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ABSTRACT: A total of 2,152 pigs (C22 × 336 PIC) were used in 4 experiments to determine the interactive effects of dietary L-carnitine and ractopamine≅HCl (RAC) on finishing pig growth performance. All trials were arranged as factorial arrangements with main effects of L-carnitine (0, 25, or 50 mg/kg in Exp. 1 and 2; 0 or 50 mg/kg in Exp. 3 and 4) and RAC (0, 5, or 10 mg/kg in Exp. 1 and 0 or 10 mg/kg in Exp. 2, 3, and 4). Dietary carnitine was fed from 38 to 109 kg (Exp. 1 and 3) or for the last 4 or 3 wk before slaughter (118 kg; Exp. 2 and 4, respectively). Ractopamine≅HCl was fed for 4 wk (Exp. 1, 2, and 3) or 3 wk (Exp. 4) before slaughter. Experiments 1 and 2 were conducted in university research facilities, and Exp. 3 and 4 were conducted in commercial research facility. All diets were formulated to contain 1.00% total Lys during the last phase of each experiment. In all experiments, pigs fed RAC had increased (P < 0.05) ADG and G:F compared with pigs fed no RAC. Feeding L-carnitine before the RAC feeding period did not affect pig growth performance. In Exp. 1 and 2, L-carnitine did not affect ADG during the last 4 wk; however, in Exp. 2, G:F tended (quadratic; P = 0.07) to improve with increasing L-carnitine. In Exp. 3, L-carnitine × RAC interactions were observed (P < 0.04) for ADG and G:F. Both added L-carnitine and RAC improved performance, but the response was not additive. In Exp. 4, pigs fed L-carnitine had increased (P < 0.04) ADG (0.88 vs. 0.84 kg) and G:F (0.36 vs. 0.35) compared with pigs fed no L-carnitine, and the response was additive to that of RAC. Analysis of treatments common to all experiments showed that pigs fed RAC had increased (P < 0.01) ADG (1.03 vs. 0.93 kg) and G:F (0.40 vs. 0.35) compared with pigs fed no RAC. Pigs fed L-carnitine tended to have increased (P = 0.07) ADG (1.00 vs. 0.96 kg) and improved (P < 0.01) G:F (0.38 vs. 0.37) compared with pigs not fed L-carnitine. These results confirm that RAC improves growth performance of finishing pigs. Added L-carnitine improved growth performance of finishing pigs, and the greatest response was observed in Exp. 3 and 4,which were conducted in commercial research environments. These experiments imply that adding L-carnitine to a finishing diet does not enhance the growth effects of RAC and that effects of RAC and L-carnitine on ADG and G:F are independent.
Journal of Animal Science 05/2013; · 2.10 Impact Factor
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ABSTRACT: Three experiments using 1,356 pigs (C22 × 336 PIC) were conducted to determine the interactive effects of dietary L-carnitine and ractopamine hydrochloride (RAC) on carcass characteristics and meat quality of finishing pigs. Experiments were arranged as factorials with main effects of L-carnitine and RAC; L-carnitine levels were 0, 25, or 50 mg/kg in Exp. 1 and 2 and 0 or 50 mg/kg in Exp. 3, and RAC levels of 0, 5, or 10 mg/kg in Exp. 1 and 0 or 10 mg/kg in Exp. 2 and 3. Dietary L-carnitine was fed from 38 kg to slaughter (109 and 118 kg in Exp. 1 and 3, respectively) or for 4 wk before slaughter (109 kg in Exp. 2). Ractopamine HCl was fed for 4 wk in all experiments. Experiments 1 and 2 were conducted at university research facilities (2 pigs per pen), and Exp. 3 was conducted in a commercial research barn (23 pigs per pen). In Exp. 1, an L-carnitine × RAC interaction (P < 0.02) was observed for LM visual color, L*, and a*/b*. In pigs fed RAC, increasing L-carnitine decreased L* and increased visual color scores and a*/b* compared with pigs not fed RAC. Ultimate pH tended to increase (linear, P < 0.07) with increasing L-carnitine. Drip loss decreased (linear, P < 0.04) in pigs fed increasing L-carnitine. In Exp. 2, firmness scores decreased in pigs fed increasing L-carnitine when not fed RAC, but firmness scores increased and drip losses decreased with increasing L-carnitine when RAC was added to the diet (L-carnitine × RAC interaction, P < 0.04). Percentage lean was greater (P < 0.01) for pigs fed RAC in Exp. 2. In Exp. 3, fat thickness decreased, and lean percentage increased, in pigs fed L-carnitine or RAC, but the responses were not additive (L-carnitine × RAC interaction, P < 0.03). Furthermore, pigs fed L-carnitine tended (P < 0.06) to have decreased LM drip loss percentage whereas pigs fed RAC had decreased (P < 0.05) 10th rib and average backfat and decreased drip loss than pigs fed diets without RAC. These results suggest that dietary RAC increased carcass leanness and supplemental L-carnitine reduced LM drip loss when fed in combination with RAC.
Journal of Animal Science 02/2013; · 2.10 Impact Factor
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ABSTRACT: Four experiments were conducted to determine the standardized ileal digestible (SID) Lys requirement of pigs (Sus scrofa) from 7 to 14 kg. In Exp. 1, 294 pigs (6.8 kg BW) were used in a 28-d growth trial with 7 pigs per pen and 7 pens per treatment. Treatment diets were fed from d 0 to 14, and a common diet was fed from d 14 to 28. The 6 SID Lys levels tested were 1.15, 1.23, 1.30, 1.38, 1.45, and 1.53%. The diets were corn- and soybean-meal [Zea mays L. and Glycine max (L.) Merr.] based, with 10% spray-dried whey, 4.5% fish meal, and contained 3.37 Mcal of ME/kg. From d 0 to 14, ADG increased (quadratic, P < 0.001) as SID Lys increased from 1.15 to 1.30% with no further increase at greater levels. Gain:feed increased (linear, P < 0.001) with increasing SID Lys. Experiments 2 to 4 were 14-d growth trials with diets containing 1.22, 1.32, 1.42, 1.52, or 1.62% SID Lys. Diets were corn- and soybean-meal based with 3.45 Mcal of ME/kg. Soybean meal and lactose were constant in all diets at 30 and 7% of the diet, respectively. In Exp. 2, 840 pigs (7.6 kg BW) were used, with 24 pigs per pen and 7 pens per treatment. Increasing SID Lys from 1.22 to 1.42% increased (quadratic, P < 0.01) ADG and G:F with no further improvement observed in pigs fed the 1.52 or 1.62% SID Lys diets during d 0 to 14. In Exp. 3, 1,260 pigs (8.5 kg BW) were used with 42 pigs per feeder (2 pens per feeder) and 6 feeders per treatment. Increasing dietary Lys increased (quadratic, P < 0.02) ADG and G:F with the greatest response observed as SID Lys increased from 1.22 to 1.32% and, then, slight improvements with 1.42 and 1.52% during d 0 to 14. In Exp. 4, 770 pigs (7.4 kg BW) were used with 22 pigs per pen and 7 pens per treatment. Increasing SID Lys increased (quadratic, P = 0.05) ADG with pigs fed 1.32 and 1.42% SID Lys diets having the greatest BW gains during d 0 to 14. Increased SID Lys decreased (linear, P < 0.001) ADFI and increased (linear, P < 0.001; quadratic, P = 0.02) G:F. In conclusion, results of these experiments indicate that the 1998 NRC Lys recommendations (e.g., 1.19% SID Lys for 5 to 10 kg pigs) are less than required for optimal growth for 7 to 14 kg pigs. One-slope straight broken-line analysis indicated that the SID Lys requirement for optimal growth was at least 1.30% for ADG and 1.37% for G:F, or at least 3.86 and 4.18 g SID Lys/Mcal ME, respectively. Quadratic broken-line analysis indicated that the SID Lys requirement for optimal growth was at least 1.37% for ADG and 1.54% for G:F, or at least 4.19 and 4.92 g SID Lys/Mcal ME, respectively.
