Standardized total tract digestible phosphorus requirement of 6 to 13 kg pigs fed diets without or with phytase.

Dietary phosphorus concentration greatly affects pig's growth performance, environmental impact and diet cost. A total of 1080 pigs (initially 5.9 ± 1.08 kg) from three commercial research rooms were used to determine the effects of increasing standardized total tract digestible (STTD) P concentrations in diets without and with phytase on growth performance and percentage bone ash. Pens (10 pigs/pen, 9 pens/treatment) were balanced for equal weights and randomly allotted to 12 treatments. Treatments were arranged in two dose titrations (without or with 2000 units of phytase) with six levels of STTD P each. The STTD P levels were expressed as a percentage of NRC (2012) requirement estimates (% of NRC; 0.45 and 0.40% for phases 1 and 2, respectively) and were: 80%, 90%, 100%, 110%, 125% and 140% of NRC in diets without phytase and 100%, 110%, 125%, 140%, 155% and 170% of NRC in diets with phytase. Diets were provided in three phases, with experimental diets fed during phases 1 (days 0 to 11) and 2 (days 11 to 25), followed by a common diet from days 25 to 46. On day 25, radius samples from one median-weight gilt per pen were collected for analysis of bone ash. During the treatment period, increasing STTD P from 80% to 140% of NRC in diets without phytase improved average daily gain (ADG; quadratic, P < 0.01), average daily feed intake (ADFI; quadratic, P < 0.05) and gain-feed ratio (G : F; linear, P < 0.01). Estimated STTD P requirement in diets without phytase was 117% and 91% of NRC for maximum ADG according to quadratic polynomial (QP) and broken-line linear (BLL) models, respectively, and was 102%, 119% and >140% of NRC for maximum G : F using BLL, broken-line quadratic and linear models, respectively. When diets contained phytase, increasing STTD P from 100% to 170% of NRC improved ADG (quadratic, P < 0.05) and G : F (linear, P < 0.01). Estimated STTD P requirement in diets containing phytase was 138% for maximum ADG (QP), and 147% (QP) and 116% (BLL) of NRC for maximum G : F. Increasing STTD P increased (linear, P < 0.01) the percentage bone ash regardless of phytase addition. When comparing diets containing the same STTD P levels, phytase increased (P < 0.01) ADG, ADFI and G : F. In summary, estimated STTD P requirements varied depending on the response criteria and statistical models and ranged from 91% to >140% of NRC (0.41% to >0.63% of phase 1 diet and 0.36% to >0.56% of phase 2 diet) in diets without phytase, and from 116% to >170% of NRC (0.52% to >0.77% of phase 1 diet and 0.46% to >0.68% of phase 2 diet) for diets containing phytase. Phytase exerted an extra-phosphoric effect on promoting pig's growth and improved the P dose-responses for ADG and G : F.

Evaluating the impact of maternal vitamin D supplementation: I. Sow performance, serum vitamin metabolites, and neonatal muscle characteristics.

In Exp. 1, 56 gestating sows (PIC 1050; 35 d postinsemination) were used in a 30-d trial to determine serum 25(OH)D response to increasing concentrations of dietary vitamin D. Sows were randomly allotted to 1 of 7 dietary D treatments (200, 800, 1,600, 3,200, 6,400, 12,800, or 25,600 IU of added D per kilogram of complete diet) with 8 sows per treatment. Increasing D increased (quadratic; < 0.001) serum 25(OH)D with the response depicted by the prediction equation: serum 25(OH)D, ng/mL = 35.1746 + (0.002353 × dietary D, IU/d) - (0.0000000156 × dietary D, IU/d). In Exp. 2, 112 sows and their litters were used to determine the effects of dietary vitamin D regimen on sow performance, subsequent preweaning pig performance, neonatal bone and muscle characteristics, and serum vitamin metabolites. Sows were allotted to 1 of 4 dietary treatments 3 to 5 d following breeding: 800, 2,000, or 9,600 IU of D per kilogram of the diet or 50 µg of 25(OH)D (2,000 IU of D equivalent from Hy-D, DSM Nutritional Products, Parsippany, NJ) per kilogram of diet. There were 25 to 27 sows per treatment. Increasing dietary D increased (linear, = 0.001) serum 25(OH)D of sows on d 100 of gestation, at farrowing, and at weaning. Increasing D in sow diets increased piglet serum 25(OH)D at birth (linear, = 0.001) and weaning (quadratic, = 0.033). Sows fed 50 µg of 25(OH)D/kg had intermediate ( < 0.004) serum 25(OH)D concentrations on d 100 of gestation, at farrowing, and at weaning compared with sows fed 2,000 IU of D/kg and sows fed 9,600 IU of D/kg. Pigs from sows fed 50 µg of 25(OH)D/kg had greater serum 25(OH)D compared with pigs from sows fed 2,000 IU of D/kg, but at weaning, serum 25(OH)D concentrations were similar. Also, pigs from sows fed 9,600 IU of D/kg had greater ( = 0.011) serum 25(OH)D at birth and weaning compared with pigs from sows fed 50 µg of 25(OH)D/kg. Maternal performance, litter characteristics, neonatal bone ash content, and neonatal muscle fiber characteristics were largely unaffected by the dietary vitamin D treatments. Overall, D and 25(OH)D are both useful at increasing serum 25(OH)D concentrations, but more D (on an equivalent IU basis) is needed to achieve similar serum 25(OH)D responses compared with feeding 25(OH)D. Concentration of maternal vitamin D supplementation in lactation impacted milk transfer of the vitamin more so than the form of the vitamin, as evidence by the weaned pig serum 25(OH)D concentrations.

