174 resultados para Rumen epithelium


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The objective of this study was to evaluate the behaviour of fibre in the digestive tract on the basis of the passage kinetics of forage and concentrate particles in cows fed different omega-6 fatty-acid sources. The scientific hypothesis of this study was that omega-6 fatty acids do not interfere with the digestion of fibre in the diets of dairy cows. Five primiparous lactating Holstein cows were used in the experiment. The experimental diets were: control (C), ground soyabean (GS), cottonseed (CS), soyabean oil (SO), calcium salts of fatty acids (CSFA). The global mean estimates for the parameters of passage rate (gamma) were 0.038 and 0.055 h(-1) for forage and concentrate, respectively. The only significant effect with respect to the passage rate was a high negative correlation between the concentrate passage rate and dry matter intake. There was less undegradable neutral detergent fibre (NDF) in treatments without added lipid. Dietary supplementation with lipid sources does not alter the kinetic parameters of roughage and concentrate particle passage or in vitro NDF degradation. Sources of omega-6 fatty acids do not alter the rumen degradation and transit of fibre.

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Two experiments evaluated the influence of supplement composition on ruminal forage disappearance, performance, and physiological responses of Angus x Hereford cattle consuming a low-quality cool-season forage (8.7% CP and 57% TDN). In Exp. 1, 6 rumen-fistulated steers housed in individual pens were assigned to an incomplete 3 x 2 Latin square design containing 2 periods of 11 d each and the following treatments: 1) supplementation with soybean meal (PROT), 2) supplementation with a mixture of cracked corn, soybean meal, and urea (68:22:10 ratio, DM basis; ENER), or 3) no supplementation (CON). Steers were offered meadow foxtail (Alopecurus pratensis L.) hay for ad libitum consumption. Treatments were provided daily at 0.50 and 0.54% of shrunk BW/steer for PROT and ENER, respectively, to ensure that PROT and ENER intakes were isocaloric and isonitrogenous. No treatment effects were detected on rumen disappearance parameters of forage DM (P >= 0.33) and NDF (P >= 0.66). In Exp. 2, 35 pregnant heifers were ranked by initial BW on d -7 of the study, allocated into 12 feedlot pens (4 pens/treatment), and assigned to the same treatments and forage intake regimen as in Exp. 1 for 19 d. Treatments were fed once daily at 1.77 and 1.92 kg of DM/heifer for PROT and ENER, respectively, to achieve the same treatment intake as percent of initial BW used in Exp. 1 (0.50 and 0.54% for PROT and ENER, respectively). No treatment effects (P = 0.17) were detected on forage DMI. Total DMI was greater (P < 0.01) for PROT and ENER compared with CON and similar between PROT and ENER (P = 0.36). Accordingly, ADG was greater (P = 0.01) for PROT compared with CON, tended to be greater for ENER compared with CON (P = 0.08), and was similar between ENER and PROT (P = 0.28). Heifers receiving PROT and ENER had greater mean concentrations of plasma glucose (P = 0.03), insulin (P <= 0.09), IGF-I (P <= 0.04), and progesterone (P = 0.01) compared to CON, whereas ENER and PROT had similar concentrations of these variables (P >= 0.15). A treatment x hour interaction was detected (P < 0.01) for plasma urea N (PUN), given that PUN concentrations increased after supplementation for ENER and PROT (time effect, P < 0.01) but did not change for CON (time effect, P = 0.62). In conclusion, beef cattle consuming low-quality cool-season forages had similar ruminal forage disappearance and intake, performance, and physiological status if offered supplements based on soybean meal or corn at 0.5% of BW.

