Digestibility Of Soybean Meal Research Articles

Ileal phosphorus digestibility of soybean meal for broiler chickens remains consistent across institutions in a collaborative study regardless of non-phytate phosphorus concentration in the pre-experimental starter diet

The same experimental protocol was used in 4 institutions to evaluate the impact of non-phytate phosphorus (nPP) concentration in the starter diet on regression method-derived ileal P digestibility of soybean meal (SBM) during the subsequent grower phase. A total of 1,536 Ross 308 male broiler chickens on d 0 post hatching were allotted to 2 pre-experimental starter diets that contained 3.5 or 4.5 g nPP/kg (96 replicate cages per diet, 8 birds per cage) for 18 d. Subsequently, 576 birds from each starter diet were selected and allocated to 3 experimental semi-purified grower diets containing 400, 510, or 620 g SBM/kg (32 replicate cages per diet, 6 birds per cage) for 3 d until collection of ileal digesta. Statistical analysis was conducted as a randomized complete block design with the starter period as whole plot and the grower period as split-plot. The only significant 2-way interaction was between grower diet and experimental institution (P < 0.05) on BW gain and gain to feed ratio. The main effect of institution and grower diet impacted (P < 0.05) feed intake, the digestibility of DM, P, and calcium, and disappearance of inositol hexakisphosphate (InsP6) in the grower diets. Birds fed the 3.5 g nPP/kg starter diet had lower (P < 0.05) BW gain and feed intake during the grower period, but presented higher (P < 0.05) digestibility of P and disappearance of InsP6 compared with the birds that were fed the 4.5 g nPP/kg starter diet. Regression method-derived ileal P digestibility of SBM was determined to be 46 or 42% for the respective 3.5 or 4.5 g nPP/kg pre-experimental starter diet and was not affected by the nPP concentration or by the institution. In conclusion, the experimental protocol used in the current study resulted in similar estimates across multiple institutions and is thus endorsed for future application in studies that aim to expand the database of digestible P content in plant source feed ingredients.

Standardized ileal digestibility of amino acids in soybean meal fed to non-pregnant and pregnant sows

BackgroundTwo studies were designed to determine standard ileal crude protein (CP) and amino acid (AA) digestibility of soybean meal (SBM) from different origins fed to non-pregnant and pregnant sows. Seven solvent-extracted SBMs from soybeans produced in the USA, Brazil, and China were selected. In Exp. 1, eight different diets were created: a nitrogen (N)-free diet and 7 experimental diets containing SBM from different origins as the only N source. Eight non-pregnant, multiparous sows were arranged in an 8 × 8 Latin square design (8 periods and 8 diets). In Exp. 2, the diet formula was the same as in Exp. 1. Eight gestating sows (parity 3) were assigned to 4 different diets in a replicated 4 × 3 Youden square design (three periods and four diets) in mid-gestation and again in late-gestation stages.ResultsWhen fed to non-pregnant and late-gestating sows, the standardized ileal digestibility (SID) of CP and most AAs from different SBM were not significantly different (P > 0.05). When fed to mid-gestating sows, the SID values for Arg, His, Lys, Phe, Cys, Gly, Ser, and Tyr in SBM 1 were lower than in SBM 4 and 5 (P < 0.05), whereas SID for Leu from SBM 5 was higher than in SBM 1 and 4 (P < 0.05). SID values for Ile, Ala, and Asp from SBM 4 were lower than in SBM 1 and 5 (P < 0.05). Sows had significantly greater SID values for Lys, Ala, and Asp during mid-gestation when compared with late-gestation stages (P < 0.05). Mid-gestating sows had greater SID value for Val and lower SID value for Tyr when compared with non-pregnant and late-gestating sows (P < 0.01), whereas non-pregnant sows had significantly greater SID value for Met when compared with gestating sows (P < 0.01).ConclusionsWhen fed to mid-gestating sows, the SID values for most AAs varied among SBM samples. The SID values for Lys, Met, Val, Ala, Asp, and Tyr in SBM were affected by sow gestation stages. Our findings provide a cornerstone for accurate SBM use in sow diets.

