Unheated Soybean Meal Research Articles

EVALUATION OF HEATED SOYBEAN MEAL USING CRESOL RED TECHNIQUE

Occasional problems with improperly heated soybean meal persist even though methods and rather good evaluation procedures are available. The technique of Olomucki and Bornstein (1960) in volves absorption of cresol red during a shaking process of a specific grind on soybean meal and will evaluate overheated as well as underheated soybean meal. Attempts have been made to determine if the (mg cresol red absorbed per g meal) reported was the lowest safe level. Unheated soybean meal samples averaged 2.55. Genetically uniform day old chicks fed heated soybean meal sample testing 3.3 averaged 61.9 g at one week compared with 68.3g for soybean meal testing 3.6. Poults fed the same meals averaged 129g and 138g respectively at one week. In both tests at two weeks these differences had decreased to only 266 vs 271. Effects on pancreas Weights were not significant except with raw soybean meals.

Effect of extrusion on trypsin inhibitor activity and nutrient digestibility of diets based on fish meal, soybean meal and white flakes

The effects of moist extrusion processing of diets containing fish meal (FM) and conventional defatted soybean meal (SBM) or untoasted defatted soybean meal (white flakes [WF]) on amino acid composition, trypsin inhibitor activity (TIA), and apparent total tract digestibility of nutrients were studied. Three diets with the nutritional characteristics of feeds for salmonid fish were formulated: one control based on FM as protein source and two others where 40% of total amino acids from FM were substituted by either SBM or WF. Each diet was fed to mink either as an unextruded mixture of the ingredients or as extruded pellets in order to determine the effect of extrusion processing. Extrusion did not change the amino acid composition of the diets significantly, but reduced the TIA of both diets containing soy products by approximately 76%. Intake of the unextruded WF diet was only one-third compared with the other diets. The dry matter concentration in faeces from mink fed diets containing soy products was significantly lower than in mink fed the FM diet. Digestibility of crude protein, all amino acids and fat was lower, but starch higher, in the unextruded WF diet than in the FM and SBM diets, whereas no significant differences were found among the extruded diets. Extrusion of the WF diet increased digestibility of protein and all amino acids. The greatest increase in digestibility after extrusion of the WF diet was observed for cysteine followed by tryptophan. Extrusion of the FM and SBM diets had no significant effect on amino acid digestibility. Digestibility of starch was, in general, increased by extrusion. It is concluded that the heat treatment involved in typical moist extrusion processing used for fish feed may be sufficient to inactivate most of the TIA in unheated soybean meal, and to increase digestibility of the protein in WF to approximately the same level as found for SBM and FM. Still, extrusion is a lenient process with minor effects on nutrient digestibility of diets containing fish meal or toasted soybean meal as major protein sources.

Estimation of protein digestibility—IV. Digestive proteinases from the pyloric caeca of coho salmon ( Oncorhynchus kisutch) fed diets containing soybean meal

The goal of this study was to better understand why dietary soybean products are poorly utilized by salmonids. The influence of dietary intake on coho salmon fingerling weight gain and specific properties of pyloric caeca enzymes was investigated. Fingerlings were fed diets containing heated or unheated soybean meal (SBM) or Promoveal™, as 15–25% herring meal replacer, for 8–12 weeks. Fish fed to apparent satiation with diets containing heated SBM replacer gained more weight than those fed unheated SBM at the same level. Fish increased in body weight at the same rate when fed restricted rations containing either 15% SBM replacer that was variously heated up to 20 min, 15% Promoveal™ replacer or the herring meal basal diet. After the experimental diets were fed, digestive proteinases were isolated from the pyloric caeca. Yield of pyloric caeca enzymes (PCE), recovery of trypsin in PCE, soybean trypsin inhibitor (SBTI) sensitivity of PCE trypsin, specific activity of PCE trypsin and in vitro casein digestibility by PCE were determined for each dietary group. Weight gain vs in vitro casein digestibility by PCE was linear for animals fed unheated SBM to apparent satiation (r 2 = 0.71, P < 0.1) but not for animals fed either heated SBM to apparent satiation or variously heated SBM as 15% replacer at restricted levels. Trypsin from fish fed diets with heated or unheated SBM, but not Promoveal™ replacer, was less sensitive to SBTI than fish fed no SBM. For fish fed diets with variously heated SBM as 15% replacer, the SBTI activity of the SBM and SBTI inhibition of PCE trypsin were inversely related (r 2 = 0.88, P < 0.05). The yield of PCE was higher for fish fed 25% of heated SBM replacer than it was for diet groups fed less SBM. The yield of PCE trypsin was higher from animals fed 25% heated SBM replacer than those fed diets with a lower percentage of heated SBM replacer. Feeding coho fingerlings rations with SBM replacer appears to promote physiological compensation of PCE. Heat stable and/or heat-activated factor(s) and SBTI appear to cause the compensation of salmon digestive proteinases from coho salmon fed diets with SBM.

