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Iron deficiency represents one of the most common global nutritional disorders in humans. Our objective was to determine whether and how supplemental inulin improved utilization of iron intrinsically present in a corn and soybean meal diet by young pigs for hemoglobin repletion. In Expt. 1,3 groups (n = 8/group) of pigs were fed a corn and soybean meal-based diet (BD, without inorganic iron addition) or BD + 2 or 4% inulin (Synergy 1: a mixture of oligofructose and long-chain inulin HP, Orafti) for 5 wk. Final blood hemoglobin concentrations and the overall hemoglobin repletion efficiency of pigs were positively (r = 0.55 and 0.69, P< 0.01) correlated with dietary inulin concentrations. Compared with pigs fed the BD, those fed 4% inulin demonstrated a 28% improvement (P < 0.01) in hemoglobin repletion efficiency and 15% (P < 0.01) improvement in the final blood hemoglobin concentration. In Expt. 2, 12 weanling pigs (n = 6/group) were fed the BD or the BD + 4% inulin for 6 wk. Pigs fed 4% inulin had higher (P < 0.05) soluble Fe concentrations in the digesta of the proximal, mid, and distal colon, and lower (P < 0.05) sulfide concentrations in the digesta of the distal colon. Supplemental inulin had virtually no effect on pH or phytase activity of digesta from any of the tested segments. In conclusion, supplementing 4% inulin improved utilization of intrinsic iron in the corn and soybean meal diet by young pigs, and this benefit was associated with soluble Fe and sulfide concentrations but not pH or phytase activity in the digesta.

A phytate-containing soy protein concentrate (SPC) diet (13.5 mg Zn/kg) and a phytate-free egg white diet (.3 mg Zn/kg) were used to determine the relative bioavailability (RBV) of Zn in dehulled soybean meal (SBM) based on Zn depletion-repletion growth bioassays in young chicks. After a 4-d Zn depletion period, chick weight gain responded linearly (P < .01) to graded increments of supplemental Zn (0 to 10 mg/kg) from ZnSO(sub 4)*7H(sub 2)O, whether added to the Zn-deficient SPC or egg white diet. Slope, however, was over twice as great for the standard curve relating weight gain to supplemental Zn intake for the egg white diet as for the SPC diet. Addition of 7 to 10 mg Zn/kg from SBM to either Zn-deficient diet increased (P < .01) weight gain, but a similar SBM addition to either diet made adequate in Zn did not increase weight gain. Using standard-curve methodology, RBV of Zn in SBM was 78% when the SPC diet was used, but it was only 40% when the egg white diet was used. The phytate contained in the SPC basal diet therefore markedly reduced the efficiency of utilizing the supplemental inorganic Zn from ZnSO(sub 4)*7H(sub 2)O. This lowered the slope of the standard curve so that, on a relative basis, the Zn in SBM had a higher RBV value than was the case for Zn utilization in SBM with the phytate-free egg white diet. The 78% Zn RBV value in SBM would seem to have the greatest relevance for practical-type corn-SBM diets. Key Words: Bioavailability, Soybean Oilmeal, Zinc

Endogenous recoveries and true ileal digestibilities of amino acids were determined in pigs fed cornstarch-based diets with untreated or protease-treated soybean meal as protein sources. Twelve pigs, fitted with a modified post valve T-cecum cannula on d 14, 15, and 16 after birth, were weaned on d 20 and assigned to one of four diets according to a two-period balanced change-over design. Diets consisted of soybean meal 1) untreated (SBM), 2) incubated (1:2 wt/vol in distilled water adjusted to pH 4.5, for 16 h at 50 [degrees] C; CI-SBM), 3) sprayed with protease (1 [Mu]L/g of soybean meal; PS-SBM), and 4) incubated, as for CI-SBM, with protease in the water (PI-SBM) at the same application rate as that for PS-SBM. Each period consisted of 5 d of adaptation to diets followed by collection of ileal digesta on d 6 and 7 to determine the apparent ileal amino acid digestibilities of the diets. On d 9, guanidinated meals were fed, followed by a 24-h continuous collection of digesta. Recoveries of chromic oxide and dysprosium from the guanidinated meals were 96.0 [+ or -] .5 and 94.5 [+ or -] 1.1%, respectively. Endogenous amino acid recoveries were similar (P > .05) for SBM, CI-SBM, and PS-SBM but less (P < .05) for PI-SBM. True digestibilities were also less (P < .05) for PI-SBM than for the other meals. Recoveries of endogenous branched-chain and aromatic amino acids were less (P < .05) during Period 2 than during Period 1, suggesting dietary change- and(or) age-dependent adaptive increases in the secretions of pepsin and pancreatic proteases. In conclusion, protease treatment did not improve the true digestibilities of amino acids in soybean meal fed to newly weaned pigs. Key Words: Pigs, Amino Acids, Proteinases, Digestibility