Development of new mutant alleles and markers for KTI1 and KTI3 via CRISPR/Cas9-mediated mutagenesis to reduce trypsin inhibitor content and activity in soybean seeds.

The digestibility of soybean meal can be severely impacted by trypsin inhibitor (TI), one of the most abundant anti-nutritional factors present in soybean seeds. TI can restrain the function of trypsin, a critical enzyme that breaks down proteins in the digestive tract. Soybean accessions with low TI content have been identified. However, it is challenging to breed the low TI trait into elite cultivars due to a lack of molecular markers associated with low TI traits. We identified Kunitz trypsin inhibitor 1 (KTI1, Gm01g095000) and KTI3 (Gm08g341500) as two seed-specific TI genes. Mutant kti1 and kti3 alleles carrying small deletions or insertions within the gene open reading frames were created in the soybean cultivar Glycine max cv. Williams 82 (WM82) using the CRISPR/Cas9-mediated genome editing approach. The KTI content and TI activity both remarkably reduced in kti1/3 mutants compared to the WM82 seeds. There was no significant difference in terms of plant growth or maturity days of kti1/3 transgenic and WM82 plants in greenhouse condition. We further identified a T1 line, #5-26, that carried double homozygous kti1/3 mutant alleles, but not the Cas9 transgene. Based on the sequences of kti1/3 mutant alleles in #5-26, we developed markers to co-select for these mutant alleles by using a gel-electrophoresis-free method. The kti1/3 mutant soybean line and associated selection markers will assist in accelerating the introduction of low TI trait into elite soybean cultivars in the future.

The digestibility of raw materials by barramundi Lates calcarifer: Emphasis on the effect of inclusion rate on the digestibility of soybean meal and soy protein concentrate

Two digestibility experiments were done with Barramundi Lates calcarifer (average weight = 386 and 297 g for experiment 1 and 2, respectively) using indirect techniques and the reference diet substitution method. Chromium oxide was used as the inert marker and faecal material was collected by stripping. The same reference diet was used in both experiments. The first experiment determined the apparent digestibility coefficients (ADC’s) of solvent extracted soybean meal (SBM) and soy protein concentrate (SPC). The SBM and SPC were tested at two dietary inclusion levels (30 or 50 %). A high-quality South American fishmeal (FM-SA) was included in the experiment for comparative purposes (30 %). The second experiment determined the ADC’s of feed grade poultry by-product meal (PBM), blood meal (BLM), corn gluten meal (CGM), standard prime fishmeal (FM-P), tuna meal (FM-T), wheat (WH) and pregelatinized wheat starch (PGWS). Each of these raw materials was tested at 30 % inclusion. The results demonstrate that dry matter and energy ADC’s of SBM were adversely affected by inclusion level, decreasing from 60 % to 45 % and from 72 % to 63 %, respectively when inclusion level was increased from 30 to 50 %. In contrast, the protein ADC of SBM was relatively high (>83 %) and was not affected by inclusion level. The SPC was more digestible than SBM and recorded similar protein ADC to FM-SA (95 %), irrespective of its inclusion level. However, both dry matter (74 %) and energy ADC’s (82 %) of SPC were lower than those for FM-SA. The digestibility of amino acids from SBM, SPC and FM-SA were similar to their respective protein ADC’s. The protein and total amino acid ADC’s from FM-P were significantly higher than those for FM-T (100 % vs 88 %), however the energy ADC’s of both products were close to 100 %. The dry matter, protein and energy ADC’s of PBM were significantly higher than those in BLM, as was the digestibility of all individual amino acids. Dry matter digestibility of WH was very low (30 %), but far higher than PGWS (4 %). The CGM was more digestible than WH in terms of dry matter and energy ADC’s, but somewhat similar in terms of protein and total amino acid digestibility. The coefficients presented here, especially the amino acid coefficients, will be useful in formulating aquafeeds for Barramundi on a digestible amino acid and energy basis as well as maximizing the dietary inclusion of products such as SBM and SPC.