Journal of Animal Science 12/2012; 90(12):4380-90. · 2.10 Impact Factor
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ABSTRACT: Our objectives were to compare a conventional dry (CD, 152.4-cm-wide, 5-space, STACO Inc., Schaefferstown, PA) and a wet-dry (WD, double-sided, each side = 38.1-cm space, Crystal Springs, GroMaster Inc., Omaha, NE) feeder, and to determine if changing the source of water to a location separate from a wet-dry feeder during the finishing period would result in improved G:F and carcass characteristics. A total of 1,296 pigs (PIC, 337 × 1050; initially 19.4 kg BW) were used, with 27 pigs/pen (14 barrows and 13 gilts) and 24 pens/feeder design. The water supply to the WD feeder was shut off and the cup waterer was turned on in 8 pens on d 69 (WD69) and in another 8 pens on d 97 (WD97). For the remaining 8 WD feeder pens, the feeder provided the sole water source for the entire experiment (WD124). From d 0 to 69, pigs fed with the WD feeder had increased (P < 0.05) ADG, ADFI, G:F, and d 69 BW compared with those using the CD. Overall (d 0 to 124), pigs using WD124 had greater (P < 0.05) ADG, ADFI, final BW, and HCW than all other treatments. Pigs fed with WD97 had greater (P < 0.05) ADG than pigs that used a CD feeder. Pigs using WD97 had greater (P < 0.05) ADFI than WD69, and CD was intermediate. The overall G:F was not different (P> 0.05) among pigs fed with the different feeder treatments. Backfat depth of pigs using WD69 was reduced (P < 0.05) compared with all other treatments, and LM depth was greater (P < 0.05) than that of pigs using a CD feeder and WD97. Pigs fed using the WD feeder visited the feeder less frequently (P < 0.05) and spent less total time at the feeder (P < 0.05) than those fed with the CD feeder. These differences in feeding patterns remained even after the access to water was removed from the WD feeder, with no change in the amount of aggressive behavior observed at the feeder. In conclusion, pigs fed with a WD feeder had an increased growth rate compared with those fed with a CD feeder. Although measures of carcass leanness were improved by changing the location of the water, removing the water from the feeder also eliminated any net improvement in BW from using a WD feeder.
Journal of Animal Science 10/2012; · 2.10 Impact Factor
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ABSTRACT: The objective was to compare the effects of a conventional dry (CD, 152.4-cm-wide, 5-space, Staco Inc., Schaefferstown, PA) and a wet-dry (WD, double-sided, each side = 38.1 cm space, Crystal Springs, GroMaster Inc., Omaha, NE) feeder using various feeder adjustment openings on the growth performance and carcass characteristics of growing-finishing pigs. In Exp. 1, 1,296 pigs (BW 19 kg) were used in a 27-d study to evaluate 3 feeder openings nested within each feeder design. From d 0 to 27, pigs fed with a WD feeder had similar ADG, but lower (P < 0.02) ADFI and better G:F, compared to pigs fed with a CD feeder. Increased adjustment opening increased (linear, P < 0.01) ADG and ADFI of pigs fed with a WD feeder, and increased (linear, P < 0.01) ADFI of pigs fed with a CD feeder. In Exp. 2, 1,248 pigs (BW 33 kg) were used to evaluate 3 feeder openings nested within each feeder design in a 93-d study. Pigs fed with a WD feeder had greater (P < 0.05) ADG, ADFI, final BW, HCW, and backfat, but decreased fat-free lean index (FFLI), compared with those fed with a CD feeder. Increased opening of the WD feeder resulted in greater (linear, P < 0.05) ADG, ADFI, HCW, and backfat, but lower FFLI. No differences among CD feeder openings were observed, and G:F was similar among all feeder treatments. In Exp. 3, 1,287 pigs (BW 38 kg) were used in a 92-d factorial experiment with 4 feeder treatments and 2 diet types (low and high by-product diets). Feeder treatments were CD at ≈2.4-cm opening, WD at 3.2-cm opening, WD changed to 2.5-cm opening on d 56, and WD changed to 2.5-cm opening on d 28 and 1.9-cm opening on d 56. Pigs fed with a WD feeder had greater (P < 0.01) ADG, ADFI, HCW, and backfat, but decreased FFLI, than pigs fed with a CD feeder. Reducing the WD feeder opening during the study decreased (P < 0.05) ADG. Pigs with the WD feeder opening reduced to 1.9 cm had decreased (P < 0.05) ADFI and backfat but increased FFLI compared with pigs with a WD feeder opening of 3.2 cm. Feed efficiency was similar among treatments. In conclusion, ADG, ADFI, HCW, and backfat were increased with the WD feeder evaluated in this experiment, but the growth of pigs fed with a WD feeder was more sensitive to differences in feeder adjustment than that of pigs fed with a CD feeder.
