Removal of the alpha-galactosides of sucrose from soybean meal using either ethanol extraction or exogenous alpha-galactosidase and broiler performance

Effect of dietary supplementation of alpha-galactosidase on the growth performance, ileal digestibility, intestinal morphology, and biochemical parameters in broiler chickens

BACKGROUND

This study was performed to investigate the effect of Alpha-galactosidase (AlphaGal) supplementation with two energy levels on the growth performance, amino acid ileal digestibility coefficient "AID%," economic value, intestinal histology, and blood biochemical parameters of broiler chickens. Two-hundred 3-day-old broiler chicks (average body weight 74.34 g ±0.52 Ross 308) were randomly assigned to a 2 × 2 factorial arrangement consisting of two energy diets groups: in the first group, the birds were fed on a recommended energy diet (RED) while the second group was reduced 120 kcal/kg diet as a low energy diet (LED) and two levels of AlphaGal (0 or 50 mg/kg diet) for RED and LED for the 35-day feeding period.

RESULTS

The interaction effects between the energy level and the AlphaGal supplementations resulted in significant decrease (P ≤ 0.05) in the body weight, body weight gain, and the relative growth rate. The feed conversion ratio was signficantly increased in LED without supplementation of AlphaGal group during the entire experimental period, this negative effect on the growth performance was corrected by AlphaGal supplementation. The AID% value was increased significantly by AlphaGal supplementation. Blood triglyceride concentrations were significantly decreased (P = 0.02) in the LED group with or without AlphaGal supplementation, while the level of high-density lipoprotein (HDL) was significantly decreased (P = 0.01) in the LED or RED groups supplemented with 50 mg RED AlphaGal. Histologically, the number of intestinal glands and goblet cells increased in both RED and LED groups supplemented with AlphaGal and their secretions were mainly neutral mucopolysaccharides and less acidic mucopolysaccharides.

CONCLUSION

AlphaGal supplementation improved the growth performance of broiler chickens fed LED and the growth performance is similar to those fed RED, thereby consequently improving the economic value of these diets. AlphaGal supplementation improves intestinal histology and morphology as well.

Effects of feeding intact, ground and/or pelleted rapeseed on nutrient digestibility and growth performance of broiler chickens

In this study, the effect of grinding or pelleting of rapeseed on the digestibility, apparent metabolisable energy (AME_N), growth performance and gizzard weight of broiler chickens was evaluated. In Exp. 1, four treatments were tested (240 broiler chickens, 20 replications, 3 birds per cage). Birds received either a basal diet or were fed with rapeseed of different sized particles (fine, medium and coarse ground, respectively). In Exp. 2, 10 treatments were assessed (360 chickens, 12 replications, 3 birds per cage), where five different diets (a basal diet and four diets with intact rapeseed, fine ground, medium ground or coarse ground rapeseed, respectively) were fed non-pelleted or pelleted. In Exp. 3, two treatments were compared (224 broiler chickens, 14 replications, 8 birds per floor pen): fine ground rapeseed (FG) and intact rapeseed (IS). Compared with medium and coarse ground rapeseed, fine grinding increased in Exp. 1 the AME_N of rapeseed and the precaecal digestibility (PD) of dry matter and ether extract (EE) (p < 0.05). In Exp. 2, the content of AME_N and the PD of EE and crude protein (CP) increased as the degree of grinding increased when diets were not pelleted (p < 0.01). In contrast, the significantly highest values for these parameters were measured after pelleting without effect of grinding, resulting in a significant interaction between pelleting and grinding (p < 0.001). In Exp. 3, performance of chickens was not affected by dietary treatments, but gizzard weight and the PD of CP were higher when IS were included in the diet (p < 0.05). The results suggested that fine grinding may be used to increase the feeding value of full-fat rapeseed for broiler chickens. Nevertheless, pelleting of diets with rapeseed seemed to be much more effective in the reduction of particle size than grinding.