A novel laxative method for crocodilians and digestibility of soybean (Glicine max) in broad-snouted caiman (Caiman latirostris)

The objectives of this study were to evaluate the laxative capacity of saline solution, vegetable oil, and a commercial drug on Caiman latirostris and determine digestibility of diets with plant derived protein sources as a supplement for this species. After a trial using three laxative treatments in different doses, caimans were treated with 1.5 mL of lactulose daily for two days. They were then force-fed their corresponding diet once per day for 7 days and then digesta residues were collected. Digestibility was determined through a dietary marker, acid digestion of digesta residues, and calculated with a standard equation. Digestion of diets were between 96 and 99%, exhibiting differences among these (P = 0.0006), with the control diet 2.45% lower than treatments diets (P = 0.0050). Digestibility of soybean meal was between 90 and 95%. There were differences according to the treatment diet (P = 0.018). The results of this study indicate that the use of lactulose as a laxative for C. latirostris is effective and does not affect health. Inclusion of soybean meal in the diet of C. latirostris at levels of 20–60% improved its digestibility and nutrients were efficiently digested. Deliberate ingestion of plant material by wild crocodilians may serve to aid digestion and absorption of dietary nutrients, and not act only as gastroliths. This information could be used to develop crocodilian diets and assist future research to determine optimum nutrient levels and ingredient combinations for farm-raised crocodilians fed compounded diets.

Phosphorus digestibility and bioavailability in soybean meal, spray-dried plasma protein, and meat and bone meal determined using different methods

Three experiments were conducted to determine phosphorus (P) digestibility and bioavailability using different methods. The objective of the first experiment was to determine ileal P digestibility of soybean meal (SBM), meat and bone meal (MBM), and spray-dried plasma protein (SDPP) using a precision-fed broiler chick assay. This assay involved feeding 8 g of SBM, MBM, or SDPP to broiler chicks at 21 D of age. At 6 h after feeding, ileal digesta were collected. Ileal P digestibility of SBM, MBM, and SDPP was 64, 42, and 94%, respectively. In the second experiment, ileal P digestibility and excreta P retention of SBM, SDPP, and MBM were determined using an ad libitum fed chick assay. On day 17 of age, chicks were placed on 1 of 12 dietary treatments that consisted of diets containing increasing levels of SBM, SDPP, or MBM. On day 21, ileal digesta and excreta were collected. True ileal P digestibility and true excreta P retention estimated using regression of ileal P or excreta P output on dietary P content yielded true ileal P digestibility values for SBM, SDPP, and MBM (2 diet methods for MBM) to be 83, 98, 61, and 23%, respectively. True excreta P retention values for SBM, SDPP, and MBM (2 methods) were determined to be 51, 99, 32, and 53%, respectively. The third experiment determined bioavailability of P in SBM, SDPP, and MBM relative to KH2PO4 using a chick bone ash bioassay. Dietary treatments included a P-deficient cornstarch–dextrose–SBM diet supplemented with 2 increasing levels of P from KH2PO4, SBM, SDPP, or MBM. Bioavailability of P based on tibia ash estimated using the multiple regression slope ratio method was 36, 125, and 76% for SBM, SDPP, and MBM, respectively, relative to KH2PO4. The results of this study indicated the digestibility/relative bioavailability of the P in SDPP was very high for all 3 methods, but values for SBM and MBM varied greatly among different methods.