Journal of Animal Science 09/2012; · 2.10 Impact Factor
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ABSTRACT: The objective was to compare the effects of a conventional dry (CD, 152.4-cm-wide, 5-space, Staco Inc., Schaefferstown, PA) and a wet-dry (WD, double-sided, each side = 38.1 cm space, Crystal Springs, GroMaster Inc., Omaha, NE) feeder using various feeder adjustment openings on the growth performance and carcass characteristics of growing-finishing pigs. In Exp. 1, 1,296 pigs (BW 19 kg) were used in a 27-d study to evaluate 3 feeder openings nested within each feeder design. From d 0 to 27, pigs fed with a WD feeder had similar ADG, but lower (P < 0.02) ADFI and better G:F, compared to pigs fed with a CD feeder. Increased adjustment opening increased (linear, P < 0.01) ADG and ADFI of pigs fed with a WD feeder, and increased (linear, P < 0.01) ADFI of pigs fed with a CD feeder. In Exp. 2, 1,248 pigs (BW 33 kg) were used to evaluate 3 feeder openings nested within each feeder design in a 93-d study. Pigs fed with a WD feeder had greater (P < 0.05) ADG, ADFI, final BW, HCW, and backfat, but decreased fat-free lean index (FFLI), compared with those fed with a CD feeder. Increased opening of the WD feeder resulted in greater (linear, P < 0.05) ADG, ADFI, HCW, and backfat, but lower FFLI. No differences among CD feeder openings were observed, and G:F was similar among all feeder treatments. In Exp. 3, 1,287 pigs (BW 38 kg) were used in a 92-d factorial experiment with 4 feeder treatments and 2 diet types (low and high by-product diets). Feeder treatments were CD at ≈2.4-cm opening, WD at 3.2-cm opening, WD changed to 2.5-cm opening on d 56, and WD changed to 2.5-cm opening on d 28 and 1.9-cm opening on d 56. Pigs fed with a WD feeder had greater (P < 0.01) ADG, ADFI, HCW, and backfat, but decreased FFLI, than pigs fed with a CD feeder. Reducing the WD feeder opening during the study decreased (P < 0.05) ADG. Pigs with the WD feeder opening reduced to 1.9 cm had decreased (P < 0.05) ADFI and backfat but increased FFLI compared with pigs with a WD feeder opening of 3.2 cm. Feed efficiency was similar among treatments. In conclusion, ADG, ADFI, HCW, and backfat were increased with the WD feeder evaluated in this experiment, but the growth of pigs fed with a WD feeder was more sensitive to differences in feeder adjustment than that of pigs fed with a CD feeder.
Journal of Animal Science 09/2012; · 2.10 Impact Factor
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ABSTRACT: Two studies were conducted to determine the effects of feeder adjustment and trough space on growth performance of finishing pigs. In Exp. 1, 234 pigs (initial BW 41.5 kg) were used in an 89-d trial. Pigs were randomly alloted to 1 of 3 treatments with 9 replications of 8 pigs/pen and 1 replicate with 6 pigs/pen. Treatments consisted of a minimum feeder gap setting of 1.27, 1.91, or 2.54 cm. Feeders were adjusted to a minimum gap setting, but the agitation plate could be moved upward to a maximum opening of 1.91, 2.54, or 3.18 cm, respectively. Feeder adjustments of 1.27, 1.91, and 2.54 cm averaged 28, 58, and 75% pan coverage, respectively. From d 0 to 58, increasing feeder gap improved (linear; P ≤ 0.04) ADG and ADFI, but decreased (linear; P < 0.05) G:F. Although the response was linear for ADG, no increase occurred (quadratic; P = 0.15) beyond the 1.91 cm feeder gap setting. From d 58 to 89, increasing feeder gap setting tended (linear; P = 0.08) to worsen G:F. Overall (d 0 to 89), pigs fed with increasing feeder gap had decreased (linear; P < 0.03) G:F due to increased (linear; P < 0.02) ADFI. In Exp. 2, 288 pigs (initial BW 41.3 kg) were used in a 91-d study to evaluate the effects of feeder trough space (4.45 vs. 8.9 cm/pig) and minimum feeder gap opening of 1.27 cm (narrow) vs. 2.54 cm (wide). The treatments were arranged in a 2 × 2 factorial with 6 replications per treatment. Feeder trough space was altered by having pens of either 8 to 16 pigs per pen with all pigs provided 0.74 m(2) floor space per pig. From d 0 to 56 and 56 to 91, no adjustment × space interactions or effects of trough space were observed. From d 0 to 56, pigs with the wide feeder gap setting had decreased (P < 0.02) G:F compared with those that had the narrow feeder gap setting. From d 56 to 91, pigs with the wider feeder gap setting had increased (P < 0.001) ADFI, but consequently had decreased (P < 0.01) G:F. Overall (d 0 to 91), no trough space × feeder adjustment interactions were observed. However, ADG tended to increase (P = 0.08) as feeder trough space increased from 4.45 to 8.9 cm/pig. Pigs fed with the wide feeder gap setting had increased (P < 0.01) feed disappearance and decreased (P < 0.01) G:F compared with pigs with the narrow feeder gap setting. These data indicate that pigs from 41 to 68 kg need approximately 58% pan coverage, whereas pigs greater than 68 kg should have approximately 28% pan coverage to optimize growth and reduce feed wastage.