Apparent ileal digestibilities of amino acids were determined in pigs fed cornstarch-based diets with untreated or protease-treated soybean meal as the protein source. Sixteen pigs were fitted with a modified post valve T-cecum cannula on d 14, 15, and 16 after birth and then returned to their sows until d 20 when they were weaned. Twelve of the pigs were selected for the study, which was conducted according to a two-period balanced change-over design. Treatments consisted of soybean meal that was 1) untreated (SBM), 2) processed by incubation (1:2 wt/vol distilled water adjusted to pH 4.5, for 16 h at 50 [degrees] C; CI-SBM), 3) sprayed with protease (supplied at 1 [Mu]L/g of soybean meal; PS-SBM), and 4) processed by incubation, as for CI-SBM, with protease in the water at the rate of 1 [Mu]L/g of soybean meal (PI-SBM). Each period consisted of 5 d of adaptation to diets followed by three 8-h collection periods (total of 24 h) that alternated with 8-h periods in which digesta were not collected. Apparent CP digestibilities were similar (P > .05) at 70.4, 72.4, 65.2, and 70.3% for the SBM, CI-SBM, PS-SBM, and PI-SBM diets, respectively. Corresponding amino acid digestibilities were also similar (P > .05), ranging from 62.5, 67.5, 57.9, and 65.0% for alanine to 83.5, 83.4, 78.7, and 84.7% for arginine. Apparent digestibilities were less (P < .05) for Period 1 (on d 7 after weaning) than for Period 2 (on d 16 after weaning). In conclusion, protease treatment of soybean meal had no effect on ileal digestibilities of CP and amino acids in newly weaned pigs. Key Words: Pigs, Amino Acids, Proteinases, Ileum, Digestibility

Our objectives were to use a soy protein isolate (SPI) diet containing 2-amino-2-methyl-1-propanol, an inhibitor of choline biosynthesis, to determine the bioavailable choline content of normal and overheated soybean meal (SBM), canola meal (CM) and peanut meal (PM). In the first four experiments, it was determined that weight gain of chicks fed the basal diet would respond linearly (P < 0.05) to graded levels of crystalline choline and would not respond to betaine, and that when fortified with adequate choline, no weight gain or feed intake response would occur upon addition of 100 g/kg SBM, CM or PM to the basal diet. Furthermore, addition of crystalline amino acids simulating the amino acid composition of 100 g/kg SBM did not alter the utilization of crystalline choline. In Experiment 5, feeding graded doses of choline, SBM, CM or PM resulted in linear (P < 0.05) increases in weight gain. Multiple linear regression analysis indicated bioavailable choline concentrations of 1708, 1545 and 1203 mg/kg for SBM, CM and PM, respectively. In Experiment 6, no differences (P > 0.05) in bioavailable choline concentrations occurred between normal and overheated SBM, CM or PM, and the bioavailable choline concentration of normal SBM, CM and PM was 2002, 1464 and 1320 mg/kg, respectively. Average bioavailable choline levels were 83, 24 and 76% of analytically determined choline levels in SBM, CM and PM, respectively. Canola meal, although three times as rich in total choline as SBM, has less bioavailable choline than SBM. A substantial portion of choline in SBM, CM and PM is unavailable, and overheating does not appear to decrease the bioavailability of choline in these products. KEY WORDS: * oilseed meals * choline * bioavailability * chicks

Ferritin and soybean meal were reevaluated as dietary treatments of iron deficiency in rats. Isotopes that had been used in the past were avoided because of contemporary knowledge of the physiological and structural complexity of ferritin protein and the solid iron mineral. Rats made anemic by iron-deficient diets were given equivalent amounts of iron as FeS[O.sub.4], horse spleen ferritin, baked soybean meal, or soybean meal plus ferritin. Full recovery (89-109%) from anemia and increased tissue iron occurred after 28 d of treatment with any of the iron sources, which contrasts to past bioavailability studies using 59Fe-labeled ferritin and generally shorter periods of observation. Cultivar-specific variability was observed in soybean seed soluble iron and ferritin content (1.9-2.0 times the control cultivar, Arksoy), which was apparently heritable. The combined data suggest that manipulating ferritin expression and other soluble components of seed iron in soybeans and possibly other seeds, using Mendelian and biotechnological approaches, could contribute to a sustainable solution to global problems of iron deficiency. INDEXING KEY WORDS: ferritin; iron deficiency; rats; soybeans

