Influence of source and micronization of soybean meal on nutrient digestibility and growth performance of weanling pigs J. D. Berrocoso, M. P. Serrano, L. Cámara, A. López and G. G. Mateos J ANIM SCI 2013, 91:309-317. doi: 10.2527/jas.2011-4924 originally published online October 16, 2012

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Influence of source and micronization of soybean meal on nutrient digestibility and growth performance of weanling pigs1 J. D. Berrocoso,* M. P. Serrano,*2 L. Cámara,* A. López,† and G. G. Mateos*3 *Departamento de Producción Animal, Universidad Politécnica de Madrid, 28040 Madrid, Spain; and †Piensos Jiménez S.L., 30800 Murcia, Spain

(P = 0.08) for pigs fed the micronized HP-SBM than for piglets fed the ground HP-SBM. During phase II (all the pigs received the same diet), no differences among treatments were observed. In general, TTAD of nutrients at 7 d of experiment was greater for the SPC than the R-SBM diet, with the HP-SBM diets being intermediate. The TTAD of CP was greater (83.8% vs. 81.9%; P ≤ 0.01) for the SPC diet than the average of the SBM diets. Also, the digestibility of OM and DM was greater (P < 0.01) for the HP-SBM either ground or micronized than the R-SBM diet. Micronization of the HP-SBM did not affect nutrient digestibility. It is concluded that when the R-SBM is substituted by SPC, CP digestibility is improved, but no effects are observed on growth performance. The use of the HP-SBM in substitution of the R-SBM in the diet improved nutrient digestibility but did not affect piglet performance. The inclusion of micronized HP-SBM in the diet improved G:F during the first week postweaning but did not affect TTAD of nutrients. In general, the inclusion of added-value soy products (SPC or micronized SBM) in the diet presents little advantage in terms of growth performance over the use of HP-SBM in pigs weaned at 28 d of age.

ABSTRACT: A total of 288 piglets weaned at 28 d and weighing 7.6 ± 0.2 kg were used in a 35-d experiment to evaluate the effect of CP content (44% vs. 49% CP) of soybean meal (SBM), micronization (fine grinding) of the 49% CP SBM (HP-SBM), and soy protein concentrate (SPC; 65% CP) on total tract apparent digestibility (TTAD) and growth performance. In phase I (d 0 to 21 of experiment), there was a positive control diet that included 6.5% of CP from a SPC with 65% CP and a negative control diet that supplied the same amount of CP as regular SBM (R-SBM) with 44% CP. The other 4 diets included the same amount of dietary CP from 2 different sources of HP-SBM that were either ground (990 μm) or micronized (60 μm). All diets were isonutritive, and the main difference was the source of SBM used. Each treatment was replicated 8 times (6 pigs per pen). In phase II (d 21 to 35), all pigs were fed a common commercial starter diet. For the entire phase I, the type of soy product did not affect growth performance of the pigs. However, from 0 to 7 d of experiment, pigs fed the micronized HP-SBM had better G:F (1.11 vs. 0.98; P < 0.05) than piglets fed the ground HP-SBM. Also, from 7 to 14 d of experiment, ADFI tended to be greater

Key words: micronization, nutrient digestibility, piglet performance, soybean meal, soy protein concentrate © 2013 American Society of Animal Science. All rights reserved. INTRODUCTION Soybean meal (SBM) is the most common protein source used in pig diets worldwide. Soybean meal contains several antinutritional factors (ANF), namely, tryp1Financial support was provided by Ministerio de Ciencia e Innovación (Project AGL2011–27004) and Ministerio de Ciencia e Tecnología (Project CDTI 25721). 2Additional financial support for M. P. Serrano was provided by Consejería de Educación de la Comunidad de Madrid and Fondo Social Europeo (Madrid, Spain). 3Corresponding author: [email protected] Received November 17, 2011. Accepted October 4, 2012.

J. Anim. Sci. 2013.91:309–317 doi:10.2527/jas2011-4924

sin inhibitors, lectins, and oligosaccharides, that reduce growth performance and nutrient digestibility and limit its use in diets for young pigs (Huisman and Jansman, 1991). Soy protein concentrate (SPC) results from processes that reduce crude fiber (CF) and ANF content of the SBM (Sohn et al., 1994). Consequently, when SPC is used as a substitute for all or a portion of the SBM in the diet of weanling pigs, an improvement in growth performance is expected (Feng et al., 2007; Lenehan et al., 2007). However, the inclusion of SPC in the diet increases feed cost, and therefore, its use is often limited to diets for pigs of less than 10 to 12 kg BW.

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The effect of particle size of the ingredients of the diet on nutrient digestibility and growth performance of pigs is the subject of debate (Goodband et al., 1995; Laurinen et al., 2000; Valencia et al., 2008). A reduction in particle size facilitates the mixing of digesta contents and enzymes, which may result in improved nutrient digestibility and feed efficiency but also might increase the fluidity of the stomach content (Brunsgaard, 1998) and the incidence of digestive disturbances. Fastinger and Mahan (2003) reported an improvement in AA digestibility of SBM with reduced particle size, whereas Lawrence et al. (2003) did not observe any effect. The aim of this experiment was to evaluate the effects of including different sources of SBM, varying in CP and particle size, on nutrient digestibility and growth performance of weanling pigs. MATERIALS AND METHODS The experimental procedures described in this research were approved by the Animal Ethics Committee of Universidad Politécnica de Madrid and were in compliance with the Spanish guidelines for the care and use of animals in research (Boletín Oficial del Estado, 2007). Pig Management and Husbandry A total of 288 crossbreds from Pietrain × Large White sires and Landrace × Large White sows with an average age of 28 ± 3 d (7.6 ± 0.2 kg BW) were selected at weaning from 40 litters at a commercial farm. After arrival at the experimental station, pigs were weighed and allotted into groups of 6, irrespective of litter, to 48 flat-deck pens. All the pens had similar average BW and an equal number of barrows and gilts. The pens (1.70 × 1.25 m) were provided with an individual feeder and 2 nipple drinkers. Room temperature was maintained at 31°C ± 1°C for the first week of the experiment, and then it was reduced by approximately 2°C per week until reaching 26°C. The pigs were kept on a 20 h/d light program and had free access to feed in pellet form (2.5 mm from 28 to 49 d and 4 mm from 49 to 63 d of age) and tap water. Pigs that showed signs of diarrhea, as assessed by veterinary inspection, were injected with 250 mg enrofloxacine (Alsir 5%; Esteve Veterinaria, Barcelona, Spain) per kilogram BW for 3 consecutive days, as recommended by the supplier. Ingredients and Experimental Diets The SPC is produced by using aqueous alcohol extraction to reduce the amount of soluble sugars and oligosaccharides in defatted and dehulled flakes of SBM of unknown origin. In the process, other minor constituents, such as trypsin inhibitors, hemagglutinins, and glycinine and β-conglycinine, are reduced. A batch of regular SBM