Journal of Animal Science 07/2012; · 2.10 Impact Factor
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ABSTRACT: Four experiments were conducted to determine the standardized ileal digestible (SID) Lys requirement of pigs from 7 to 14 kg. In Exp. 1, 294 pigs (6.8 kg BW) were used in a 28-d growth trial with 7 pigs per pen and 7 pens per treatment. Treatment diets were fed from d 0 to 14 and a common diet was fed from d 14 to 28. The 6 SID Lys levels tested were 1.15, 1.23, 1.30, 1.38, 1.45, and 1.53%. The diets were corn-soybean meal-based with 10% spray-dried whey and 4.5% fish meal and contained 3.37 Mcal of ME/kg. From d 0 to 14, ADG increased (quadratic, P < 0.001) as SID Lys increased from 1.15 to 1.30% with no further increase at greater levels. Gain:feed increased (linear, P < 0.001) with increasing SID Lys. Experiments 2 to 4 were 14-d growth trials with diets containing 1.22, 1.32, 1.42, 1.52, or 1.62% SID Lys. Diets were corn-soybean meal-based with 3.45 Mcal of ME/kg. Soybean meal and lactose were constant in all diets at 30 and 7% of the diet, respectively. In Exp. 2, 840 pigs (7.6 kg BW) were used with 24 pigs per pen and 7 pens per treatment. Increasing SID Lys from 1.22 to 1.42% increased (quadratic, P < 0.01) ADG and G:F with no further improvement observed in pigs fed the 1.52 or 1.62% SID Lys diets during d 0 to 14. In Exp. 3, 1,260 pigs (8.5 kg BW) were used with 42 pigs per feeder (2 pens per feeder) and 6 feeders per treatment. Increasing dietary Lys increased (quadratic, P < 0.02) ADG and G:F with the greatest response observed as SID Lys increased from 1.22 to 1.32% and, then, sight improvements with 1.42 and 1.52% during d 0 to 14. In Exp. 4, 770 pigs (7.4 kg BW) were used with 22 pigs per pen and 7 pens per treatment. Increasing SID Lys increased (quadratic, P = 0.05) ADG with pigs fed 1.32 and 1.42% SID Lys diets having the greatest gains during d 0 to 14. Increased SID Lys decreased (linear, P < 0.001) ADFI and increased (linear, P < 0.001; quadratic, P = 0.02) G:F. In conclusion, results of these experiments indicate that the 1998 NRC Lys recommendations (e.g., 1.19% SID Lys for 5 to 10 kg pigs) are less than required for optimal growth for 7 to 14 kg pigs. One-slope straight broken-line analysis indicated that the SID Lys requirement for optimal growth was at least 1.30% for ADG and 1.37% for G:F, or at least 3.86 and 4.18 g SID Lys/Mcal ME, respectively. Quadratic broken-line analysis indicated that the SID Lys requirement for optimal growth was at least 1.37% for ADG and 1.54% for G:F, or at least 4.19 and 4.92 g SID Lys/Mcal ME, respectively.
Journal of Animal Science 06/2012; · 2.10 Impact Factor
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ABSTRACT: Two experiments were conducted to evaluate the effect of nursery diet sources, porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae (M. hyo) vaccines, and vaccination timing on pig performance. In Exp. 1, a total of 400 pigs (5.6 SD 1.03 kg BW) were used in a 20-d study. Treatments were arranged in a 4 × 2 factorial in a blocked design (5 pigs/pen and 10 pens/treatment) with main effects of diet manufacturing source (A, B, C, or D) and vaccination timing (d 0 or 8). On either d 0 (weaning) or 8, pigs received two vaccines (Circumvent PCV; Intervet/Schering-Plough Animal Health, Millsboro, DE, and RespiSure One; Pfizer Animal Health, New York, NY). A pre-determined amount of segregated early weaning (SEW) diet (0.45 kg/pig) was fed followed by a transition diet until d 8 and a common diet from d 8 to 20. Diet source affected (P < 0.001) ADG during the first 4 d and affected (P ≤ 0.02) ADG and ADFI from d 4 to 8. There were no differences (P ≥ 0.18) among diet sources once pigs were fed a common diet (d 8 to 20). Overall, diet source did not affect ADG; but ADFI tended (P = 0.06) to be decreased for pigs fed diet C compared with those fed diets A, B, and D. Pigs vaccinated on d 0 had decreased (P ≤ 0.01) ADG and ADFI (d 4 to 8 and d 0 to 8), resulting in lighter (P = 0.003) BW on d 8 than those of pigs not yet vaccinated (d 8). However, overall ADG was not affected by vaccination timing. In Exp. 2, 360 pigs (5.9 SD 0.91 kg BW) were used in a 35-d trial to evaluate the effects of different vaccines. Treatments were arranged in a 3 × 2 factorial in a blocked design (5 pigs/pen and 12 pens/treatment). Main effects included PCV2 vaccine (none; CircoFLEX, Boehringer Ingelheim Vetmedica, Inc, St. Joseph, MO; or Circumvent PCV); with or without a M. hyo vaccine (RespiSure, Pfizer Animal Health, New York, NY). Overall, pigs vaccinated with Circumvent PCV had decreased (P < 0.02) ADG and ADFI compared to CircoFLEX-vaccinated or control pigs. On d 35, pigs vaccinated with Circumvent PCV weighed less (P < 0.01) than CircoFLEX-vaccinated or control pigs.RespiSure-vaccinated pigs had decreased (P ≤ 0.05) ADG compared with control pigs from d 14 to 21 and d 21 to 29. On d 35, RespiSure-vaccinated pigs tended (P = 0.06) to weigh and consume less than control pigs. These data indicate diet source and vaccination timing affects pig performance after weaning. Vaccination for PCV2 and M. hyo independently reduced ADG and ADFI, but the effect was product-dependent.
Journal of Animal Science 06/2012; · 2.10 Impact Factor
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ABSTRACT: This study was conducted to determine the effects of dietary crude glycerol and dried distillers grains with solubles (DDGS) on growing-finishing pig performance, carcass characteristics, and carcass fat quality. We hypothesized that because dietary crude glycerol has been observed to increase carcass SFA, it might ameliorate the negative effects of DDGS on fat quality. The 97-d study was conducted at a commercial swine research facility in southwestern Minnesota with 1,160 barrows (initial BW = 31.0 ± 1.1 kg). Pigs were blocked by initial BW, and pens were randomly allotted to 1 of 6 dietary treatments with 7 replications per treatment. Treatments were arranged in a 2 × 3 factorial with main effects of crude glycerol (0, 2.5, or 5%) and DDGS (0 or 20%). All corn-soybean meal-based diets contained 3% added fat (choice white grease). There were no glycerol × DDGS interactions for any response criteria evaluated. Increasing dietary glycerol did not affect finishing pig growth performance. Adding 20% DDGS to the diet did not affect ADG; however, finishing pigs fed diets with added DDGS had greater (2.47 vs. 2.41 kg/d; P = 0.02) ADFI and poorer (0.39 vs. 0.40; P = 0.01) G:F than pigs not fed DDGS. Feeding increasing dietary glycerol or 20% DDGS did not affect carcass characteristics. For carcass fat quality, feeding 20% DDGS resulted in decreased (P < 0.01) palmitic and oleic acids, total SFA and total MUFA, and increased (P < 0.01) linoleic, total PUFA, total unsaturated fatty acids, and iodine value in jowl fat, belly fat, and backfat. Increasing dietary crude glycerol increased myristic acid (linear, P < 0.05) and MUFA (quadratic, P < 0.05) in jowl fat and increased (quadratic, P < 0.05) oleic acid and MUFA in backfat. In conclusion, feeding 20% DDGS to finishing pigs increased ADFI, reduced G:F, and increased carcass fat iodine value, whereas feeding crude glycerol did not influence growth performance, carcass characteristics, and had a minor influence on fatty acids of carcass fat. Both of these biofuel coproducts can be used in combination without affecting finishing pig performance or carcass traits; however, feeding crude glycerol did not fully mitigate the increased unsaturation of carcass fat observed when feeding DDGS.
