. No interactions were observed between pelleting and Defusion. Pigs fed the NC had decreased ( < 0.01) ADG and ADFI, and pelleting improved ( < 0.01) ADG to PC levels, driven by improved ( < 0.01) G:F. Adding nutrients or Defusion had no effect. Overall, these studies show that Defusion and pelleting can help overcome some of the negative effects of DON, whereas other feed additives and additional nutrients do not.
    Full-text · Article · Mar 2015 · Journal of Animal Science

  • No preview · Conference Paper · Mar 2015
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    ABSTRACT: Use of in-feed antibiotics such as chlortetracycline (CTC) in food animals is fiercely debated as a cause of antimicrobial resistance in human pathogens; as a result, alternatives to antibiotics such as heavy metals have been proposed. We used a total community DNA approach to experimentally investigate the effects of CTC and copper supplementation on the presence and quantity of antimicrobial resistance elements in the gut microbial ecology of pigs. Total community DNA was extracted from 569 fecal samples collected weekly over a 6-week period from groups of 5 pigs housed in 32 pens that were randomized to receive either control, CTC, copper, or copper plus CTC regimens. Qualitative and quantitative PCR were used to detect the presence of 14 tetracycline resistance (tet) genes and to quantify gene copies of tetA, tetB, blaCMY-2 (a 3rd generation cephalosporin resistance gene), and pcoD (a copper resistance gene), respectively. The detection of tetA and tetB decreased over the subsequent sampling periods, whereas the prevalence of tetC and tetP increased. CTC and copper plus CTC supplementation increased both the prevalence and gene copy numbers of tetA, while decreasing both the prevalence and gene copies of tetB. In summary, tet gene presence was initially very diverse in the gut bacterial community of weaned pigs; thereafter, copper and CTC supplementation differentially impacted the prevalence and quantity of the various tetracycline, ceftiofur and copper resistance genes resulting in a less diverse gene population. Published by Elsevier B.V.
    No preview · Article · Feb 2015 · Preventive Veterinary Medicine
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    ABSTRACT: Porcine Epidemic Diarrhea Virus (PEDv) has profoundly affected the U.S. swine industry since it emerged May 2013. Since late January 2014, it has been suspected that PEDv outbreaks have been associated with consumption of PEDv positive feed or feed ingredients. However, information is lacking which confirms the ability of feed to be a vector in PEDv transmission and no data is available which describes the minimum infectious dose of PEDv in a feed matrix. Additionally, it is believed that the normal temperature and retention times utilized by commercial pellet mills will be adequate to mitigate PEDv infectivity; however, no research has been conducted to test this hypothesis. Therefore, the purpose of this project was: 1) determine the minimum infectious dose of PEDv in a feed matrix and 2) determine if the retention time and temperatures used in commercial pellet mills will influence PEDv infectivity. Our results confirmed that feed can be a vehicle for PEDv transmission and that the minimum infectious dose of PEDv in a feed matrix is quite low. A PEDv dose that corresponded to a PCR Ct value of 37 was low enough to lead to infectivity. In layman’s terms, this is theoretically equivalent to 1 g of infected pig feces being diluted in approximately 500 tons of feed. Our results also showed that the pelleting process utilized in many commercial mills can act as a point-in-time mitigation step in PEDv-associated risk prevention plans because none of the virus-inoculated and processed feed lead to infectivity in the pig bioassay model, even though the PCR analysis indicated that PEDv RNA was present in the processed feed. In contrast, the non-processed feed did lead to PEDv infectivity.
    No preview · Technical Report · Jan 2015