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Feed Protein (feed + protein)
Selected AbstractsOptimization of a gastrointestinal model applicable to the evaluation of bioaccessibility in fish feedsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 7 2009Mariam Hamdan Abstract BACKGROUND: Although several types of in vitro digestibility assays have been applied to nutritional evaluation of feeds for aquatic organisms, all of them are based on the use of closed reactors and do not simulate the gastric phase of the digestion. Our objective was to evaluate the suitability of a gastrointestinal model based on the use of a digestion cell provided by a semi-permeable reaction chamber, which allows continuous removal of digestion products as they are produced. We tested the effects of some factors, like the inclusion of a gastric phase, reaction temperature or bile salts on the hydrolysis of feed proteins by fish enzymes. RESULTS: We found that the most suitable operational conditions to simulate the digestion process must include a short acid pre-digestion as well as the use of bile salts in the reaction mixture. Acid pre-digestion resulted in a significant increase in the liberation of amino acids which represented more than twice that measured when using a single phase. The addition of two bile salts (45 µmol L,1 sodium taurocholate + chenodesoxycolate) resulted in almost a threefold increase in the hydrolysis of feed protein. The use of the described open system also allows the evaluation of carbohydrate hydrolysis as well as determination of residual undigested matter, in a similar manner to that carried out in ruminants with the DAISY system. CONCLUSION: Results suggest the system can be a very suitable model for evaluation of bioaccessibility in fish feeds. Copyright © 2009 Society of Chemical Industry [source] Effect of extrusion on in situ ruminal protein degradability and in vitro digestibility of undegraded protein from different feedstuffsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 15 2008Estela M Solanas Abstract BACKGROUND: The effect of extruding maize, barley, whole soybean (WSB), peas, lupins and soybean meal (SBM) on their in situ ruminal protein degradability and in vitro digestibility of the rumen undegraded protein (RUP) was studied. Two mixtures containing 0.75 WSB or lupins and 0.25 maize were also formulated. RESULTS: Extrusion of maize resulted in an increase of its effective protein degradability from 0.538 to 0.734 (P < 0.001), whereas the opposite occurred with barley (from 0.854 to 0.797; P < 0.001). Extrusion increased the in vitro digestibility of the RUP of both cereals, increasing therefore the amount of barley crude protein (CP) digested in the intestines (PDI) from 62 to 176 g kg,1 CP (P < 0.01), whereas maize resulted in lower (332 versus 229 g kg,1 CP; P < 0.01). Extrusion decreased (P < 0.001) the protein degradability of the three legume seeds and increased (P < 0.001) the in vitro digestibility of the RUP, resulting in a PDI increase (P < 0.001), from 60 to 367 g kg,1 CP for peas, from 69 to 265 g kg,1 CP for WSB and from 107 to 205 g kg,1 CP for lupins. This effect was enhanced when WSB was extruded jointly with maize. The extrusion of SBM also resulted in an increase in the PDI from 296 to 384 g kg,1 CP (P < 0.001). CONCLUSION: Extrusion decreases the rumen protein degradability of legume seeds, soybean meal and barley, and increases the digestibility of the RUP, resulting in an increase in the feed protein digested in intestine. The extrusion of soybean seeds together with maize enhances these effects. Copyright © 2008 Society of Chemical Industry [source] Using a complex non-TDN based model (the DVE/OEB system) to predict microbial protein synthesis, endogenous protein, degradation balance, and total truly absorbed protein supply of different varieties of cereal oats for ruminantsANIMAL SCIENCE JOURNAL, Issue 3 2009Peiqiang YU ABSTRACT Recently a new super-genotype of oat has been developed in the Crop Development Center called CDC SO-I (,SuperOat': low lignin and high fat). In a previous study, we evaluated total metabolizable protein using a TDN-based model-NRC-2001 which is popular in North America. However, the TDN-based NRC model is not accepted universally. The objectives of this study were to use a complex non-TDN based model, the DVE/OEB system, to evaluate potential nutrient supply to ruminants from the SuperOat in comparison with two normal varieties of oats (CDC Dancer and Derby) in western Canada. The