with 44% CP (R-SBM) of Argentinean (ARG) origin was obtained from a local trader (Interpec, Cádiz, Spain), ground to a geometric mean diameter (GMD) of approximately 1,150 μm, and used as such. A batch of SBM with 49% CP (HP-SBM) was obtained directly from the United States (Carolina Soya, Warsaw, NC), and a second batch of HP-SBM of ARG origin was obtained from a commercial supplier (Esasa, Valladolid, Spain). These 2 batches of HP-SBM were divided into 2 portions; the first portion was ground with a hammer mill with a 2.5-mm screen (Buhler AG, Uzwil, Switzerland) to a GMD of approximately 990 μm, and the second portion was micronized to a GMD of approximately 60 μm. For micronization of the SBM, an impact mill (Circoplex 1000 ZPS; HosokawaAlpine, Augsburg, Germany) with a mill speed of 193 × g, an extraction capacity of 1.200 m3/h, and a throughput rate of 180 kg/h was used. The determined chemical composition, GMD, and CP quality variables of the soy products tested are shown in Table 1. During phase I (d 0 to 21 of experiment), there was a positive control diet with 10% SPC inclusion as the main protein source and a negative control diet with the same amount of dietary CP provided as R-SBM. In addition, there were 4 other diets with HP-SBM as a main source of protein that resulted from the combination of 2 sources of SBM (ARG or U.S.) and 2 GMD (ground to 990 μm or micronized to 60 μm). Approximately 6.5% of the CP of the 6 diets of phase I was provided by the different soy products tested (10% SPC, 14.8% R-SBM, or 13.3% HPSBM). Adjustments in ingredient composition were made to ensure that all diets had similar NE (2510 kcal/kg) and standardized ileal digestible Lys (1.35% to 1.38%) contents. Other limiting indispensable AA (Ile, Met, Thr, Trp, and Val) and Cys were formulated according to the ideal protein concept as indicated by Fundación Española Desarrollo Nutrición Animal (2006). Celite (acid-washed diatomaceous earth; Celite Hispánica S.A., Alicante, Spain) was added to all diets (1%) as an additional AIA source and used as a marker. No antibiotics or growth promoters, other than copper sulfate (160 mg/kg), were included in these diets. During phase II (d 21 to 35 of experiment), all pigs were fed a common pelleted commercial diet based on cereals and SBM. The ingredient composition and the calculated (Fundación Española Desarrollo Nutrición Animal, 2010) and determined chemical composition of the experimental diets are shown in Tables 2 and 3, respectively. All diets were fed as pellets. Experimental Design and Measurements A completely randomized design with 6 different phase I diets was used. Each treatment was replicated 8 times, and the experimental unit for all measurements was

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Table 1. Determined chemical composition (as-fed basis; % unless otherwise indicated), CP quality evaluation, and geometric mean diameter (GMD) of the soybean products used Item Determined analysis4 DM Total ash CP Ether extract GE, kcal/kg Crude fiber NDF AA Ile Lys Met Met + Cys Thr Trp Val Sucrose Raffinose Stachyose CP quality TIA,5 mg/g Urease activity, mg N/g PDI,6 % KOH solubility, % Reactive Lys,7 % Nonreactive Lys,7 % Particle size GMD ± SD,8 μm

Soy protein concentrate 93.0 6.1 64.0 1.0 4372 3.9 8.5 3.03 4.03 0.92 1.86 2.54 0.78 3.17 0.6 0.6 0.04

HP-SBM,2 ARG origin

R-SBM,1 44% CP

Micronized

90.5 6.7 43.7 1.9 4239 6.4 13.5

93.2 6.6 51.4 1.9 4334 5.4 9.9

2.04 2.75 0.62 1.31 1.78 0.62 2.16 5.4 1.9 4.69

1.1 0.0 6.9 66.5 90.0 6.2

1.8 0.0 12.4 81.0 89.4 8.4

501 ± 2

1150 ± 2

2.33 3.10 0.68 1.44 2.00 0.69 2.44 6.9 1.2 5.20 2.5 0.01 20.6 83.5 88.9 8.2 64 ± 1

Ground 89.8 6.8 49.0 1.7 4295 4.9 10.0

HP-SBM,3 U.S. origin Micronized 93.0 6.6 51.6 1.8 4341 4.6 8.2

2.23 2.97 0.65 1.42 1.91 0.67 2.33 6.8 1.2 5.03

2.34 3.14 0.70 1.47 2.02 0.70 2.46 6.3 1.5 6.10

Ground 91.1 7.2 49.3 1.6 4318 4.9 8.1 0.10 2.22 2.99 0.66 1.41 1.92 0.67 2.34 6.1 1.1 5.90

2.5 0.0 14.7 83.9 88.1 8.1

2.4 0.0 19.8 82.2 88.4 8.4

2.7 0.0 16.2 81.2 89.4 8.5

998 ± 3

56 ± 2

982 ± 2

1Regular soybean meal (SBM) of Argentinean origin. 2High-protein SBM (49% CP) of Argentinean origin 3High-protein SBM (49% CP) of U.S. origin. 4In duplicate. 5Trypsin inhibitor activity. 6Protein dispersibility index. 7Percentage of total Lys. 8Log SD.

the pen (6 pigs/pen). In phase II (d 21 to 35 of experiment), all pigs were fed a common commercial diet. Pigs were weighed individually at 0, 7, 14, 21, and 35 d of experiment, and feed intake was measured by pen. Feed wastage was collected daily from pans placed beneath the feeders. Mortality was recorded. The ADG, ADFI, and G:F were calculated from these data by phase (d 0 to 21 and 21 to 35 of experiment) and cumulatively (d 0 to 35 of experiment). At d 7 of experiment, representative samples of feces (300 g) were collected by rectal massage from at least 3 pigs from each pen, pooled by replicate, dried at 70°C for 48 h, and stored at -20°C until chemical analysis. Before analysis, fecal samples were thawed overnight, homogenized, and ground (Model Z-I; Retsch, Stuttgart, Germany) through a 1-mm screen. Total tract apparent digestibility (TTAD) of CP, DM, OM, and GE were determined as indicated by Medel et al. (1999).