Six mature wethers (BW 72 kg) with ruminal, duodenal, and ileal cannulas were fed a basal (no added soybean meal [SBM]) diet or diets containing unheated SBM or SBM roasted at 165 [degrees] C for 75, 150, 180 or 210 min in a 6 X 6 Latin square experiment. Concentrations of indicators of heat exposure (NDF, ADF, and ADIN) in SBM increased with increasing roasting time. Organic matter digestion characteristics were not affected (P > .05) by supplementation or roasting of SBM. Daily intakes of NDF, ADF, and ADIN were higher (P < .05) when wethers were fed SBM-containing diets than when they were fed the basal diet and also were higher (P < .05) when wethers were fed diets containing roasted SBM than when fed the diet containing unheated SBM. Roasting time of SBM had a quadratic effect (P < .05) on intakes of NDF, ADF, and ADIN, with the lowest intakes observed for diets containing unheated SBM or SBM roasted for 75 min and the highest intakes observed for diets containing SBM roasted for 180 or 210 min. Disappearance of ADF in the stomach (grams per day) was not affected by supplementation or roasting of SBM. Disappearance of NDF and ADIN in the stomach (grams per day) were higher (P < .05) when wethers were fed SBM-containing diets than when they were fed the basal diet and also were higher (P < .05) when wethers were fed diets containing roasted SBM than when they were fed those containing unheated SBM. Disappearance of NDF and ADIN in the stomach (grams per day) increased (P < .05) linearly with increasing roasting time of SBM. Disappearance of NDF, ADF, and ADIN in the stomach (percentages of intake) were not affected (P > .05) by supplementation or roasting of SBM. Disappearance of NDF, ADF, and ADIN in the total tract (grams per day) were higher (P < .05) when wethers were fed SBM-containing diets than when they were fed the basal diet and also were higher (P < .05) when wethers were fed diets containing roasted SBM rather than those containing unheated SBM. Disappearance of NDF and ADIN in the total tract (percentages of intake) followed trends similar to those expressed as grams per day. It seems that, as concentrations of NDF, ADF, and ADIN in SBM increased due to heating, disappearance of these heating indices in the total tract also increased, the greatest proportion disappearing in the stomach. Key Words: Soybean Meal, Roasting, Sheep, Digestion, Heating Indices

Six mature wethers (BW 72 kg) with ruminal, duodenal, and ileal cannulas were fed a control (no added soybean meal [SBM]) diet or diets containing unheated SBM or SBM roasted at 165 [degrees] C for 75, 150, 180, or 210 min in a 6 X 6 Latin square experiment. Concentrations of indicators of heat exposure (ADIN, ADF, NDF) in SBM increased with increasing roasting time. Duodenal flows of total N, non-bacterial N, and SBM N increased (P < .05) linearly with increased roasting time. Small intestinal (SI) digestibility (percentage entering SI) of total N and SBM N was influenced quadratically (P < .05) by roasting time; SI digestibilities were modestly increased by heating SBM to 150 min, then declined dramatically when SBM was heated for 180 and 210 min. These responses resulted in a quadratic (P < .05) increase in quantity of total and SBM N disappearing in the SI; quantities increased as SBM was heated to 150 min and remained unchanged when SBM was heated for 180 and 210 min. These responses resulted in a quadratic (P < .05) increase in quantity of total and SBM N disappearing in the SI; quantities increased as SBM was heated to 150 min and remained unchanged when SBM was heated for 180 and 210 min. Duodenal flows and SI digestibilities of total and non-bacterial amino acids (AA) and of most individual AA followed patterns similar to those observed for N. Maximum quantities of total and individual AA disappeared from the SI when wethers were fed SBM roasted at 165 [degrees] C for 150 min. Evaluation of the effects of heat treatment on the nutritive value of a protein source for ruminants should include considerations for both ruminal protein escape and SI availability of escaped protein and for the nature of the AA supply absorbed from the SI. Key Words: Soybean Meal, Roasting, Sheep, Digestion, Nitrogen, Amino Acids

The objectives of this study were to examine the effects of feeding zinc-treated soybean meal (Zn-SBM) on ruminal fermentation patterns and duodenal AA flows in steers fed diets based on corn silage and corn. Six steers (385 kg) fitted with ruminal, duodenal, and ileal cannulas were used in a replicated 3 x 3 Latin square design experiment with 14-d periods. Diets were supplemented with solvent-extracted soybean meal (SBM), Zn-SBM, or a 50:50 combination (CP basis) of SBM:Zn-SBM. Ruminal escape N content of SBM and Zn-SBM were 30.0 and 57.0%, respectively, based on 12-h Dacron bag incubation. Protein sources provided approximately 30% of total CP in diets containing 12.6% CP (DM basis). Dry matter intake was equalized throughout the study at 2.2% of average initial BW. Total N flow at the duodenum was similar (P = .47) among treatments, but a trend (P = .15) for increased nonmicrobial N flow occurred when SBM and Zn-SBM were fed in combination. Microbial N flow and true efficiency of microbial CP synthesis were not affected by treatment (P = .87 and .37, respectively). Ruminal fermentation characteristics generally were unaffected (P |is greater than~ .10) by protein source. A positive quadratic response (P |is less than~ .06) was observed for total and essential AA flows to the small intestine because flows of total and essential AA from ruminally undegraded dietary protein tended (P = .12) to increase when SBM and Zn-SBM were fed in combination. Absorption of AA from the small intestine also showed a positive quadratic (P |is less than~ .06) response for SBM:Zn-SBM. Microbial AA flow to the small intestine was similar (P = .87) among treatments. Although estimated ruminal escape N content of Zn-SBM was twice that of solvent-extracted SBM, supplementing diets with Zn-SBM or with SBM alone resulted in similar flows of N and AA to the small intestine. However, feeding ruminally degradable and undegradable SBM in combination improved the flow of absorbable AA to the small intestine compared with feeding either protein source alone.