Evaluating the impact of maternal vitamin D supplementation on sow performance: II. Subsequent growth performance and carcass characteristics of growing pigs.

A of subsample of 448 growing pigs (PIC 327 × 1050) weaned from 52 sows fed varying dietary vitamin D regimens were used in a split-plot design to determine the effects of maternal and nursery dietary vitamin D on growth performance. Sows were previously administered diets containing vitamin D as vitamin D (800, 2,000, or 9,600 IU/kg) or as 25(OH)D (50 µg [or 2,000 IU vitamin D equivalent]/kg from HyD; DSM Nutritional Products, Parsippany, NJ). Once weaned, pigs were allotted to pens on the basis of previous maternal vitamin D treatment, and then pens were randomly assigned to 1 of 2 nursery vitamin D dietary regimens (2,000 IU of vitamin D/kg or 50 µg 25(OH)D/kg). Pigs remained on nursery vitamin D treatments for 35 d, and then they were provided common finishing diets until market (135 kg). Growing pig serum 25(OH)D suggested that maternal dietary vitamin D influenced ( < 0.001 at weaning) serum concentrations early after weaning, but nursery vitamin D regimen had a larger impact ( < 0.001) on d 17 and 35 postweaning. Overall growth performance was not influenced by nursery vitamin D dietary treatments. From d 0 to 35 in the nursery, pigs from sows fed increasing vitamin D had increased (quadratic, < 0.003) ADG and ADFI, but G:F was similar regardless of maternal vitamin D regimen. Also, pigs from sows fed 50 µg/kg of 25(OH)D had increased ( = 0.002) ADG compared with pigs weaned from sows fed 800 IU of vitamin D. Throughout finishing (d 35 postweaning until 135 kg), ADG was increased (quadratic, = 0.005) and G:F was improved (quadratic, = 0.049) with increasing maternal dietary vitamin D. Also, pigs from sows fed 50 µg/kg of 25(OH)D had increased ( = 0.002) ADG compared with pigs weaned from sows fed 800 IU of vitamin D. Carcass data were collected from a subsample population separate from that used for the growth performance portion of the study, and a total of 642 carcasses from progeny of sows fed the varying dietary vitamin D treatments were used. Live BW of pigs at marketing and HCW were heavier ( < 0.030) for pigs from sows previously fed 25(OH)D compared with pigs from sows fed 9,600 IU of vitamin D. Overall, pigs from sows fed 2,000 IU of vitamin D grew faster after weaning compared with pigs from sows fed 800 or 9,600 IU of vitamin D. Pigs from sows fed 25(OH)D hag greater ADG compared with pigs from sows fed 800 IU of vitamin D, and they had increased final BW and HCW compared with pigs from sows fed 9,600 IU of vitamin D.

Equations generated to predict iodine value of pork carcass back, belly, and jowl fat.

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.

Effects of drought-affected corn and nonstarch polysaccharide enzyme inclusion on nursery pig growth performance.

