Effects Of Dietary Carbohydrate Sources Research Articles

Effects of Dietary Carbohydrate Sources on Growth Performance, Glucose Metabolism, and Digestive Enzyme Activity of Litopenaeus vannamei

This study evaluated the effects of different sources of dietary carbohydrates on the growth, antioxidant capacity, and digestive enzyme activity, and carbohydrate metabolic enzyme activity of Litopenaeus vannamei were evaluated. The experimental diets, including glucose, sucrose, potato starch, corn starch, and wheat starch, were fed to L. vannamei for 35 days. We found that shrimp fed on corn starch and wheat starch grew better, whereas shrimp fed on wheat starch showed the highest digestive enzyme activity. In addition, the starch group showed higher total superoxide dismutase (T-SOD) activity and lower malondialdehyde (MDA) content. The glucose, sucrose, starch, and corn starch fed shrimp showed significantly higher levels of hepatopancreatic hexokinase (HK), whereas those fed on glucose and potato starch also showed significantly higher levels of hepatopancreatic phosphofructokinase (PFK) activity. The activities of phosphoenolpyruvate carboxykinase (PEPCK) and glucose 6-phosphatase (G6Pase) were higher in shrimp fed on glucose, whereas higher fructose 1,6-bisphosphatase (FBPase) activity was observed in shrimp fed on wheat starch, glucose, and sucrose. The insulin content of shrimp in the glucose group and potato starch group was higher, whereas that of the glucose group was higher than that of the potato starch group. In brief, the addition of wheat starch to the diet plays a positive role in the growth, glycolysis, gluconeogenesis, and antioxidant activity of shrimp, and is a promising choice for juvenile shrimp culture.

Effect of dietary carbohydrate sources on the growth, glucose metabolism and insulin pathway for swimming crab, Portunus trituberculatus

An eight-week feeding trial was conducted to investigate the effects of dietary carbohydrate sources on growth performance, glycogen content in tissue, insulin signaling pathway, hepatic glucose transport and metabolism in juvenile swimming crab (Portunus trituberculatus). Four isonitrogenous (approximately 45.4% crude protein) and isolipidic (approximately 9.0% crude lipid) experimental diets were formulated to contain corn starch, wheat starch, dextrin and potato starch. Each diet was randomly assigned to triplicate groups of 30 juvenile swimming crabs (approximately 5.6 ± 0.1 g) that were stocked in rectangle plastic baskets. The results indicated that crabs fed with corn starch, wheat starch and dextrin diets had significantly higher final body weight (FBW), weight gain (WG), specific growth rate (SGR) and feed efficiency (FE) than those fed with potato starch diet. However, crabs fed with potato starch diet had the highest feed intake (FI) among all treatments. Crabs fed with corn starch, wheat starch and dextrin diets exhibited significantly higher glycogen in tissue and ATP content in hepatopancreatic than those fed with potato starch diet. The lowest concentration of insulin-like and hyperglycemic hormone were observed in crabs fed with potato starch diet. The lowest relative expression levels of PK, FBpase, PEPCK, GLUT1, GLUT2, GK, G6PDH, 6PGDH, ACC, IGF1R, PI3K and FOXO were occurred at crabs fed with dextrin diet. In conclusion, swimming crab could make better use of corn starch, wheat starch and dextrin, however, potato starch is not suitable as carbohydrate source. The results demonstrated that the ratio of amylose/amylopectin in diets was positively correlated with expression levels of genes related to glycolipid metabolism, glucose transport and insulin pathway.