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Cassava leaves have been widely used as a protein source for ruminants in the tropics. However, these leaves contain high level of hydro-cyanic acid (HCN) and condensed tannins (CT). There are evidences that making hay can eliminate more than 90% of HCN and that long-term storage can reduce CT levels. A complete randomized design with four replicates was conducted to determine the effect of different storage times (0-control, 60, 90 and 120 days) on chemical composition, in vitro rumen fermentation kinetics, digestibility and energy value of cassava leaves hay. Treatments were compared by analyzing variables using the GLM procedure (SAS 9.1, SAS Institute, Inc., Cary, NC). Crude protein (CP) and ether extract (EE) of the cassava hay were not affected (P > 0.05) by storage time (17.7% and 3.0%, respectively). Neutral detergent fiber, acid detergent fiber, total carbohydrate and non-fiber carbohydrate were not affected either (P>0.05) by storage time (47.5, 32.6, 72.3 and 25.8% respectively). However, other parameters were influenced. CT was lower (P<0.05) in hay after 120 days of storage compared with control (1.75% versus 3.75%, respectively). Lignin and insoluble nitrogen in neutral detergent, analyzed without sodium sulfite, were higher (P<0.01) after 120 days of storage, compared with the control (11.22 versus 13.57 and 1.65 versus 3.81% respectively). This suggests that the CT has bound to the fiber or CP and became inactive. Consequently, the in vitro digestibility of organic matter (50.36%), total digestible nutrients (44.79%) and energy (1.61 Mcal/KgMS), obtained from gas production data at 72 h of incubation, has increased (P<0.05) with storage times (56.83%, 51.53% and 1.86 Mcal/KgMS, respectively). The chemical composition and fermentative characteristics of cassava hay suffered variations during the storage period. The best values were obtained after 90 days of storage. This is probably due to the reduction in condensed tannins.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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This work evaluated the beef quality parameters of 108 bulls randomly administered to three treatments during rearing in pastures and two treatments during fatting in feedlots, including mineral and rumen-protected lipids. Meat and fat color, cooking yield, shear force, sensorial traits and chemical and fatty acid compositions were evaluated. Generally, the beef quality parameters were not affected by the rumen protected lipids; however, supplementation with rumen-protected lipids during the rearing period yielded darker beef and brighter fat and increased beef tenderness in meat aged for 28 days compared to the meat from animals that received only mineral supplementation. In addition, the percent of meat polyunsaturated fatty acids was negatively affected by the inclusion of protected lipids, yielding 5.58 and 3.72% in animals fed with and without rumen-protected lipids, respectively, during the fatting period. (C) 2014 Elsevier Ltd. All rights reserved.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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This paper proposes a method for segmentation of cell nuclei regions in epithelium of prostate glands. This structure provides information to diagnosis and prognosis of prostate cancer. In the initial step, the contrast stretching technique was applied in image in order to improve the contrast between regions of interest and other regions. After, the global thresholding technique was applied and the value of threshold was defined empirically. Finally, the false positive regions were removed using the connected components technique. The performance of the proposed method was compared with the Otsu technique and statistical measures of accuracy were calculated based on reference images (gold standard). The result of the mean value of accuracy of proposed method was 93% ± 0.07.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The purpose of this study was to determine the effect of PEGylation on the interaction of poly(amidoamine) (PAMAM) dendrimer nanocarriers (DNCs) with in vitro and in vivo models of the pulmonary epithelium. Generation-3 PAMAM dendrimers with varying surface densities of PEG 1000 Da were synthesized and characterized. The results revealed that the apical to basolateral transport of DNCs across polarized Calu-3 monolayers increases with an increase in PEG surface density. DNC having the greatest number of PEG groups (n = 25) on their surface traversed at a rate 10-fold greater than its non-PEGylated counterpart, in spite of their larger size. This behavior was attributed to a significant reduction in charge density upon PEGylation. We also observed that PEGylation can be used to modulate cellular internalization. The total uptake of PEG-free DNC into polarized Calu-3 monolayers was 12% (w/w) vs 2% (w/w) for that with 25 PEGs. Polarization is also shown to be of great relevance in studying this in vitro model of the lung epithelium. The rate of absorption of DNCs administered to mice lungs increased dramatically when conjugated with 25 PEG groups, thus supporting the in vitro results. The exposure obtained for the DNC with 25PEG was determined to be very high, with peak plasma concentrations reaching 5 mu gmL(-1) within 3 h. The combined in vitro and in vivo results shown here demonstrate that PEGylation can be potentially used to modulate the internalization and transport of DNCs across the pulmonary epithelium. Modified dendrimers thereby may serve as a valuable platform that can be tailored to target the lung tissue for treating local diseases, or the circulation, using the lung as pathway to the bloodstream, for systemic delivery.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Prevotella is one of the most abundant genera in bovine rumen, although no genome has yet been assembled by a metagenomics approach applied to Brazilian Nelore. We report the draft genome sequence of Prevotella sp., comprising 2,971,040 bp, obtained using the Illumina sequencing platform. This genome includes 127 contigs and presents a low 48% GC.

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The development of the domestic mammals’ stomach is a complex process, especially in ruminants. The objective of this research was to perform the analysis of structures of this organ during prenatal period. Samples of Nelore fetuses rumen (Bos Taurus indicus) were divided into five groups: 1 - fetuses with 9 to 15 weeks (8 to 21cm) of gestation, 2 - fetuses with 16 to 22 weeks (23 to 37cm), 3 - fetuses at 23 to 29 weeks (40 to 58cm) 4 - fetuses with 30 to 36 weeks (61 to 77cm) and 5 - fetuses with 37 to 43 weeks (79 to 88cm). Sections were stained with Hematoxylin and eosin and Mallory's trichrome and examined at light microscope. In group 1, in fetuses with 11 cm, could be seen all the layers, mucosa with high epithelium and light cells, lamina propria fused with submucosa, the muscular layer was with two thin sublayers similar in thickness and serosa was thin too. With 13.5 cm, was observed the first irregularities in the mucosa with epithelium projections and lamina propria that will lead rumen papillae. With 16.5 cm there was differentiation of the lamina propria to the submucosa. In group 2, in fetuses with 28 cm were observed complete papillae. From this stage, the remaining groups, there was an increase in thickness of the epithelium, lamina propria, submucosal and muscular layer whit the inner sublayer more thicker than the external and serosa. It was concluded that the main variations occur in fetuses of groups 1 and 2, and after this phase, there is increased in thickness of all layers until the end of the pregnancy period.