The effectiveness of carbohydrase enzymes has been inconsistent in corn-based swine diets; however, the increased substrate of nonstarch polysaccharides in drought-affected corn may provide an economic model for enzyme inclusion, but this has not been evaluated. A total of 360 barrows (PIC 1050 × 337, initially 5.85 kg BW) were used to determine the effects of drought-affected corn inclusion with or without supplementation of commercial carbohydrases on growth performance and nutrient digestibility of nursery pigs. Initially, 34 corn samples were collected to find representatives of normal and drought-affected corn. The lot selected to represent the normal corn had a test weight of 719.4 kg/m3, 15.0% moisture, and 4.2% xylan. The lot selected to represent drought-affected corn had a test weight of 698.8 kg/m3, 14.3% moisture, and 4.7% xylan. After a 10-d acclimation period postweaning, nursery pigs were randomly allotted to 1 of 8 dietary treatments in a completely randomized design. Treatments were arranged in a 2 × 4 factorial with main effects of corn (normal vs. drought affected) and enzyme inclusion (none vs. 100 mg/kg Enzyme A vs. 250 mg/kg Enzyme B vs. 100 mg/kg Enzyme A + 250 mg/kg Enzyme B). Both enzymes were included blends of ß-glucanase, cellulose, and xylanase (Enzyme A) or hemicellulase and pectinases (Enzyme B). Pigs were fed treatment diets from d 10 to 35 postweaning in 2 phases. Feed and fecal samples were collected on d 30 postweaning to determine apparent total tract digestibility of nutrients. The nutrient concentrations of normal and drought-affected corn were similar, which resulted in few treatment or main effects differences of corn type or enzyme inclusion. No interactions were observed (P > 0.10) between corn source and enzyme inclusion. Overall (d 10 to 35), treatments had no effect on ADG or ADFI, but enzyme A inclusion tended to improve (P < 0.10; 0.74 vs. 0.69) G:F, which was primarily driven by the improved feed efficiency (0.76 vs. 0.72; P < 0.05) of pigs fed Enzyme A in Phase 2 (d 10 to 25 postweaning) and was likely a result of improved xylan utilization. In conclusion, drought stress did not alter the nonstarch polysaccharide concentration of corn beyond xylan concentration, so it was not surprising that enzyme inclusion showed little benefit to nursery pig growth performance. However, improved feed efficiency of pigs fed diets containing Enzyme A from d 10 to 25 postweaning warrants further investigation

Evaluation of conditioning time and temperature on gelatinized starch and vitamin retention in a pelleted swine diet.

Two key feed processing parameters, conditioning temperature and time, were altered to determine their effects on concentration of gelatinized starch and vitamin retention in a pelleted finishing swine diet. Diet formulation (corn­soybean meal based with 30% distillers dried grains with solubles) was held constant. Treatments were arranged in a 2 × 3 factorial design plus a control with 2 conditioning temperatures (77 vs. 88°C) and 3 conditioner retention times (15, 30, and 60 s). In addition, a mash diet not subjected to conditioning served as a control for a total of 7 treatments. Samples were collected after conditioning but before pelleting (hot mash), after pelleting but before cooling (hot pellet), and after pelleting and cooling (cold pellet) and analyzed for percentage total starch, percentage gelatinized starch, and riboflavin, niacin, and vitamin D3 concentrations. Total percentage starch was increased by greater conditioning temperature (P = 0.041) but not time (P > 0.10), whereas higher temperature and longer time both increased (P < 0.05) percentage gelatinized starch, with increasing time resulting in a linear increase in percentage starch gelatinization (P = 0.013). The interaction between conditioning temperature and time increased percentage gelatinized starch (P = 0.003) but not percentage total starch (P > 0.10). Sample location also affected both percentage total starch and gelatinized starch (P < 0.05), with the greatest increase in percentage gelatinized starch occurring between hot mash and hot pellet samples. As expected, the pelleting process increased percentage gelatinized starch (P = 0.035; 7.3 vs. 11.7% gelatinized starch for hot mash vs. hot pellet samples, respectively), but there was no difference in total starch concentrations (P > 0.10). Finally, neither conditioning temperature nor time affected riboflavin, niacin, or vitamin D3 concentrations (P > 0.10). In summary, both increasing conditioningtemperature and time effect percentage gelatinized starch, but not to the extent of forcing the diet through a pelleting die.

The effects of feeder design and dietary dried distillers' grains with solubles on the performance and carcass characteristics of finishing pigs.

