Evaluation of different oil sources for nursery pigs

A total of 210 pigs (PIC 327 × 1050, initially 28.9 lb BW) were used in a 21-d trial to evaluate the effects of increasing oil sources on nursery pig growth performance. The 2 oil sources included a commercial source of soybean oil and a proprietary source of corn oil originating from the ethanol industry (Corn Oil ONE, Feed Energy Co., Pleasant Hill, IA). The 5 experimental diets included: a control diet without added oil, diets with 2.5 or 5% added soybean oil, or diets with 2.5 and 5% added corn oil. Diets were formulated with an identical standardized ileal digestible lysine:calorie ratio and were fed in meal form. There were 6 pens per treatment with 7 pigs per pen. Overall, from d 0 to 21, no oil source × level interactions were observed. Increasing corn oil or soybean oil had no effect on ADG or final BW. Increasing corn oil or soybean oil decreased (linear, P \u3c 0.05) ADFI, which resulted in improved (linear, P \u3c 0.01) F/G. Caloric efficiency was not affected by oil source or level. Feed cost per pig tended to decrease (linear, P = 0.066) for pigs fed increasing levels of soy oil. Cost per pound of gain decreased for both Corn Oil ONE (linear, P = 0.032) and soybean oil (linear, P = 0.008) as oil level increased. Value of the weight gain and income over feed cost was similar for pigs fed diets with Corn Oil ONE and soybean oil (P = 0.833). This study shows the benefits of adding a dietary oil source in late-phase nursery diets to achieve improved feed efficiency. Corn Oil ONE is a suitable alternative for soybean oil, and cost and availability should dictate which source is used.; Swine Day, Manhattan, KS, November 20, 201

Effects of distillers dried grains with solubles and added fat fed immediately before slaughter on growth performance and carcass characteristics of finishing pigs

Citation: Coble, K. F., DeRouchey, J. M., Tokach, M. D., Dritz, S. S., Goodband, R. D., & Woodworth, J. C. (2017). Effects of distillers dried grains with solubles and added fat fed immediately before slaughter on growth performance and carcass characteristics of finishing pigs. Journal of Animal Science, 95(1), 270-278. doi:10.2527/jas2016.0679The addition of dietary fat has been shown to increase HCW and carcass yield in pigs fed low-fiber corn-soy diets; however, data on added fat in high-fiber, low-energy diets is less available. Therefore, the potential for dietary fat to ameliorate the negative effect high-fiber diets have on carcass yield during the last 3 wk before slaughter is of high importance. This experiment was conducted to determine the interactive effects of 30% distillers dried grains with solubles (DDGS) and 5% added fat fed before slaughter on growth performance and carcass characteristics. A total of 1,258 pigs in 2 groups (initially 105.8 +/- 0.1 kg BW; group 1 PIC 337 x 1,050; group 2 PIC 327 x 1,050) were used in a 20-d experiment. All pigs were fed a common diet with 30% DDGS until 20 d before slaughter. Then, all pens were weighed and allotted to treatments with 20 replicate pens per treatment. Dietary treatments were arranged in a 2 x 2 factorial with 2 diet types (corn-soybean meal-based with or without 30% DDGS) and added fat (0 or 5%; group 1 = tallow; group 2 = choice white grease). Diets were formulated to a constant standardized ileal digestible Lys: NE ratio. There were no treatment x group interactions for any response criteria. Thus, data for the 2 groups were combined for analysis. Overall, there was a tendency for a diet type x added fat interaction for ADG (P = 0.054), whereas this was significant for G: F (P = 0.008). This was a result of 5% added fat increasing ADG and G: F to a greater magnitude for pigs fed the diet containing 30% DDGS (8.6 and 10.4%, respectively) than for pigs fed the corn-soy diet (2.0 and 2.9%, respectively). Although diet type did not affect final live BW, pigs fed the diet containing DDGS had decreased HCW and carcass yield (P < 0.05). Adding 5% fat did not affect carcass yield. In conclusion, adding 5% fat to finishing pig diets containing 30% DDGS approximately 20 d before slaughter improved ADG and G: F but did not overcome the reduction in carcass yield from feeding DDGS