Insulin-mediated glycemic responses and glucose homeostasis in black sea bream (Acanthopagrus schlegelii) fed different carbohydrate sources

The present study was conducted to investigate the effects of dietary carbohydrate sources on insulin mediated glycemic responses and glucose homeostasis in black seabream. Four isonitrogenous (48%) and isolipidic (12%) diets were formulated to contain 20% glucose (GLU), sucrose (SUC), dextrin (DEX) and wheat starch (WS), respectively. The black seabream was randomly distributed into 12 tanks (n = 3) at a stocking density of 12 fish per tank. After 2 weeks of feeding, fishes were starved for 48 h then re-fed and sampled at 0, 1, 3, 6, 12, and 24 h. The results showed that the concentration of serum glucose increased at 1 h, peaked at 3 h, decreased at 12 h, and returned to basal level at 24 h in all dietary groups (p < 0.05). In contrast, there were significant differences in postprandial insulin levels among all treatments, especially in the DEX group, which showed higher insulin level at 3 h after feeding (p < 0.05). Compared with 0 h, liver glycogen in the WS and DEX groups increase significantly at 6 h and was depleted at 24 h (p < 0.05). Hepatic enzyme activities such as glucokinase (GCK) and pyruvate kinase (PK) were influenced by sampling time and dietary carbohydrate sources (p < 0.05). Fish fed with the DEX diet showed the highest hepatic GCK and PK activities and the lowest phosphoenol pyruvate carboxykinase (PEPCK) activity at 3 h among all the treatments. Slightly but not significantly higher phosphofructo kinase (PFK) activity was observed in fish fed with the SUC diet than those fed with the GLU diet at 6 h post prandial (p > 0.05). The relative expression of insulin signaling pathways such as insulin receptor substrate1 (irs1) and protein kinase B (akt1) were significantly up-regulated at 3 h in the DEX group (p < 0.05). Meanwhile, the mRNA expression levels of glucokinase (gk) and pyruvate kinase (pk) were sensitive to hepatic glycolysis, and their expressions were up-regulated at 1, 3, 6 h, especially at 3 h in the DEX group. Genes such as glucose 6 phosphatase (g6pc) and phosphoenol pyruvate carboxykinase (pepck) played an important role in hepatic gluconeogenesis, and their expressions were inhibited at 1, 3 h. Overall, the results of present study indicated that dietary carbohydrate sources resulted in a hyperglycaemic situation 3 h after feeding, most likely as a response to glucose loading. Moreover, glucose metabolic responses were regulated by different carbohydrate sources at different time points, and plays a important role in clearing glucose through increased activity of insulin, glycolysis, and glycogenesis, along with gluconeogenesis suppression.

Effects of dietary carbohydrate sources on growth performance, immunity and glycometabolic enzyme activity ofRhynchocypris lagowskiiDybowski

We examined the effects of dietary carbohydrate sources on growth performance, digestive ability, immunity and glycometabolic enzyme activity of Rhynchocypris lagowskii Dybowski. The fish were fed with glucose, sucrose, dextrin and corn starch for 8 weeks. Final body weight, weight gain rate, specific growth rate, feed efficiency ratio and protein efficiency ratio were positively related to the complexity of carbohydrates in diet as were the levels of total antioxidant capacity, complement 3, protease, glutathione peroxidase, amylase, alkaline phosphatase, lysozyme, catalase, superoxide dismutase, fructose-1,6-bisphosphatase, hexokinase and pyruvate kinase. Malondialdehyde content, hepatic glycogen, glucose-6-phosphate dehydrogenase, hepatosomatic index, viscerosomatic index and crude lipid content were negatively related to the complexity of carbohydrates in diet. Therefore, Rhynchocypris lagowskii Dybowski fed with corn starch or dextrin showed positive effects in terms of growth, digestion and absorption, glycolysis, gluconeogenesis, antioxidant capacity and immunity than those fed with glucose or sucrose.

Effects of dietary carbohydrate sources on lipid metabolism and SUMOylation modification in the liver tissues of yellow catfish.