Impact of a multicarbohydrase containing α-galactosidase and xylanase on ileal digestible energy, crude protein digestibility, and ileal amino acid digestibility in broiler chickens

Exogenous enzymatic supplementation of poultry feeds, including α-galactosidase and xylanase, has been shown to increase metabolically available energy, although little information has been published on the impact on amino acid digestibility. An experiment was conducted to investigate a multicarbohydrase containing α-galactosidase and xylanase on amino acid digestibility, ileal digestible energy (IDE), and CP in male broiler chicks. The experiment was a 2 × 2 (diet × enzyme) factorial arrangement with 15 replicates of 8 male broilers per replicate raised for 21 d in a battery setting. The 2 dietary treatments included a positive control (PC) and a negative control (NC) diet formulated to contain 2.5% less calculated AME and digestible amino acids. Each of these diets was fed with and without enzyme. Broilers were fed a starter diet from 0-14 d (crumble) and a grower from 14-21 d (pellet). Birds were sampled on day 21 to determine ileal amino acid digestibility, IDE, and CP digestibility. Titanium dioxide (TiO2) was used as an indigestible marker for the determination of digestibility coefficients. Total ileal amino acid digestibility was increased (P = 0.008) by 3.80% with the inclusion of enzyme. Methionine and lysine digestibility was improved (P < 0.05) with the inclusion of enzyme by 3.37% and 2.61%, respectively. Enzyme inclusion increased (P = 0.001) cysteine digestibility by 9.3%. Diet-influenced ileal amino acid digestibility with tryptophan, threonine, isoleucine, and valine digestibility being increased (P < 0.05) in the PC when compared to the NC. IDE was decreased (P = 0.037) in broilers fed the NC diet by 100 kcal/kg feed when compared to broilers fed the PC diet. Enzyme inclusion increased (P = 0.047) IDE value by 90 kcal/kg. Crude protein digestibility was not influenced by diet; however, similar improvements in CP digestibility with enzyme inclusion were observed as with energy. These data support the benefits of a multicarbohydrase containing α-galactosidase and xylanase inclusion to improve nutrient and ileal amino acid digestibility across multiple dietary nutrient profiles.

Effect of replacing conventional soybean meal with low oligosaccharide soybean meal fed to weanling piglets

An experiment was conducted to investigate the effect of replacing conventional soybean meal (CSBM) with low-oligosaccharide soybean meal (LOSBM) on growth performance, blood urea nitrogen (BUN), intestinal morphology, viscosity of the intestinal contents, and visceral organ weight of weanling pigs. Thirty-two 19-d old individually housed pigs (6.2 ± 0.4 kg BW) were blocked by BW, and randomly assigned from within blocks to 1 of 4 dietary treatments: (1) CSBM with inclusion of fish meal and spray dried plasma protein (CSBM+), (2) CSBM without inclusion of fish meal and spray dried plasma protein (CSBM-), (3) LOSBM with inclusion of fish meal and spray dried plasma protein (LOSBM+), and (4) LOSBM without inclusion of fish meal and spray dried plasma protein (LOSBM-) according to a 2 × 2 factorial arrangement. Pigs were fed the experimental diets ad libitum for 14 d. Average daily gain and ADFI were not affected ( > 0.05) by the dietary treatments. However, inclusion of fish meal and spray dried plasma protein improved ( = 0.04) the gain to feed ratio. Replacing CSBM with LOSBM reduced ( = 0.01) viscosity of the intestinal contents. Dietary treatments had no effect ( > 0.05) on the small intestinal length and weights of organs including the pancreas, liver, heart, kidney, and spleen. No differences ( > 0.05) were observed between dietary treatments in villus height, crypt depth, and the ratio of villus height to crypt depth in the ileum, and crypt depth and the ratio of villus height to crypt depth in the jejunum; however, jejunal villus height was reduced ( = 0.02) when replacing CSBM with LOSBM. Concentration of BUN was higher ( = 0.01) for pigs fed the LOSBM diets compared with pigs fed the diets containing CSBM. In conclusion, LOSBM reduced the intestinal digesta viscosity but had no effects on growth performance and intestinal morphology when fed to piglets during the first 2 wk after weaning.