Journal of Animal Science 03/2012; 90(3):840-52. · 2.10 Impact Factor
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ABSTRACT: A total of 240 weanling pigs (34 d of age with an average body weight of 17.1 lb) were used in a 35-d growth trial to compare the growth performance effects of copper (Cu) and feed-grade antimicrobials. The 6 dietary treatments were arranged in a 2 × 3 facto- rial with 2 added Cu levels (basal level of 16.5 ppm or basal + 125 ppm from copper sulfate) and 3 antimicrobial treatments including a control, chlortetracycline (CTC; Alpharma, Fort Lee, NJ) at 500 g/ton (10 mg/kg BW), and tylosin (Tylan; Elanco Animal Health, Greenfield, IN) at 100 g/ton. Each treatment had 8 pens with 5 pigs per pen. Treatments were allotted to pen in a randomized complete block design, with location within the barn serving as the blocking factor. Following the brief acclimatization period prior to starting the experiment (13 d), pigs were fed dietary treatments for 21 d followed by another 14 d on the control diet to examine any carryover effects. No significant copper × antimicrobial interactions were observed (P > 0.07) for any pig performance response. From d 0 to 21, pharmacological Cu tended to increase (P < 0.07) both ADG and ADFI compared with pigs provided basal levels of Cu. Dietary CTC inclusion increased (P < 0.01) ADG and tended to improve (P < 0.09) ADFI and F/G over pigs not fed diets with CTC. Dietary Tylan did not alter (P > 0.19) ADG, ADFI, or F/G compared with pigs provided the control diets. From d 21 to 35, pigs that previously had received pharmacological Cu tended to have lower (P < 0.06) ADG compared with those never receiving pharmacological Cu. Also, pigs previously receiving Tylan had lower (P < 0.01) ADG than those never receiving Tylan. For the overall trial (d 0 to 35), adding Cu for the first 21 d had no impact (P > 0.32) on ADG, ADFI, or F/G. Similarly, Tylan did not influence (P > 0.30) pig performance. The benefits of CTC during the first 21 d led to a tendency for increased (P < 0.06) ADG and ADFI compared with those not receiving CTC. Overall, pharmacological Cu and antimicrobials may offer performance advantages when incorporated in nursery pig diets; however, that advantage will not increase and may be lost after Cu and/or antimicrobials are removed from diet.
Swine Day; 11/2011
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ABSTRACT: In a previous study with limit-fed gestating gilts, we observed that gilts fed 6 times/d had greater ADG than those fed the same amount over 2 feedings. To confirm these earlier responses, we used finishing pigs as a model in two 42-d trials and two 28-d trials to evaluate the effects of restricted feed intake and feeding frequency (2 vs. 6 times/d, floor fed) on pig performance between 68 and 114 kg. In all experiments, pigs (10/pen) were housed in 1.8 × 3.1 m pens with a half-solid, half-slatted concrete floor. Pigs were fed a corn- and soybean meal-based diet formulated to 1.15% standardized ileal digestible Lys and 3,294 kcal of ME/kg. In Exp. 1 to 3, energy and Lys were supplied to pigs according to NRC (1998) calculations to target an ADG of 0.80 kg. In Exp. 4, the diet was supplied to pigs to target an ADG of 0.80 kg (low feed intake) or 0.95 kg (high feed intake) to determine if the amount of energy above the maintenance requirement and feeding frequency affected pig performance. Pigs were fed by dropping similar amounts of feed onto the solid concrete floor either 2 (0700 or 1400 h) or 6 times (3 meals within 2 h at the morning and afternoon feedings) per day with an Accu-Drop Feed Dispenser (AP Systems, Assumption, IL). In Exp. 1 and 2, pigs fed 6 times daily had increased (P < 0.02) ADG and G:F compared with pigs fed 2 times per day. Greater feeding frequency increased (P < 0.05) the duration of time spent feeding and standing and reduced the lying time. In Exp. 3, a third treatment was included to determine whether the improvements in performance were due to decreased feed wastage. This treatment was designed to minimize feed wastage by dropping feed closer to the floor for pigs fed 2 times per day. Pigs fed 6 times daily had improved (P < 0.05) ADG and G:F compared with pigs in either treatment fed 2 times per day. No difference (P > 0.05) in performance was observed between pigs fed 2 times per day when feed was dropped from the feed drop or by the modified method. In Exp. 4, increasing the feeding frequency from 2 to 6 times per day improved (P < 0.01) ADG and G:F for pigs fed the low feed intake and tended to increase (P < 0.06) ADG and improved (P < 0.05) G:F for pigs fed the high feed intake. In limit-feeding situations, increasing the frequency of feeding from 2 to 6 times per day improved pig performance, which confirmed our earlier findings in gestating gilts.
Journal of Animal Science 10/2011; 89(10):3326-33. · 2.10 Impact Factor
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ABSTRACT: The objective of this study was to evaluate the relationships of sow and litter characteristics with piglet birth weight and the implications for growth, survival, and carcass characteristics of pigs on a commercial farm. Data were obtained from 212 litters born in 22 consecutive days, and included individual pig identification and collection of BW at birth (n = 2,204), weaning (≈ 25 d of age), and approximately 180 d of age (weaning-to-finish, n = 1,736). All general management and feeding practices were performed according to normal farm procedures throughout the study. Fostering was practiced primarily within 24 h of birth, but the transfer or removal of individual pigs was recorded. Therefore, pigs were categorized by size of litter of origin (≤ 11, 12 to 14, and ≥ 15 total born), parity of birth dam (1, 2, 3, 4 and 5, and 6 to 9), fostered status (yes or no), parity of dam suckled (1, 2 and 3, and 4 to 9), birth weight (< 1.15, 1.15 to 1.35, 1.40 to 1.50, 1.55 to 1.65, 1.70 to 1.80, 1.85 to 2.05, and > 2.05 kg), and gender (barrow or gilt). Carcass data were obtained from a sample of 418 pigs harvested in a single day at a commercial processor. Although birth weight decreased (P < 0.05) with increasing litter size, pigs born to parity 2 to 5 sows originated from larger (P < 0.05) litters with greater (P < 0.05) mean birth weight when compared to parity 1 and parity 6 to 9 sows. The SD of birth weight within litter of origin increased (P < 0.05) with litter size and parity of the birth dam. Pre-weaning ADG and survival improved (P < 0.05) with increasing birth weight. Weaning-to-finish and lifetime ADG, final BW (180 d of age), and likelihood of achieving full market value were improved (P < 0.05) for pigs with greater birth weight and for barrows. Fat-free lean index (adjusted for HCW) was improved (P < 0.05) for gilts and pigs with greater birth weight. Although birth weight and gender were most important, fostering revealed that parity of the sow suckled (rather than the parity of the birth dam) was also important for subsequent growth. Pre-weaning and lifetime ADG improved (P < 0.05) for pigs suckling parity 2 and older sows. These data provide further evidence of the fundamental importance of birth weight for growth and survival of pigs on a commercial farm. Although birth weight generally decreased with larger litter sizes, the data indicate that an optimum herd parity structure and improved fostering practices may ameliorate the potential consequences of increased litter size for overall pig growth.