Effects of Ruminal Exposure on the Amino Acid Profile of Heated and Formaldehyde-Treated Soybean Meal

Rumen cannulated Holstein steers, fed corn silage and a corn-soybean grain mixture twice a day, were used to compare the effectiveness of heat and formaldehyde treatments in preserving the amino acid profile of soybean meal exposed to ruminal fermentation for 12h. Formaldehyde treatments were 0, .3, .6, and .9g/100g soybean meal. Defatted soybean flakes treated at 250, 250, 215, and 180°C for 30, 20, 20, and 25min, respectively, and unheated soybean meal comprised the heat treatments. The in situ polyester bag technique was used to obtain estimates of ruminal degradation of the treated and untreated soybean meals and to obtain undegraded residues from the soybean meals following 12h of rumen exposure. Diaminopimelic acid was used to assess the extent of bacterial contamination. Significant amounts of apparent diaminopimelic acid were detected in unexposed samples (2.0 to 7.6% of soybean nitrogen) and in residues (4.8 to 12.7% of residue nitrogen). Significant differences in amino acid contents were detected between untreated and heat-treated soybean meals and their respective residues. Formaldehyde treatment was effective in preserving the original amino acid profile of soybean meal.

Effect of Heated or Unheated Soybean Meal With or Without Niacin on Rumen Protozoa1,2

Cattle fed heated soybean meal as a protein supplement had lower rumen protozoal counts than did those fed unheated soybean meal. Adding niacin to unheated soybean meal increased protozoal counts, but the difference was not significant. Adding niacin to heated soybean meal increased holotrich, entodiniomorph, and total protozoal counts. Apparently conventional heating of soybean meal makes niacin unavailable to rumen protozoa.

Influence of dietary heat-labile factors in soybean meal upon bile acid pools and turnover in the chick.

Heat-labile components of soybeans depress absorption of dietary tri glycA©rides when fed to young chicks (up to 2 weeks of age). Feeding dietary sodium taurocholate along with soybeans improves fat absorption. These observations sug gested that factors present in soybeans cause a bile acid insufficiency when they are included in diets for young chicks. Experiments were conducted to estimate the half- life, pool size and excretion rate of bile acids in two ages of chicks fed diets with and without unheated soybean meal. We have obtained half-life estimates of 6 to 9 days and bile acid pools of 18 to 23 mg/100 g body weight in chicks fed a control diet. Using 14C-labeledbile acids and gas-liquid Chromatographie analysis of bile acids in bile and excreta in studies with both control chicks and those fed a diet containing unheated soybean meal we have demonstrated that a) factors present in unheated soybean meal markedly increased fecal excretion and lowered the half-life of bile acids; b) differences in pool sizes occurred from feeding unheated soybean meal, suggesting that young chicks are unable to replenish excreted bile acids as readily as older chicks; and c) bile acids are associated with insoluble contents from the gastro intestinal tract of chicks fed unheated soybean meal.

Exocrine function of the chick pancreas as affected by dietary soybean meal and carbohydrate.