Three experiments were conducted to compare the effects of a conventional dry (five 30.5-cm spaces 152.4 cm wide; Staco Inc., Schaefferstown, PA) vs. a wet-dry (double sided; each side = 38.1-cm space; Crystal Spring; GroMaster Inc., Omaha, NE) finishing feeder (Exp. 1 and 2) and to evaluate the effects of feeder design and dietary level of dried distillers' grains with solubles (DDGS; >10% oil; Exp. 3) on performance and carcass characteristics of finishing pigs. In Exp. 1, 1,186 pigs (32.1 kg BW) were used in a 69-d experiment. There were 26 to 28 pigs per pen and 22 pens per feeder design, and all pigs received the same diets in 4 phases. In Exp. 2, 1,236 pigs (28.7 kg BW) were used in a 104-d experiment, with 25 to 28 pigs per pen and 23 pens per feeder design, and all pigs received the same diets in 5 phases. Carcass measurements were obtained from 11 pens of each feeder design after harvest. In Exp. 3, 1,080 pigs (35.1 kg BW) were used in a 99-d 2 × 2 factorial with main effects of feeder design (dry vs. wet-dry feeders) and DDGS (20 vs. 60%) with 10 pens of 27 pigs per treatment and all diets fed in 4 phases. Jowl fat samples were collected from 2 pigs per pen for fatty acid analysis and iodine value (IV) determination. In all experiments, pigs fed with the wet-dry feeder had greater (P < 0.05) ADG, ADFI, and final BW. In Exp. 2 and 3, HCW and backfat depth were increased (P < 0.05) for pigs fed with a wet-dry feeder, but G:F and fat-free lean index (FFLI) were reduced. Jowl IV was also reduced (P < 0.05) with a wet-dry feeder in Exp. 3. Pigs fed 60% DDGS in Exp. 3 had decreased (P < 0.05) ADG, G:F, final BW, HCW, and backfat but increased jowl IV and a tendency (P < 0.07) toward greater FFLI regardless of feeder type. In conclusion, pigs fed with this specific type of wet-dry feeder had improved ADG and ADFI, poorer G:F, and increased backfat depth compared to pigs fed with a conventional dry feeder. The poorer growth performance and increased jowl IV of pigs fed diets with 60% DDGS was similarly exhibited for pigs fed on both feeders.

An evaluation of the effects of added vitamin D3 in maternal diets on sow and pig performance.

A total of 84 sows (PIC 1050) and their litters were used to determine the effects of supplementing maternal diet with vitamin D3 on sow and pig performance, serum 25-hydroxyvitamin D3 (25(OH)D3), milk vitamin D3, neonatal bone mineralization, and neonatal tissue vitamin D3. After breeding, sows were randomly assigned to 1 of 3 dietary vitamin D3 treatments (1,500, 3,000, or 6,000 IU/kg of complete diets). Sows were bled on d 0 and 100 of gestation and at farrowing and weaning (d 21). Pig BW was recorded at birth and weaning, and serum was collected from 2 pigs/litter at birth, on d 10 and at weaning. A total of 54 pigs (18/treatment) were euthanized at birth and necropsied to sample bones and tissues. Sow and suckling pig performance and neonatal bone ash and bone density did not differ among maternal vitamin D3 treatments; however, sow 25(OH)D3 and milk vitamin D3 increased (linear, P < 0.01) with increasing maternal vitamin D3 supplementation. Piglet serum 25(OH)D3 increased (quadratic, P < 0.03) with increased maternal vitamin D3. Neonatal kidney vitamin D3 tended (quadratic, P = 0.08) to decrease with increasing maternal vitamin D3, but liver vitamin D3 tended (linear, P = 0.09) to increase with increasing maternal vitamin D3. At weaning, a subsample of 180 pigs (PIC 327 × 1050) were used in a 3 × 2 split plot design for 35 d to determine the effects of maternal vitamin D3 and 2 levels of dietary vitamin D3 (1,800 or 18,000 IU/kg) from d 0 to 10 postweaning on nursery growth and serum 25(OH)D3. Overall (d 0 to 35), nursery ADG and G:F were not affected by either concentration of vitamin D3, but ADFI tended (quadratic, P < 0.06) to decrease with increasing maternal vitamin D3 as pigs from sows fed 3,000 IU had lower ADFI compared with pigs from sows fed 1,500 or 6,000 IU/kg. Nursery pig serum 25(OH)D3 increased with increasing maternal vitamin D3 (weaning) on d 0 (linear, P < 0.01), and maternal × diet interactions (P < 0.01) were observed on d 10 and 21 because pigs from sows fed 1,500 IU had greater increases in serum 25(OH)D3 when fed 18,000 IU compared with pigs from sows fed 3,000 IU. In conclusion, sow and pig serum 25(OH)D3, milk vitamin D3, and neonatal tissue vitamin D3 can be increased by increasing maternal vitamin D3, and nursery pig 25(OH)D3 can be increased by increasing dietary vitamin D3; however, sow and pig performance and neonatal bone mineralization was not influenced by increasing vitamin D3 dietary levels.