The availability of soy bean meal threonine for use of rats and chicks was assessed by providing the test animals with threonine-supplemented diets. The resulting growth rate was interpreted as a measure of feed conversion and bioavailability of threonine. Results indicated that threonine in soybean meal has 91% bioavailability for rats and 103% for chicks as compared to crystalline L-threonine. Supplementing the diet with other amino acids did not influence the bioavailability of threonine.

Crossbred gilts (n = 180) and barrows (n = 180) from the Louisiana State University (LSU) Agricultural Center and the University of Illinois (UI) were used to compare the effect of soybean meal in swine diets, relative to other protein sources, on growth performance and carcass traits of growing-finishing pigs. Four replications with five pigs each at each location were allotted to nine dietary treatments: soybean meal control (SBM), crystalline AA (corn-AA), extruded soybeans (ESB), canola meal (CAN), peanut meal (PNT), sunflower meal (SFLR), ground peas, meat and bone meal (MBM), and poultry by-product meal (PLTY). The diets were formulated to meet or exceed NRC nutrient requirements and to have equal Lys:ME according to dietary phase and sex. Corn was the grain source in all diets and the protein sources were the sole source of supplemental protein in all diets except when AA were added to meet the requirement. Pigs (three per pen at each location) were killed at an average final BW of 114 kg in the LSU or UI Meat Science Laboratories. Pigs fed SBM had greater (P [is less than] 0.05) ADG than pigs fed the corn-AA, CAN, SFLR, MBM, or PLTY and greater (P [is less than] 0.05) ADFI relative to pigs fed the corn-AA, ESB, MBM, or PLTY. Gain:feed was decreased (P [is less than] 0.05) in pigs fed corn-AA or SFLR but increased (P [is less than] 0.05) in pigs fed ESB compared with pigs fed the SBM diet. Loin muscle area was decreased (P [is less than] 0.05) in pigs fed the corn-AA or MBM diets compared with pigs fed the SBM diet. Tenth-rib backfat thickness was greater (P [is less than] 0.10) in pigs fed corn-AA, peas, or MBM than in those fed SBM. The NPPC percentage acceptable quality lean and kilograms of lean were decreased (P [is less than] 0.10) in pigs fed corn-AA, peas, or MBM compared with those fed SBM. Results from this experiment suggest that pigs fed SBM have equal or better growth performance and carcass traits than pigs fed other protein sources. Key Words: Carcass Composition, Protein Sources, Soybean Meal

Three growth trials were conducted with young chicks to evaluate crude protein (CP) utilization in soybean meal (SBM) as affected by dietary addition of microbial phytase. In assay 1, chicks were fed two CP-deficient (50 or 150 g CP/kg) levels of dehulled SBM, and each SBM level was then supplemented with equimolar amounts of cystine or methionine (Met) or with 1200 U phytase/kg. At 50 g CP/kg, cystine or Met supplementation improved (P [is less than] 0.05) measures of growth performance, but when 150 g CP/kg from SBM was fed, only Met addition improved (P [is less than] 0.05) weight gain, food efficiency and protein efficiency ratio (PER). Thus, Cys was more limiting than Met in the diet that contained 50 g CP/kg, but Met was clearly first-limiting in the diet that contained 150 g CP/kg. Phytase supplementation did not improve (P [is greater than] 0.10) chick performance at either level of CP. Chicks in assay 2 were fed 100 g CP/kg furnished by SBM, casein or corn gluten meal in the absence and presence of 1200 U phytase/kg. Weight gain, gain/food and PER values were greater (P [is less than] 0.05) in chicks fed SBM than in those fed casein, and greater (P [is less than] 0.05) in chicks fed casein than in those fed corn gluten meal. Phytase supplementation had no effect (P [is greater than] 0.10) on any measure of chick performance, regardless of the protein source fed. In assay 3, three deficient levels of CP (50, 100 and 150 g/kg) from SBM were fed in the absence and presence of 1200 U dietary phytase/kg. Weight gain, food efficiency and protein accretion increased linearly (P [is less than] 0.05) as a function of protein intake, but phytase supplementation had no effect (P [is greater than] 0.10) on slopes of the body weight and protein accretion curves. Likewise, phytase addition did not affect (P [is greater than] 0.10) measures of protein utilization, i.e., weight gain/protein intake and protein gain/protein intake at any of the CP levels that were fed. Because sulfur amino acids are the growth-limiting factors when protein-deficient levels of SBM are fed to young chicks, we conclude that dietary addition of phytase does not improve sulfur amino acid utilization in SBM. J. Nutr. 131: 1792-1797, 2001. KEY WORDS: * dietary phytase * soybean meal * methionine * cystine * chicks * protein utilization