Effect of aα-galactosidase supplementation of cereal-soya-bean-pea diets on the productive performances, digestibility and lower gut fermentation in growing and finishing pigs

An experiment was carried out to study the effect of addingα-galactosidase to the diet on the performance and digestive parameters of growing-finishing pigs. Fifty-four gilts, average body weight (BW) of 43 (s.e. 0·4) kg, were allocated to 18 pens and used in a production experiment divided in two consecutive periods of 28 days each (growing and finishing). In each period gilts were given a diet based on cereals, soya-bean meal and peas, supplemented (Enzyme) or unsupplemented (Control) with 200 units per kg ofα-galactosidase. All diets included 2 g Cr2O3per kg as a digestibility marker. Food intake and body weight were recorded every 2 weeks and faecal samples by pen were collected at the end of each period. Average daily gain (ADG), food: gain ratio and faecal digestibility of dry matter (DM), crude protein (CP) and neutral-detergent fibre (NDF) were calculated. At the end of the production experiment nine gilts from each treatment were selected and given the finishing diet for a further 10 days before being slaughtered. Samples of digesta from the ileum and caecum were collected and ileal digestibility of monosaccharides determined. Short chain volatile fatty acids (SCVFA ) and purine bases (PB) in caecal digesta were analysed. The use ofα-galactosidase improved the ADG (P< 0·01) and the food: gain ratio (P< 0·01) simultaneous to increases in the faecal digestibility of DM (P< 0·05), CP (P< 0·05) and NDF (P= 0·07) in the finishing period. Alpha-galactosidase supplementation also improved the ileal digestibility of some monosaccharides (galactose, rhamnose, mannose and fucose) of the dietary fibre fraction (P< 0·05); and reduced total caecal concentration of SCVFA (P= 0·15), proportion of branched-chain VFA (P< 0·001), and concentration of total PB (P< 0·001). It is concluded that addingα-galactosidase to a cereal-soya-bean meal-pea diet improves ADG, food: gain ratio and digestibility in fattening pigs, and reduces the amount of fermentable substrate flowing to the large intestine.

Nutritional evaluation of new reduced oligosaccharide soybean meal in poultry

The nutritional values of a novel reduced-oligosaccharide soybean meal (SBM-RO) and conventional SBM (SBM-CV) were evaluated and compared in 4 experiments. The first experiment was a TMEn assay with conventional roosters. The second experiment was a precision-fed cecectomized rooster assay that was conducted to determine TMEn and amino acid (AA) digestibility. The third experiment was a standardized ileal AA digestibility assay, in which broiler chicks were fed semi-purified diets containing 20% protein (from only the test ingredient) for 17 to 21 d of age and ileal digesta were collected on d 21. The fourth experiment was a growth performance trial (7 to 20 d of age) where broiler chicks were fed corn-SBM diets (adequate in all AA) containing 38.84% SBM-RO or SBM-CV. The protein content (100% DM basis) of the SBM-CV and SBM-RO was 51.9 and 54.8%, respectively. The gross energy of the 2 SBM was similar. The TMEn values in both conventional roosters and cecectomized roosters were significantly higher (P < 0.05) for SBM-RO than for SBM-CV (difference was approximately 200 kcal/kg of DM). Amino acid digestibility in cecectomized roosters was not different between SBM-CV and SBM-RO, with the exception of Trp, Ala, Asp, and Cys (SBM-RO > SBM-CV, P < 0.05). No significant differences between the SBM were found for AA digestibility in the standardized ileal AA digestibility assay. In the growth performance trial (experiment 4), the corn-SBM diet containing SBM-RO yielded significantly higher feed efficiency than the diet containing SBM-CV (P < 0.001). The results indicated that the SBM-RO contains higher ME than the SBM-CV and that digestibility of AA in SBM-RO is similar to SBM-CV.