Dysregulation in hepatic lipid synthesis by excess dietary carbohydrate intake is often relevant with the occurrence of fatty liver; therefore, the thorough understanding of the regulation of lipid deposition and metabolism seems crucial to search for potential regulatory targets. In the present study, we examined TAG accumulation, lipid metabolism-related gene expression, the enzyme activities of lipogenesis-related enzymes, the protein levels of transcription factors or genes involving lipogenesis in the livers of yellow catfish fed five dietary carbohydrate sources, such as glucose, maize starch, sucrose, potato starch and dextrin, respectively. Generally speaking, compared with other carbohydrate sources, dietary glucose promoted TAG accumulation, up-regulated lipogenic enzyme activities and gene expressions, and down-regulated mRNA expression of genes involved in lipolysis and small ubiquitin-related modifier (SUMO) modification pathways. Further studies found that sterol regulatory element binding protein 1 (SREBP1), a key transcriptional factor relevant to lipogenic regulation, was modified by SUMO1. Mutational analyses found two important sites for SUMOylation modification (K254R and K264R) in SREBP1. Mutant SREBP lacking lysine 264 up-regulated the transactivation capacity on an SREBP-responsive promoter. Glucose reduced the SUMOylation level of SREBP1 and promoted the protein expression of SREBP1 and its target gene stearoyl-CoA desaturase 1 (SCD1), indicating that SUMOylation of SREBP1 mediated glucose-induced hepatic lipid metabolism. Our study elucidated the molecular mechanism of dietary glucose increasing hepatic lipid deposition and found that the SREBP-dependent transactivation was regulated by SUMO1 modification, which served as a new target for the transcriptional programmes governing lipid metabolism.

Effects of dietary carbohydrate sources on growth performance, glycogen accumulation, insulin signaling pathway and hepatic glucose metabolism in largemouth bass, Micropterus salmoides

The present study was conducted to investigate the effects of dietary carbohydrate sources, α-cassava-starch, potato starch, pea starch and dextrin, on growth performance, glycogen accumulation, insulin signaling pathway and hepatic glucose metabolism in largemouth bass (initial body weight: 36.34 ± 0.30 g) for 11 weeks. Results showed that pea starch significantly improved the specific growth rate (SGR), daily weight gain (DWG) and net fish yield (NFY) of largemouth bass compared to other starch, which maybe related to the depressed feed conversion ratio (FCR). Meanwhile, fish fed the diet with pea starch obtained the minimum hepatic glycogen content, which is significantly lower than that of α-cassava starch. The above result indicated that the fish was more tolerant to pea starch than other carbohydrate sources in accordance with the result of postprandial glucose content. The expression of insulin receptor (IR), insulin receptor substrate 1 (IRS1) and phosphoinositide 3-kinase regulatory subunit 1 (PI3KR1) was significantly up-regulated in fish fed the diet with pea starch than others, indicating the significantly higher activity of insulin pathway in the pea starch group at least at the transcription level. Meanwhile, pea starch led to a significantly increased expression of glucokinase (GK) and liver-type 6-phosphofructokinase isozyme (PFKL), while dietary starch sources had no significant influence on the expression of phosphoenolpyruvate carboxykinase (PEPCK) and fructose-1,6-bisphosphatase-1 (FBP1). The improved glycolysis and poor inhibited gluconeogenesis may account for the reduced hepatic glycogen content of pea starch. Therefore, pea starch was most suitable starch among the sources used for largemouth bass.

Effects of dietary carbohydrate sources on growth, digestive enzyme activity, gene expression of hepatic GLUTs and key enzymes involved in glycolysis-gluconeogenesis of giant grouper Epinephelus lanceolatus larvae

