901 resultados para FED
Resumo:
Rates of protein synthesis (PS) and turnover are more rapid during the neonatal period than during any other stage of postnatal life. Vitamin A and lactoferrin (Lf) can stimulate PS in neonates. However, newborn calves are vitamin A deficient and have a low Lf status, but plasma vitamin A and Lf levels increase rapidly after ingestion of colostrum. Neonatal calves (n = 6 per group) were fed colostrum or a milk-based formula without or with vitamin A, Lf, or vitamin A plus Lf to study PS in the jejunum and liver. l-[(13)C]Valine was intravenously administered to determine isotopic enrichment of free (nonprotein-bound) Val (AP(Free)) in the protein precursor pool, atom percentage excess (APE) of protein-bound Val, fractional protein synthesis rate (FSR) in the jejunum and liver, and isotopic enrichment of Val in plasma (APE(Pla)) and in the CO(2) of exhaled air (APE(Ex)). The APE, AP(Free), and FSR in the jejunum and liver did not differ significantly among groups. The APE(Ex) increased, whereas APE(Pla) decreased over time, but there were no group differences. Correlations were calculated between FSR(Jej) and histomorphometrical and histochemical data of the jejunum, and between FSR(Liv) and blood metabolites. There were negative correlations between FSR(Liv) and plasma albumin concentrations and between FSR(Jej) and the ratio of villus height:crypt depth, and there was a positive correlation between FSR(Jej) and small intestinal cell proliferation in crypts. Hence, there were no effects of vitamin A and Lf and no interactions between vitamin A and Lf on intestinal and hepatic PS. However, FSR(Jej) was correlated with histomorphometrical traits of the jejunum and FSR(Liv) was correlated with plasma albumin concentrations.
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The effect of tocopheryl phosphate on atherosclerosis progression has been studied in rabbits, fed with a 2% cholesterol diet and compared with an equivalent amount of alpha-tocopheryl acetate. The results show that the atherosclerotic-preventing effect of the phosphate derivative was more pronounced than that of the acetate derivative. alpha-Tocopheryl phosphate was also more potent in diminishing the expression of CD36 than the acetate derivative.
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The relationship between breast-feeding and childhood obesity is of great interest. Since 2000, several studies have been published with conflicting data regarding the potential protective effect of breast-feeding on childhood obesity. Meta-analyses suggested a small but significant protective effect of breast-feeding, but a recent study was not able to show such an effect. This paper summarises one of these meta-analyses and discusses the strengths and limitations of the meta-analysis approach.
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Methylation of cytosine residues at CpG sites is involved in various biological processes to control gene regulation and gene expression. Global DNA methylation is changed in different tumors and in cloned animals. Global DNA methylation can be accurately quantified by dot blot analysis with infrared (IR) fluorophores. Methylated lambda DNA was used as model DNA to develop and validate an immunochemical assay with IR fluorescence detection. Two different IR fluorophores were used, one to detect 5-methylcytosine and another to account for DNA loading. A sensitive infrared detection method was established which is suitable for accurate and reproducible quantification of global DNA methylation across a wide dynamic range. This method was subsequently employed to quantify global DNA methylation in liver and in muscle tissues of boars which have received either a control diet or a methyl supplemented diet in an ongoing study. A significant difference in global DNA methylation is indicated in muscle but not in liver tissue between the two groups of boars.
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A 192-day experiment involving 144 young Angus steers fed growing and finishing diets containing 20% corn gluten feed was conducted to evaluate feeding a soluble source of readily available cobalt. No benefits were observed in rate of gain, feed intake or carcass value by feeding the available source of cobalt.
Resumo:
This experiment was conducted to evaluate the efficacy of daily feeding a live microbial preparation containing two live organisms to finishing cattle. One organism was a lactobacillus, and the other was a propionibacterium, thought to work in concert to improve fermentation in the rumen and overall digestion. The study was conducted with Angus steers with an average initial weight of 550 lbs that were fed a finishing ration containing 50% wet corn gluten feed on a dry basis for 184 days. Feeding the microbial product improved daily gain and feed efficiency 1.7% and 2.4%, respectively, but the differences were not statistically significant. The microbial preparation increased carcass weights 1% but had no effects on quality or yield grades. It is concluded that potential benefits of this product are more likely to be greater when cattle are fed high grain rations rather than diets containing high concentrations of corn gluten feed.
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Corn steep liquor is a liquid by-product containing condensed steep water and condensed distillers solubles from a wet corn milling plant. Finishing steers weighing nine hundred and seventy-five pounds were fed cornbased finishing diets containing 0%, 6%, or 12% corn steep liquor for 84 days. Feeding corn steep liquor did not affect performance of the steers or carcass characteristics. Based on value of feeds replaced in the diet, steep liquor had a value of $55 to $60/ton (50% dry matter) when used to replace corn and supplemental protein in a corn-based finishing diet.
