The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
William H Karasov - One of the best experts on this subject based on the ideXlab platform.
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Activity of intestinal Carbohydrases responds to multiple dietary signals in nestling house sparrows.
The Journal of Experimental Biology, 2013Co-Authors: Paweł Brzęk, Kevin D Kohl, Enrique Caviedes-vidal, William H KarasovAbstract:The ‘adaptive modulation hypothesis’ predicts that activity of digestive enzymes should match the amount of their substrates in diet. Interestingly, many passerine birds do not adjust the activity of intestinal Carbohydrases to dietary carbohydrate content. It is difficult to assess the generality of this rule, because in some studies passerines fed on low-carbohydrate and high-lipid diet showed reduced activity of intestinal Carbohydrases. However, as Carbohydrase activity may be inhibited by high dietary lipid content, it is unclear whether observed effects reflected lack of induction by the low carbohydrate levels or suppression by the high lipid levels. Here, we isolated the specific effects of dietary carbohydrate and lipid on Carbohydrases. We hand-fed house sparrow nestlings on diets with 25% starch and 8% lipid (diet HS), no starch and 20% lipid (HL), or 25% starch and 20% lipid (HSL). Our results show that activity of intestinal Carbohydrases is simultaneously induced by dietary carbohydrates and decreased by dietary lipid, although the latter effect seems stronger. Activities of maltase and sucrase summed over the total intestine decreased in the order HS>HSL>HL. We observed a complex interaction between diet composition and intestinal position for mass-specific activity of these enzymes, suggesting site-specific responses to changes in digesta composition along the intestines caused by digestion and absorption. We re-interpret results of earlier studies and conclude that there is no unequivocal example of adaptive modulation of intestinal Carbohydrases by dietary carbohydrate in adult passerine birds, whereas the present experiment confirms that nestlings of at least some species possess such capacity. * BBM : brush-border membrane HL : high-lipid and starch-free diet HS : low-lipid and high-starch diet HSL : high-lipid and high-starch diet
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Activity of intestinal Carbohydrases responds to multiple dietary signals in nestling house sparrows.
The Journal of experimental biology, 2013Co-Authors: Paweł Brzek, Kevin D Kohl, Enrique Caviedes-vidal, William H KarasovAbstract:The 'adaptive modulation hypothesis' predicts that activity of digestive enzymes should match the amount of their substrates in diet. Interestingly, many passerine birds do not adjust the activity of intestinal Carbohydrases to dietary carbohydrate content. It is difficult to assess the generality of this rule, because in some studies passerines fed on low-carbohydrate and high-lipid diet showed reduced activity of intestinal Carbohydrases. However, as Carbohydrase activity may be inhibited by high dietary lipid content, it is unclear whether observed effects reflected lack of induction by the low carbohydrate levels or suppression by the high lipid levels. Here, we isolated the specific effects of dietary carbohydrate and lipid on Carbohydrases. We hand-fed house sparrow nestlings on diets with 25% starch and 8% lipid (diet HS), no starch and 20% lipid (HL), or 25% starch and 20% lipid (HSL). Our results show that activity of intestinal Carbohydrases is simultaneously induced by dietary carbohydrates and decreased by dietary lipid, although the latter effect seems stronger. Activities of maltase and sucrase summed over the total intestine decreased in the order HS>HSL>HL. We observed a complex interaction between diet composition and intestinal position for mass-specific activity of these enzymes, suggesting site-specific responses to changes in digesta composition along the intestines caused by digestion and absorption. We re-interpret results of earlier studies and conclude that there is no unequivocal example of adaptive modulation of intestinal Carbohydrases by dietary carbohydrate in adult passerine birds, whereas the present experiment confirms that nestlings of at least some species possess such capacity.