The incidence of atherosclerosis can be modified by diet, and plant-derived proteins have a beneficial effect, but the underlying mechanisms remain unclear. It has been suggested that oxidized LDL (oxLDL) and autoantibodies against oxLDL are important in the development of atherosclerosis. We analyzed these factors in rabbits fed a nonpurified diet supplemented with high cholesterol (10.0 g/kg) containing either 270.0 g/kg casein (CAS, n = 10) or 270.0 g/kg soy protein isolate (SPI, n = 10) for 2 mo. Plasma and purified serum LDL from rabbits were analyzed at d 0, 15, 30, 45 and 60 of treatment, and the size of atherosclerotic lesions was evaluated at d 60 of treatment. CAS-fed rabbits had significantly higher plasma cholesterol at d 15-45 and LDL cholesterol levels at d 15 and 30. Levels of trilinolein and phosphatidylcholine hydroperoxides were higher in the LDL fraction of rabbits fed CAS than in those fed SPI. Also, CAS-fed rabbits had higher levels of highly oxidized LDL [monoclonal antibody (mAb) 24-reactive oxLDL] in plasma at d 60, whereas SPI-fed rabbits had higher levels of minimally oxidized LDL (mAb 28-reactive oxLDL) at d 45. These results were consistent with the earlier formation of anti-oxLDL antibodies and the presence of a larger area of atherosclerotic lesion in rabbits fed the CAS diet. These data indicate the importance of both the type of dietary protein used in the induction of atherosclerosis and the relevance of immunologic mechanisms in addition to biochemical and physiologic factors in the pathogenesis of atherosclerosis. J. Nutr. 130: 2641-2647, 2000. KEY WORDS: * casein * soy protein isolate * lipoprotein oxidation * atherosclerosis * rabbits.

We examined the effects of dietary fat type (10% of either soybean oil, S, or beef tallow, T) and xylanase supplementation (-, without; +, with 1 g of Avizyme 1300 per kg diet) in rye- based diets (56%) on tissue protein synthesis in male broilers. Birds were injected with a large flooding dose of a phenylalanine solution (150 mmol/L, 38 atom percentage excess [[sup.15]N] phenylalanine) and tissues were obtained after a 10-min incorporation period. [[sup.15] N]-enrichment in tissue free phenylalanine and tissue protein bound phenylalanine were measured by gas-chromatography mass-spectrometry and by gas-chromatography combustion isotope ratio mass-spectrometry, respectively in order to calculate tissue specific fractional rates of protein synthesis ([k.sub.s]). The [k.sub.s] (%/d) in (S-), (S+), (T-) and (T+)-fed birds were 56, 64, 84 and 61 (SEM = 3.7) in duodenum, 51, 52, 75 and 58 in jejunum (SEM = 3.1), 66, 67, 105 and 68 (SEM = 7.0) in jejunal mucosa cells, 53, 56, 68 and 50 (SEM = 3.7) in ileum and 52, 45, 118 and 39 (SEM = 20.2) in pancreas, respectively. Significant fat, enzyme or interaction effects in these tissues were mainly caused by the elevated [k.sub.s] in (T-)-fed birds which was closely associated with intestinal viscosity. We conclude that the effect of soluble nonstarch polysaccharides (NSP) and of NSP-hydrolyzing enzymes may be explained partially by modification in tissue protein synthesis of the intestinal tract. J. Nutr. 130: 827-834, 2000. KEY WORDS: * broilers * protein synthesis rate * rye * fat type * xylanase

A diet low in cholesterol, total fat and saturated fat is the first step in the treatment of hypercholesterolemia. However, many children cannot achieve plasma cholesterol goals by using this dietary approach. It has been long recognized that there is a hypocholesterolemic effect of soy protein when it is partially substituted for animal protein. The objective of our study was to evaluate the effect of soy protein on LDL cholesterol reduction when soy products are used as part of a regular diet at home. The product used were Archer Daniels Midland isolated protein and textured protein (soy meat and soymilk). We carried out a clinical random study including 26 hypercholesterolemic children; 13 were in the control group and 13 were in the intervention group (mean age 10.3 [+ or -] 2.04 y, range 7-15 y). During the 8-wk experimental period, both groups consumed a Step 1 diet ([is less than] 30% total fat, [is less than] 10% saturated fat, [is less than] 250 mg cholesterol). The intervention group also consumed the soy products as part of their regular meals. Food intake and adherence to the protocol were assessed during weekly home visits. Daily soybean protein intake in the intervention group was 20.88 [+ or -] 5.59 g/d, range 14.24-33 g/d. Preliminary data from 18 children (9 in each group) showed that the mean LDL-cholesterol reduction was significantly (P [is less than] 0.005) higher in the intervention group (15.5%) than in the control group (5.5%). There were no significant differences in total cholesterol reduction. The addition of soy protein to a Step 1 diet in hypercholesterolemic children was associated with a specific reduction in LDL cholesterol. We therefore propose that soy protein may offer a nonpharmacologic alternative to reducing elevated LDL cholesterol in children. [Supported by Inciensa-FODESAF, Costa Rica; American Soybean Association and United Soybean Board.]