Evaluating the efficacy of a novel phytase source

Citation: Flohr, J. R., DeRouchey, J. M., Tokach, M. D., Dritz, S. S., Woodworth, J. C., & Goodband, R. D. (2016). Evaluating the efficacy of a novel phytase source. Journal of Animal Science, 94, 111-112. doi:10.2527/msasas2016-236A total of 350 nursery pigs (PIC 1050 barrows, initially 15.1 kg BW) were used in a 21-d study to determine the available phosphorus (aP) release curve for a novel phytase product (Microtech 5000, VTR Bio-tech Co., Guangdong, China). Pigs were randomly allotted to pens at arrival to facilities and on d 0 of the trial pens were allotted to 1 of 7 treatments in a randomized complete block design. There were 5 pigs per pen and 10 pens per treatment. Pigs were fed corn-soybean meal-based diets formulated to contain 1.25% SID Lys. Experimental treatments consisted of 3 diets formulated to 0.12, 0.18, and 0.24% aP with the only source of added P being an inorganic source (monocalcium P). Then, phytase was added to the diet formulated to 0.12% aP at 4 levels (250, 500, 750, and 1000 FTU/kg). Diets were analyzed for phytase using the AOAC method, and analyzed concentrations were lower than formulated. Diets formulated to contain 250, 500, 750, and 1000 FTU/kg had analyzed concentrations of 155, 335, 465, and 780 FTU/kg, respectively. On d 21, one pig per pen was euthanized and fibulas were collected to determine bone ash weight and percentage bone ash. From d 0 to 21, increasing P from inorganic P or increasing phytase increased ADG (linear, P < 0.01), G:F (linear, P < 0.01 for inorganic P; quadratic, P < 0.03 for phytase), and final BW (linear, P < 0.01). Bone ash weight and percentage were increased (linear, P < 0.01) with increasing inorganic P and increasing phytase. Response criteria, which remained in the linear portion of the quadratic phytase curve (ADG, bone ash weight, and percentage bone ash), were used to calculate aP release curves. When analyzed phytase values and percentage bone ash are used as the predictor variables, aP release percentage for up to 780 FTU/kg of Microtech 5000 phytase can be predicted by the equation (y = 0.000002766761x– 0.000000002225x2– 0.000201841391; r2 = 0.948), where x is the phytase concentration in the diet (FTU/kg)

Development of equations to predict the influence of floor space on average daily gain, average daily feed intake, and gain-to-feed ratio of finishing

Citation: Flohr, J. R., Woodworth, J. C., Tokach, M. D., Dritz, S. S., DeRouchey, J. M., & Goodband, R. D. (2016). Development of equations to predict the influence of floor space on average daily gain, average daily feed intake, and gain-to-feed ratio of finishing. Journal of Animal Science, 94, 7-7. doi:10.2527/msasas2016-015Data from existing literature examining the influence of floor space allowance on the growth of finishing pigs was used to develop prediction equations for ADG, ADFI, and G:F. Two databases were used: the first included information from studies examining the influence of floor space allowance, and the second included the aforementioned papers along with papers examining the impact of floor space after pigs were removed from the pen. The first database included 27, 25, and 25 papers for ADG, ADFI, and G:F, respectively, and the second database contained 30, 28, and 28 papers for ADG, ADFI, and G:F, respectively. The predictor variables tested were floor space (m2/pig), k (floor space/final BW0.67), initial BW, final BW, feed space (pigs per feeder hole), water space (pigs per waterer), group size (pigs per pen), gender, floor type, and study length (d). Floor space treatments within each experiment were the experimental unit and random effects of decade, paper within decade, and experiment within paper × decade interactions were included in the statistical model. A weighted variance term was included in the statistical model to account for heterogeneity of experimental designs and replication across the existing literature. The statistical significance for inclusion of terms in the model was determined at P < 0.10. Further evaluation of models with significant terms was then conducted based on the Bayesian information criterion (BIC). Once the ADG and ADFI models for each respective database were determined, then the G:F model was evaluated as the predicted ADG/predicted ADFI. The optimum equations to predict finishing ADG, ADFI, and G:F for the first database were ADG, g = 395.57 + (15,727 × k) ? (221,705 × k2) ? (3.6478 × initial BW, kg) + (2.209 × final BW, kg) + (67.6294 × k × initial BW, kg); ADFI, g = 802.07 + (20,121 × k) ? (301,210 × k2) ? (1.5985 × initial BW, kg) + (11.8907 × final BW, kg) + (159.79 × k × initial BW, kg); and G:F = predicted ADG/predicted ADFI. The optimum equations to predict ADG, ADFI, and G:F for the second database were ADG, g = 337.57 + (16,468 × k) ? (237,350 × k2) ? (3.1209 × initial BW, kg) + (2.569 × final BW, kg) + (71.6918 × k × initial BW, kg); ADFI, g = 833.41 + (24,785 × k) ? (388,998 × k2) ? (3.0027 × initial BW, kg) + (11.246 × final BW, kg) + (187.61 × k × initial BW, kg); and G:F = predicted ADG/predicted ADFI. All multiterm models improved BIC values compared with single-term predictor models, signifying that multiterm models proved to better fit their respective databases