Laboratory Analysis The GMD of the SPC and the ground SBM was determined in triplicate in 100-g samples using a shaker (Retsch, Stuttgart, Germany) with 8 sieves ranging in mesh from 5,000 to 40 μm according to methodology outlined by the American Society of Agricultural Engineers (ASAE; 1995). The ASAE (1995) method is not valid for very fine raw materials, and therefore, the GMD of the micronized SBM was determined using laser diffraction equipment (Helos Compact KA; Sympatec GmbH, Clausthal-Zellerfeld, Germany) with a dry-powder dispenser at 2 bar (Heuer and Leschonski, 1985) as described by Valencia et al. (2008). Ingredients, feeds, and feces were ground (1-mm screen; model Z-I; Retsch) and analyzed for moisture by oven-drying (method 930.15), total ash by muffle furnace (method 942.05), and nitrogen by Dumas (method 968.06)

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Table 2. Ingredient composition and calculated analysis (as-fed basis; % unless otherwise indicated) of the experimental diets

Table 3. Determined chemical composition (as-fed basis; % unless otherwise indicated) of the experimental diets during phase I (0 to 21 d of experiment)1 HP-SBM,3 ARG origin

Phase I1 HP-SBM,3 49% CP

Item Ingredient Barley Corn Wheat SBM, 44% CP SBM,5 49% CP

Soy protein R-SBM,2 Micronconcentrate 44% CP ized Ground Phase II4 10.00 24.76 25.00 — —

10.00 19.03 25.00 14.80 —

10.00 21.08 25.00 — 13.30

10.00 21.08 25.00 — 13.30

22.66 12.98 34.00 21.60 —

Soy protein concentrate, 65% CP

10.00

—

—

—

—

Fishmeal, 68% CP Dried whey Soybean oil Calcium carbonate

9.50 15.00 2.70 0.07

9.50 15.00 3.70 0.04

9.50 15.00 3.20 0.07

9.50 15.00 3.20 0.07

1.83 — 3.55 0.56

0.22

0.17

0.14

0.14

0.65

0.10 0.16

0.10 0.17

0.10 0.16

0.10 0.16

0.40 0.15

0.40

0.42

0.40

0.40

0.56

0.17 0.07 1.00 0.60

0.16 0.06 1.00 0.60

0.15 0.05 1.00 0.60

0.15 0.05 1.00 0.60

0.13 0.08 — 0.60

0.25

0.25

0.25

0.25

0.25

Monocalcium phosphate, 22.6% P Sodium chloride DL-Met, 99% L-Lys·HCl, 78% Lys L-Thr, 99% Thr L-Trp, 98% Trp Celite6 Formic acid (90%) Vitamin and mineral premix7 Calculated analysis8 NE, kcal/kg CP SID9 of AA Ile Lys Met Met + Cys Thr Trp Val Ether extract Crude fiber NDF Ca Digestible P

2,510 21.0 0.78 1.38 0.51 0.78 0.88 0.24 0.87 5.4 2.2 7.4 0.60 0.40

2,510 21.0 0.73 1.35 0.51 0.77 0.83 0.26 0.83 6.3 2.6 7.9 0.60 0.40

2,510 21.0 0.75 1.36 0.51 0.78 0.84 0.26 0.86 5.9 2.2 7.1 0.60 0.40

2,510 21.0

2,480 18.8

0.75 1.36 0.51 0.78 0.84 0.26 0.86 5.9 2.2 7.1 0.60 0.40

0.64 1.21 0.40 0.51 0.67 0.26 0.72 5.7 3.6 11.4 0.50 0.36

1From 0 to 21 d of experiment (28 to 49 d of age).

2High-protein soybean meal (SBM) of Argentinean or U.S. origin. 3From 21 to 35 d of experiment (49 to 63 d of age). 4Regular SBM of Argentinean origin.

5Depending on the experimental treatment, meals were included in the diet either ground or micronized. 6Acid-washed diatomaceous earth (Celite Hispánica S.A., Alicante, Spain). 7Provided per kilogram of diet: vitamin A (trans-retinyl acetate), 12,000 IU; vitamin D3 (cholecalciferol), 1,900 IU; vitamin E (all-rac-tocopherol-acetate), 30 IU; vitamin B1 (thiamine mononitrate), 1.8 mg; riboflavin, 5 mg; niacin, 25 g; pyridoxine (pyridoxine HCl), 2.4 mg; vitamin B12 (cyanocobalamin), 0.03 mg; vitamin K3 (bisulfate menadione complex), 1.8 mg; pantothenic acid (dCa pantothenate), 15 mg; folic acid, 0.6 mg; d-biotin, 0.1 mg; Se (Na2SeO3), 0.2 mg; I (KI), 1 mg; Cu (CuSO4·5H2O), 160 mg; Fe (FeSO4·7H2O), 225 mg; Mn (MnSO4·H2O), 100 mg; and Zn (ZnO), 120 mg. 8According to Fundación Española Desarrollo Nutrición Animal (2010). 9Standardized ileal digestibility.

Item

Soy protein R-SBM,2 Micronconcentrate 44% CP ized Ground

DM GE, kcal/kg Total ash CP Total AA5 Ile Lys Met Met + Cys Thr Trp Val

HP-SBM,4 U.S. origin Micronized Ground

91.1 4049 6.1 19.6

91.1 4102 6.3 20.9

91.6 4079 6.1 21.2

90.7 4092 6.2 21.0

91.6 4102 6.2 21.1

90.7 4073 6.2 20.8

0.85 1.40 0.55 0.88 0.96 0.30 0.98

0.89 1.41 0.56 0.89 0.97 0.30 1.00

— — — — — — —

0.88 1.39 0.57 0.90 0.96 0.29 0.99

— — — — — — —

0.87 1.42 0.56 0.89 0.98 0.30 0.98

1In duplicate. 2Regular soybean meal (SBM) of Argentinean (ARG) origin. 3High-protein SBM (49% CP) of ARG origin. 4High-protein SBM (49% CP) of U.S. origin. 5The AA content of the diets based on SBM 49% CP (Argentinean or U.S.) was determined in the ground samples exclusively.