This study aimed to evaluate effects of dietary carbohydrate sources on growth, digestive enzyme activity, gene expression of hepatic glucose transporters (GLUTs) and key enzymes involved in glycolysis-gluconeogenesis in giant grouper Epinephelus lanceolatus larvae through a 21-day growth trial. Four isonitrogenous (50%) and isolipidic (15.4%) experimental diets, including a cellulose control diet and three diets with glucose, maltose or maize starch, were formulated. Dietary CHO level was 18%. The 29 DPH (days post hatching) grouper larvae (initial average weight: 0.078±0.0018g) were cultured in small floating cages (L 120cm×W 70cm×H 50cm) at a density of 80 fish per cage. Experimental cages were labeled and located in three connective 6-m3 indoor concrete tanks (L 3m×W 3m×H 2m) with 4 cages occurring in each tank.Results showed that at 50 DPH, fish fed with maize starch diet had significantly higher weight gain (WG) and thermal growth coefficient (TGC) than fish fed with glucose, maltose or cellulose. Fish fed with glucose had the lowest WG among all experimental treatments. Fish fed with maize starch or cellulose had significantly higher mRNA expression levels of hepatic fructose 1,6 bisphosphatase (FBP) gene compared to fish fed with glucose or maltose at 50 DPH. The highest mRNA expression level of hepatic glucose-6-phosphate dehydrogenase (G6PDH) gene was observed in fish fed with glucose at 50 DPH. Fish fed with maize starch had higher mRNA expression levels of hepatic pyruvate kinase (PK) and hexokinase (HK) genes than fish fed with cellulose, glucose and maltose at 50 DPH. The mRNA expression level of hepatic glucose transporter 4 (GLUT4) gene was significantly lower in fish fed with cellulose compared to that in fish fed with digestible CHOs at 50 DPH. There were no significant differences in mRNA expression levels of hepatic glucose transporter 1 (GLUT1) gene among all experimental fish at 50 DPH. In terms of digestive enzymes, activities of pancreatic trypsin and intestinal lipase increased during the development of fish larvae, but pancreatic α-amylase specific activity showed an opposite trend of variation as those of trypsin and lipase. During the development of experimental fish larvae from 29 DPH to 50 DPH, pancreatic trypsin specific activity in fish fed with glucose was significantly lower than that in fish fed with cellulose or maltose but did not differ from that in fish fed with maize starch. Intestinal lipase specific activity in fish fed with maize starch or maltose were significantly higher than those in fish fed with cellulose but did not differ from those in fish fed with glucose. Generally, giant grouper larvae fed maize starch had better growth than those fed cellulose, glucose or maltose; the mRNA expressions of hepatic HK, PK, FBP and G6PDH genes involved in glycolysis-gluconeogenesis were significantly affected by dietary CHO sources.

Effects of Dietary Carbohydrate Sources on Growth and Body Composition of Juvenile Abalone (Haliotis discus, Reeve)

ABSTRACT A 16-wk feeding trial was conducted to assess the effects of different types of dietary carbohydrate on growth and body composition of juvenile abalone (Haliotis discus). A total of 1,680 abalone were randomly distributed among 24 containers (70 per container) and fed one of eight diets, including seven experimental diets containing different types of carbohydrates, including dextrin (DT), glucose (GC), corn starch (CS), α-cellulose (CL), maltose (MT), sucrose (SC), and wheat flour (WF), and Undaria to compare effect of experimental diets. Water stability of the diets was measured 12, 24, and 48 h after seawater immersion. Water stability of the diets was different over all periods of time and their significant interaction was also observed. Survival was not significantly affected by diet. Weight gain and specific growth rate were greatest in abalone fed on the CL diet. Shell length, width, height, and soft body weight were greatest in abalone fed the CL diet, followed by the WF, DT, SC, CS, GC, ...

Effects of dietary carbohydrate source on growth performance, diet digestibility and liver glucose enzyme activity in blunt snout bream, Megalobrama amblycephala

Abstract A 3-month feeding trial was conducted to investigate the effects of dietary carbohydrate source on the growth performance, apparent digestibility coefficients and liver glucose enzyme activity in juvenile blunt snout bream. Six experimental diets were formulated to contain 33% wheat starch, corn starch, dextrin, maltose, glucose or cellulose. At the end of the experiment, the best final body weight (18.4 g), specific growth rate (SGR, 2.46%/day), feed conversion ratio (FCR, 1.41 g feed/g gain) and protein efficiency ratio (PER, 2.22 g gain/protein) were found in the group fed with the dextrin diet, while the poorest values were observed in the group fed with the cellulose diet among the treatments. Fish fed with the glucose (1.55 g feed/g gain) or maltose (1.53 g feed/g gain) diet showed significantly higher FCR than those fed with the dextrin diet (1.41 g feed/g gain). Dietary cellulose caused the highest feed intake (2.91 g/fish/day) and FCR (1.87 g feed/g gain) among the treatments. The apparent digestibility coefficient (ADC) of dry matter was significantly lower in fish fed with the cellulose diet than those fed with other diets. ADC of protein was independent of dietary carbohydrate source. The highest ADC of energy was observed in fish fed with diets containing glucose, maltose or dextrin; followed by wheat starch, corn starch and cellulose. Carbohydrate source did not affect whole body moisture, protein and ash contents, and plasma total protein and cholesterol contents. Lipid contents of whole body and plasma triglyceride contents increased with increasing carbohydrate complexities. Plasma glucose contents and liver enzyme activities were affected by sampling time and dietary carbohydrate source. Fish fed with the dextrin diet showed the highest liver glucokinase (GK), pyruvate kinase (PK) and glucose-6-phosphate dehydrogenase (G6PDH) activities, and the lowest glucose-6-phosphatase (G6Pase) activity among all the groups. Significantly higher G6Pase activity was observed in fish fed with the glucose diet than those fed with the dextrin or wheat starch diet at 2 h postprandial. These results indicated that dextrin was the best dietary carbohydrate source for juvenile blunt snout bream, based on growth performance, feed utilization, ADC and liver glucose enzyme activities.