Effects of diet form and type on growth performance, carcass yield, and iodine value of finishing pigs

Citation: Nemechek, J. E., Tokach, M. D., Dritz, S. S., Goodband, R. D., DeRouchey, J. M., & Woodworth, J. C. (2015). Effects of diet form and type on growth performance, carcass yield, and iodine value of finishing pigs. Journal of Animal Science, 93(9), 4486-4499. doi:10.2527/jas2015-9149Two 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 x 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 (P < 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, P < 0.05). Pigs fed the low-fiber, low-fat diet throughout had increased (P < 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 (P < 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 (P < 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 (P < 0.05) ADG, carcass yield, and HCW compared with pigs fed the control or corn oil diets and decreased (P < 0.001) G:F compared with pigs fed added corn oil. Belly IV was greatest (P < 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

Evaluating the removal of pigs from a group and subsequent floor space allowance on the growth performance of heavy-weight finishing pigs

Citation: Flohr, J. R., Tokach, M. D., DeRouchey, J. M., Woodworth, J. C., Goodband, R. D., & Dritz, S. S. (2016). Evaluating the removal of pigs from a group and subsequent floor space allowance on the growth performance of heavy-weight finishing pigs. Journal of Animal Science, 94(10), 4388-4400. doi:10.2527/jas2016-0407A total of 1,092 finishing pigs (initially 36.3 kg) were used in a 117-d study to evaluate the impact of initial floor space allowance and removal strategy on the growth of pigs up to 140 kg BW. There were 4 experimental treatments with 14 pens per treatment. The first treatment provided 0.91 m(2) per pig (15 pigs/pen). The other 3 treatments initially provided 0.65 m(2) per pig (21 pigs/pen) with 3 different removal strategies. The second treatment (2:2:2) removed the 2 heaviest pigs from pens on d 64, 76, and 95 when floor space allowance was predicted to be limiting. Treatment 3 (2:4) removed the 2 heaviest pigs on d 76 and the 4 heaviest pigs on d 105. Treatment 4 (6) removed the heaviest 6 pigs on d 105. All pigs remaining in pens after removals were fed to d 117. Overall (d 0 to 117), pigs initially provided 0.91 m(2) of floor space had increased (P < 0.05) ADG compared to pigs in pens on the 2: 4 or 6 removal strategy, but ADG was not different compared with pigs on the 2:2:2 removal strategy. Total BW gain per pen was greater (P < 0.05) for pens initially stocked at 0.65 m(2) compared to pens initially stocked at 0.91 m(2). Feed usage per pen was less (P < 0.05) for pens initially stocked at 0.91 m(2) compared to pens initially providing 0.65 m(2) of floor space and on removal strategies; however, feed usage per pig was greater (P < 0.05) for pigs initially stocked at 0.91 m(2) compared to pigs initially stocked at 0.65 m(2) and on removal strategies. Feed usage, on a pig or pen basis, was less (P < 0.05) for pigs on the 2: 2: 2 removal strategy compared to pigs on the 2:4 or the 6 removal strategy. Income over feed and facility cost (IOFFC) was less (P < 0.05) for pigs initially provided 0.91 m(2) compared to pigs initially provided 0.65 m(2) and on removal strategies. Also, IOFFC was less (P < 0.05) for pigs on the 2:2:2 compared to the 2:4 and 6 removal strategies. In conclusion, increasing the floor space allowance or the time points at which pigs are removed from the pen improved the growth of pigs remaining in the pen; however, IOFFC may be reduced because fewer pigs are marketed from each pen (pigs stocked at 0.91 m(2) throughout the study) or from reducing total weight produced (2:2:2 removal strategy)