Effects of feeder design and changing source of water to a location separate from the wet-dry feeder at 4 or 8 weeks before harvest on growth, feeding behavior, and carcass characteristics of finishing pigs.

Our objectives were to compare a conventional dry (5-space, 152.4-cm-wide) and a wet-dry (double-sided, each side = 38.1-cm-wide single space) feeder and to determine if changing the source of water to a location separate from a wet-dry feeder would result in improved G:F and carcass characteristics. Water supply to the wet-dry feeder was shut off and the cup waterer was turned on in 8 pens at 8 (d 69) or 4 (d 97) wk prior to harvest. For the remaining 8 wet-dry feeder pens, the feeder provided the sole water source for the entire experiment. 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. From d 0 to 69, pigs fed with the wet-dry feeder had increased (P < 0.05) ADG, ADFI, G:F, and d 69 BW compared with those using the conventional dry feeder. Overall (d 0 to 124), pigs using fed with the water source in the wet-dry feeder the entire time had greater (P < 0.05) ADG, ADFI, final BW, and HCW the other treatments. The overall G:F was not different (P > 0.05) among pigs fed with the different feeder treatments. Pigs fed with the wet-dry feeder where water source was changed at 4 wk before harvest had greater (P < 0.05) ADG than pigs that used a conventional dry feeder. Pigs where the water source was changed at 4 wk had greater (P < 0.05) ADFI than those were the water source was changed 8 wk prior to harvest, and for pigs fed with the conventional dry feeder ADFI was intermediate. Back fat depth of pigs where the water source was changed at 8 wk before harvest was reduced (P < 0.05) compared with all other treatments and LM depth was greater (P < 0.05) than that of pigs using a conventional dry feeder and where the water source was changed at 4 week before harvest. Pigs fed using the wet-dry 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 conventional dry feeder. The differences in feeding patterns remained even after the access to water was removed from the wet-dry feeder, with no change in the amount of aggressive behavior observed at the feeder. Pigs fed with a wet-dry feeder had an increased growth rate compared with those fed with a conventional dry 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 wet-dry feeder.

Effects of two feeder designs and adjustment strategies on the growth performance and carcass characteristics of growing-finishing pigs.

Our objective was to compare 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 (Sus scrofa). 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 greater G:F than pigs fed with a CD feeder. Increased adjustment opening increased (linear, P < 0.01) ADG and ADFI by pigs fed with a WD feeder, and increased (linear, P < 0.01) ADFI by 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) than 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 did not differ 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 byproduct diets). Feeder treatments were CD at approximately a 2.4-cm opening, WD at a 3.2-cm opening, WD changed to a 2.5-cm opening on d 56, and WD changed to a 2.5-cm opening on d 28 and a 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. Decreasing the WD feeder opening during the study decreased (P < 0.05) ADG. Pigs with the WD feeder opening decreased to 1.9 cm had reduced (P < 0.05) ADFI and backfat, but increased FFLI compared with pigs with a WD feeder opening of 3.2 cm. Feed efficiency did not differ 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.

Effects of diet source and vaccination for porcine circovirustype 2 and Mycoplasma hyopneumoniae on nursery pig performance.

Two experiments were conducted to evaluate the effect of nursery diet sources, porcine circovirustype 2 (PCV2) and Mycoplasma hyopneumoniae (M. hyo) vaccines, and vaccination timing on pig (Sus scrofa) performance. In Exp. 1, a total of 400 pigs (5.6 BW, 1.03 kg SD) were used in a 20-d study. Treatments were arranged in a 4 × 2 factorial in a blocked design (5 pigs/pen and10 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 2 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 by 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 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 with 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.

Efficacy of commercial enzymes in diets containing various concentrations and sources of dried distillers grains with solubles for nursery pigs.

In 2 experiments, 530 pigs were used to evaluate the effects of adding commercial enzymes to diets containing dried distillers grains with solubles (DDGS) on pig growth performance. In the first experiment, 180 pigs (9.0 kg initial BW) were fed a corn-soybean meal-based control diet, a diet containing 30% corn DDGS, or the 30% DDGS diet with 0.05% of enzyme A, B, or C. There were 6 pigs per pen and 6 pens per treatment. Overall (d 0 to 27), neither DDGS nor enzyme addition increased ADG and G:F. Pigs fed enzyme B had decreased (P < 0.05) ADG as a result of a tendency (P 0.10) enzyme x DDGS source interactions observed. Corn DDGS did not influence (P > 0.10) ADG, ADFI, or G:F. Sorghum DDGS reduced (P = 0.003) G:F, with no difference (P > 0.10) between sorghum DDGS sources. Adding the commercial enzyme to the 30% DDGS diets did not improve performance. In summary, feeding diets with sorghum DDGS resulted in poorer G:F with no change in ADG compared with feeding the control diet or diets containing corn DDGS. Adding the enzymes used in this study to corn-soybean meal-based diets containing 30% DDGS did not improve growth performance.