09/2011;
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ABSTRACT: The objectives of this research were to evaluate the effects of dietary astaxanthin (AX) and ractopamine HCl (RAC) on the growth, carcass characteristics, LM color, and color shelf-life of LM chops of barrows and gilts. Pigs were TR4 × C22 (PIC, Hendersonville, TN) and diets were corn-soybean meal-based in all experiments. In Exp. 1, 48 barrows (98 kg initial BW) were fed 26 d to evaluate the effects of AX, with 2 pigs/pen and 6 pens/treatment. The 4 dietary treatments consisted of 0, 5, 10, and 20 ppm AX from Xanthophyllomyces dendrorhous (yeast). No differences in growth performance were observed in this experiment; however, pigs fed increasing AX tended (quadratic, P < 0.08) to have decreased backfat depth and increased fat-free lean index. After 30-min bloom at 24 h postmortem, the 10th-rib LM surface of pigs fed AX tended (P < 0.08) to be darker (lower CIE L*) and less yellow (lower CIE b*). In Exp. 2, 72 barrows and 72 gilts (102 kg initial BW) were fed 26 d to evaluate the effects of AX and RAC. Pigs were blocked by BW with 2 barrows or gilts/pen and 4 pens of each gender/treatment. The 9 dietary treatments consisted of 0, 5, 7.5, and 10 ppm AX from yeast, 5 ppm synthetic AX, and 10 ppm RAC with 0, 2.5, 5, and 7.5 ppm AX from yeast. Feeding RAC increased ADG, G:F, final BW, HCW, and LM area, but no differences were associated with feeding AX. No differences occurred in initial color scores, but discoloration scores of LM chops increased (linear, P < 0.01) during 7 d of retail display, and were greater (P < 0.01) for barrow chops on d 7 (d × gender interaction, P < 0.01). Also, overall discoloration scores and d 0 to 3 objective total color change were lower (P < 0.01) for gilt chops and those from pigs fed RAC. In Exp. 3, 80 barrows and 80 gilts (90 kg initial BW) were fed 26 d to evaluate the effects of AX and RAC, with 1 barrow and gilt/pen and 10 pens/treatment. The 8 treatments were 0, 7.5, 15, 30, 60, and 120 ppm AX from yeast, and 10 ppm RAC with 7.5 and 20 ppm AX from yeast. Feeding RAC increased ADG, G:F, final BW, HCW, and LM area. Among non-RAC fed pigs, G:F improved (quadratic, P < 0.05) and ADG increased (quadratic, P < 0.06) with increasing AX up to 60 ppm. As in Exp. 2, discoloration scores of LM chops did not differ initially, but increased (linear, P < 0.01) during display and were greater (P < 0.02) for chops from barrows and non-RAC fed pigs on d 6 (d × gender and d × treatment, P < 0.04). Also, overall discoloration scores and total color change during a 6-d retail display were lower (P < 0.02) for chops from gilts and pigs fed RAC. These results suggest that color shelf-life of LM chops from gilts and pigs fed 10 ppm RAC was extended, but was not influenced by feeding AX.
09/2011;
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ABSTRACT: A 360-d study was performed to evaluate the effects of different environmental conditions on storage stability of exogenous phytases. Coated and uncoated products from 3 phytase sources [Ronozyme P (DSM Nutritional Products, Basel, Switzerland), OptiPhos (Phytex LLC, Sheridan, IN), and Phyzyme (Danisco Animal Nutrition, Marlborough, UK)] were stored as pure forms, in a vitamin premix, or in a vitamin and trace mineral (VTM) premix. Pure products were stored at -18, 5, 23, and 37°C (75% humidity). Premixes were stored at 23 and 37°C. Sampling was performed on d 0, 30, 60, 90, 120, 180, 270, and 360. Sampling of the pure products stored at -18 (lack of sample) and 5°C (because of mold growth) was discontinued after d 120. Stability was reported as the residual phytase activity (% of initial) at each sampling point. For the stability of the pure forms, all interactive and main effects of the phytase product, coating, time, and storage temperature were significant (P < 0.01), except for the time × coating interaction. When stored at 23°C or less, pure phytases retained at least 91, 85, 78, and 71% of their initial phytase activity at 30, 60, 90, and 120 d of storage, respectively. However, storing pure products at 37°C reduced (P < 0.01) phytase stability, with OptiPhos retaining the most (P < 0.01) activity. Coating mitigated (P < 0.01) the negative effects of high storage temperature for Ronozyme and OptiPhos (from d 90 onward), but not for Phyzyme. For the stability of phytase in different forms of storage, all interactive and main effects of phytase product, form, coating, time, and temperature of storage were significant (P < 0.01). When stored at room temperature (23°C), retained phytase activities for most the phytase sources were more than 85, 73, and 60% of the initial activity up to 180 d when stored as pure products, vitamin premixes, or VTM premixes, respectively. When stored at 37°C, pure phytase products had greater (P < 0.01) retention of initial phytase activity than when phytases were mixed with the vitamin or VTM premixes. Coated phytases stored in any form had greater (P < 0.01) activity retention than the uncoated phytases at all sampling periods. Results indicate that storage stability of commercially available phytases is affected by duration of storage, temperature, product form, coating, and phytase source. Pure products held at 23°C or less were the most stable. In premixes, longer storage times and higher temperatures reduced phytase activity, but coating mitigated some of these negative effects.