using a Leco analyzer (model FP-528, Leco Corp., St. Joseph, MI) as described by AOAC International (2000). Ether extract of the soybean products was analyzed after 3 N HCl acid hydrolysis (method 4.b) as described by Boletín Oficial del Estado (1995). Crude fiber was determined by sequential extraction with diluted acid and alkali (method 962.09; AOAC International, 2000), whereas the NDF was determined as described by Van Soest et al. (1991), and the values were expressed on an ash-free basis. The GE of feeds and feces was determined using an isoperibol bomb calorimeter (model 1356; Parr Instrument Company, Moline, IL) and the AIA content as described by De Coca-Sinova et al. (2011). The AA contents of the soybean sources and the phase I diets were determined by ion exchange chromatography (Hewlett-Packard 1100; Hewlett-Packard, Waldbronn, Germany) after acid hydrolysis as described by De CocaSinova et al. (2008). Briefly, the samples were prepared by hydrolysis with 6 N HCl for 22 h at 110°C under reflux conditions. Nitrogen was bubbled through the mixture during the hydrolysis period. Protein hydrolysates and AA calibration mixture were derivatized with o-phthalaldehyde. For the determination of Met and Cys concentrations, separate samples were oxidized with performic acid before hydrolysis and measured as Met sulfone and cysteic acid, respectively. Tryptophan was determined by HPLC with fluorescence detection after 0.2 M NaOH hydrolysis for 22 h at 110°C. The determination of sucrose and oligosaccharide (raffinose and stachyose) content of the soy products was

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performed by extracting the carbohydrate in water for 1 h at 50°C and analyzing the extract by HPLC (model 3110; PerkinElmer Inc., Waltham, MA) as described by González et al. (2009). Trypsin inhibitor activity (TIA) of the soy ingredients (expressed in mg/g product) was assayed as indicated by De Coca-Sinova et al. (2008), and the urease activity was assayed according to Boletín Oficial del Estado (1995). The protein dispersibility index (PDI) was determined by method Ba 10a-05 [American Oil Chemists’ Society (AOCS) 2000] using a Hamilton blender (model G936; VOS Instrument, Zaltbommel, Netherlands), and the solubility in KOH was determined as indicated by Araba and Dale (1990). Reactive and nonreactive Lys of the SBM samples were measured according to the procedure described by Fontaine et al. (2007). All the analyses were conducted in duplicate except for AIA of the diets, which were conducted in quadruplicate. Statistical Analysis Data on growth performance and nutrient digestibility were analyzed as a completely randomized design, with type of diet as the main effect, using the GLM procedure (SAS Inst. Inc., Cary, NC). The individual pen represented the experimental unit for all measurements. In addition, comparisons of treatment means were made using these preplanned orthogonal contrasts: 1) SPC vs. all SBM diets, 2) micronized vs. ground HP-SBM, 3) HP-SBM of ARG origin vs. HP-SBM of U.S. origin, 4) R-SBM vs. HP-SBM diets, and 5) interaction between the source and the degree of grinding of the HP-SBM. All differences were considered significant at P < 0.05, and P-values between 0.05 and 0.10 were considered a trend. RESULTS Laboratory Analysis The CP and AA content of the different soy products were similar to expected values (Table 1). The 2 micronized HP-SBM contained more CP than the 2 ground HP-SBM because of greater DM content. The CF and NDF contents were greater for R-SBM than for the 2 HP-SBM or the SPC. The proportion of sucrose and oligosaccharides were least for the SPC and similar for all SBM samples. The TIA content was 1.1 mg/g for the SPC and less than 2.7 mg/g for all SBM samples. The PDI and KOH values were less for the SPC than the SBM. Also, PDI was greater for the micronized SBM than for the ground SBM. Reactive Lys, as a percentage of total Lys, was similar (88.1% to 90.0%) for all soybean sources. The determined nutrient contents of the diets were similar to expected values, indicating that the diets were mixed correctly (Tables 2 and 3).

Growth Performance During phase I (d 0 to 21 of experiment), dietary treatment did not affect growth performance of the pigs, but from d 0 to 7 of experiment, pigs fed the micronized HPSBM had better G:F (1.11 vs. 0.98; P < 0.05) than piglets fed the ground HP-SBM (Table 4). Also, from 7 to 14 d of experiment, micronization of the HP-SBM tended to improve ADFI (446 vs. 427 g; P = 0.08) compared with ground HP-SBM. Growth performance was similar for pigs fed R-SBM and pigs fed ground HP-SBM (data not shown). During phase II, when all the pigs were fed a common commercial diet, previous dietary treatment did not affect growth performance (Table 5). Mortality rate was 2.8% and was not related to treatment (data not shown). Total Tract Apparent Digestibility of Nutrients The type of soybean product used affected nutrient digestibility in different ways. The TTAD values were greatest for SPC and least for R-SBM, with values for HP-SBM being intermediate (Table 6). In fact, the TTAD of OM (86.3% vs. 84.9%; P < 0.01) and DM (82.6% vs. 81.1%; P < 0.01) were greater for HP-SBM, either ground or micronized, than for R-SBM. The source of HP-SBM did not affect nutrient digestibility, except for GE, which tended (P = 0.09) to be greater for the U.S. meal than for the ARG meal. Micronization of the HP-SBM did not affect the digestibility of any of the nutrients studied. DISCUSSION Effect of Soy Protein Concentrate In the current study, growth performance was similar for piglets fed SPC, HP-SBM, and R-SBM. These results are in contrast to the data of Li et al. (1991), Sohn et al. (1994), and Feng et al. (2007), who reported that the substitution of SBM with SPC reduced the ANF content of the feed and improved pig performance. Ao et al. (2010) reported that the substitution of SPC for R-SBM in the diet at a rate of 5% did not affect ADFI or ADG from 21 to 51 d of age but feed efficiency was improved. The inconsistencies observed on the effects of including SPC in the diet on growth performance of the pigs might be related to differences in the level of inclusion or in the manufacturing process, which may affect the physicochemical properties and nutritive value of the commercial product. Solá-Oriol et al. (2011) reported that young pigs showed reduced feed preference for diets containing 10% of a fermented soy product concentrate than diets containing similar amounts of HPSBM (41.5% vs. 61.9%) or R-SBM (41.5% vs. 69.4%). Moreover, under practical conditions, the recommended level of inclusion of SPC obtained by aqueous alcohol ex-