Effects of high moisture airtight storage of barley with exogenous enzymes on phosphorus digestibility of barley fed to pigs alone or in combination with soybean meal

The aim was to study the effect of storage (high moisture airtight (HMA) storage vs. dry storage) and a combination of phytase, xylanase, β-glucanase, and protease on nutrient solubility and digestibility of barley. Experiment 1 studied the effect of HMA stored barley at 29%, 35%, and 40% moisture and enzyme combination to define the optimum moisture level for the maximum nutrient solubility of barley. The ‘35% moisture’ was chosen for HMA storage of barley because this treatment (without or with enzymes) enhanced phytate degradation (31–73%) and the solubility of P (125–177%), nitrogen (N) (95–125%) and protein (56–68%) compared to dry storage (P < 0.05) and at the same time seemed to prevent a loss of energy and N (ammonia) by microbial fermentation. In Exp. 2, 6 female growing pigs (43 ± 2 kg) were used per diet (8 diets, 48 pigs) in a 12-d nutrient digestibility study to assess the effect of HMA stored barley at 35% moisture and enzyme combination on coefficient of total tract apparent digestibility (CTTAD) of P in barley fed alone or together with soybean meal (SBM). Also, HMA storage of barley at ‘35% moisture’ without and with enzyme combination enhanced phytate degradation (43–58%) and P solubility (2.5–3.3 fold) (P < 0.05). Thus, HMA stored barley (solely endogenous enzymes) enhanced CTTAD of P to almost the same extent as dry stored barley with enzyme combination (endogenous enzymes plus added enzymes) in the barley diet (45–49%) and the barley-SBM diet (15–25%) (P < 0.05). Adding the enzyme combination to HMA stored barley achieved the greatest increase of CTTAD of P in the barley diet (70%) and the barley-SBM diet (36%) (P < 0.05). The inclusion of the enzyme combination to HMA stored barley tended to enhance the calculated CTTAD of P of SBM (29%) compared with no enzyme combination (P = 0.06) due to the lower endogenous enzymes activity in HMA stored barley. It is necessary to add the enzyme combination to enhance P digestibility of SBM when fed together with HMA stored barley. Overall, HMA storage with enzyme combination is a potential method to enhance P digestibility of barley in pigs to reduce the dietary need for inorganic P addition and P excretion to the environment.

Influence of feed provisioning prior to digesta sampling on precaecal amino acid digestibility in broiler chickens

ABSTRACTA regression approach was applied to determine the influence of feed provisioning prior to digesta sampling on precaecal (pc) amino acid (AA) digestibility in broiler chickens. Soybean meal was used as an example test ingredient. Five feed-provisioning protocols were investigated, four with restricted provision and one with ad libitum provision. When provision was restricted, feed was provided for 30 min after a withdrawal period of 12 h. Digesta were sampled 1, 2, 4 and 6 h after feeding commenced. A diet containing 300 g maize starch/kg was prepared. Half or all the maize starch was replaced with soybean meal in two other diets. Average pc digestibility of all determined AA in the soybean meal was 86% for the 4 and 6-h protocols and 66% and 60% for the 2 and 1-h protocols, respectively. Average pc AA digestibility of soybean meal was 76% for ad libitum feed provision. Feed provisioning also influenced the determined variance. Variance in digestibility ranked in magnitude 1 h > ad libitum > 2 h > 6 h > 4 h for all AA. Owing to the considerable influence of feed-provisioning protocols found in this study, comparisons of pc AA digestibility between studies applying different protocols prior to digesta sampling must be treated with caution. Digestibility experiments aimed at providing estimates for practical feed formulation should use feed-provisioning procedures similar to those used in practice.

Results of an international phosphorus digestibility ring test with broiler chickens