Chicks develop an enlarged pancreas when fed unheated soybean meal. Autoclaving the meal destroys or inactivates the heat-labile component(s) which cause this effect on the pancreas 5. Recent histological studies in our laboratory 24 have confirmed that this enlargment is due to hyperplasia of the pancreatic acinar cells, but the cause of this hyperplasia is not known 2. Homogenates of the enlarged pancreas have lower amounts of amylase, but higher levels of trypsin and chymotrypsin 20. Grossman et al. 9. and more recently Desnuelle et al. 6, suggested that differences in levels of pancreatic enzymes could be due to different rates of synthesis in response to dietary composition and/or an altered rate of secretion of enzymes from the pancreas. Most of the published results on pancreatic changes were obtained with pancreatic homogenates, a technique that precludes distinction between the suggested alternatives.The purpose of the present study was to determine the effect of changing the nature, or source, o...

Digestibility of Autoclaved Soybean Meal After Temporal Adaptation of Chicks to Unheated Soybean Meal

ALUMOT and Nitsan (1961) reported that intestinal proteolysis was com pletely inhibited in chicks fed unheated soybean meal up to three weeks of age. By four weeks of age proteolysis had increased and approached the normal by six weeks. These workers obtained a correlation between dietary anti-trypsin inhibitors and proteolytic activity in the intestinal contents. Pubols et al. (1964) found higher trypsin activity and lower amylase activity in pancreatic homogenates from fasted birds previously fed unheated soybean meal. These levels of enzymes were maintained fairly constantly during feeding, in contrast to the variations observed when autoclaved soybean meal was fed after a 16-hour fasting period. Applegarth et al. (1964) showed that pancreata from chicks fed unheated soybean meal were completely depleted of zymogen and attributed the decrease in proteolytic activity of the pancreas following feeding of unheated soybean meal to a loss of zymogen granules. Recent work by Salman et .

Chemical and microscopic nature of pancreata from chicks fed unheated soybean meal.

SummaryWhen chicks were fed diets containing 25% protein, those which had been fed unheated soybean meal developed pancreata which were much larger than pancreata from chicks which had been fed heated soybean meal. Histological examination did not indicate any variance between pancreata from either of the two treatments. The DNA, RNA, and protein levels, per unit weight, were not different whether unheated or autoclaved soybean meal was the source of protein in the diets. In addition, the moisture level in pancreata from both treatments was identical. These data indicate that the pancreas enlargement caused by feeding raw soybean meal is a result of hyperplastic rather than hypertrophic changes.

Changes in Pancreatic Enzymes as a Function of Diet in the Chick.

The phenomena of enzyme induction and repression are very well established in microorganisms, yet for vertebrates and mammals these have not been thoroughly investigated. The ratio of pancreatic enzymes is variable among species(,,,). Determinations of enzymes in homogenates of pancreata from rats fed either starch-rich or casein-rich diet show that specific activities of amylase and chymotrypsin reflect the starch and casein content of the diet(). In chicks, the pancreata enlarge when unheated soybean meal is consumed. These pancreata show depletion of zymogen granules to a greater extent than the corresponding pancreata from chicks fed autoclaved soybean meal diet. This histological evidence was confirmed by chemical analysis (). We investigated the rate of synthesis of enzymes by the pancreas of chickens after an adaptation period of 4 weeks on either unheated or autoclaved soybean meal. Experimental. Two groups of chicks were fed either unheated or autoclaved soybean meal for 4 weeks. The composition of the basal diet was essentially that used by Dal Borgo(). After this adaptation period, the chicks were fasted: 3 birds of each group were sacrificed at 0, 6, 12, 16, and 22 hours after the start of fast. After 16 hours of fasting, each group was divided into 2 subgroups, one of which was fed the same diet as before the fast. and the other the alternate diet. Three chicks from each of the 4 subgroups were sacrificed after 2 and 6 hours on the diet. The pancreata were excised aid weighed (after removal of extraneous tissue), then stored at −15°C. Trypsin and chymotrypsin were ashayed using p-toluene-sulphonyl-L-arginine-methyl ester (TAME) and N-Benzoyl-L- tyrosine ethyl ester (BTEE), respectively (). Amylase activity was determined by the 3,5,-(dini-trosalicylate method(). Protein in the pancrcatic homogenates was determined by measuring the absorbancy at 280 and 260 μ to correct for nucleic acids ().