Growth, body composition, ammonia tolerance and hepatopancreas histology of white shrimpLitopenaeus vannameifed diets containing different carbohydrate sources at low salinity

Juvenile Litopenaeus vannamei farmed at 3.0 psu were fed five diets containing glucose, sucrose, wheat starch, corn starch or potato starch as the carbohydrate (CBH) source. Shrimp were fed for 50 days to explore the effect of dietary CBH source on growth, body composition and ammonia tolerance. The specific growth rate of body length of shrimp fed glucose was the highest and significantly higher than those fed potato starch. The survival rate of shrimp fed glucose was 89.44%, and it was the highest and significantly higher than those fed wheat starch. Whole shrimp body crude protein and lipid of the corn starch group were 140.2 g kg−1 and 10.1 g kg−1 respectively. And they were significantly higher than those fed wheat starch. Shrimp fed potato starch had higher hepatopancreas and muscle glycogen. Shrimp fed sucrose had higher glucose-6-phosphate dehydrogenase and lower pyruvate kinase activities (P < 0.05). Besides, shrimp fed starch produced more B cells in hepatopancreas tubules than those fed glucose or sucrose. Shrimp fed different sources of CBH differed in the number of R cells. After 96-h of ammonia nitrogen challenge, the survival rate of the treatments from high to low in turn was glucose, wheat starch, corn starch, sucrose and potato starch, and no significant differences were observed among all treatments. Based on shrimp growth and the economic problems of practical production, we recommend wheat starch as CBH source in practical diets for L. vannamei farmed at low salinities.

The effects of dietary carbohydrate sources and forms on metabolic response and intestinal microbiota in sea bass juveniles, Dicentrarchus labrax

The aim of this work was to investigate the catabolic process of three kinds of dietary carbohydrates in the gut of sea bass juveniles, with the possible contribution of the intestinal microbiota to the nutrition of the host, and the subsequent effects on intermediary metabolism. A first diet contained waxy maize (99% amylopectin), a highly digestible form of starch. A second diet was less quickly digestible due to its high amylose content of resistant starch. Two other diets contained fibre instead of starch, either only cellulose as control, or also other non-starch polysaccharides brought by lupin meal. The effect of the diets on the host confirmed previous results, with the stimulation of glucose storage in the liver in sea bass fed the starchy diets, which caused a significant increase in liver weight, while lupin meal caused an increase in visceral mass. Glycaemia was higher 7 ± 1 h after the last meal in the group fed resistant starch, compared to the other dietary groups, while the fast digestion of waxy maize resulted already in hypertriglyceridemia, possibly due to hepatic neolipogenesis. At the same sampling time, the activity of free amylase was reduced in the intestine of sea bass fed resistant starch, but maltase activity was stimulated in the brush border membranes of enterocytes in the same group, confirming thus the timely digestion of resistant starch. Hepatic mRNA transcripts indicated that glucose metabolism was oriented towards neoglucogenesis by the high-fibre diets, and towards glucose storage by the starchy diets, especially with waxy maize. The diet influenced both faecal and mucosal microbiota, though in different ways, likely due to the interaction with the host. Lupin meal seemed potentially interesting as a source of prebiotic polysaccharides, by modifying the balance between Vibrio spp. and Clostridium sp. Both forms of starch were also partly metabolised by microbiota, resulting in an increased concentration of acetate in the faeces. • The diet of sea bass juveniles can contain at least 25% starch. • The metabolic response to dietary carbohydrates is flexible. • More than 30% lupin meal can be introduced, with possible prebiotic effect. • Intestinal microbiota is influenced by the diet. • Microbes contribute to starch digestion, as shown by acetate production in faeces.