The objective of this ring test was to investigate the prececal phosphorus (P) digestibility of soybean meal (SBM) in broiler chickens using the trial protocol proposed by the World's Poultry Science Association. It was hypothesized that prececal P digestibility of SBM determined in the collaborating stations is similar. Three diets with different inclusion levels of SBM were mixed in a feed mill specialized in experimental diets and transported to 17 collaborating stations. Broiler chicks were raised on commercial starter diets according to station-specific management routine. Then they were fed the experimental diets for a minimum of 5 d before content of the posterior half of the ileum was collected. A minimum of 6 experimental replicates per diet was used in each station. All diets and digesta samples were analyzed in the same laboratory. Diet, station, and their interaction significantly affected (P < 0.05) the prececal digestibility values of P and calcium of the diets. The prececal P digestibility of SBM was determined by linear regression and varied among stations from 19 to 51%, with significant differences among stations. In a subset of 4 stations, the prececal disappearance of myo- inositol 1,2,3,4,5,6-hexakis (dihydrogen phosphate)-P; InsP6-P) also was studied. The prececal InsP6-P disappearance correlated well with the prececal P digestibility. We hypothesized that factors influencing InsP6 hydrolysis were main contributors to the variation in prececal P digestibility among stations. These factors were probably related to the feeding and housing conditions (floor pens or cages) of the birds in the pre-experimental phase. Therefore, we suggest that the World's Poultry Science Association protocol for the determination of digestible P be should extended to the standardization of the pre-experimental period. We also suggest that comparisons of P digestibility measurements among studies are made only with great caution until the protocol is more refined.

Digestion of Soybean Meal in Alpacas

The objective of this experiment was to determine the degradation parameters of grass hay (GH) supplemented with soybean meal (SBM) and to determine the effects of SBM on compartment 1 (C1) ammonia (NH3-N) and volatile fatty acid (VFA) concentrations in alpacas. Four C1 fistulated adult male alpacas (7±1.5 years old; 61±5 kg BW) were housed in metabolism crates and received water ad libitum during the treatment periods of this study. The GH and SBM treatments were fed at 0700 every day. Treatment periods were for 14 d in which GH or SBM treatments were randomly allocated to each alpaca. On d14 volatile fatty acids (VFA), pH and NH3-N were determined at 1, 3, 6, 10, 14, 18 and 24 hrs post feeding. C1 degradation of GH and SBM was determined with the alpacas being fed GH only and the samples incubated for 0, 2, 4, 8, 14, 24, 48 and 72 hrs. Dry matter (DM) and crude protein (CP) degradation were determined and divided into three categories: a = immediately soluble; b = non-soluble but degradable; and u = non-degradable/unavailable, potential extent of degradation (PE), degradation rate (c) and effective degradation (ED; kp = 5.5%∙hr-1). Total DM intake was different between the two treatments, while CP intake was increased (72.5 to 191.0 g/d; P

Comparative amino acid digestibility for broiler chickens and White Pekin ducks

A total of 608 three-week-old male broiler chickens and White Pekin ducks were used in a 5-d trial to compare ileal amino acid (AA) digestibility of soybean meal (SBM) and canola meal (CM) using the regression method. A corn-casein-cornstarch-based diet was mixed to contain 15% CP. Cornstarch was replaced with test ingredient (SBM or CM) to contain 18 or 21% of CP in 4 other diets. A nitrogen-free diet (NFD) was used for standardization of apparent digestibility. Birds received a standard starter diet (23% CP) from d 0 to 14 posthatch and then 6 experimental diets for 5 d. On d 19 posthatch, birds were asphyxiated with CO2, and digesta from the distal section of ileum was collected. The ileal digestibility of AA from the test ingredients was assessed by multiple linear regression analysis using data on daily apparent ileal digestible AA and total AA intakes. The basal endogenous losses of N and all AA for ducks were significantly higher than those for broilers. For ileal AA digestibility by regression of apparent digestible AA intake against AA intake, there was a higher (P < 0.05) digestibility for Cys and Pro in ducks compared with broilers (P < 0.05). Within species, digestibility was not different between SBM and CM except for Lys of ducks, and Lys and Pro of broilers (P < 0.05). The results of this study showed that ducks have higher basal endogenous AA losses compared with broiler chickens as well as higher ileal Cys and Pro digestibility estimates derived from regression approach, indicating that data obtained from broilers should not be used to formulate diets for ducks.