We previously showed that soy protein consumption improves lipoprotein concentrations and reduces progression of atherosclerosis in cynomolgus monkeys. The mechanism for these beneficial effects is unclear. The purpose of this study was to determine potential mechanisms for the atheroprotective effects and to determine whether these effects extend to diabetic monkeys. As such, we designed an experiment with a 2 x 2 factorial design in which adult male monkeys (n = 23) were fed an atherogenic diet; the protein source was soy isolate (n = 11) or casein lactalbumin (n = 12), and monkeys were either control (n = 12) or streptozotocin-induced diabetic (n = 11). Diabetics had significantly increased fasting glucose and glycated hemoglobin levels; this relationship was not affected by protein consumption. Soy consumption significantly reduced total cholesterol and increased HDL cholesterol concentrations in both control and diabetic monkeys. To determine plasma and arterial LDL metabolism, radiolabeled LDL was injected before necropsy, 125I-LDL was injected 48 h and 131I-tyramine cellobiose-LDL was injected 1 h before necropsy to determine arterial LDL concentration and permeability, respectively. An increase in whole-body plasma LDL fractional catabolic rate was found with soy consumption. Soy reduced arterial LDL concentration across all arterial sites and LDL permeability in the carotid bifurcation and internal carotid arteries. Arterial delivery of LDL was calculated as LDL permeability X plasma LDL concentration and was also reduced across all arterial sites. There was no additional effect of diabetes. In conclusion, these beneficial effects of soy on both plasma and arterial LDL metabolism would be expected to reduce atherosclerosis progression and were found in both control and diabetic monkeys.

Two consecutive studies were conducted to evaluate the efficacy of replacing conventionally processed soybean meal (SBM) with extruded/expelled SBM (ESBM) in swine diets from weaning to slaughter. Experiment 1 was a randomized block design and used 480 pigs (240 barrows and 240 gilts; initial BW = 4.1 kg) in a 28-d nursery trial. There were two, 14-d feeding phases, and pigs were given ad libitum access to feed and water. Pen was the experimental unit, and pigs were fed either a control diet (C) or a diet containing ESBM (E). Diets were formulated on an equal lysine basis. Pigs fed C grew 16% faster (P < 0.05) and were 14% more efficient (P < 0.05) than those fed E. There was no difference in ADFI. However, plasma urea concentrations (PUC) were greater (P < 0.05) for pigs fed the E diet than for pigs fed C. Experiment 2 was a growing-finishing trial that used 240 pigs (120 barrows and 120 gilts) from Exp. 1 (initial BW = 12.5 kg) in a 2 x 2 factorial arrangement. Pigs were fed either a C or E diet and there were four possible Exp. 1-Exp. 2 diet combinations (C-C, C-E, E-C, or E-E). Diets were formulated on an equal lysine basis, and there were three feeding phases (12 to 50, 50 to 80, and 80 to 106 kg). Blood samples were taken at the end of each phase to measure PUC. Backfat (BF) and longissimus muscle area (LMA) were measured by real-time ultrasound on the final day of the trial, and carcass measurements were gathered at the slaughter facility. Pigs fed C had 4.8% and 3% greater (P < 0.05) ADG and ADG/ADFI than pigs fed E during Phase 1. There were no differences in BF or LMA between treatments. Pigs fed C had heavier hot carcass weights (P < 0.05) and 2.83% more pounds of lean (P < 0.05) than pigs fed E. The results suggest that using ESBM in nursery diets may not provide optimal growth performance. Growth performance was also hindered slightly in pigs fed ESBM during the growing-finishing trial. Key Words: Pigs, Extruded/Expelled soybean meal, Growth