Journal of Animal Science 09/2011; 89(12):4262-71. · 2.10 Impact Factor
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ABSTRACT: Four experiments were conducted to examine the effect of porcine circovirus type 2 (PCV2) vaccination on the response of growing and finishing pigs (PIC 337 × 1050) to increasing dietary Lys. Experiments 1 and 2 evaluated 38- to 65-kg gilts and barrows, respectively, and Exp. 3 and 4 evaluated 100- to 120-kg gilts and barrows, respectively. Gilts and barrows were housed separately in different barns. Treatments were allotted in a completely randomized design into 2 × 4 factorials with 2 PCV2 treatments (PCV2-vaccinated and nonvaccinated) and 4 standardized ileal digestible (SID) Lys:ME ratios (2.24, 2.61, 2.99, and 3.36 g/Mcal in Exp. 1 and 2 and 1.49, 1.86, 2.23, and 2.61 g/Mcal in Exp. 3 and 4) within each experiment. There were 5 pens per treatment. At the start of Exp. 1 and 2, there were more pigs per pen (P < 0.001) in vaccinated pens because vaccinated pigs had a greater survival rate than nonvaccinated pigs, and this increase was maintained throughout the experiments. Removal rate approached 30% in nonvaccinated barrows and more than 20% in nonvaccinated gilts. Observation suggested that the removals were largely due to PCV2-associated disease. No PCV2 vaccination × SID Lys:ME ratio interactions (P > 0.10) were observed in any of the 4 studies. In Exp. 1 and 2, PCV2-vaccinated pigs had increased (P < 0.001) ADG compared with nonvaccinated pigs. The growth response was primarily due to increases in ADFI, which suggests that vaccinated pigs have a greater Lys requirement (g/d) than nonvaccinated pigs. In Exp. 1, increasing the SID Lys:ME ratio increased (quadratic; P < 0.04) ADG and G:F, with pigs fed the 2.99 g/Mcal ratio having the greatest ADG and G:F. In Exp. 2, increasing the SID Lys:ME ratio improved (linear; P < 0.001) G:F. In Exp. 3, ADG and G:F increased (P < 0.05) in a quadratic manner as the SID Lys:ME ratio fed increased. In Exp. 4, increasing the SID Lys:ME ratio increased ADG (linear; P < 0.001) and G:F (quadratic; P = 0.03). Although PCV2 vaccination improved growth, the corresponding increase in ADFI did not increase the optimal SID Lys:ME ratio for growing and finishing barrows and gilts.
Journal of Animal Science 08/2011; 90(1):361-72. · 2.10 Impact Factor
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ABSTRACT: Three experiments were conducted to determine the effects of increasing dietary standardized ileal digestible (SID) Lys on growing and finishing gilts. Diets in all 3 experiments were corn-soybean meal-based and contained 0.15% l-Lys•HCl and 3% added fat from choice white grease. Desired SID Lys concentrations were achieved by altering levels of corn and soybean meal in the diet. Each experiment consisted of 6 treatments with 7 pens per treatment and approximately 27 gilts (PIC 337 × 1050) per pen. In Exp. 1, 1,085 gilts (initially 38.2 kg) were fed diets formulated to contain SID Lys concentrations of 0.7, 0.8, 0.9, 1.0, 1.1, or 1.2% for 28 d, which were analyzed to be total Lys concentrations of 0.78, 0.86, 0.99, 1.06, 1.14, and 1.24%, respectively. As SID Lys increased, ADG and G:F improved (quadratic, P < 0.003) with optimal performance reached at the SID Lys level of 1.1% or SID Lys:ME ratio of 3.16 g/Mcal. Broken-line analysis indicated breakpoints of 1.03 and 1.05% SID Lys for ADG and G:F, respectively. Gilts in this trial required approximately 21.8 g of SID Lys intake per kilogram of BW gain from 38 to 65 kg. In Exp. 2, 1,092 (initially 55.2 kg) gilts were fed diets formulated to contain SID Lys concentrations of 0.66, 0.74, 0.82, 0.90, 0.98, or 1.06% for 28 d, which were analyzed to be total Lys concentrations of 0.75, 0.73, 0.84, 0.90, 0.95, and 0.97%, respectively. Both ADG (quadratic, P = 0.12) and G:F improved (linear, P < 0.001) as SID Lys increased, with broken-line analysis of ADG indicating a requirement estimate of 0.90%, which corresponds to a SID Lys:ME ratio of 2.58 g/Mcal. Gilts in this trial required approximately 19.6 g of SID Lys per kilogram of BW gain from 55 to 80 kg. In Exp. 3, 1,080 gilts (initially 84.1 kg) were fed diets formulated to contain SID Lys concentrations of 0.54, 0.61, 0.68, 0.75, 0.82, or 0.89% for 29 d, which were analyzed to be total Lys concentrations of 0.62, 0.92, 0.79, 0.99, 0.93, and 1.07%, respectively. As the SID Lys concentration increased, ADG and G:F improved (linear, P < 0.001), and performance responses were maximized at the greatest SID Lys level of 0.89% or SID Lys:ME ratio of 2.55 g/Mcal of ME. Gilts in this trial required 23.0 g of SID Lys per kg of BW gain from 85 to 110 kg. The ideal SID Lys:ME ratio was based on the requirement determined by broken-line analysis in Exp. 1, 2, and 3, with the greatest level being tested in Exp. 3. This equation, SID Lys:ME ratio = -0.011 × BW, kg + 3.617, estimates the optimal SID Lys:ME ratios for growth of gilts (PIC 337 × 1050) in this commercial finishing environment. These studies showed growth performance advantages to increasing SID Lys for growing and finishing gilts over previously reported optimal levels, particularly in the later finishing stages.
Journal of Animal Science 06/2011; 89(11):3587-95. · 2.10 Impact Factor
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ABSTRACT: A total of 120 barrows (initial BW = 47.9 ± 3.6 kg; PIC 1050) were used in an 83-d study to determine the effects of dietary iodine value (IV) product (IVP) on growth performance and fat quality. Pigs were blocked by BW and randomly allotted to 1 of 6 treatments with 2 pigs per pen and 10 pens per treatment. Dietary treatments were fed in 3 phases and formulated to 3 IVP concentrations (low, medium, and high) in each phase. Treatments were 1) corn-soybean meal control diet with no added fat (low IVP), 2) corn-extruded expelled soybean meal (EESM) diet with no added fat (medium IVP), 3) corn-soybean meal diet with 15% distillers dried grains with solubles and choice white grease (DDGS + CWG; medium IVP), 4) corn-soybean meal diet with low CWG (medium IVP), 5) corn-EESM diet with 15% DDGS (high IVP), and 6) corn-soybean meal diet with high CWG (high IVP). On d 83, pigs were slaughtered and backfat and jowl fat samples were collected and analyzed. The calculated and analyzed dietary IVP values were highly correlated (r(2) = 0.86, P < 0.01). Pigs fed the control diet, EESM, or high CWG had greater (P < 0.05) ADG than pigs fed EESM + DDGS. Pigs fed the control diet had greater (P < 0.05) ADFI than pigs fed all other diets. Pigs fed EESM + DDGS and high CWG had improved (P < 0.05) G:F compared with pigs fed the control diet or DDGS + CWG. Pigs fed diets with DDGS had greater (P < 0.05) backfat and jowl fat IV, C18:2n-6, and PUFA and less SFA than pigs fed all other treatments. Pigs fed EESM had greater (P < 0.05) backfat and jowl fat IV, C18:2n-6, and PUFA than pigs fed the control diet, low CWG, or high CWG. Pigs fed low CWG or high CWG had greater (P < 0.05) jowl fat IV than control pigs. Feeding ingredients high in unsaturated fatty acids, such as DDGS and EESM, had a greater impact on fat IV than CWG, even when diet IVP was similar. Therefore, IVP was a poor predictor of carcass fat IV in pigs fed diets with different fat sources and amounts of unsaturated fats formulated with similar IVP. Dietary C18:2n-6 content was a better predictor of carcass fat IV than diet IVP.