Digestibilidade &lt;em&gt;in vitro&lt;/em&gt; de alimentos com inóculos de líquido de rúmen ou de fezes de bovinos

The present experiment was developed to compare ruminal fluid collected by ruminal cannula or esophageal probe and bovine feces in two dilutions, 200/200 (buffer/feces) or 100/300, as inoculum source, for the determination of in vitro (DAISYII/ANKOM&reg; ) digestibility of wheat meal, ground corn, soybean and canola meal, and Coast-cross and Tifton 85 hay, with three replications. Different inoculum did not influence (p > 0.05) in vitro dry matter digestibility (IVDMD) of wheat meal and ground corn. However, the digestibility of soybean meal and Coast-cross hay with inoculum of feces dilution 200/200 was lower (p < 0.05) than that of the other food. In the case of canola meal and Tifton 85 hay, the IVDMD with inoculum from ruminal cannula and esophageal probe was better (p < 0.05) than the others. Except for canola meal and Tifton 85 hay, the bovine feces as an inoculum source (100/300) was efficient to evaluate IVDMD.

Selecting soybean meal characteristics preferred for swine nutrition1

As environmental constraints become more important issues for the animal industry, selecting feed ingredients that yield good animal performance but also minimize environmental impact of animal production becomes critical. The objective of this research was to identify which compositional features would be desirable for soybean meal to maximize nutritional value and minimize animal waste. Eight soybean samples were selected from a database of 72, such that maximal variability for CP, NDF, and ADF content was obtained. Samples were subsequently processed into meal using standardized procedures. In Experiment 1, 8 cannulated pigs were used to determine ileal digestibility following a Latin square design. In Experiment 2, 5 of the samples were used in complete feeds and 10 pigs were used in a crossover Latin square design to determine the total tract digestibility, odorants in fresh and 5-d-old manure, and ammonia emission from manure. Differences up to 6% in ileal DM digestibility and 8% in ileal CP digestibility were observed. This difference was reduced to 1.1% for total tract DM digestibility and 4% for total tract CP digestibility. Differences in odorant concentration were 3-fold and for in vitro ammonia emission were 42%. The only compositional variable with a significant effect on digestibility was stachyose, which negatively affected ileal digestibility of DM (r = -0.80, P = 0.02) and energy (r = -0.73, P = 0.04). None of the compositional variables measured affected ileal CP digestibility. Ileal CP digestibility, however, was correlated with estimated CP fermentation in the large intestine (r = -0.86, P = 0.06) and with in vitro ammonia emission after 48 h (r = -0.81, P = 0.09). In conclusion, nutritionally relevant variability exists in soy varieties. Low stachyose content is important for maximizing ileal energy digestibility of soybean meal. Although no compositional variable was identified that explained differences in ileal CP digestibility, maximizing ileal CP digestibility is of interest for maximizing the nutritional value of soybean meal and possibly for reducing ammonia and odor emissions.

Effects of extrusion processing on digestibility of peas, lupins, canola meal and soybean meal in silver perch Bidyanus bidyanus (Mitchell) diets