Dietary Carbohydrate Source Alters Gene Expression in the Uterine and Ovarian Tissues of Pre-Pubertal Female Pigs.

The objective of this study was to assess the effects of dietary carbohydrate source and high fat intake on mRNA concentrations within the reproductive tissues of pre-pubertal female pigs. Gilts (28 d-old) were fed either control or high-fat diets for 8 weeks. High-fat diets contained either complex (corn) or simple (glucose or fructose) carbohydrates. Control pigs were pair-fed with high-fat pigs, resulting in similar final body weight across treatments. Ultrasound back-fat depth (indicative of body adiposity) was 84% higher in gilts consuming high-fat diets, and simple carbohydrate diets tended to increase back-fat. Reproductive tissues were collected after exsanguination for analysis of gene expression by RT-qPCR. Concentrations of ESR1, ESR2, GDF9, IGF1 and IGF1R mRNA were measured in whole ovarian and uterine tissues while expression of LHCGR, FSHR and CYP19A1 was measured in whole ovarian tissue only. Dietary treatment effects on reproductive tissues were almost exclusively based on carbohydrate source. Simple carbohydrate diets resulted in heavier uteri and ovaries and more antral follicles compared to control or complex carbohydrate diets. Gilts fed simple carbohydrate diets tended to have higher uterine ESR1 concentrations than those fed control or complex carbohydrate diets. And while ovarian ESR1 did not differ amongst dietary treatments, ovarian ESR2 was lower in gilts fed the simple carbohydrate diets compared to control or complex carbohydrate diets. Opposing trends in expression of GDF9 were also observed, with higher uterine GDF9 and lower ovarian GDF9 in gilts fed simple carbohydrate diets compared to control or complex carbohydrate treatments. Gilts consuming the simple carbohydrate diet also had a greater than two-fold increase in uterine IGF1 concentrations. Furthermore, ovarian IGF1R and FSHR concentrations were greater in the simple carbohydrate group. There were no observed differences in LHCGR or CYP19A1 gene expression. Total tract weights of the gilts consuming control and complex carbohydrate diets were positively correlated with ovarian expression of IGF1R and FSHR, and negatively correlated with ovarian expression of ESR2 and GDF9. None of these correlations existed for the gilts fed the simple carbohydrate diets. Despite similar body weights, the reproductive tracts of gilts fed diets differing in carbohydrate source were strikingly different. Gilts consuming simple carbohydrate diets appeared to be closer to ovulation and puberty than those consuming control or complex carbohydrate diets. The competency of their follicles and the oocytes contained within those follicles remains to be determined.

Effects of dietary carbohydrate sources on plasma glucose, insulin and IGF-I levels in multiparous sows

Effects of different carbohydrate sources on plasma glucose, insulin and insulin-like growth factor-I (IGF-I) levels were compared to subsequently be able to study effects of insulin-stimulating diets on follicle development in sows. The following feed components were tested in 12 sows during six consecutive test periods of 9.5 days: dextrose (DEX), sucrose (SUC), lactose (LAC), dextrose plus lactose (DL), sucrose plus lactose (SL), dextrose plus sugarbeet pulp (DSBP) and control (CON). On day 2, 5 and 9 of each test period, plasma glucose (only at day 9), insulin and IGF-I profiles were determined. Despite similar glucose profiles for all diets, the postprandial insulin response was higher for DL and SL compared with CON and LAC; the other diets were intermediate. Plasma IGF-I levels were higher in CON, LAC and SL compared with DSBP, but differences were only marginal. It was concluded that dextrose and sucrose have the potential to stimulate fast and high insulin peaks, especially when combined with additional lactose. Despite the high dextrose in the DSBP diet, the insulin response was flattened, probably due to the viscosity of sugarbeet pulp. The results show that modulation of plasma insulin levels by dietary carbohydrates seems possible in anabolic sows, but IGF-I levels are less easily modified.