Effects of stocking density on finishing pig growth performance

Citation: Thomas, L. L., Goodband, R. D., Tokach, M. D., DeRouchey, J. M., Woodworth, J. C., & Dritz, S. S. (2016). Effects of stocking density on finishing pig growth performance. Journal of Animal Science, 94, 54-54. doi:10.2527/msasas2016-115A total of 405 pigs (PIC 327 × 1050) from 2 consecutive finishing groups (group 1 initially 66 ± 1.8 kg BW, group 2 initially 61 ± 2.5 kg BW) were used to examine the effects of stocking density on finishing pig growth performance. Pens of pigs were balanced by initial BW and randomly allotted to 1 of 3 treatments with either 7 or 8 replications per treatment (group 1 and 2, respectively). Pens were stocked with 9 pigs, and adjustable gates provided treatments that allowed for 0.84, 0.74, or 0.65 m2 per pig. All pigs were fed the same diets fed in 3 phases. Pigs were provided with 7.91 cm of feeder space per pig. In both studies, as stocking density decreased, ADG and ADFI increased (linear, P < 0.019), but there was no difference in G:F. As a result, final weight was 3.9 and 5.3 kg greater (linear, P ? 0.005) in groups 1 and 2, respectively, when comparing the lowest to the highest stocking density treatments. When comparing growth performance to a suggested required k-value of 0.0336, performance should have been affected above 122, 102, and 83 kg at 0.84, 0.74, and 0.65 m2 per pig. In group 1, performance should not have been affected until after 109.0 kg, 94.0 kg, and 80.3 kg for the 0.84, 0.74, and 0.65 m2 per pig treatments, respectively. However, in group 1 even after d 14 (less than 74.5 kg), negative effects of increased stocking density were observed on ADFI (linear, P < 0.08). In group 2, performance should not have been affected until after 118 kg, 87 kg, and 74 kg for the 0.84, 0.74, and 0.65 m2 per pig treatments. Similar to group 1, feed consumption and consequently ADG decreased linearly (P ? 0.033) as stocking density increased, before pigs reached the k-value that should have influenced performance. Overall, this study indicates that increasing stocking density resulted in poorer ADG driven by a reduction in ADFI and the accepted k-value of 0.0336 might underestimate the impact of increased stocking density

Effects of commercial formaldehyde inclusion and lysine level on nursery pig performance

Citation: Sica, L. G., Cochrane, R. A., Woodworth, J. C., Dritz, S. S., Stark, C. R., & Jones, C. K. (2016). Effects of commercial formaldehyde inclusion and lysine level on nursery pig performance. Journal of Animal Science, 94, 191-192. doi:10.2527/msasas2016-410Previous research has demonstrated that commercial formaldehyde products may reduce the risk of microbiological hazards in feed, but there is concern about the product binding Lys and reducing growth performance. Therefore, the objective of this experiment was to evaluate the role of 2 commercially-available formaldehyde sources on growth performance of pigs fed a Lys-sufficient or Lys-deficient diet. A total of 299 pigs (PIC 327 × 1050; initial BW 15.2 kg) were used in a 14-d study. Dietary treatments were arranged in a 3 × 2 factorial design with 3 formaldehyde inclusions: none vs. 3.25 kg per tonne SalCURB (Kemin Industries, Inc., Des Moines, IA) vs. 3.0 kg per tonne Termin-8 (Anitox Corp, Lawrenceville, GA) and 2 Lys levels: Adequate (1.25% SID Lys) vs. Low (1.10% SID Lys). Product concentrations were established from supplier recommendations, and diets were treated with in commercial mills utilizing supplier-specific equipment. Pens of pigs were balanced by initial BW and randomly allotted to treatments with 5 pigs per pen and 10 pens per treatment. Data were analyzed in a factorial design using the GLIMMIX procedure of SAS. Overall, there was a tendency (P 0.10). In summary, SalCURB inclusion did not alter nursery pig growth performance compared to the untreated basal diet, regardless of Lys level. However, the inclusion of Termin-8 tended to result in poorer G:F in adequate Lys diets and poorer ADG and G:F in low Lys diets compared to an untreated control