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Table 4. Effect of inclusion of soy protein concentrate (SPC) and different sources of soybean meal (SBM) on growth performance of pigs during phase I1 Item 0 to7 d ADG ADFI G:F 7 to 14 d ADG ADFI G:F 14 to 21 d ADG ADFI G:F 0 to 21 d ADG ADFI G:F

HP-SBM processing

P-value5

HP-SBM source

SPC

R-SBM,2 44% CP

Micronized

Ground

ARG6

U.S.7

SEM3

P-value4

1

2

3

4

130 127 1.02

148 143 1.03

151 136 1.11

139 141 0.98

142 136 1.04

148 140 1.06

14 10 0.07

0.81 0.82 0.46

0.30 0.26 0.46

0.38 0.64 0.04

0.63 0.66 0.83

0.83 0.67 0.95

355 425 0.84

334 425 0.79

359 446 0.81

350 427 0.82

359 441 0.82

350 432 0.81

12 11 0.03

0.48 0.37 0.80

0.72 0.47 0.39

0.48 0.08 0.56

0.48 0.38 0.91

0.12 0.37 0.48

449 584 0.77

459 587 0.78

461 609 0.76

452 595 0.76

461 615 0.75

453 589 0.77

19 22 0.03

0.83 0.66 0.96

0.55 0.55 0.90

0.50 0.54 0.89

0.42 0.29 0.93

0.78 0.56 0.35

311 379 0.82

314 385 0.81

324 397 0.82

314 387 0.81

320 397 0.81

317 387 0.82

10 11 0.02

0.82 0.65 0.97

0.48 0.32 0.91

0.28 0.39 0.63

0.57 0.37 0.68

0.73 0.55 0.71

1Pigs weaned at 28 ± 3 d (7.6 ± 0.2 kg BW). 2Regular SBM of Argentinean (ARG) origin. 3Pooled SEM (8 pens of 6 pigs/pen per treatment). 4Overall treatment effect; interactions between SBM source and the degree of grinding of the HP-SBM, P > 0.05. 51: SPC vs. average of all SBM diets; 2: micronized vs. ground HP-SBM; 3: ARG HP-SBM vs. U.S. HP-SBM; and 4: R-SBM vs. HP-SBM. 6High-protein SBM (49% CP) of U.S. origin. 7High-protein SBM (49% CP) of ARG origin.

traction is less than that used in the current research (3% to 6% vs. 10%). In this respect, Lenehan et al. (2007) compared diets containing 40% HP-SBM with diets containing 28.6% of alcohol-extracted SPC and reported a reduction in voluntary feed intake in pigs fed the SPC diets. The inclusion of SPC in the diet improved CP digestibility, which is consistent with its low TIA content (Li et al., 1991; Leske et al., 1993; Cervantes-Pahm and Stein,

2010). Ao et al. (2010) reported that the inclusion of 5% of a fermented SPC as a substitution of R-SBM in the diet improved TTAD of CP at 31 d of age. Also, SPC had less glycinin and β-conglycinin concentrations than SBM, and consequently, intestinal mucosal hypersensibility might be reduced in young pigs fed SPC (Li et al., 1991; Liu et al., 2007). Oligosaccharides and NDF content were less for SPC than for SBM, and a decrease in these feed fractions

Table 5. Effect of inclusion of soy protein concentrate (SPC) and different sources of soybean meal (SBM) on growth performance of piglets during phase II and cumulatively1 Item 21 to 35 d ADG ADFI G:F 0 to 35 d ADG ADFI G:F

HP-SBM processing

SPC

R-SBM,2 44% CP

Micronized

522 775 0.67

541 820 0.66

395 537 0.74

405 559 0.72

P-values5

HP-SBM source

Ground

ARG6

U.S.7

SEM3

P-value4

1

2

3

4

551 810 0.68

544 808 0.67

555 820 0.68

540 799 0.68

17 23 0.02

0.72 0.63 0.97

0.18 0.13 0.93

0.36 0.91 0.68

0.65 0.38 0.99

0.77 0.66 0.46

415 562 0.74

406 556 0.73

414 566 0.73

406 552 0.74

11 14 0.01

0.69 0.59 0.96

0.23 0.14 0.90

0.39 0.62 0.48

0.40 0.31 0.83

0.71 0.98 0.65

1Pigs weaned at 28 ± 3 d (7.6 ± 0.2 kg BW). 2Regular SBM of Argentinean (ARG) origin. 3Pooled SEM (8 pens of 6 pigs/pen per treatment). 4Overall treatment effect; interactions between SBM source and the degree of grinding of the HP-SBM, P > 0.05. 51: SPC vs. average of all SBM diets; 2: micronized vs. ground HP-SBM; 3: ARG HP-SBM vs. U.S. HP-SBM; and 4: R-SBM vs. HP-SBM. 6High-protein SBM (49% CP) of ARG origin. 7High-protein SBM (49% CP) of U.S. origin.

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Table 6. Effect of inclusion of soy protein concentrate (SPC) and different sources of soybean meal (SBM) on total tract apparent digestibility of nutrients at 7 d of experiment1 Item

SPC

R-SBM,2 44% CP

OM DM GE CP

86.4 82.5 83.4 83.8

84.9 81.1 81.8 81.1

HP-SBM processing Micronized 86.3 82.6 83.0 81.9

P-value5

HP-SBM source

Ground

ARG6

U.S.7

SEM3

P-value4

1

2

3

4

86.2 82.5 82.7 82.3

86.2 82.6 82.3 82.0

86.3 82.6 83.4 82.2

0.4 0.5 0.6 0.7

0.06 0.13 0.19 0.18

0.31 0.58 0.22 0.01

0.70 0.88 0.71 0.64

0.90 0.97 0.09 0.83

0.002 0.004 0.14 0.26

1Pigs weaned at 28 ± 3 d (7.6 ± 0.2 kg BW). 2Regular SBM of Argentinean (ARG) origin. 3Pooled SEM (8 pens of 6 pigs/pen per treatment). 4The overall treatment effect; interactions between SBM source and the degree of grinding of the HP-SBM, P > 0.05. 51: SPC vs. average of all SBM diets; 2: Micronized vs. ground HP-SBM; 3: ARG HP-SBM vs. U.S. HP-SBM; and 4: R-SBM vs. HP-SBM. 6High-protein SBM (49% CP) of ARG origin. 7High-protein SBM (49% CP) of U.S. origin.