Effects of exogenous enzymes and dietary energy on performance and digestive physiology of broilers

The study was conducted to compare the effects of XG with AG and BM at different metabolizable energy diets on growth performance, digestive physiology and energy utilization of broilers fed with corn-SBM diet. A 2 × 4 factorial design was used with two basal diets (the positive control group, PC; negative control with ME reduction 100 kcal/kg, NC) and with or without the addition of three exogenous enzymes (0.02% BM; 0.01% AG; 0.05% XG) respectively. 1,200 one-day-old broilers were randomly allocated to 8 treatments with 10 pens of 15 broilers. There was no significant difference on BW, BWG, and FI at 0-21d, 21-42d or 0-42d for diet, enzymes or their interactions, but FI at 22-42d and 0-42d were tend to be decreased with the addition of enzymes. The F/G was significantly improved by the addition of enzymes especially in NC diet. The dietary AME and TME in PC or NC diet were significantly increased by XG or AG in NC diet. The villus length and V/C of ileum were significantly increased by the addition of BM or XG. XG improved the activities of trypsin, chymotrypsin and amylase, BM improved the activity of trypsin at 21d, and AG improved the activity of chymotrypsin at 21d. Comparing to PC diet, the addition of enzymes in PC or NC diet decreased feed cost per kg body weight gain especially in NC diet (except AG in PC diet) with the highest profits for XG in NC diet. In conclusion, supplementation of 0.02% BM or 0.01% AG or 0.05% XG could improve feed conversion of broilers in corn-soybean meal diet by improving energy utilization and digestive physiology, and also supplementation of 0.05% XG had a preferable efficacy in low energy diet.

Apparent metabolizable energy and apparent ileal amino acid digestibility of low and ultra-low oligosaccharide soybean meals fed to broiler chickens

Four experiments were conducted using 1,992 Ross × Ross 708 male broilers to determine AME(n) and apparent ileal amino acid digestibility (AIAAD) of low-oligosaccharide (LOSBM), ultra-low oligosaccharide (ULSBM), and control soybean meal (CSBM) fed to broilers from 20 to 31 d of age. An AME(n) assay was conducted in experiments 1 and 2, whereas AIAAD was determined in experiments 3 and 4. Chicks were randomly assigned to 3, 4, 2, or 3 dietary treatments, respectively, for experiments 1, 2, 3, or 4. The additional treatment in experiments 2 and 4 was to evaluate ULSBM. In the AME(n) assays, treatments were fed from 20 to 29 d of age and a 48-h excreta collection period was conducted from 27 to 29 d of age. Treatment 1 consisted of a basal diet and treatments 2, 3, and 4 consisted of 70% of the basal diet plus 30% CSBM, LOSBM, or ULSBM, respectively. The difference method was used to determine AME(n) utilizing an N correction factor to account for N retention. To determine AIAAD, broilers were fed semi-purified diets with CSBM, LOSBM, or ULSBM as the sole source of amino acids (AA) from 26 to 31 d of age with digesta collection occurring at 31 d of age. In experiment 1, LOSBM had 194 kcal/kg more AME(n) compared with CSBM (P = 0.011). Apparent ME(n) value of LOSBM was 141 and 134 kcal/kg higher (P = 0.012) compared with CSBM and ULSBM, respectively, in experiment 2. Digestible Lys, Met, Ile, and Val concentrations were higher (P < 0.001) for LOSBM vs. CSBM in experiment 3 even though digestibility coefficients were lower (P < 0.001) for LOSBM. In experiment 4, higher (P < 0.001) concentrations of digestible Met, Lys, Thr, Val, and Ile were observed for ULSBM and LOSBM compared with CSBM. In conclusion, genetically selected soybean meals with reduced stachyose and raffinose concentrations had higher AME(n) and AIAAD values compared with CSBM.