Resumo:
White corn was compared with yellow corn in a 180-day finishing trial with 600 lb. Angus steers fed 90% concentrate diets. Steers fed yellow corn consumed 3.3% less feed and were 3.8% more efficient in feed utilization. Rate of gain and carcass characteristics were similar for steers fed white or yellow corn. The color of subcutaneous fat over the ribs was significantly whiter from carcasses of steers fed white corn compared with those fed yellow corn. The results of this study indicate that white corn may be used instead of barley to produce whiter fat in beef carcasses.
Resumo:
An experiment was conducted using Angus cross steer calves of three frame sizes (small, medium, and large) to compare performance of two different grow/finish feeding programs. Half of the cattle in each frame size group were fed a high energy ration through the growing period, similar to calves going directly into the feedlot. The other half was fed a low energy ration, similar to a backgrounding diet, for a period prior to the finishing phase. All cattle were fed a high energy ration through the finishing period. The data showed the cattle fed the low energy growing diet experienced some compensatory gains as shown by ultrasound backfat and average daily gains coupled with intakes greater than the increases seen in the high energy treatment. Carcass data and overall performance data showed no ill effects due to the low energy growing ration.
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Alfalfa, smooth bromegrass, and big bluestem hays harvested at two maturities differing by four weeks were fed at mature-to-immature hay ratios of 1:0, 2:1, 1:2, and 0:1 to yearling heifers in an experiment with a three 4 x 4 Latin square design with 14 day periods. Concentrations of in vitro digestible dry matter and crude protein were greater and concentrations of neutral detergent fiber, acid detergent fiber, and indigestible neutral detergent fiber (determined by either a manual method with a 96 hour incubation or an automated method with a 48 hour incubation) were less in alfalfa hay than in the two grass hays and in smooth bromegrass hay than in big bluestem hay. Concentrations of in vitro digestible dry matter and crude protein decreased whereas those of neutral detergent fiber, acid detergent fiber and indigestible neutral detergent fiber increased with increasing forage maturity. Consumptions of dry matter, digestible dry matter, in vitro digestible dry matter, and crude protein were greater for heifers fed alfalfa hay diets than those fed the two grasses. Consumptions of total neutral detergent fiber and indigestible neutral detergent fiber, determined by the automated method with a 48 hour incubation, were greater by heifers fed diets containing big bluestem than those fed alfalfa or smooth bromegrass diets. Consumptions of acid detergent fiber and indigestible neutral detergent fiber, determined by a manual method with a 96 hour incubation, were greater for heifers fed alfalfa or big bluestem hay diets than those of heifers fed smooth bromegrass diets. Consumption of dry matter, in vivo or in vitro digestible dry matter, crude protein, neutral detergent fiber, acid detergent fiber and automated indigestible neutral detergent fiber decreased as the mature-to-immature hay ratio decreased. Diet digestibility was not affected by forage species, but increased as the mature-toimmature hay ratio decreased. Fecal excretion of dry matter and neutral detergent fiber did not differ between forage species or mature-to-immature hay ratios. Forage dry matter intake expressed as a percentage of body weight was significantly related to the concentrations of in vitro digestible dry matter (r2=.14), crude protein (r2=.17), neutral detergent fiber (r2=.20), and manual indigestible neutral detergent fiber (r2=.18) of the hays and the concentration of digestible dry matter of the diets (r2=.43).
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Six wethers, fitted with ruminal and duodenal cannulae, were utilized in a 6 x 6 Latin Square metabolism trial to determine efficiency of microbial protein synthesis in the rumen of sheep fed forages with varying nutritional quality. Ground alfalfa hay, oat-berseem clover hay, and baled corn crop residues were fed at an ad libitum or limited intake level. Chromium-mordanted fiber, cobalt- EDTA, and purines were used to determine digesta flow and solid passage rate, dilution rate, and microbial protein production, respectively. Sheep fed alfalfa hay had greater organic matter (OM) intakes, and amounts of OM apparently and truly ruminally digested (g/d; P < .05) than sheep fed either oat-berseem clover or corn crop residues at the ad libitum intake level. Rates of slow solid and liquid passage, and postfeeding ruminal ammonia-nitrogen (N) and volatile fatty acids (VFA) concentrations were lower (P < .05) in sheep fed corn crop residues than those fed alfalfa or oat-berseem clover hay. Total duodenal flows (g/d) and efficiencies of ruminal synthesis (g crude protein/100 g of OM truly digested; P < .05) of microbial protein were less in sheep fed corn crop residues than in sheep fed alfalfa, and oatberseem clover ad libitum. Whereas total duodenal microbial-N flow was related to organic matter intake (OMI; r2 = .97) and OM truly digested in the rumen (OMTDR; r2 = .97), microbial efficiency was related to g of nitroge truly digested in the rumen (NTDR)/100 g of OMTDR (r2 = .82) and slow solid passage rate (r2 = .91).