To assess differences in soybean meal quality that are related to location of production, researchers in IL, KS, NC, NL (Netherlands), and OH each collected locally processed soybean meal samples. Samples were from the 1998 harvest season and taken at least 15 days apart after processing. These samples were assayed for ileal digestibility and compared to a common shared source of soybean meal and soy protein concentrate as controls. A low-protein (4.5% CF) casein diet was used for determining endogenous nitrogen and amino acid losses. Digestibility was determined at each research station using seven 35 kg barrows surgically fitted with ileal canulas. The pigs were used in a 7x7 Latin square design. The experimental diets had 17% CP originating only from the test material, except for the casein diet. The pigs were fed twice daily 12 h apart. The feeding allowance was 45 [gkg.sup.-0.75][meal.sup.-1]. Following a 5-d adaptation period, ileal digesta were collected for two 12-h periods in 2 consecutive days for determination of ileal digestibility. Variation in amino acid digestibility was minor among and within sites with a tendency for one KS and one NL sample to have a higher digestibility than two other NL samples. Overall, the NL samples had less digestible Lys and Met than all other samples. Variation in digestibility of amino acids was small between locations. The soybean meals tested in this experiment were approximately 4% higher in total amino acids than that reported in the NRC (1998). True digestibilities, however, were similar to NRC values except for Cys and Thr, which were 5 and 3 percentage points lower in this experiment. These results show that the soybean meals evaluated from several locations were relatively consistent in their digestibility. Key Words: Swine, Digestible amino acids, Soybean meal

Two experiments were conducted to determine the effects of different extruder temperatures and meal manufacturers on the feeding value of dry extruded-expelled soybean meal (EESOY) for swine. In Exp. 1, pigs (n=330, 13.2 kg BW) were fed a control diet containing solvent-extracted soybean meal (SBM) or one of five diets containing EESOY extruded at 143.3, 148.9, 154.4, 160.0 or 165.6 [degrees] C. All diets were formulated on an equal digestible lysine: ME ratio. From d 0 to 20, ADG was 570, 525, 528, 553, 535, 551 g/d and G/F was 0.61, 0.56, 0.59, 0.60, 0.57, 0.59 for pigs fed either SBM or EESOY with processing temperatures of 143.3 through 165.6 [degrees] C, respectively. No differences were observed in ADG or ADFI (P>0.32). However, G/F improved (quadratic, P Key Words: Nursery pig, Soybean meal, Processing

Two experiments were conducted to test a hypothesis that dietary supplementation of a carbohydrase mixture (mainly composed of [alpha]-1,6-galactosidase and [beta]-1,4-mannanase) improves nutrient utilization of soybean meal by growing-finishing pigs. In the first experiment, eight,surgically cannulated, finishing pigs were fed soybean meal based diets containing the carbohydrase to evaluate supplemental effects (0.05 and 0.10%) on apparent and true ileal digestibility of soybean meal. A low-protein (4.4% CP) casein diet was fed to measure endogenous protein loss. Both apparent and true ileal digestibilities of major limiting amino acids, i.e., lysine, threonine, and tryptophan, were improved (P < 0.05) when the carbohydrase was added to the diet at 0.05% and 0.10% levels. Energy was utilized more efficiently (P < 0.05) by pigs fed the diet containing 0.05% carbohydrase than the control diet. In the second experiment, one hundred growing pigs (24.1 [+ or -] 0.6 kg) were fed either a control diet (3,278 Mcal ME/kg diet) or a low energy diet containing carbohydrase (3,109 Meal ME/kg diet, 5% lower ME than the control diet) for four weeks. Supplemental level of the carbohydrase was 0.05%. Pigs fed the low energy diet with carbohydrase had similar average daily gain to that of pigs fed the control diet either by each week or during the entire experimental period. Average daily feed intake of pigs did not differ between treatments during the first, second, and third weeks. During the fourth week, pigs fed the low energy diet with carbohydrase had higher feed intakes (P < 0.05) than pigs fed the control diet. However, there was no difference in average daily feed intake during the entire experimental period. Gain:feed ratio did not differ between the treatments either by each week or during the entire experimental period. According to the results, supplementing a carbohydrase mixture (mainly composed of [alpha]- 1,6-galactosidase and [beta]-1,4-mannanase) improves nutrient digestibility of soybean meal. Pigs fed the low energy diet had similar growth performance to that of pigs fed the control diet. Key Words: Pigs , Carbohydrase, Soybean meal

A study evaluated the effect of soybean meal (SBM) particle size reduction on subsequent amino acid and energy ileal digestibilities. Four levels of a SBM source were processed through a hammer mill to achieve average particle sizes of approximately 900, 600, 300, and 150 microns. Included in the seven treatments were two control diets, one containing another source of SBM (900 microns) and the other soy protein concentrate (SPC). The seventh treatment was a low-protein (5% casein) diet that was used to determine endogenous amino acid losses for calculating true digestibilities. Fourteen crossbred barrows with a mean body weight of 28 kg were surgically fitted with cannulas at the distal ileum. The experiment was a 7 x 7 Latin Square design conducted in two replicates. Treatment diets were fed at a constant level during each 7-d period with ileal digesta samples collected for 2-d following a 5-d adaptation period. The amount of feed provided was based upon metabolic body weight (0.09 x [kg.sup..75]) and was increased 150 to 200 g between each collection period. Apparent and true digestibility of amino acids was calculated using 0.50% chromic oxide as a dietary marker. Apparent digestibility of isoleucine, methionine, phenylalanine, and valine increased linearly (P < 0.05) as particle size decreased. True digestibility of isoleucine, methionine, phenylalanine, and valine increased linearly (P < 0.05) as particle size decreased. The average of the ten essential amino acids showed that both apparent and true digestibility increased as particle size decreased, whereas the average of the non-essential amino acid digestibilities was not affected. Energy digestibility was not affected by SBM particle size reduction. These results suggest that a reduction in particle size of SBM increased essential amino acid digestibility but had no effect on non-essential amino acid digestibility. The largest improvement in digestibility was obtained when soybean meal was approximately 600 microns. Key Words: Soybean meal, Ileal digestibility, Particle size