quantitative predictions were made in terms of: (i) truly absorbed rumen synthesized microbial proteins in the small intestine; (ii) truly absorbed rumen undegraded feed protein in the small intestine; (iii) endogenous protein in the digestive tract; (iv) total truly absorbed protein in the small intestine; and (v) protein degraded balance. Results showed that using the DVE/OEB system to predict the potential nutrient supply, it was found that the SuperOat had similar truly absorbed rumen synthesized microbial protein levels (61, 63, 59 g/kg DM, P > 0.05, for SuperOat, CDC Dancer and Derby, respectively), higher truly absorbed rumen undegraded feed protein than CDC Dancer (22 vs. 17 g/kg DM P < 0.05, for SuperOat, CDC Dancer, respectively), but similar to Derby (22 vs. 21 g/kg DM; P > 0.05), and similar endogenous protein (16, 16, 18 g/kg DM; P > 0.05). Total truly absorbed protein in the small intestine is only numerically higher in the SuperOat (67 vs. 65, 62 g/kg DM, P > 0.05, for CDC Dancer and Derby, respectively). However, the protein degraded balance was significantly different (P < 0.05) with a positive value for the SuperOat (7.0 g/kg DM) and negative values for two normal varieties (,1.5, ,6.8 g/kg DM for CDC Dancer and Derby, respectively). In conclusion, the model predicted significantly different protein degradation balance. The SuperOat had positive degradation balance but other two normal varieties had negative protein degraded balance However, the SuperOat had similar total absorbed protein value to the two normal varieties of oats. [source] Protein feeds coproduction in biomass conversion to fuels and chemicalsBIOFUELS, BIOPRODUCTS AND BIOREFINING, Issue 2 2009Bruce E. Dale Abstract Agriculture has changed greatly in the past in response to changing human needs. Now agriculture is being called on to provide raw materials for very large-scale fuel and chemical production. Agriculture will change again in response to this demand and all producers and users of agricultural feedstocks will be affected by this change. For example, livestock feeding practices have already changed in response to the availability of distillers' grains from corn ethanol production. A fuels industry based on herbaceous biomass energy crops will be many-fold larger than the existing corn ethanol industry and will produce its own set of impacts on livestock feeding. We explore here one of these impacts: the availability of large new sources of feed protein from biomass energy crops. In addition to structural carbohydrates, such as cellulose and hemicellulose, herbaceous biomass energy crops can easily be produced with approximately 10% protein, called ,leaf protein'. This leaf protein, as exemplified by alfalfa leaf protein, is superior to soybean meal (SBM) protein in its biological value. Leaf protein recovery and processing fit well into many process flow diagrams for biomass fuels. When leaf protein is properly processed to concentrate it and remove antinutritional factors, as we have learned over the years to do with soybean meal protein, protein in leaf protein concentrate (LPC) will probably be at least as valuable in livestock diets as SBM protein. If LPC is used to meet 20% of total animal protein requirements (i.e., market penetration of 20%) then the potential utilization of leaf protein concentrate could reach as much as 24 million metric tons annually. This leaf protein will replace protein from SBM and other sources. This much leaf protein will reduce by approximately 16 million hectares the amount of land required to provide protein for livestock. Likewise the amount of land required to meet fuel needs will effectively be reduced by 8 million hectares because this land will effectively do ,double duty' by producing needed animal protein as well as feedstocks for fuel production. © 2009 Society of Chemical Industry and John Wiley & Sons, Ltd [source] Projected mature technology scenarios for conversion of cellulosic biomass to ethanol with coproduction thermochemical fuels, power, and/or animal feed proteinBIOFUELS, BIOPRODUCTS AND BIOREFINING, Issue 2 2009Mark Laser Abstract Seven process designs for producing ethanol and several coproducts from switchgrass are evaluated: four involving combinations of ethanol, thermochemical fuels (including Fischer-Tropsch liquids, hydrogen, and methane) and/or power, and three coproducing animal feed protein. Material and energy balances , resulting from detailed Aspen Plus models , are reported and used to estimate processing costs