Evaluation of enzymatically modified potato starches in diets for weanling pigs.

We conducted three growth trials to evaluate replacing carbohydrate sources with enzymatically modified potato starches in diets for weanling pigs. In Exp. 1, 180 pigs (initially 5.3 kg and 21+/-2 d of age) were used to compare the effects of corn (36.5%), edible-grade oat flour (36.5%), two enzymatically modified potato starches (12%), and added lactose (12%) on pig performance. Potato Starch 1 had a dextrose equivalent (DE) of 6 and Potato Starch 2 had a DE of 20; both were spray-dried maltodextrans. Pigs that were fed Potato Starch 2 had greater (P<.05) ADG and ADFI than pigs fed diets that contained corn or oat flour from d 0 to 14 after weaning, and pigs fed either Potato Starch 1 or added lactose had intermediate ADG and ADFI. However, for the overall trial (d 0 to 35), no differences (P>.10) in growth performance were observed. In Exp. 2, 198 pigs (initially 4.3 kg and 19+/-2 d of age) were used to determine whether modified Potato Starch 2 could replace a portion of the corn or lactose in the diet. The control diet contained 10% dried whey, and additional treatments were formulated by adding 7 or 14% modified Potato Starch 2 or lactose in place of corn. A positive control diet was formulated containing 29% dried whey. From d 0 to 14 after weaning, increasing dietary lactose improved (linear, P<.04) ADG and ADFI. Increasing the potato starch had no effect on ADG but increased ADFI (linear, P<.02). In Exp. 3, 180 pigs (initially 3.9 kg and 14+/-3 d of age) were used to evaluate Potato Starch 2 or 3 (DE = 30, a spray-dried glucose syrup) as replacements for either corn or lactose in the diet. Pigs were fed a control diet containing 15% dried whey and 12% added lactose. Twelve percent modified Potato Starch 2 or 3 replaced either corn or lactose in the diet on a wt/wt basis. From d 0 to 14 and d 0 to 21, pigs fed either modified potato starch substituted for corn had greater (P<.07) ADG than those fed the control diet. Pigs fed diets with either modified starch substituted for lactose had similar ADG as those fed the control diet. These results suggest that when substituted for corn, Potato Starch 2 can improve growth performance of weanling pigs.

Evaluation of potato proteins on the growth performance of early-weaned pigs.

We conducted five experiments to evaluate conventional and low-glycoalkaloid potato protein (CPP and LGPP, respectively) in diets for early-weaned pigs. In Exp. 1, 150 weanling pigs (initially 4.4 +/- .9 kg and 15.5 +/- 2 d of age) were fed either a control diet containing 3% spray-dried animal plasma (SDAP) or diets with additional SDAP (2.5 or 5% added; 5.5 or 8% total) or CPP (2.6% or 5.1%) substituted on a total lysine basis. From d 0 to 14 after weaning, increasing SDAP increased (linear, P < .05) ADG and ADFI, whereas increasing CCP had no effect on growth performance. In Exp. 2, 180 weanling pigs (initially 5.9 +/- 1.2 kg and 20 +/- 2 d of age) were fed diets containing a LGPP replacing 25, 50, 75, or 100% of the 7% dietary SDAP on a digestible lysine basis. From d 0 to 7 after weaning, increasing LGPP increased and then returned to control levels ADG and ADFI (quadratic, P < .01) and gain:feed ratio (quadratic, P < .05). In Exp. 3, 175 weanling pigs (initially 5.5 +/- 1.1 kg and 20 +/- 3 d of age) were fed either a control diet containing 20% dried whey, 17.5% dried skim milk, and 4% select menhaden fish meal (SMFM) or diets consisting of lactose and either 3.5 and 7.0% SDAP or 4.0 and 8.0% LGPP added at the expense of dried skim milk on a digestible lysine basis. From d 0 to 7 after weaning, ADG and ADFI increased (linear, P < .05) with increasing SDAP. With increasing LGPP, ADG and ADFI increased and then decreased (quadratic, P < .10 and P < .05, respectively). Gain:feed ratio (G/F) was not affected by SDAP and was improved (linear, P < .05) for pigs fed increasing LGPP. In Exp. 4, 270 weanling pigs (initially 6.2 +/- 1.6 kg and 20 +/- 3 d of age) were used to compare three diets that contained either 2.5% spray-dried blood meal (SDBM), 4.8% SMFM, or 3.92% CPP; test feedstuffs were substituted on a total lysine basis and diets were fed from d 7 to 28 after weaning. Pigs fed CPP had decreased (P < .05) ADG and G/F compared with those fed the other protein sources. In Exp. 5, 255 weanling pigs (initially 5.3 +/- 1.2 kg and 17 +/- 2 d of age), were used to compare five diets that contained either 2.5% SDBM, 5.51% SMFM, 4.17% CPP, 4.17% LGPP or 8.34% LGPP; feedstuffs were substituted on a digestible lysine basis and diets were fed from d 7 to 28 after weaning. No differences (P > .10) were observed in growth performance among pigs fed any of the protein sources within the experiment. However, pigs fed the LGPP had numerically greater ADG and better G/F than those fed CPP. In conclusion, these results suggest that LGPP can be an effective replacement for a portion of the SDAP in diets for weanling pigs.