Apparent ileal digestibility of energy, nitrogen, and amino acids of soybean meals of different origin in broilers

The coefficient of apparent ileal digestibility (CAID) of DM, gross energy (GE), N, and amino acids (AA) of 6 soybean meal (SBM) samples were compared in 21-d-old broilers. In addition, the digestibility of DM and N of diets that contained these SBM were tested in vitro. Four of the SBM were of South American origin, had a CP content varying from 45.2 to 47.2% and a trypsin inhibitor activity (TIA) varying from 4.1 to 6.5 mg/g, and were collected from local traders. The other 2 SBM were from US origin; one was a branded product with 48.6% CP and 1.8 mg of TIA/g and the other was obtained from soybeans of US origin that were dehulled and processed in Spain (50.6% CP and 2.4 mg of TIA/g). The experimental design was completely randomized with 6 diets and 6 replicates per treatment. Chicks were fed a commercial diet from 1 to 16 d of age and then their respective experimental diets for 5 d. The diets were based on sucrose and corn starch, with the SBM tested as the only source of protein. At 21 d of age, digesta was collected from the distal ileum and the CAID of nutrients was determined using celite as an indigestible marker. Diets that included the 2 SBM with the greatest CP content had greater CAID of DM (P Collapse

Key Words Collapse

MESH Headings

• Amino Acids/analysis
• Amino Acids/metabolism
• Animal Feed/analysis
• Animal Feed/standards
• Animal Nutritional Physiological Phenomena
• Animals
• Chickens/metabolism
• Diet/veterinary
• Dietary Fats/analysis
• Dietary Fats/metabolism
• Digestion/physiology
• Female
• Ileum/metabolism
• Male
• Nitrogen/analysis
• Nitrogen/metabolism
• Glycine max/chemistry

Collapse

Grants Collapse

Affiliation(s)

A de Coca-Sinova Urcacyl, 47007 Valladolid, Spain
D G Valencia
E Jiménez-Moreno
R Lázaro
G G Mateos

Collapse

Understanding the nutritional chemistry of lupin (Lupinus spp.) seed to improve livestock production efficiency

In their raw, unprocessed form, lupins have many desirable characteristics for feeding both ruminants and single-stomached animals. An emphasis on these desirable characteristics when formulating diets, combined with an advanced knowledge of how components of lupins can influence nutritional value, will ensure they make a cost-effective contribution to livestock diets. The main lupin species used in livestock diets include Lupinus albus, L. angustifolius and L. luteus. Supplementation of ruminant diets with lupins has been shown to have many positive effects in terms of growth and reproductive efficiency, comparable with supplements of cereal grain. The true value of lupins in ruminants, however, can only be determined following a better definition of animal requirements and a closer match of ration specifications. Pigs can effectively utilize L. angustifolius and L. luteus, but detailed research has yet to reveal the reason for poor utilization of diets containing L. albus. Poultry can tolerate high levels of lupins in their diets but levels are often restricted to avoid problems associated with excess moisture in the excreta. Variable responses to enzymes have been observed when attempting to rectify this problem. Lupins have unique carbohydrate properties characterized by negligible levels of starch, high levels of soluble and insoluble NSP, and high levels of raffinose oligosaccharides, all of which can affect the utilization of energy and the digestion of other nutrients in the diet. In addition to carbohydrates, an understanding of lupin protein, lipid and mineral composition together with a knowledge of potential anti-nutritional compounds is required if the use of this legume is to be optimized.

Soybean: feed quality and safety. Part 1: biologically active components. A review

A large number of soybean components have diverse biological activities. These include hormonal, immunological, bacteriological and digestive effects. The presently known allergens are listed. The divergence between chemical evaluation and biological value is highlighted. The following components are discussed: Kunitz inhibitor, Bowman-Birk inhibitor, saponins, soyacystatin, phytoestrogens (daidzein, glycitein, genistein), Maillard products, soybean hydrophobic protein, soy allergens, lecithin allergens, raffinose, stachyose, 2-pentyl pyridine. The studies describing the effects of the isolated components are reviewed.