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dietary modulation of intestinal enzymes of the house sparrow passer domesticus testing an adaptive hypothesis
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2000Co-Authors: Enrique Caviedesvidal, Daniel Afik, William H KarasovAbstract:Insectivorous:frugivorous passerine species studied so far lack the ability to modulate intestinal maltase activity, in contrast to galliformes. We tested for dietary modulation of small intestine (SI) enzymes including maltase in house sparrows to understand whether the difference between the galliformes on the one hand, and the passerines on the other, reflects a phylogenetic pattern (maltase modulated in galliformes but not passerines), a dietary pattern (maltase modulated in granivores but not insectivore:frugivores), some other pattern, or chance. We also tested the prediction that intestinal peptidase activity would be increased on a high protein (HP) diet. Birds were fed three diets high in starch, protein, or lipid for 10 days. For birds on the HP diet (60.3% protein) we observed the predicted upward modulation of aminopeptidase-N activity, as compared with the lower-protein, high starch (HS) (12.8% protein) diet. In contrast, birds eating the HS diet had similar maltase and sucrase activities, and only slightly higher isomaltase activity, compared with birds eating the high protein (HP), starch-free diet. Birds eating high lipid (HL) diet had low activities of both Carbohydrases and peptidase. Considering that the statistical power of our tests was adequate, we conclude that house sparrows show little or no increase in Carbohydrases in response to elevated dietary carbohydrate. We cannot reject the hypothesis that maltase lability among avian species has a phylogenetic component, or that high dietary fat has a depressing effect on both Carbohydrase and peptidase activities. © 2000 Elsevier Science Inc. All rights reserved.
Wilhelm Guenter - One of the best experts on this subject based on the ideXlab platform.
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The Effect of Fat Type, Carbohydrase, and Lipase Addition on Growth Performance and Nutrient Utilization of Young Broilers Fed Wheat-Based Diets
Poultry Science, 2004Co-Authors: X. Meng, Bogdan A. Slominski, Wilhelm GuenterAbstract:Abstract A 2 × 2 × 2 factorial experiment was conducted to evaluate the effects of fat type (beef tallow [50 g/kg diet] or canola oil [50 g/kg of diet]), Carbohydrase addition (none or Carbohydrases [0.4 g/kg diet]), and lipase addition (none or lipase [0.2 g/kg of diet]) on growth performance and nutrient utilization of male broilers fed a wheat-based diet from 5 to 18 d. The Carbohydrase supplement contained xylanase, glucanase, cellulase, and other enzyme activities. The experimental diets were formulated to be suboptimal in major nutrients and each was fed in a mash form to 10 replicate pens of 5 broilers per pen. Body weight gain was not affected by fat type but a poorer feed/gain ratio (P
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the effect of fat type Carbohydrase and lipase addition on growth performance and nutrient utilization of young broilers fed wheat based diets
Poultry Science, 2004Co-Authors: X. Meng, Bogdan A. Slominski, Wilhelm GuenterAbstract:A 2 × 2 × 2 factorial experiment was conducted to evaluate the effects of fat type (beef tallow [50 g/kg diet] or canola oil [50 g/kg of diet]), Carbohydrase addition (none or Carbohydrases [0.4 g/kg diet]), and lipase addition (none or lipase [0.2 g/kg of diet]) on growth performance and nutrient utilization of male broilers fed a wheat-based diet from 5 to 18 d. The Carbohydrase supplement contained xylanase, glucanase, cellulase, and other enzyme activities. The experimental diets were formulated to be suboptimal in major nutrients and each was fed in a mash form to 10 replicate pens of 5 broilers per pen. Body weight gain was not affected by fat type but a poorer feed / gain ratio (P < 0.001) was noted for tallow-containing diets. Regardless of fat type, Carbohydrase enzyme supplementation improved (P < 0.001) BW gain and feed / gain ratio. There was no effect of lipase addition on chicken performance and nutrient utilization. When compared with canola oil, tallow-containing diets had a lower (P < 0.001) apparent fat digestibility and consequently a lower dietary AME n content. Carbohydrase enzyme addition improved (P < 0.001) fat, starch, nitrogen, and nonstarch polysaccharide (NSP) digestibilities in the small intestine, improved AME n , and reduced (P < 0.001) jejunal digesta viscosity in both fat types. Carbohydrase supplementation increased water-soluble (P < 0.001) and decreased water-insoluble (P < 0.001) NSP concentrations in the small intestine. The interaction between fat type and Carbohydrase addition was only significant for fat digestibilities, with greater improvements seen for diets containing tallow. Significant interactions between Carbohydrase addition and intestinal segment were noted for fat, starch, nitrogen, and NSP digestibilities, with the enzyme effects being greater in the jejunum than the ileum. It is evident from the present study that an appropriate Carbohydrase preparation could eliminate the negative effects of soluble NSP on animal fat utilization in a wheat-based broiler diet.
Delbert M Gatlin - One of the best experts on this subject based on the ideXlab platform.