Two experiments were conducted to investigate effects of processing on apparent digestibility coefficients (ADCs) of legumes and oilseeds for juvenile silver perch, Bidyanus bidyanus (∼49 g). The first experiment evaluated interactive effects of ingredients (lupins or field peas), processing (whole seed; hulls on or hulls off) and extrusion cooking (raw or extruded) on ADCs for juvenile silver perch (∼4 g fish−1). The second experiment was a three-fixed-factor anova designed to evaluate interactive effects of ingredients (soybean meal or canola meal), extrusion cooking (raw or extruded) and inclusion content (30% or 50% of the diet) on ADCs for juvenile silver perch (∼4 g fish−1). Lupin protein was more digestible than that of peas (ADC for crude protein 91% vs. 85% for peas) but the organic matter was less digestible (ADC for organic matter 50% vs. 67% for peas). Dehulling lupins significantly improved ADCs for all indices (dry matter, organic matter, energy and crude protein), but extrusion had no effect because lupins do not contain starch or heat-labile anti-nutrients. Conversely, for starch-rich peas that contain heat-labile trypsin inhibitors, both dehulling and extrusion significantly improved ADCs. Digestibility of soybean meal was much higher than that of canola meal. For soybean meal, neither processing, content nor their interaction affected digestibility but extrusion improved ADCs for dry matter, organic matter and energy but there was an interaction with content. Although higher overall, digestibility for these indices declined with increasing content for extruded product while there were only minor effects of inclusion for raw product. Benefits of extrusion were attributed to reductions in anti-nutrients, including phytic acid. For canola, there were no interactions between extrusion and content for any ADC. Increasing content reduced ADCs for crude protein, dry matter and organic matter but did not effect energy. Surprisingly, extrusion of canola also reduced digestibility for all ADCs. Dehulling improved both lupins and peas. Crude protein for all ingredients was well digested with ingredients ranked: lupins>soybean meal>peas>canola meal. Energy digestibility was best for soybean meal and worst for lupins. Extrusion greatly improved digestibility of peas and to a lesser extent soybean meal, gave no benefits to lupins and was detrimental for canola.

Comparison of the digestibility of diets based on fish meal and soybean meal in Litopenaeus Vannamei Boone 1931, using different temperatures and salinities for culture

The digestibility of fish meal and soybean meal by Litopenaeus vannamei was determined at different temperatures (22ºC and 28ºC) and salinities (16‰ and 35‰) using practical diets based on ingredients available in Mexico. The digestibility of soybean meal was consistently higher compared to that of fish meal, in terms of the apparent digestibilities of dry matter, crude protein and aminoacids, suggesting that soybean meal proteins are more readily digested. For fish meal, the apparent digestibility of the dry matter was reduced by high salinity at 28ºC, and the carbohydrate apparent digestibility was reduced by high salinity at both temperatures. The high salinity also reduced the digestibility of dry-matter, lipids and carbohydrates in soybean meal at 28°C, but had no effect on crude protein digestibility. This may have implications for the role of carbohydrates as source of energy in practical diets for shrimp. The results also suggest that the fish meal used might have been of reduced quality.

Intestinal digestibility of rumen undegraded N of concentrates measured by the mobile nylon bag technique

Two experiments were carried out on sheep to measure the effects of some factors of the mobile nylon bag (MNB) technique on the intestinal digestibility (DgI) of rumen undegraded N of meat and bone meal (MBM), soybean meal (SBM) and wheat bran (WB). The pore size of the nylon cloth (10 and 42.5 μm) influenced ( P < 0.05) DgI of SBM and MBM N irrespective of the site of recovery of the bags (ileum and faeces) and the incubation time of concentrate feeds in the rumen (0, 2, 4, 8, 16 and 24 h). The faecal recovery of the bags increased ( P < 0.05) DgI of SBM N in comparison with ileal recovery. The opposite was found with WB incubated 4, 8, 16 and 24 h in the rumen. DgI of MBM N was not influenced by site of bag recovery ( P > 0.05). Increasing incubation times in the rumen decreased ( P < 0.05) DgI of undegraded feed N. The total tract digestibility (rumen plus intestines) was independent of incubation time in the rumen for MBM and SBM, excepted for SBM incubated 4 or 8 h in the rumen when bags were collected in the ileum. Previous ruminal incubation of WB for 4, 8, 16 and 24 h increased ( P < 0.05) the amount of N digested in the total tract in comparison with unincubated WB and WB incubated for only 2 h. In the second experiment, residues obtained from the incubation of the feeds in the rumen (0, 2, 4, 8, 16, 24 and 48 h) were mixed in different proportions in order to obtain the true fraction of the undegraded feed in the rumen. This method was based on the DM degradability of the concentrate feeds and the outflow rate constant of feeds from the rumen, supposed equal to 6% h −1. Bags containing feeds mixed according to this method were incubated in a solution of pepsin-HCl for 0, 1, 2 and 3 h to simulate abomasal digestion and the DgI of N was measured afterwards with the MNB technique. Increasing action of pepsin led to higher digestibilities of N at this stage ( P < 0.05) but decreased the digestibility of N in the intestines excepted for MBM incubated in pepsin-HCl for 3 h and in any case for SBM. However, the omission of the incubation in pepsin had little influence on the amount of N postruminally digested.