Effect of Using Sugar or Starch in the Diet on Biological Responses in the Chick to Autoclaving Hexane Extracted Soybean Meal

INTRODUCTIONNUMEROUS studies showing improvement of raw soybean meal by autoclaving have been reported and the relation of this improvement to protein utilization, trypsin inhibition and pancreatic secretion has been investigated. The influence of variations in composition of the basal diet, aside from protein and amino acid levels, on response to autoclaving raw soybean meal has not been thoroughly investigated. Bray (1964) reported that a diet with unheated soybean meal for laying hens gave egg production results considerably lower than the results reported by Saxena et al. (1963), who also used unheated soybean meal as the dietary protein. Aside from the soybean meal component of the diet, two other components were notably different: (1) starch was used by Bray (1964), whereas Saxena et al. (1963) used glucose; and (2) no supplementary methionine was used by Bray (1964) and 0.5% was added to the diet used by Saxena et al. (1963)… .

Effects of Cystine Deficiency and Trypsin Inhibitor on the Metabolism of Methionine

While seeking methods capable of determining the cystine nutriture of animals, it was found that the addition of L-cystine to diets made with purified soybean protein resulted in an increased production of 14CO2 from labeled methionine when compared with animals not receiving cystine. A similar enhancement of CO2 production occurred if unheated soybean meal was fed, rather than heated meal, or if purified soybean trypsin inhibitor was given orally to rats maintained with either the heated or unheated meal. It is proposed that both cystine and trypsin inhibitor diminish the conversion of methionine to cysteine through the cystathionine pathway. Two mechanisms of soybean trypsin inhibitor action are proposed, one an interference with the incorporation of cystine into protein which increases the body pool of cystine which represses cystathionine synthase and the other, an interference of soybean trypsin inhibitor directly with cystathionine synthase.

Digestibility of Unheated Soybean Meal for Laying Hens

The digestibility of protein and energy in diets containing heated and unheated soybean meal was determined with colostomized laying hens. The data obtained showed that protein in diets containing unheated soybean meal was only 54% digested compared with 85% for heated meal. The difference in protein digestibility was sufficient to account for the difference in energy digestibility. The metabolizable energy value of diets with heated or unheated soybean meal was determined after 12, 36, 67, and 97 days of feeding. There was no evidence of a change in the metabolizable energy value of the diets with time. Adult chickens did not respond differently from young chicks to diets containing unheated soybean meal. These experiments also showed that hens did not adapt, following a prolonged feeding period, so that they were better able to digest unheated soybean meal.

Relationship of Fractions of Soybeans and a Crystalline Soybean Trypsin Inhibitor to the Effects of Feeding Unheated Soybean Meal to Chicks

Serveral experiments were conducted to study the effects of fractions isolated from unheated soybean meal on pancreatic hypertrophy, fat absorption, utilization of non-fat components of the diet, and growth rate of chicks, to determine whether these measurements were affected by specific components of the meal. Unheated soybean meal was fractionated into a water-insoluble residue, pH 4.4. insoluble proteins, salts insoluble at pH 8, and whey proteins recovered by dialysis and lyophilization of the portion of the meal soluble at pH 4.4. When fed to chicks at levels of 1.3 to 1.9% of the diet, the soybean whey proteins markedly depressed growth rate, caused pancreatic hypertrophy, reduced fat absorption, and lowered metabolizable energy value of the diet. Whey proteins were batch separated on DEAE cellulose into 2 fractions, one high in hemagglutinin activity and one high in trypsin inhibitor activity. Neither fraction when fed alone affected growth rate, fat absorption or metabolizable energy value of the diet to the same extent as a combination of the 2 fractions. A diet containing 0.6% of a crystalline Kunitz soybean trypsin inhibitor depressed growth rate of chicks and metabolizable energy value of the diet, caused pancreatic hypertrophy, but had no other undesirable effects. These experiments suggest that multiple factors are present in unheated soybean meal which cause the detrimental effects observed.