A total of 1,200 gilts was used to evaluate the effects of replacing conventionally processed soybean meal with extruded-expelled soybean meal on finishing pig growth performance. Dietary treatments were arranged in a 2 x 3 factorial with two sources of soybean meal (solvent extracted or extruded-expelled) and three levels of added fat (none, 3.4, and 7% initially than decreasing in the next three dietary phases). Energy levels were based such that the higher energy in extruded-expelled soybean meal (with or without added fat) was equal to that provided by solvent extracted soybean meal with added fat. From 24.5 to 61.2 kg, pigs fed extruded-expelled soybean meal had greater ADG and G/F compared to those fed solvent extracted soybean meal. Increasing added fat in either extruded-expelled- or solvent extracted soybean meal-based diets, increased ADG and G/F (linear, P0.61) by increasing energy density. However, ADFI was decreased (P Key Words: Soybean meal, Processing, Finishing pigs

One hundred ninety-two lactating sows were used to evaluate the effect on sow and litter performance, sow body condition change, milk composition, and days to first estrous when field peas (Pisum sativum) replaced 10, 20, and 30% of the dietary soybean meal. Parity and lactation days for the four treatments were 3.10, 3.27, 2.96, and 2.90, and 19.2, 18.7, 19.0, and 19.2 days, respectively. Daily feed intake and calculated metabolizable energy (ME) consumption of 19.3, 20.9, 19.4, and 20.2 Mcal/day were similar across treatments suggesting field pea replacements for soybean meal up to 30% of the diet did not compromise diet acceptance or dietary energy consumption. Sow performance was unaffected by the level of pea grain in the lactation diet, and, as such, lactation sow weight change from farrowing to weaning, and days to first estrous did not differ. Mid-lactation milk composition on d 14 to include milk solids, protein, and fat, and body fat depth change did not differ between the corn/soy control and test diets containing 10 to 30% peas. Litter performance favored pigs nursing sows receiving the 10% pea test diet. Sows receiving the 10% pea diet weaned more (P Key Words: Sows, Field peas, Lactation

Two digestion/N balance trials were conducted to evaluate the potential of different levels of porcine blood cells (PBC) to stimulate nutrient utilization. In the first trial, a 5 x 5 Latin square design used five Hampshire x Polypay lambs (4 mo, 32 kg) fed diets in which 0, 20, 40, 60, and 80% of the soybean meal (SBM) protein was replaced with PBC protein. Diets contained 90% concentrate, 10% roughage and 15.7, 15.5, 15.9, 15.5, and 16.1% CP, respectively. Daily rations (2.2% BW) were fed in equal portions at 0800 and 2000. Urine and feces were collected for 7 d following a 14-d adjustment period. Digestibilities of DM, NDF, ADF, and N were not affected by dietary PBC percentage. Daily N retention, expressed as a percent of N intake, resulted in a cubic effect (P = 0.03), with 20 and 40% PBC producing the highest values (23.4 and 21.3, respectively). Percentage of digested N retained followed a cubic trend (P = 0.03), with 20 and 40% PBC again producing the highest values (29.1 and 25.6). The same five lambs (9 mo, 40 kg), assigned to a second 5 x 5 Latin square, were fed diets containing 90% concentrate and 10% roughage. Diets contained 13.9, 13.8, 13.9, 14.0, and 14.6% CP when PBC protein replaced 0, 25, 50, 75, and 100% of the SBM protein, respectively. Rations, provided at 2.2% BW, were fed in equal portions at 0800 and 2000 each day. Urine and feces were collected for 5 d following a 9-d adjustment period. Dry matter, NDF, and ADF digestibilities tended to decrease linearly (P = 0.08, P = 0.1, P = 0.1) as the level of dietary PBC increased. Unlike the first trial, no differences for N retention were found. These results indicate N utilization in young, lightweight lambs can be improved when PBC protein replaces 20 to 40% of dietary protein supplied by SBM. However, no benefit of PBC substitution was found in 9 mo-old, 40-kg lambs. Key Words: Porcine blood cells, Lambs, Nitrogen