Effects of algae-derived β-glucans with zinc on nursery pig growth performance and immune response under commercial conditions

An experiment was conducted to determine the impact of increasing levels of Algamune ZPC (Algal Scientific Corporation, Plymouth, MI) on growth performance and porcine circovirus type 2 (PCV2)-specific immune response of nursery pigs housed under commercial conditions. Algamune ZPC is a polysaccharide-zinc complex feed additive composed of 35% β-1,3-glucan extracted from algae and 10% zinc. A total of 2,484 pigs (PIC 337 × 1050, initially 15.7 lb) were used in a 40-d trial. After feeding a common pelleted diet for 7 d after weaning, pigs were allotted to 1 of 6 dietary treatments in a randomized complete block design with 14 or 16 replicate pens and 27 pigs per pen. All pigs were vaccinated with PCV2 and M. hyopneumoniae vaccines (1 mL Fostera PCV and 1 mL Respisure- One; Zoetis, Florham Park, NJ) at d 3 after birth and at weaning. Blood samples of 72 pigs (12 pens per treatment) were collected on d 2, 18, and 38. The 6 experimental diets were fed in two phases (d 0 to 12 and 12 to 40). Dietary treatments included: a negative control diet fed in both phases (1,910 and 110 ppm of zinc oxide in Phase 1 and 2, respectively); the negative control diet with 104, 208, 423, and 625 ppm added Algamune ZPC for both Phase 1 and Phase 2; and a negative control diet with 423 ppm added Algamune ZPC fed during phase Phase 1 followed by the negative control in Phase 2. From d 0 to 40, increasing Algamune ZPC tended to decrease then increase (quadratic, P = 0.09) ADG and increase (linear, P = 0.10) ADFI. No differences were observed in F/G. There were no differences (P \u3e 0.54) in ADG, ADFI or F/G in pigs fed 423 ppm Algamune ZPC in both phases compared with pigs fed 423 ppm Algamune ZPC only in Phase 1 and the negative control diet fed in Phase 2. The lowest removal rates were observed among pigs assigned to 423 ppm Algamune ZPC only in Phase 1 or in both phases (0 and 0.27%, respectively). No evidence of differences was detected in PCV2-neutralizing antibody titers on d 16, but the titers decreased on d 38 (linear, P = 0.04) with increasing Algamune ZPC. In conclusion, including up to 625 ppm of Algamune ZPC in nursery pig diets from 16 to 56 lb had minimal impact on growth performance. Also, modulation of the specific immune response to PCV2 on d 38 after weaning was negatively related to increasing Algamune ZPC under commercial conditions. Key words: β-glucans, immune response, nursery 1 The authors thank Algal Scientific Corporation, Plymouth, MI, for providing Algamune ZPC and for partial financial support. 2 Appreciation is expressed to New Horizon Farms for use of pigs and facilities and to Lanny Bosma, Shannon Paulson, and Marty Heintz for technical assistance. 3 Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University. 64 SWINE DAY 2014 Introduction Feed additives that could modulate the immune response of nursery pigs may serve as an alternative to growth-promoting antimicrobials. β-glucans are polysaccharides containing only glucose and are found as cellulose in plants; cell walls of yeast, fungi, or bacteria; and bran of cereal grains. Research has shown that dietary inclusion of 0.025% of yeast-derived β-glucans in nursery pig diets increased ADG, ADFI, and pig BW on d 28 after weaning (Dritz et al., 19954). In addition, pigs fed 0.025% β-glucans had an increased mortality rate compared with pigs fed the negative control or 0.05% β-glucans, but Li et al. (20065) observed an improvement in the immune system of pigs fed yeast-derived β-glucans. Most research has been performed with β-glucans extracted from specific yeast cell wall components. A new product, Algamune ZPC (Algal Scientific Corporation, Plymouth, MI), contains β-glucans extracted from algae and is a polysaccharide-zinc complex (35% β-1,3-glucan and 10% zinc). Therefore, the objective of this experiment was to determine the impact of Algamune ZPC on growth performance, removal rate, and PCV2-specific immune response of nursery pigs housed under commercial conditions. Procedures The protocol for this experiment was approved by the Kansas State University Institutional Animal Care and Use Committee. The study was conducted at a commercial research nursery in southwestern Minnesota. The facility was totally enclosed, environmentally controlled, and mechanically ventilated. Pens were distributed across 2 rooms and had completely slatted flooring and deep pits for manure storage. Each pen was equipped with a 5-hole stainless steel dry self-feeder and a pan waterer for ad libitum access to feed and water. Daily feed additions to each pen were accomplished through a robotic feeding system (FeedPro; Feedlogic Corp., Willmar, MN) capable of providing and measuring feed amounts for individual pens. A total of 2,484 pigs (PIC 337 × 1050, initially 15.7 lb BW) were used in a 40-d trial. Pigs were weaned at 19 d of age and were initially fed a common pelleted diet for 7 d before the start of the experiment. On d 7 after weaning, pigs were weighed and pens of pigs were allotted to 1 of 6 dietary treatments in a randomized complete block design. Each treatment had 14 or 16 replicate pens and 27 pigs per pen, with each pen containing a mix of barrows and gilts. All pigs were vaccinated with porcine circovirus type 2 (PCV2) and M. hyopneumoniae vaccines (1 mL Fostera PCV and 1 mL Respisure-One; Zoetis, Florham Park, NJ) on d 3 after birth and at weaning. Blood samples of 72 pigs (12 pens per treatment, 1 pig per pen) were collected on d 2, 18, and 38 of the trial and were submitted to the Kansas State Veterinary Diagnostic Laboratory to measure PCV2 antibody titers using indirect immunofluorescence (IFA) assay.; Swine Day, Manhattan, KS, November 20, 201