improved CP digestibility (Schulze et al., 1994; Smiricky et al., 2002; Dilger et al., 2004), which is consistent with the results of the current experiment. However, no differences between SPC and SBM were observed for OM, DM, and GE digestibility, which disagrees with the data of Sohn et al. (1994), who observed that TTAD of DM increased when the SBM of the diet was replaced by fermented SPC. In contrast, Ao et al. (2010) did not find any benefit of the inclusion of fermented SPC in the diet on DM digestibility in pigs at 41 and 51 d of age, which agrees with the results of the current experiment. Probably, the beneficial effects of the low ANF contents of the SPC on nutrient digestibility were counteracted by its decreased sucrose content, resulting in similar OM and GE digestibility. Effect of CP Content of the Soybean Meal (R-SBM vs. HP-SBM) Growth performance of the pigs was not affected by CP content of the SBM, which disagrees with the results of De Coca-Sinova et al. (2010), who reported better growth performance in broilers fed HP-SBM than in broilers fed R-SBM. The TTAD of OM and DM was greater for HP-SBM than for R-SBM, which was consistent with the greater CP and lower NDF content of the HP-SBM. Similarly, Gerber et al. (2006) reported better DM and GE retention in broilers fed isonutritive diets when the R-SBM was substituted by HP-SBM. Moreover, De Coca-Sinova et al. (2010) compared isonutritive diets based on SBM with 46.3% or 48.6% CP and observed that DM digestibility was greater for the HP-SBM. In the current research, CP digestibility was not affected by the CP content of SBM. In contrast, Baker and Stein (2009) reported an increase in ileal digestibility of CP in growing pigs when the level of CF in the diet decreased from 11.4% to 6.1%. Also, De Coca-Sinova et al. (2008) reported in broilers a negative relation between CF and AA digestibility of the SBM.

Effect of Particle Size The effect of particle size of the diet on growth performance of piglets remains to be elucidated. Most studies conducted with cereals reported a straight positive relationship between GMD of the cereal and G:F (Goodband and Hines, 1988; Healy et al., 1994). In fact, a GMD of less than 600 μm has been recommended for cereals to be included in piglet diets (Goodband and Hines, 1988; Mavromichalis et al., 2000). However, Medel et al. (2000) found no improvement on piglet growth when the screen used to grind the barley was reduced from 4.5 to 2.5 mm. Healy et al. (1994) reported that the beneficial effects of fine grinding (900 vs. 300 μm) of corn on growth performance were greatest during the first 2 wk after weaning and were decreased with increasing age of the pig. In the current experiment, particle size of the HP-SBM had little effect on growth performance, except for G:F for the first week and ADFI for the second week of phase I, which were improved with SBM micronization. In this respect, Lawrence et al. (2003) did not find any beneficial effect of grinding SBM (965, 742, or 639 μm) on growth performance of pigs from 35 to 49 d of age. Nutrient digestibility was not affected by a reduction in particle size of the HP-SBM, consistent with the findings of Valencia et al. (2008), who did not observe any effect of GMD (881 or 47 μm) on nutrient digestibility at 33 d of age. A decrease in particle size facilitates the contact between nutrients and endogenous enzymes, and consequently, fine grinding should improve nutrient digestibility (Guillon and Landeau, 2000) and feed efficiency (Owsley et al., 1981; Wondra et al., 1995). In this respect, Fastinger and Mahan (2003) observed a linear increase in the digestibility of the most limiting indispensable AA as the GMD of the SBM was reduced from 900 to 150 μm. The reasons for these discrepancies are not known but might be related to factors such as size and uniformity of the feed particles, feed form (pellet vs. mash), and age and health status of the piglets. For

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example, a reduction in feed particle size might improve nutrient digestibility because of better mixing of dietary components and enzymes but also might affect the motility of the gastrointestinal tract and the general health status of the pig (Mikkelsen et al., 2004; Hedemann et al., 2005, 2006). Both effects counteract each other, and the magnitude of the observed response will vary among experiments. Effect of Source of High-Protein Soybean Meal In the current experiment, the source of HP-SBM (U.S. vs. ARG) did not affect growth performance or nutrient digestibility in pigs except for GE digestibility, which tended to be greater for the U.S. than the ARG SBM. Processing (Palacios et al., 2004; De Coca-Sinova et al., 2008) and chemical composition of the original beans (Cromwell et al., 1999; Dilger et al., 2004) may affect the response of pigs to the inclusion in the diet of different batches of SBM. Mateos et al. (2011) reported that SBM from U.S. beans had more CP and sucrose, less NDF, and greater KOH solubility and PDI values than SBM from ARG. Consequently, the source of the SBM might affect CP digestibility and energy content of the meal. In the current study, the differences in CP content and other chemical analyses and CP quality traits between the 2 HP-SBM used were small, and therefore, little difference in nutrient digestibility between the 2 sources of SBM was expected. It is concluded that micronization (fine grinding) of SBM improves ADFI and G:F of pigs during the first days postweaning but not thereafter. The inclusion of a SPC obtained by aqueous alcohol extraction improves apparent digestibility of most dietary components but does not result in increased growth performance. The inclusion of high-protein SBM in the substitution of regular SBM in diets for young pigs results in an improvement in OM and DM digestibility. In general and on the basis of current ingredient prices, the data do not favor the use of added-value soy products such as micronized SBM or SPC in substitution of high-protein SBM in diets for healthy pigs weaned at 28 d of age after the first 7 to 14 d postweaning. LITERATURE CITED Ao, X., H. J. Kim, Q. W. Meng, L. Yan, J. H. Cho, and I. H. Kim. 2010. Effects of diet complexity and fermented soy protein on growth performance and apparent ileal amino acid digestibility in weanling pigs. Asian-Aust. J. Anim. Sci. 23:1496–1502. AOAC International. 2000. Official methods of analysis. 17th ed. AOAC Int., Arlington, VA. AOCS. 2000. Official methods and recommended practices. 5th ed. Am. Oil Chem. Soc., Urbana, IL. Araba, M., and N. M. Dale. 1990. Evaluation of protein solubility as an indicator of overprocessing of soybean meal. Poult. Sci. 69:76–83.