The effects of extrusion processing of carbohydrate sources on weanling pig performance.

Three experiments were conducted to study the effects of extrusion processing on growth performance of weanling pigs. In Exp. 1, 350 weanling pigs (initially 4.4 +/- 1.0 kg BW and 10 +/- 2 d of age) were used to study the effects of various carbohydrate sources (corn, cornstarch, broken rice, wheat flour, and grain sorghum), with or without moist extrusion processing, on growth performance in a 5 x 2 factorial arrangement of treatments. No carbohydrate source x extrusion processing interactions were observed (P > .10). Growth performance was not affected by extrusion processing; however, pigs fed corn had poorer growth performance (P < .05) than those fed other carbohydrate sources. In Exp. 2, 360 weanling pigs (initially 5.0 +/- .5 kg BW and 10 +/- 2 d of age) were used to determine the interactive effects of ingredient processing and diet complexity on growth performance. Three processing combinations were used with either a simple or complex diet formulation in a 3 x 2 factorial arrangement of treatments. The three processing conditions were 1) pelleted only (control); 2) corn that was moist-extruded and then the complete diet was pelleted (extruded); or 3) the complete diet was expanded and then pelleted (expanded). Pigs fed extruded diets had a greater improvement in ADG as diet complexity increased than those fed other diets (processing x diet complexity interaction, P < .10). Pigs fed moist-extruded corn had the best growth performance (P < .01). In Exp. 3, 210 weanling pigs (initially 6.8 +/- 1.5 kg BW and 21 +/- 2 d of age) were fed pelleted diets containing nonextruded corn (14.5% gelatinization; control) or corn extruded to provide 38.7, 52.7, 64.4, or 89.3% gelatinization. Average daily gain and ADFI decreased and then increased (P < .05), but apparent digestibility of DM, CP, and energy (P < .01) increased and then decreased with increasing gelatinization. These results indicate that moist extrusion processing of carbohydrate sources has variable effects on growth performance of early-weaned pigs and that the degree of gelatinization does not seem to be a major factor in explaining this variation.

Evaluation of spray-dried animal plasma and select menhaden fish meal in transition diets of pigs weaned at 12 to 14 days of age and reared in different production systems.

We conducted two experiments with pigs weaned at 12 to 14 d of age to evaluate the effects of adding spray-dried animal plasma (SDAP) and select menhaden fish meal (SMFM) to the diets fed from 5 to 19 (Exp. 1) and 7 to 21 d (Exp. 2) after weaning. This 14-d period represents the transition from the nutrient-dense diet fed to all pigs after weaning to the simpler corn-soybean meal-based diet fed to all pigs for an additional 14 (Exp. 1) or 7 d (Exp. 2) after the experimental period. Pigs averaged 5 kg at the start of the experimental period. In Exp. 1, pigs had a high health status and were weaned to an off-site nursery (SEW) and fed 12 experimental diets in a 3 (0, 2.5, or 5% SDAP) x 4 (0, 2.5, 5, or 7.5% SMFM) factorial arrangement. Diets were formulated to contain 1.6% lysine and contained 20% dried whey, 5% soybean oil, and 2.5% spray-dried blood meal. The SDAP and(or) SMFM replaced corn and soybean meal on an equal lysine basis. Average daily gain and ADFI were not affected by treatment during any period of the experiment. Gain:feed was improved by the addition of SDAP (linear, P < .05) and SMFM (linear, P < .07) during the period from 5 to 19 d. Over the 33-d experiment, SDAP and SMFM improved (linear, P < .05) gain:feed. In Exp. 2, pigs were weaned on-site to an all-in/all-out by room nursery and fed diets identical to those fed in Exp. 1, with 0 or 2.5% SDAP and 0, 2.5, or 5% SMFM in a 2 x 3 factorial arrangement. The addition of 2.5% SDAP improved ADG and gain:feed during the period from 7 to 14 d (P < .05) and 0 to 28 d (P < .10), but not over the period from 7 to 21 d. The addition of SMFM did not affect ADG during any period, but it resulted in a quadratic improvement in gain:feed during the periods from 7 to 14 (P < .05) and 7 to 21 (P < .10) d. These results suggest that high-health SEW pigs respond less to SDAP and SMFM in the transition diet than pigs with a lower health status reared in an on-site nursery. The data further suggest that formulation of transition diets should consider the type of production system if pig performance and diet cost are to be optimized.