Effect of enzyme addition on the digestibilities of cell wall polysaccharides and oligosaccharides from whole, dehulled, and ethanol-extracted white lupins in chickens

Three experiments were conducted to examine the effects of a commercial enzyme preparation on chicks performance and digestibilities of nonstarch polysaccharides (NSP), raffinose (R), stachyose (S), and total oligosaccharides (O) in diets containing whole and dehulled lupin and ethanol-extracted dehulled lupin meal. Ethanol extract was also used to produce a rich oligosaccharide fraction. In the first experiment, the dehulling treatment and the addition of enzyme to the diet improved (P < 0.05) weight gain (24 and 15%), feed-to-gain ratio (13 and 9%), dry matter retention (32 and 8%), apparent protein digestibility (6 and 3%) and ileal digestibilities of raffinose (19 and 119%), stachyose (85 and 204%), and total oligosaccharides (68 and 178%), respectively. In addition, enzyme treatment improved (P < 0.05) excreta digestibility values for NSP (from -1.7 to 5.5%), R (from 64.6 to 92.6%), S (from 48.8 to 82.4%), and O (from 55.8 to 83.5%). In the second experiment, extraction of the ethanol soluble components from dehulled lupin decreased (P < 0.0001) weight gain (51%), and increased (P < 0.0001) feed consumption (34%), feed-to-gain ratio (32%), relative gizzard weight (14%), and the relative ceca length (20%). The addition of the isolated fraction of oligosacharides to the corn-extracted lupin diet (7.5 and 15%) yielded performance values similar to those obtained with the unextracted dehulled lupin. The addition of enzymes to the diets significantly improved the weight gain (11%) and feed to gain ratio (6%), and decreased relative gizzard weight (12%) and relative ceca length (7%). Ileal digestibilities of R, S, and O were considerably lower than corresponding excreta digestibilities. The excreta digestibility of NSP and excreta and ileal digestibilities of R, S, and O were lower (P < 0.05) in chicks fed the lupin diet containing the high concentration of extract compared with those fed the same diet containing the lower concentration of extract. Enzymes, when added to the diets, increased (P < 0.05) the digestibilities of R, S, and O with the relative effects being much greater for ileal than excreta samples. In the third experiment, the ethanol extract (7.5 and 15%) added to a corn-soybean diet improved weight gain, feed consumption, and feed-to-gain ratio by 19, 13, and 6%, respectively. Ileal digestibilities of R, S, and O were low (< 45%), especially in chicks fed the diets containing the high amount of added oligosaccharide fraction. There was no effect of enzyme addition on the performance parameters. However, supplemental dietary enzymes improved (P < 0.05) ileal and excreta digestibilities of oligosaccharides from 15.6 and 68.6% to 52.3 and 84.8%, respectively. In summary, dehulling greatly improved the nutritional value of lupin, while removal of the ethanol soluble materials, including raffinose and stachyose considerably decreased its value. The oligosaccharide fraction does not seem to have an antinutritive effect and the addition of enzymes increased the digestibilities of NSP, raffinose, and stachyose but did not significantly improve chick performance.

The effect of enzyme treatment of soybean meal on oligosaccharide disappearance and chick growth performance