ASAE. 1995. Method of determining and expressing fineness of feed materials by sieving. In: Agriculture engineers yearbook of standards. Am. Soc. Agric. Eng. Standard S319.2. Am. Soc. Agric. Eng., St. Joseph, MO. p. 461–462. Baker, K. M., and H. H. Stein. 2009. Amino acid digestibility and concentration of digestible and metabolizable energy in soybean meal produced from conventional, high-protein, or low-oligosaccharide varieties of soybeans and fed to growing pigs. J. Anim. Sci. 87:2282–2290. Boletín Oficial del Estado. 1995. Real Decreto 2257/1994 por el que se aprueban los métodos oficiales de análisis de piensos o alimentos para animales y sus primeras materias. Bol. Of. Estado 52:7161–7237. Boletín Oficial del Estado. 2007. Ley 32/2007 de 7 de Noviembre para el cuidado de los animales, en su explotación, transporte, experimentación y sacrificio. Bol. Of. Estado 268:45914–45920. Brunsgaard, G. 1998. Effects of cereal type and feed particle size on morphological characteristics, epithelial cell proliferation, and lectin binding patterns in the large intestine of pigs. J. Anim. Sci. 76:2787–2798. Cervantes-Pahm, S. K., and H. H. Stein. 2010. Ileal digestibility of amino acids in conventional, fermented, and enzyme-treated soybean meal and in soy protein isolate, fish meal, and casein fed to weanling pigs. J. Anim. Sci. 88:2674–2683. Cromwell, G. L., C. C. Calvert, T. R. Cline, J. D. Crenshaw, T. D. Crenshaw, R. A. Easter, R. C. Ewan, C. R. Hamilton, G. M. Hill, A. J. Lewis, D. C. Mahan, E. R. Miller, J. L. Nelssen, J. E. Pettigrew, L. F. Tribble, T. L. Veum, and J. T. Yen. 1999. Variability among sources and laboratories in nutrient analyses of corn and soybean meal. NCR-42 Committee on Swine Nutrition. North Central Regional-42. J. Anim. Sci. 77:3262–3273. De Coca-Sinova, A., E. Jiménez-Moreno, J. M. González-Alvarado, M. Frikha, R. Lázaro, and G. G. Mateos. 2010. Influence of source of soybean meal and lysine content of the diet on performance and total tract apparent retention of nutrients in broilers from 1 to 36 days of age. Poult. Sci. 89:1440–1450. De Coca-Sinova, A., G. G. Mateos, J. M. González-Alvarado, C. Centeno, R. Lázaro, and E. Jiménez-Moreno. 2011. Comparative study of two analytical procedures for the determination of acid insoluble ash for evaluation of nutrient retention in broiler diets. Span. J. Agric. Res. 9:761–768. De Coca-Sinova, A., D. G. Valencia, E. Jiménez-Moreno, J. M. González-Alvarado, R. Lázaro, and G. G. Mateos. 2008. Apparent ileal digestibility of nitrogen, amino acids, and energy of soybean meals from different origins in broilers. Poult. Sci. 87:2613–2623. Dilger, R. N., J. S. Sands, D. Ragland, and O. Adeola. 2004. Digestibility of nitrogen and amino acids in soybean meal with added soyhulls. J. Anim. Sci. 82:715–724. Fastinger, N. D., and D. C. Mahan. 2003. Effect of soybean meal particle size on amino acid and energy digestibility in grower-finisher swine. J. Anim. Sci. 81:697–704. Feng, J., X. Liu, Z. R. Xu, Y. P. Lu, and Y. Y. Liu. 2007. The effect of Aspergillus oryzae fermented soybean meal on growth performance, digestibility of dietary components and activities of intestinal enzymes in weaned piglets. Anim. Feed Sci. Technol. 134:295–303. Fontaine, J., V. Zimmee, P. Moughan, and S. M. Rutherford. 2007. Effect of heat damage in an autoclave on the reactive lysine contents of soy products and corn distillers dried grains with soluble. Use of the results to check on lysine damage in common qualities of these ingredients. J. Agric. Food Chem. 55:10737–10743. Fundación Española Desarrollo Nutrición Animal. 2006. Necesidades nutricionales para ganado porcino. C. De Blas, J. Gasa, and G. G. Mateos, editors. Fund. Esp. Desarro. Nutr. Anim., Madrid.

Downloaded from www.journalofanimalscience.org by Gonzalo Mateos on February 13, 2013