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dietary supplementation of exogenous Carbohydrase enzymes in fish nutrition a review
Aquaculture, 2015Co-Authors: Sergio Castillo, Delbert M GatlinAbstract:Abstract A current priority in the aquaculture industry is the replacement of fishmeal with alternative feedstuffs, including plant-based protein ingredients, to ensure its sustainability. However, most plant-based feedstuffs have a wide variety of anti-nutritional factors, which may impair nutrient utilization, interfering with fish performance and health. The use of exogenous enzymes as feed additives to improve nutrient digestibility of plant-based feedstuffs has been researched extensively in poultry and swine. In aquaculture, the use of phytase to improve phosphorus utilization has emerged quite readily. However, the use of Carbohydrase enzymes has not been as nearly as common in aquatic species, despite their promising effects in improving nutrient digestibility by hydrolyzing non-starch polysaccharides present in plant feedstuffs. Based on the information gathered in this review, supplementation of exogenous Carbohydrases to plant-based fish diets should improve nutrient digestibility and reduce nutrient excretion. On the other hand, the effects of exogenous Carbohydrases on fish performance are still unclear due to the difficulty in cross-study comparisons. Overall, based on the information gathered in this review, it is clear that research on exogenous Carbohydrase supplementation in aquaculture nutrition is not extensive. According to promising results and opportunities found in other non-ruminant animals, and favorable effects found in aquaculture species studied to date, it may be significant to increase research on this subject because it could be a useful tool to improve and sustain commercial aquaculture.
Tao Wang - One of the best experts on this subject based on the ideXlab platform.
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enzyme enhanced extraction of antioxidant ingredients from red algae palmaria palmata
Lwt - Food Science and Technology, 2010Co-Authors: Rosa Jonsdottir, Hordur G Kristinsson, Gudmundur Oli Hreggvidsson, Jon Oskar Jonsson, Gudjon Thorkelsson, Tao Wang, Guðrun OlafsdottirAbstract:The effect of various protease and Carbohydrase treatments on the extraction of polyphenols and other antioxidant ingredients from the red algae Palmaria palmata (dulse) was investigated. In addition, the relative contribution of different fractions to the overall antioxidant capacity of the hydrolysate was evaluated. Considerable differences were observed both in total phenolic content (TPC) and antioxidant activities of the hydrolysates evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, oxygen radical absorbance capacity (ORAC) and ferrous ion-chelating ability assays. All the proteases tested had significant enhancing effect on the extraction of polyphenols and other active components compared to Carbohydrases and cold water extraction (control). The Umamizyme extract had the highest TPC and consequently exhibited the strongest scavenging capacity against DPPH and peroxyl radicals. Further fractionation of the Umamizyme extract revealed that the crude polyphenol fraction possessed the highest peroxyl radical scavenging activity, whereas the crude polysaccharide fraction was more effective for chelating ferrous ions. The data from this study suggest the potential of protease treatment to improve value-added utilization of dulse extracts as antioxidants in functional foods and nutraceuticals.
L D Campbell - One of the best experts on this subject based on the ideXlab platform.
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the effects of protease and Carbohydrase supplementation on the nutritive value of canola meal for poultry in vitro and in vivo studies
Animal Feed Science and Technology, 1996Co-Authors: J Simbaya, B A Slominski, W Guenter, A Morgan, L D CampbellAbstract:Abstract An in vitro incubation system was used to assess a variety of enzyme preparations regarding activities toward protein and carbohydrate components in canola meal with the objective of identifying those preparations that possessed potential for improvement of the nutritive value of canola meal. Promising preparations were evaluated further in 2-week growth trials utilizing 4-day-old broiler chickens. Enhanced protein hydrolysis was demonstrated for several of the protease enzyme preparations studied in the in vitro incubation system. Protein hydrolysis was most effective when either pancreatin or pronase were included in the incubation medium along with the protease enzyme and for the most effective protease preparations values for percent of total protein hydrolyzed exceeded those for pancreatin or pronase acting alone. The most effective protease preparation also resulted in improved broiler chick growth performance when added to semipurified canola meal diets. While some Carbohydrase enzyme preparations were shown to be effective in the in vitro test of cell wall polysaccharide solubilization, only a trend toward improved growth performance was noted when broiler chickens were fed semipurified canola meal diets containing these enzyme preparations. A synergistic response in growth of young (4–11 days of age) broiler chickens was noted when phytase, Carbohydrase and protease enzymes were added to a wheat/canola meal based diet deficient in available phosphorus.