Research was conducted to determine the effects of enzymatically hydrolyzing raffinose and stachyose from soybean meal (SBM) on fecal oligosaccharide concentration and growth performance of chicks fed a corn-SBM diet. The alpha-galactosidase treatment was optimized for oligosaccharide degradation. Enzyme treatment degraded raffinose and stachyose in SBM by 69 and 54%, respectively, compared to untreated soybean meal (USBM). Diets containing enzyme-treated soybean meal (ESBM) resulted in excreta raffinose and stachyose concentrations reduced to below measurable levels (<0.1 mg/ g feces). Enzyme treatment increased (P < 0.05) TME from 2,974 to 3,328 kcal/kg. Three chick growth studies were conducted to determine the effect of feeding ESBM on growth performance. There were no statistical differences (P > 0.05) in growth performance among treatments. Chicks fed the ESBM diet had an increased (P < 0.05) fecal neutral detergent fiber (NDF) content in one of two studies. A fourth experiment was conducted to determine if heating, used to enhance enzyme treatment, would decrease lysine availability. Heating significantly (P < 0.05) reduced lysine availability compared to USBM. These experiments demonstrated that feces could be made void of raffinose and stachyose, but chick growth performance was not significantly (P > 0.05) improved by enzyme treatment.

Soybean (Glycine max) cell wall composition and availability to feed enzymes

Defatted untoasted soybean cotyledons and hulls were fractionated as water solutes (WSc and WSh) and water unextractable (WUc and WUh). Further fractionation of WUc through deproteinization yielded the isolation of a water unextractable solid (WUS) fraction that was mainly composed (molar percent) of galactose (28.1%), glucose (27.8%), arabinose (13.3%), and uronic acids (17.6%), which accounted for 76% of the water insoluble polysaccharides in soybean cotyledons (WUc). The cell wall (WUS) was sequentially fractionated with chelating agents (chelating agent soluble solids, ChSS) and a gradient of agents (dilute alkali, DASS; 1 M alkali, 1MASS; and 4M alkali, 4MASS), which gave a final cellulosic residue. The ChSS and DASS extracts were characterized as pectin-rich fractions, whereas 1MASS and 4MASS were hemicellulose- and cellulose-rich fractions. Incubation in vitro of the WUc fraction with pectinase, cellulase, and xylanase resulted in the release of low amounts (not more than 5% bound basis) of monosaccharides, mostly uronic acids, xylose, and arabinose. Protein extraction hardly increased this release after enzymatic incubation (<7%). However, progressive fractionation of the cell wall matrix markedly increased the release of monosaccharides from pectin- (ChSS and DASS) and hemicellulose-rich fractions (1MASS and 4MASS). Significant degradation of cellulose (up to 20%) was achieved only after complete protein, pectin, and hemicellulose extraction.

Effects of feed enzymes on nutritive value of soyabean meal fed to broilers

1. The effects of two enzyme products on the nutritive value of soyabean meal (SBM) were investigated with the emphasis on changes in composition of non-starch polysaccharides (NSP) along the digestive tract. Enzyme A was a commercially available product containing mainly hemicellulase, pectinase, beta-glucanase and some protease activities and Enzyme B was an experimental product with mainly beta-galactanase activity. 2. Enzymes were added at the recommended dosage (normal) and at 5 times the recommended dosage (high) to a semi-purified diet based on maize with SBM as the sole protein source. 3. The enzymes had no effect on digesta viscosity in the jejunum or ileum. 4. Enzyme A at the high dosage significantly (P<0.05) improved AMEN, reduced excreta moisture content and improved ileal protein digestibility. The addition of the same enzyme at the recommended dosage had no effect on any of the above parameters. 5. Analysis of the monosaccharide composition revealed that Enzyme A tended to reduce the amounts of rhamnose and galactose in the soluble and insoluble NSP fractions in thejejunal and ileal digesta. The reduction was significant (P<0.05) when the same enzyme was added at the high dosage. 6. Enzyme B significantly (P<0.05) improved AMEN of the diet but not the growth or the feed conversion ratio (FCR) of the birds. Enzyme B at the high dosage significantly reduced (P<0.05) ileal protein digestibility. 7. Enzyme B significantly (P<0.05) increased the amount of free sugars in thejejunum and reduced (P<0.05) the concentration of soluble NSP in the ileum. 8. Analysis of the monosaccharide composition in the jejunal and ileal digesta showed that this enzyme was highly effective in releasing galactose from both the soluble and insoluble NSP fractions. 9. It is concluded that glycanases with galactanase and pectinase activities supplemented at appropriate dosages can improve the digestibility of the NSP in SBM and increase the metabolisable energy content of the diet containing high levels of SBM. 10. Furthermore, the addition of Enzyme B at the high dosage significantly (P<0.05) reduced protein digestibility without any measurable reduction in growth performance.