Effects of dietary carbohydrate sources on the growth performance and hepatic carbohydrate metabolic enzyme activities of juvenile cobia (Rachycentron canadum Linnaeus.)

An 8-week feeding trial was conducted to evaluate the effect of dietary carbohydrate sources on the growth performance and hepatic carbohydrate metabolic enzyme activities of juvenile cobia. Six experimental diets were formulated to contain 20% glucose, sucrose, maltose, dextrin, corn starch and wheat starch respectively. The results indicated that fish fed the wheat starch and dextrin diets showed significantly better weight gain, specific growth rate and protein efficiency ratio compared with those fed the other diets. However, fish fed the glucose diet had a significantly lower survival and condition factor than those fed the other diets. There were significant differences in the total plasma glucose and triglyceride concentration in fish fed diets with different dietary carbohydrate sources. Haematocrit, haemoglobin, red blood cell and leucocytes were significantly affected by the dietary carbohydrate sources. The activities of glucose-6-phosphate dehydrogenase (G6PD), 6-phosphofructokinase (PFK) and fructose-1,6-bisphosphatase (FBPase) were significantly affected by the dietary carbohydrate sources, while fish fed the glucose diet showed higher G6PD, PFK and FBPase activities than those fed the other diets. These data indicated that dextrin and wheat starch were the most optimal carbohydrate sources for juvenile cobia.

Dietary Carbohydrate Source Alters Gene Expression Profile of Intestinal Epithelium in Mice

High-sucrose consumption is associated with increased risk of human colon cancer. Our previous research indicated that high-sucrose diets (vs. cornstarch) promote intestinal epithelial cell proliferation and tumorigenesis as well as increase serum glucose and hepatic IGF-I mRNA levels in APC Min mice. To examine the role of functional pathways, in particular of IGF-I signaling, in sucrose-induced intestinal epithelial cell proliferation and tumorigenesis, we examined the effects of dietary carbohydrate source (sucrose vs. cornstarch) on gene expression in the intestinal epithelium using cDNA microarray and quantitative RT-PCR analysis. Dietary carbohydrate source significantly ( P < 0.05) altered mRNA expression of 109 known genes in the small intestinal epithelium, including many involved in metabolic pathways. Consumption of high-sucrose diets altered expression levels of genes involved in cell adhesion, cell cycle control, and transduction signaling, consistent with increased risk of intestinal tumorigenesis. High-sucrose intake also affected expression of genes involved in IGF-I signaling, including upregulating IGF-II and downregulating IGFBP3, which supports our hypothesis that IGF-I signaling could play a role in intestinal epithelial cell proliferation and tumorigenesis promoted by high-sucrose consumption.

Effects of dietary carbohydrate sources on degradation kinetics of nitrogen from plant protein sources in the rumen

AbstractThe effects of the nature of carbohydrate source on in sacco protein degradation of 15 samples of plant protein sources were studied in four mature fistulated rams fed a control diet (C) of meadow hay and soyabean meal (83:15 on dry matter basis) and three diets in which 36, 34 or 40% of diet dry matter was sugar beet pulp, maize or wheat (diets P, M and W respectively). Degradation parameters were estimated from the exponential equation p = a + b[1 − exp(−ct)]. Diet composition significantly affected (P &lt; 0.001) all the degradation parameters, the effect being more pronounced on the degradation rate (c). This parameter was stimulated (P &lt; 0.05) by beet pulp but depressed (P &lt; 0.05) by cereal inclusion in the diets, in particular when animals were fed the W diet (4.46, 5.65, 3.74 and 3.05% h−1 for the C, P, M and W diets respectively). An interaction effect between carbohydrate source and incubated plant protein sources was observed (P &lt; 0.001). The reason(s) for these differential effects were not elucidated. The practical consequences of these findings are discussed. Copyright © 2005 Society of Chemical Industry

Energy metabolism in relation to physical activity in growing pigs as affected by type of dietary carbohydrate.