Effects of increasing zinc from zinc sulfate or zinc hydroxychloride on finishing pig growth performance and carcass characteristics

Citation: Carpenter, C. B., Coble, K., Woodworth, J. C., DeRouchey, J. M., Tokach, M. D., Goodband, R. D., . . . Usry, J. L. (2016). Effects of increasing zinc from zinc sulfate or zinc hydroxychloride on finishing pig growth performance and carcass characteristics. Journal of Animal Science, 94, 141-141. doi:10.2527/msasas2016-301A variety of zinc sources are available for use in swine trace mineral premixes. However, more research is needed to compare zinc sources and dietary levels in growing and finishing pigs in a commercial environment. A total of 1008 pigs [TR4 × (Fast Large White × L02 PIC); initially 32.1 kg BW)] were used in a 103-d growth study to determine the effects of Zn source and level on finishing pig growth performance and carcass characteristics. The 6 dietary treatments were arranged as a 2 × 3 factorial with main effects of Zn source (ZnSO4 Agrium Advance Technology, Loveland, CO or Zn Hydroxychloride; IntelliBond Z®; Micronutrients, Indianapolis, IN) or level (50, 100, or 150 ppm added Zn). There was no additional Zn provided from the trace mineral premix. There were 21 pigs per pen and 8 pens per treatment. Overall, there were no Zn source × level interactions observed for ADG or ADFI, however G:F tended (linear, P = 0.069) to be poorer when pigs were fed increasing levels of Zn from ZnSO4. Overall, there were no Zn source effects for growth performance observed. For Zn level main effects, ADG was maximized (quadratic, P = 0.007) and ending BW was heaviest (quadratic, P = 0.011) when diets contained 100 ppm of Zn. Feed efficiency was poorer (linear, P = 0.006) when pigs were fed increasing levels of Zn. For carcass characteristics, pigs fed diets with Zn Hydroxychloride had heavier (P = 0.041) HCW than those fed ZnSO4. Also carcass yield increased (linear, P = 0.027) when pigs were fed increasing levels of Zn and HCW was maximized (quadratic, P = 0.006) when diets contained 100 ppm of Zn. These results suggest that a total of 100 ppm added Zn is enough to maximize ending BW, ADG and HCW, but G:F worsened as Zn level increased. Zn source did not impact growth performance; however, pigs fed Zn Hydroxychloride had increased HCW compared to those fed ZnSO4