Journal of Animal Science 05/2011; 89(5):1419-28. · 2.10 Impact Factor
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ABSTRACT: A total of 120 pigs (60 barrows and 60 gilts; TR4 × PIC 1050; 54.4 kg initial BW) were used in an 83-d study to evaluate the effects of added fat in corn- and sorghum-based diets on growth performance, carcass characteristics, and carcass fat quality. Treatments were arranged in a 2 × 3 factorial with grain source (corn or sorghum) and added fat (0, 2.5, or 5% choice white grease; CWG) as factors. There were 2 pigs (1 barrow and 1 gilt) per pen and 10 replicate pens per treatment. Pigs and feeders were weighed on d 14, 22, 39, 53, 67, and 83 to calculate ADG, ADFI, and G:F. At the end of the trial, pigs were slaughtered and jowl fat and backfat samples were collected and analyzed for fatty acid profile. No interactions were observed for growth performance. Pigs fed sorghum-based diets had greater (P < 0.01) ADG than pigs fed corn-based diets. Adding CWG improved (linear, P < 0.01) ADG. Pigs fed corn-based diets tended to have greater (P < 0.09) carcass yield, 10th-rib backfat, and percentage lean than pigs fed sorghum-based diets. Adding CWG increased (linear, P = 0.02) 10th-rib backfat, tended to increase (linear, P = 0.08) HCW, and tended to decrease (linear, P = 0.07) percentage lean. There was no grain source × fat level interaction for iodine value (IV) in backfat, but an interaction (P = 0.03) was observed for IV in jowl fat. Adding CWG increased (P < 0.01) IV in jowl fat for pigs fed sorghum- and corn-based diets; however, the greatest increase was between 0 and 2.5% CWG in sorghum-based diets and between 2.5 and 5% CWG in corn-based diets. Pigs fed corn-based diets had less (P = 0.01) C18:1 cis-9 and MUFA but greater (P = 0.01) C18:2n-6, PUFA, and backfat IV than pigs fed sorghum-based diets. Increasing CWG in the diet increased (linear, P = 0.01) backfat IV. Of the 2 fat depots, backfat generally had a reduced IV than jowl fat. In summary, feeding sorghum-based diets reduced carcass fat IV and unsaturated fats compared with corn-based diets. As expected, adding CWG increased carcass fat IV regardless of the cereal grain in the diet.
Journal of Animal Science 03/2011; 89(3):773-82. · 2.10 Impact Factor
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ABSTRACT: Three experiments were conducted to evaluate the effects of increasing dietary Cu and Zn on weanling pig performance. Diets were fed in 2 phases: phase 1 from d 0 to 14 postweaning and phase 2 from d 14 to 28 in Exp. 1 and 2 and d 14 to 42 in Exp. 3. The trace mineral premix, included in all diets, provided 165 mg/kg of Zn from ZnSO(4) and 16.5 mg/kg of Cu from CuSO(4). In Exp. 1, treatments were arranged in a 2 × 3 factorial with main effects of added Cu from tri-basic copper chloride (TBCC; 0 or 150 mg/kg) and added Zn from ZnO (0, 1,500, or 3,000 mg/kg from d 0 to 14 and 0, 1,000, or 2,000 mg/kg from d 14 to 28). No Cu × Zn interactions were observed (P > 0.10). Adding TBCC or Zn increased (P < 0.05) ADG and ADFI during each phase. In Exp. 2, treatments were arranged in a 2 × 3 factorial with main effects of added Zn from ZnO (0 or 3,000 mg/kg from d 0 to 14 and 0 or 2,000 mg/kg from d 14 to 28) and Cu (control, 125 mg/kg of Cu from TBCC, or 125 mg/kg of Cu from CuSO(4)). No Cu × Zn interactions (P > 0.10) were observed for any performance data. Adding ZnO improved (P < 0.02) ADG and ADFI from d 0 to 14 and overall. From d 0 to 28, supplementing CuSO(4) increased (P < 0.02) ADG, ADFI, and G:F, and TBCC improved (P = 0.006) ADG. In Exp. 3, the 6 dietary treatments were arranged in a 2 × 2 factorial with main effects of added Cu from CuSO(4) (0 or 125 mg/kg) and added Zn from ZnO (0 or 3,000 mg/kg from d 0 to 14 and 0 or 2,000 mg/kg from d 14 to 42). The final 2 treatments were feeding added ZnO alone or in combination with CuSO(4) from d 0 to 14 and adding CuSO(4) from d 14 to 42. Adding ZnO increased (P < 0.04) ADG, ADFI, and G:F from d 0 to 14 and ADG from d 0 to 42. Dietary CuSO(4) increased (P < 0.004) ADG and ADFI from d 14 to 42 and d 0 to 42. From d 28 to 42, a trend for a Cu × Zn interaction was observed (P = 0.06) for ADG. This interaction was reflective of the numeric decrease in ADG for pigs when Cu and Zn were used in combination compared with each used alone. Also, numerical advantages were observed when supplementing Zn from d 0 to 14 and Cu from d 14 to 42 compared with all other Cu and Zn regimens. These 3 experiments show the advantages of including both Cu and Zn in the diet for 28 d postweaning; however, as evident in Exp. 3, when 3,000 mg/kg of Zn was added early and 125 mg/kg of Cu was added late, performance was similar or numerically greater than when both were used for 42 d.
Journal of Animal Science 03/2011; 89(8):2440-51. · 2.10 Impact Factor