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Colostrum (COL) contains cytokines and growth factors that may enhance intestinal development in neonates. The hypothesis of this study was that besides providing immunoglobulins, COL is important for intestinal function and meconium release in foals. Newborn foals were either fed COL (n = 5) or an equal amount of milk replacer (MR, n = 7) during the first 24 hours of life. To ensure passive immunity, all foals received 1 L plasma. Postnatal development, meconium release, intestinal motility, white blood cell count, insulin-like growth factor 1, and intestinal absorptive function (xylose absorption test) were evaluated. Clinical findings and meconium release were not affected by feeding of COL or MR. Ultrasonography revealed a slightly larger jejunum and stomach in group COL versus MR (P < 0.05). The percentage of polymorphonuclear leucocytes was higher in foals of group MR versus group COL (P < 0.05) and the percentage of lymphocytes was lower in MR compared with COL foals (P < 0.05). Plasma insulin-like growth factor 1 concentration increased during the first 14 days after birth in both groups. A xylose absorption test on Day 5 revealed similar increases in plasma xylose concentrations after oral intake. In conclusion, feeding of COL versus MR was without effect on meconium release and intestinal absorptive function. Differences between foals fed COL and MR with regard to intestinal function are apparently without clinical relevance. In foals that have not received maternal COL, there is no major risk of intestinal problems if they are fed MR and provided with immunoglobulins by transfusion of plasma.
Resumo:
INTRODUCTION The omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) are the immediate precursors to a number of important mediators of immunity, inflammation and bone function, with products of omega-6 generally thought to promote inflammation and favour bone resorption. Western diets generally provide a 10 to 20-fold deficit in omega-3 PUFAs compared with omega-6, and this is thought to have contributed to the marked rise in incidence of disorders of modern human societies, such as heart disease, colitis and perhaps osteoporosis. Many of our food production animals, fed on grains rich in omega-6, are also exposed to a dietary deficit in omega-3, with perhaps similar health consequences. Bone fragility due to osteoporotic changes in laying hens is a major economic and welfare problem, with our recent estimates of breakage rates indicating up to 95% of free range hens suffer breaks during lay. METHODS Free range hens housed in full scale commercial systems were provided diets supplemented with omega-3 alpha linolenic acid, and the skeletal benefits were investigated by comparison to standard diets rich in omega-6. RESULTS There was a significant 40-60% reduction in keel bone breakage rate, and a corresponding reduction in breakage severity in the omega-3 supplemented hens. There was significantly greater bone density and bone mineral content, alongside increases in total bone and trabecular volumes. The mechanical properties of the omega-3 supplemented hens were improved, with strength, energy to break and stiffness demonstrating significant increases. Alkaline phosphatase (an osteoblast marker) and tartrate-resistant acid phosphatase (an osteoclast marker) both showed significant increases with the omega-3 diets, indicating enhanced bone turnover. This was corroborated by the significantly lower levels of the mature collagen crosslinks, hydroxylysyl pyridinoline, lysyl pyridinoline and histidinohydroxy-lysinonorleucine, with a corresponding significant shift in the mature:immature crosslink ratio. CONCLUSIONS The improved skeletal health in laying hens corresponds to as many as 68million fewer hens suffering keel fractures in the EU each year. The biomechanical and biochemical evidence suggests that increased bone turnover has enhanced the bone mechanical properties, and that this may suggest potential benefits for human osteoporosis.
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In search of transmittable epigenetic marks we investigated gene expression in testes and sperm cells of differentially fed F0 boars from a three generation pig feeding experiment that showed phenotypic differences in the F2 generation. RNA samples from 8 testes of boars that received either a diet enriched in methylating micronutrients or a control diet were analyzed by microarray analysis. We found moderate differential expression between testes of differentially fed boars with a high FDR of 0.82 indicating that most of the differentially expressed genes were false positives. Nevertheless, we performed a pathway analysis and found disparate pathway maps of development_A2B receptor: action via G-protein alpha s, cell adhesion_Tight junctions and cell adhesion_Endothelial cell contacts by junctional mechanisms which show inconclusive relation to epigenetic inheritance. Four RNA samples from sperm cells of these differentially fed boars were analyzed by RNA-Seq methodology. We found no differential gene expression in sperm cells of the two groups (adjusted P-value>0.05). Nevertheless, we also explored gene expression in sperm by a pathway analysis showing that genes were enriched for the pathway maps of bacterial infections in cystic fibrosis (CF) airways, glycolysis and gluconeogenesis p.3 and cell cycle_Initiation of mitosis. Again, these pathway maps are miscellaneous without an obvious relationship to epigenetic inheritance. It is concluded that the methylating micronutrients moderately if at all affects RNA expression in testes of differentially fed boars. Furthermore, gene expression in sperm cells is not significantly affected by extensive supplementation of methylating micronutrients and thus RNA molecules could not be established as the epigenetic mark in this feeding experiment.