The effect of dietary carbohydrate source on physical activity in relation to metabolic rate in pigs was studied. Six groups of 12 pigs (50-kg, castrated males) were fed one of two diets: a starch diet or a non-starch polysaccharide (NSP) diet. Both diets had a similar calculated net energy content. The starch diet contained 13% tapioca, and the NSP diet contained 17% sugar beet pulp silage. Pigs were housed in groups and fed at approximately two times maintenance (approximately 900 kJ ME.kg-.75.d-1). Nitrogen and energy balances were measured per group during a 7-d experimental period, which was preceded by a 2-wk adaptation period. Heat production and physical activity were measured during successive discrete 9-min intervals. Metabolizability of gross energy was 79.4% and 78.2% for the starch-fed and NSP-fed pigs, respectively (P < .10). Activity differed between treatments. Activity-related heat production tended to be higher for the starch-fed pigs than for those fed the NSP diet (P < .10); 118 and 90 kJ.kg-.75.d-1, respectively. During the dark phase of the day (from 2000 to 0800) activity-related heat production was 8 kJ.kg-.75.d-1 higher for the starch fed pigs than for those fed the NSP diet (P > .1) whereas during the light phase, this difference was 48 kJ.kg-.75.d-1 (P < .10). Retained energy was similar for both treatments. These results show that dietary composition can change physical activity of pigs and thereby affect their energy utilization.

Effect of dietary carbohydrate source on soluble protein glucose concentration and enzyme activity (aldolase) of European eels ( Anguilla anguilla L.)

1. 1. This study was undertaken to determine the influence of dietary carbohydrate sources: wheat meal, bread meal, soluble corn starch, native potato starch and sorghum meal, on soluble protein, enzyme activity (aldolase) and glucose concentration in muscle and liver of European eels ( Anguilla anguilla). 2. 2. There was less soluble protein in both muscle and liver of eels fed 30% wheat meal or bread meal than the other experimental groups. 3. 3. However, eels fed 30% bread meal or soluble corn starch had a higher glucose concentration in muscle and liver than the other experimental groups. 4. 4. High enzyme activity (aldolase) was found in the liver of eels fed 30% wheat meal, bread meal or soluble starch.

Studies on a purified diet for prawn. XIII. Effect of dietary carbohydrate source on the growth and feed efficiency of prawn.

In order to find a favorable source of dietary carbohydrate for prawn, Penaeus japonicus, the effects of various types, i.e glycogen, starch, dextrin, glucose, and sucrose on the growth and feed efficieocy of the prawn were examined by using a purified diet. The highest gain in percent was obtained with the group fed on the diet containing sucrose, and a slightly lower percent gain was noticed with the group maintained on the diet with glycogen, whereas the diet including glucose resulted in the lowest gain of prawn. The feed efficiency was highest in the group maintained on the diet containing starch, followed by glycogen, sucrose, and dextrin in decreasing order. The poorest feed efficiency and a notably high mortality were found with the group fed on the diet containing glucose. Also, the diets containing starch and dextrin produced high mortalities. On the other hand, the two groups maintained on the diets with glycogen and sucrose had a low mortality. From these results, it is concluded that sucrose and glycogen are desirable sources of dietary carbohydrate for the prawn, while glucose is unsuitable.

Effects of dietary carbohydrate source on growth, plasma metabolites and lipogenesis in rats, pigs, and chicks.

Rats, chicks, and pigs were fed diets containing fructose or glucose. Plasma triglyceride levels were elevated in rats but not in chicks or pigs fed diets containing fructose. The rate of fatty acid synthesis in rat liver but not in chick liver was elevated when fructose-containing diets were fed. Conversely, the rate of fatty acid synthesis in rat adipose tissue but not in pig adipose tissue tended to be depressed when fructose-containing diets were fed. These results indicate that there are species-specific as well as organ-specific metabolic responses to various dietary carbohydrates.