EFFECT OF SODIUM TAUROCHOLATE ON FAT MALABSORPTION INDUCED BY FEEDING UNHEATED SOYBEAN PROTEINS.

SummaryThe reduction in ability to absorb fat by chicks receiving diets containing unheated soybean meal can be overcome by supplementing the diet with sodium tauro-cholate or soybean lecithin. Cystine and taurine supplementation of the diet was not beneficial to fat absorption in chicks fed unhealed soybean meal. Composition and secretion of bile collected from the gall bladder was not affected by feeding unheated soybean protein.

Pancreatic Enzyme Levels in Chicks Fed Unheated Soybean Meal.

SummaryAn unheated, water insoluble fraction of soybean meal, while adding only .024% trypsin inhibitor to the diet, causes pancreatic hypertrophy in the chick. The hypertrophic pancreas has a higher trypsin specific activity than controls. Amylase specific activity was lower after feeding raw soybean meal but there was no difference after feeding the water insoluble fraction. These observations suggest that a heat-labile component other than trypsin inhibitor may be responsible for pancreatic hypertrophy and associated changes in enzyme levels in animals fed raw soybean meal.

Pancreatic Hypertrophy in Laying Pullets Induced by Unheated Soybean Meal

UNHEATED soybean meal depresses rate of gain and induces a hypertrophy of the pancreas in chicks, Saxena et al. (1961). Saxena et al. (1963) confirmed the finding of Fisher et al. (1957) that unheated soybean meal, adequately supplemented with methionine and vitamin B12, does not depress rate of lay when fed as the primary source of protein in semi-purified diets. Furthermore, Saxena et al. (1963) reported no effect of unheated meal on body or pancreas weight of laying pullets. In contrast, the data presented herein indicate that unheated meal, when fed as the sole source of protein and amino acids, does depress egg production and body weight as well as induce pancreatic hypertrophy and increase the moisture content of pancreatic tissue. EXPERIMENTAL AND RESULTSThe basal diet (Table 1) contained 20 mg./kg. of supplemental vitamin B12 but no supplemental methionine. Each of the diets indicated in Table 2 was fed…

The effectiveness of essential amino acid supplementation in overcoming the growth depression of unheated soybean meal

The effectiveness of essential amino acid supplementation in overcoming the growth depression of unheated soybean meal

Effect of Unheated Soybean Meal on Blood Coagulation of Chicks

INTRODUCTIONBALLOUN and Johnson (1953) reported that the feeding of unheated, solvent-extracted soybean meal significantly increased blood-clotting time of chicks, and that vitamin K did not affect this condition. During the course of an experiment devised to investigate the methionine requirement of growing chicks fed meals heated for various lengths of time (Griminger et al., 1954) we subjected a number of chicks from each lot to blood-clotting tests, and found no such differences; these diets contained ample amounts of vitamin K. In another preliminary experiment chicks were fed a ration which had been employed by Griminger et al. (1953) to produce a vitamin K deficiency in young chicks. This diet was modified by replacing the commercial soybean meal sample with a desolventized meal (“raw grits”) that had undergone a minimum of heat treatment during extraction, or by samples of meal heated for 45 and 90 minutes respectively at atmospheric pressure… .

Anticoagulant properties of unheated soybean meal in chick diets

Blood-clotting time of chicks was significantly increased by feeding diets containing unheated, solvent-extracted soybean meal. Vitamin K was not the limiting factor since clotting time was not reduced by the addition of this vitamin to the diet. The anticoagulant was heat labile because autoclaving completely abolished the anti-blood-clotting properties of the meal. Age and previous dietary treatment of chicks were not factors affecting the anticlotting action of unheated soybean meal.