Nutritional evaluation of soybean meals varying in oligosaccharide content

Three conventional soybean meals (CSBM) and five low-oligosaccharide soybean meals (LOSBM) were evaluated. Meals were prepared by solvent-extracting flakes from generic soybean lines and soybean lines genetically modified to contain varying oligosaccharide content. The mean raffinose, stachyose, and galactinol levels in the CSBM were 0.58, 3.23, and 0%, respectively. The mean (range) raffinose, stachyose, and galactinol levels in the LOSBM were 0.08 (0.03 to 0.17%), 0.42 (0.04 to 1.08%), and 0.104 (0 to 0.24%), respectively. The crude fiber, fat, and ash contents of all SBM were similar, whereas the CP and sucrose contents of the LOSBM were slightly higher than the CSBM. The effect of SBM type on digesta passage rate, dry matter digestibility, and TMEN was assessed in conventional and cecectomized roosters using a precision-fed rooster assay (8 x 2 factorial design). Quantitative collection of excreta for 4, 8, 12, 16, 20, 24, and 48 h postfeeding indicated little or no effect of SBM type on digesta passage rate. The dry matter digestibility and TMEN values for the SBM were lower for cecectomized roosters compared with conventional roosters (P < 0.05), and there was no significant SBM x bird type interaction. The mean TMEN values (kcal/kg DM) for the CSBM and LOSBM were 2,739 and 2,931, respectively, which was a difference of 7% (P < 0.05). The two LOSBM with the lowest total raffinose, stachyose, and galactinol levels (0.07% and 0.25%) had average TMEN values that were 9.8% (P < 0.05) higher than their respective genetic controls. Digestibilities of raffinose and stachyose were much higher (P < 0.05) in conventional roosters than in cecectomized roosters. The results of this study indicated that the TMEN of LOSBM was higher than that of CSBM.

Nutrient content and protein and energy digestibilities of ethanol-extracted, low alpha-galactoside soybean meal as compared to intact soybean meal

A study was conducted with adult Leghorn roosters to determine TMEn, dry matter digestibility, amino acid content and digestibility, and cellulose and hemicellulose content and digestibility of ethanol-extracted, low alpha-galactoside soybean meal (SBM). Results were compared to that of commercially available 47% CP SBM. Twenty-one roosters were utilized; seven roosters were precision-fed each of the two soybean meal treatments, and seven served as feed-deprived controls. Excreta were collected for 48 h after feeding. A second experiment compared the TMEn, as determined with roosters, to AMEn, as determined with male broiler chicks, of 44% and 47% CP SBM and three different ethanol extraction procedures to remove alpha-galactosides. The ethanol extraction procedure concentrated CP, gross energy, and TMEn. Dry matter digestibility of SBM increased from 52.1% (control SBM) to 63.3% (ethanol-extracted SBM) because of the ethanol extraction procedure. The average amino acid digestibility of ethanol-extracted SBM was 91.6%, compared to 88.0% for control SBM. The digestibility of methionine, alanine, valine, and lysine was improved by the ethanol extraction procedure. Total cellulose and hemicellulose digestion, measured as digestion of specific monosaccharide components, was increased by the ethanol extraction. The TMEn and AMEn values for the different control and extracted SBM were similar. These data indicate that the ethanol extraction of SBM to remove alpha-galactosides resulted in a product that is more protein and energy dense than commercial SBM. Advantages in digestion of amino acids and fiber may contribute to the increase in TMEn observed in both young and adult birds.