Evaluation of the interrelationships among lactose and protein sources in diets for segregated early-weaned pigs.

We conducted two experiments to evaluate the interactions among lactose and protein sources in diets for segregated early-weaned pigs. In Exp. 1, 360 barrows (initially 5.3 kg and 19 +/- 2 d of age) were fed diets containing crystalline lactose (0, 20, and 40%), spray-dried animal plasma (0 and 7.5%), and soybean meal (0 and 20%) in a 3 x 2 x 2 factorial arrangement. We used a blend of select menhaden fish meal and casein to replace the lysine provided by soybean meal or animal plasma. Diets contained 1.7% total lysine and were fed from d 0 to 14 after weaning. Pigs were fed a common diet from d 14 to 34. From d 0 to 14 after weaning, ADG and ADFI increased with increasing dietary lactose when the diet contained soybean meal but decreased when soybean meal was not in the diet (lactose x soybean meal, P < .05 and .10, respectively). Pigs fed animal plasma had increased (P < .05) ADG and ADFI from d 0 to 14 but decreased (P < .05) ADG from d 14 to 34. In Exp. 2, 324 barrows (initially 3.7 kg and 10 +/- 2 d of age) were fed diets from d 0 to 10 similar to those used in Exp. 1 with the exception that extruded soy protein concentrate replaced the lysine provided by soybean meal or animal plasma. From d 0 to 10 after weaning, increasing lactose improved (linear, P < .05) ADG and ADFI, and pigs fed animal plasma had higher ADFI (P < .05). In conclusion, soybean meal had no negative effect on ADG; however, animal plasma and lactose increased ADG and ADFI for pigs weaned between 10 and 19 d of age.

Effects of substituting deproteinized whey and(or) crystalline lactose for dried whey on weanling pig performance.

We conducted two trials to determine the effects of replacing the lactose provided by spray-dried, edible-grade whey with edible-grade deproteinized whey or crystalline lactose on pig performance. In Exp. 1, 180 weanling pigs (initially 4.1 kg and 22 +/- 4 d of age) were allotted randomly to dietary treatments containing 18% lactose supplied by 1) 25% dried whey, 2) 12.5% dried whey and 9% crystalline lactose, 3) 18% crystalline lactose, 4) 12.5% dried whey and 10.9% deproteinized whey, or 5) 21.7% deproteinized whey. Casein was used to replace the lysine provided by dried whey in diets containing lactose and deproteinized whey. From d 0 to 14 after weaning, no differences (P > .10) were observed in ADG or ADFI. Pigs fed diets containing 18% crystalline lactose or 21% deproteinized whey had a higher (P < .05) gain:feed ratio (G/F) than did pigs fed diets containing 25% dried whey or 12.5% dried whey and 9% lactose. In addition, pigs fed diets containing 21% deproteinized whey had increased G/F compared to pigs fed the diet containing 10.9% deproteinized whey and 12.5% dried whey. In Exp. 2, 344 pigs (initially 4.4 kg and 14 +/- 2 d of age) were fed dietary treatments based on four sources of crystalline lactose replacing the lactose provided by dried whey in the positive control diet (20% dried whey). In addition, a negative control diet was formulated with 7.2% crystalline lactose. Casein was used to replace the lysine provided by dried whey. From d 0 to 14 after weaning, no differences (P > . 10) were observed in performance. However, pigs initially fed the positive control diet subsequently (d 14 to 28) consumed more feed than pigs fed the negative control diet. These results indicate that edible-grade deproteinized whey and crystalline lactose can replace the lactose provided by high-quality dried whey without affecting pig performance.