and perform discounted cash flow analysis to assess plant profitability. In these mature technology designs, fossil fuel displacement is decidedly positive and production costs competitive with gasoline. © 2009 Society of Chemical Industry and John Wiley & Sons, Ltd [source] Comparative analysis of efficiency, environmental impact, and process economics for mature biomass refining scenariosBIOFUELS, BIOPRODUCTS AND BIOREFINING, Issue 2 2009Mark Laser Abstract Fourteen mature technology biomass refining scenarios , involving both biological and thermochemical processing with production of fuels, power, and/or animal feed protein , are compared with respect to process efficiency, environmental impact , including petroleum use, greenhouse gas (GHG) emissions, and water use,and economic profitability. The emissions analysis does not account for carbon sinks (e.g., soil carbon sequestration) or sources (e.g., forest conversion) resulting from land-use considerations. Sensitivity of the scenarios to fuel and electricity price, feedstock cost, and capital structure is also evaluated. The thermochemical scenario producing only power achieves a process efficiency of 49% (energy out as power as a percentage of feedstock energy in), 1359 kg CO2 equivalent avoided GHG emissions per Mg feedstock (current power mix basis) and a cost of $0.0575/kWh ($16/GJ), at a scale of 4535 dry Mg feedstock/day, 12% internal rate of return, 35% debt fraction, and 7% loan rate. Thermochemical scenarios producing fuels and power realize efficiencies between 55 and 64%, avoided GHG emissions between 1000 and 1179 kg/dry Mg, and costs between $0.36 and $0.57 per liter gasoline equivalent ($1.37 , $2.16 per gallon) at the same scale and financial structure. Scenarios involving biological production of ethanol with thermochemical production of fuels and/or power result in efficiencies ranging from 61 to 80%, avoided GHG emissions from 965 to 1,258 kg/dry Mg, and costs from $0.25 to $0.33 per liter gasoline equivalent ($0.96 to $1.24/gallon). Most of the biofuel scenarios offer comparable, if not lower, costs and much reduced GHG emissions (>90%) compared to petroleum-derived fuels. Scenarios producing biofuels result in GHG displacements that are comparable to those dedicated to power production (e.g., >825 kg CO2 equivalent/dry Mg biomass), especially when a future power mix less dependent upon fossil fuel is assumed. Scenarios integrating biological and thermochemical processing enable waste heat from the thermochemical process to power the biological process, resulting in higher overall process efficiencies than would otherwise be realized , efficiencies on par with petroleum-based fuels in several cases. © 2009 Society of Chemical Industry and John Wiley & Sons, Ltd [source] Optimization of a gastrointestinal model applicable to the evaluation of bioaccessibility in fish feedsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 7 2009Mariam Hamdan Abstract BACKGROUND: Although several types of in vitro digestibility assays have been applied to nutritional evaluation of feeds for aquatic organisms, all of them are based on the use of closed reactors and do not simulate the gastric phase of the digestion. Our objective was to evaluate the suitability of a gastrointestinal model based on the use of a digestion cell provided by a semi-permeable reaction chamber, which allows continuous removal of digestion products as they are produced. We tested the effects of some factors, like the inclusion of a gastric phase, reaction temperature or bile salts on the hydrolysis of feed proteins by fish enzymes. RESULTS: We found that the most suitable operational conditions to simulate the digestion process must include a short acid pre-digestion as well as the use of bile salts in the reaction mixture. Acid pre-digestion resulted in a significant increase in the liberation of amino acids which represented more than twice that measured when using a single phase. The addition of two bile salts (45 µmol L,1 sodium taurocholate + chenodesoxycolate) resulted in almost a threefold increase in the hydrolysis of feed protein. The use of the described open system also allows the evaluation of carbohydrate hydrolysis as well as determination of residual undigested matter, in a similar manner to that carried out in ruminants with the DAISY system. CONCLUSION: Results suggest the system can be a very suitable model for evaluation of bioaccessibility in fish feeds. Copyright © 2009 Society of Chemical Industry [source] | ||||||||||