Soybean meal sources in piglet diets Fundación Española Desarrollo Nutrición Animal. 2010. Normas FEDNA para la formulación de piensos compuestos. 3rd ed. C. De Blas, G. G. Mateos, and P. G. Rebollar, editors. Fund. Esp. Desarro. Nutr. Anim., Madrid. Gerber, L. F. P., A. M. Penz, and A. M. L. Ribeiro. 2006. Effect of soybean meal composition on broilers performance and metabolism. Braz. J. Vet. Res. Anim. Sci. 4:1359–1365. González, M., M. Hermida, S. Sueiro, M. P. Serrano, and G. G. Mateos. 2009. Estudio comparativo del contenido en azucares (sacarosa, estaquiosa y rafinosa) de la harina de soja según procedencia. In: M. Joy, J. H. Calvo, M. A. Latorre, and J. Balcells, editors. XIII Jornadas sobre Producción Animal AIDA. Asoc. Interprof. Desarro. Agrario, Zaragoza, Spain. p. 211–213. Goodband, R. D., and R. H. Hines. 1988. An evaluation of barley in starter diets for swine. J. Anim. Sci. 66:3086–3093. Goodband, R. D., M. D. Tokach, and J. L. Nelssen. 1995. The effects of diet particle size on animal performance. MF–2050. Feed manufacturing. Kansas State Univ. Agric. Exp. Stn. Coop. Ext. Serv., Manhattan. Guillon, D., and E. Landeau. 2000. Granulometrie et nutrition porcine. INRA Prod. Anim. 13:137–145. Healy, B. J., J. D. Hancock, G. A. Kennedy, P. J. Bramel-Cox, K. C. Behnke, and R. H. Hines. 1994. Optimum particle size of corn and hard and soft sorghum for nursery pigs. J. Anim. Sci. 72:2227– 2236. Hedemann, M. S., M. Eskildsen, H. N. Laerke, C. Pedersen, J. E. Lindberg, P. Laurinen, and K. E. Bach Knudsen. 2006. Intestinal morphology and enzymatic activity in newly weaned pigs fed contrasting fiber concentrations and fiber properties. J. Anim. Sci. 84:1375–1386. Hedemann, M. S., L. L. Mikkelsen, P. J. Naughton, and B. B. Jensen. 2005. Effect of feed particle size and feed processing on morphological characteristics in the small and large intestine of pigs and on adhesion of Salmonella enterica serovar Typhimurium DT12 in the ileum in vitro. J. Anim. Sci. 83:1554–1562. Heuer, M., and K. Leschonski. 1985. Results obtained with a new instrument for the measurement of particle size distributions from diffraction patterns. Part. Part. Syst. Characterization 2:7–13. Huisman, J., and A. J. M. Jansman. 1991. Dietary effects and some analytical aspects of antinutritional factors in peas (Pisum sativum), common beans (Phaseolus vulgaris) and soybeans (Glycine max L.) in monogastric farm animals. A literature review. Nutr. Abstr. Rev. 61:901–921. Laurinen, P., H. Siljander-Rasi, J. Karhunen, T. Alaviuhkola, M. Nasi, and K. Tuppi. 2000. Effects of different grinding methods and particle size of barley and wheat on pig performance and digestibility. Anim. Feed Sci. Technol. 83:1–16. Lawrence, K. R., C. W. Hastad, R. D. Goodband, M. D. Tokach, S. S. Dritz, J. L. Nelssen, J. M. DeRouchey, and M. J. Webster. 2003. Effects of soybean meal particle size on growth performance of nursery pigs. J. Anim. Sci. 81:2118–2122. Lenehan, N. A., J. M. De Rouchey, R. D. Goodband, M. D. Tokach, S. S. Dritz, J. L. Nelssen, C. N. Groesbeck, and K. R. Lawrence. 2007. Evaluation of soy protein concentrates in nursery pig diets. J. Anim. Sci. 85:3013–3021. Leske, K. L., C. J. Jevne, and C. N. Coon. 1993. Effect of oligosaccharide additions on nitrogen-corrected true metabolizable energy of extruded soybean meal. Poult. Sci. 72:664–668.

317

Li, D. F., J. L. Nelssen, P. G. Reddy, F. Blecha, R. Klemm, and R. D. Goodband. 1991. Interrelationship between hypersensitivity to soybean proteins and growth performance in early weaned pigs. J. Anim. Sci. 69:4062–4069. Liu, X., J. Feng, Z. Xu, Y. Lu, and Y. Liu. 2007. The effects of fermented soybean meal on growth performance and immune characteristics in weaned piglets. Turkish J. Vet. Anim. Sci. 31:341–345. Mateos, G. G., S. Sueiro, M. González, M. Hermida, J. Fickler, P. G. Rebollar, M. P. Serrano, and R. Lázaro. 2011. Differences among origins on nutritional and quality parameters of soybean meal. Poult. Sci. 90(Suppl. 1):57. (Abstr.) Mavromichalis, I. J., D. Hancock, B. W. Senne, T. L. Gugle, G. A. Kennedy, R. H. Hines, and C. L. Wyatt. 2000. Enzyme supplementation and particle size of wheat in diets for nursery and finishing pigs. J. Anim. Sci. 78:3086–3095. Medel, P., M. García, R. Lázaro, C. de Blas, and G. G. Mateos. 2000. Particle size and heat treatment of barley in diets for early-weaned piglets. Anim. Feed Sci. Technol. 84:13–21. Medel, P., S. Salado, J. C. De Blas, and G. G. Mateos. 1999. Processed cereals in diets for early-weaned piglets. Anim. Feed Sci. Technol. 82:145–156. Mikkelsen, L. L., P. J. Naughton, M. S. Hedemann, and B. B. Jensen. 2004. Effects of physical properties of feed on microbial ecology and survival of Salmonella enterica serovar Typhimurium in the pig gastrointestinal tract. Appl. Environ. Microbiol. 70:3485–3492. Owsley, W. F., D. A. Knabe, and T. D. Tanksley Jr. 1981. Effect of sorghum particle size on digestibility of nutrients at the terminal ileum and over the total digestive tract of growing-finishing pigs. J. Anim. Sci. 52:557–566. Palacios, M. F., R. A. Easter, K. T. Soltwedel, C. M. Parsons, M. W. Douglas, T. Hymowitz, and J. E. Pettigrew. 2004. Effect of soybean variety and processing on growth performance of young chicks and pigs. J. Anim. Sci. 82:1108–1114. Schulze, H., P. van Leeuwen, M. W. Verstegen, J. Huisman, W. B. Souffrant, and F. Ahrens. 1994. Effect of level of dietary neutral detergent fiber on ileal apparent digestibility and ileal nitrogen losses in pigs. J. Anim. Sci. 72:2362–2368. Smiricky, M. R., C. M. Grieshop, D. M. Albin, J. E. Wubben, V. M. Gabert, and G. C. Fahey Jr. 2002. The influence of soy oligosaccharides on apparent and true ileal amino acid digestibilities and fecal consistency in growing pigs. J. Anim. Sci. 80:2433–2441. Sohn, K. S., C. V. Maxwell, D. S. Buchanan, and L. L. Southern. 1994. Improved soybean protein sources for weanling pigs: I. Effects on performance and total tract amino acid digestibility. J. Anim. Sci. 72:622–630. Solá-Oriol, D., E. Roura, and D. Torrallardona. 2011. Feed preference in pigs: Effect of selected protein, fat, and fiber sources at different inclusion rates. J. Anim. Sci. 89:3219–3227. Valencia, D. G., M. P. Serrano, R. Lázaro, M. A. Latorre, and G. G. Mateos. 2008. Influence of micronization (fine grinding) of soya bean meal and fullfat soya bean on productive performance and digestive traits in young pigs. Anim. Feed Sci. Technol. 147:340– 356. Van Soest, P. J., J. B. Robertson, and A. Lewis. 1991. Methods for dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition. J. Dairy Sci. 74:3583–3597. Wondra, K. J., J. D. Hancock, K. C. Behnke, R. H. Hines, and C. R. Stark. 1995. Effects of particle size and pelleting on growth performance, nutrient digestibility, and stomach morphology in finishing pigs. J. Anim. Sci. 73:757–763.

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