Effect of roasting on site and extent of digestion of soybean meal by sheep: II. Digestion of artifacts of heating.

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.(ABSTRACT TRUNCATED AT 250 WORDS)

Digestibility of Different Protein Sources byPenaeus monodonRaised in Brackish Water and in Sea Water

The digestibility of fish meal, soybean meal, and casein by Penaeus monodon was determined in both brackish water (16 ppt) and in seawater (32 ppt). Casein was the most digestible protein, followed by soybean meal and fish meal; the differences were significant (P <: 0.05). Salinity did not affect the digestibility of casein and fish meal but did affect digestibility of soybean meal: It was significantly lower when P. monodon was raised at 32 ppt.

Digestion of soybean meal and canola meal protein and amino acids in the digestive tract of young ruminants.

Eight male Holstein calves (body weight 68 +/- 5 kg; age 75 +/- 6 d), each with a permanent re-entrant pancreatic cannula and T-type ileal and duodenal cannulas, were used in a crossover design with four animals per group to determine amino acid kinetics and digestibilities in the digestive tract of calves fed soybean meal (SBM) and canola meal (CM) protein. The SBM and CM diets were fed twice daily at a level of 900 g at each feeding time (air-dry basis). With the exception of methionine, crude protein and amino acid flows at the proximal duodenum, expressed as a percentage of intake, were not influenced by dietary protein source. Apparent ileal and total tract digestibilities of CP and amino acids were reduced (P less than .05) by feeding CM compared to SBM, but apparent ileal digestibility of methionine was not affected by dietary protein source. Except for methionine, net disappearance of all amino acids in the small intestine, relative to the amount fed, was higher for the SBM diet than for the CM diet. Net disappearance or synthesis of amino acids in the large intestine were not affected by dietary protein source. Similarly, dietary protein source did not affect (P greater than .05) the secretion of pancreatic juice or concentrations of protein, chymotrypsin and trypsin in pancreatic juice. Soybean meal protein has higher ileal and total gastrointestinal tract digestibility than CM protein for young, growing calves.

Effect of predigestion factors on the apparent digestibility of protein for swine determined by the Mobile Nylon Bag Technique.

Five Yorkshire x Lacombe barrows (45 kg initial wt) fitted with duodenal cannulas approximately 10 cm from the pyloric sphincter were used to determine the influence of the pH of the predigestion solution (pH 1.0, 1.5, 2.0 or 2.5), pepsin activity (189 vs 377 IU/liter) and duration of predigestion (0, 1.5, 2.5 or 4.0 h) on the apparent digestibility of the protein in soybean meal (SBM), meal and bone meal (MBM) or canola meal (CM) determined with the Mobile Nylon Bag Technique (MNBT). An additional six barrows were used to determine protein digestibility by conventional methods. Protein digestibilities determined using conventional digestibility techniques were 93.1 +/- .7, 79.1 +/- 1.8 and 79.3 +/- 1.4% for the SBM, MBM and CM diets, respectively. Protein digestibilities determined with the MNBT were highest at pH 2.0 for all three protein sources. Increasing pepsin activity from 189 to 377 IU/liter resulted in a slight increase in the digestibility of SBM and CM, but not of MBM. The absence of predigestion (0 h) resulted in a dramatic reduction in protein digestibility; predigestion times of 1.5 or 2.5 h usually resulted in lower protein digestibilities than did a predigestion time of 4.0 h. The closest agreement between results obtained by the MNBT and conventional digestibility studies occurred with a pH of 2.0, a predigestion time of 4.0 h and a pepsin activity of 377 IU/liter.