278 research outputs found
THE EFFECT OF N-NH3 INCLUSION ON THE DEGRADATION OF TANNIN OF SORGHUM GRAIN BY RUMEN MICROBES
Full text linkTwo experiments were conducted to study the effect of N-NH3 inclusion in the rumen liquor on the degradation of tannin of whole sorghum grain. The first experiment was carried out to determine the effect of N-NH3 inclusion doses in the rumen liquor on the degradation of sorghum grain tannin. The urea as a source of N-NH3 were included in rumen liquor at doses of 0, 0.5, 1.0, and 1.5% from the weight of whole sorghum grain (w/w). The degradation of sorghum grain tannin was increased (P<0.05) by the doses of N-NH3 inclusion, but the degradation of sorghum grain tannin began to decrease at 1.5% of N-NH3 inclusion dose. In the second experiment, the 1% of N-NH3 inclusion dose was used to evaluate the duration of fermentation in the rumen liquor. The whole sorghum grain were fermented for 12h, 24h, 48h, and 48h in the rumen liquor. The 48h of fermentation gave a highest production of total protein
production. The growth of tannase producing rumen microbes could be enhanced by inclusion of N-NH3
Effects of fermentation products of silage on its intake by cattle
Full text linkThe end-products of silage fermentation have been implicated as factors limiting its intake by ruminant animals, although the contribution of individual chemical
components is not clearly understood. A series of experiments were conducted to investigate the effect of short-term intra-ruminal infusions of silage fermentation end products on roughage intake by cattle.
Infusions of lactic acid, the predominant organic acid found in well preserved silages were found to reduce the short-term intake of roughage by both steers and dairy
cows. The short-term intake of hay- and silage- fed steers was reduced by infusions of 32 g lactic acid/kgDMI. The reduction in intake was greater when the acid was infused
over two hours as opposed to one hour. The same amount of lactic acid (32 g/kgDMI) reduced the intake of silage fed dairy cows. These results were substantiated by a further
experiment in which intra-ruminal infusions of 16, 32 or 48 g lactic acid/kgDMI over a two hour period reduced the short-term intake of silage-fed steers in a dose related
manner.
The mechanism by which lactic acid reduces intake was not clear from these trials. Infusions of acetic and propionic acids in the molar proportions to which lactic acid is metabolised in the rumen depressed silage intake by dairy cows, but this was attributed to a fall in rumen pH.
Urea, used to mimic silage ammonia had no effect on voluntary intake of hayand silage- fed cattle. This supports the theory that rather than ammonia per se limiting
intake it is other fermentation end-products, such as silage amines, produced in similar conditions to ammonia that are responsible for poor intakes.
Amines were detected in noticeable amounts in silages made at Hurley. The predominant one being gamma amino-n-butyric acid (Gaba). Infusion of Gaba intraruminally, reduced the intake of silage-fed steers by up to 22%. Given in combination with putrescine the depressing effect of intake depression was doubled (44%), although these results were not significant. Physical gut fill was found to have
little effect in the limitation of short-term silage intake. Rumen emptying studies showed that the maximum amount of digesta present within the rumen, in terms of DM, OM and NDF occurred after the cessation of the first meal
Surgical Treatment of Thyroid Nodules. Argon Plasma and Minimally Invasive Thyroid Resection - Indications and Surgical Techniques // Хирургическо лечение на възлите в щитовидната жлеза. Аргон плазмени и миниинвазивни тиреоидни резекции - индикации и хирургични техники
No full textВъзлите в щитовидната жлеза са най-честата ендокринна патология, с която се среща хирургът. Основен проблем и предизвикателство пред клинициста е изборът на адекватно поведение, правилният подбор на възлите, изискващи хирургическо лечение. В последните години на XX век в хирургията на щитовидната жлеза навлязоха съвременните принципи и техники на миниинвазивната хирургия, чиято стойност, индикации и ограничения тепърва ще се уточняват. Целта на дисертацията е да се проучат, разработят и внедрят в клиничната практика тиреоидните резекции с миниинвазивен открит достъп и аргон плазмените тиреоидни резекции в рамките на оптимизиран диагностично-лечебен подход при болните с тиреоидни възли. От 01.01.2003 г. при оперативното лечение на тиреоидните възли е внедрена от автора миниинвазивна техника на открита тиреоидна резекция, с която до 30.06.2005 г. са оперирани 237 болни. За същия период от време при 97 болни, оперирани с конвенционален достъп, и при 67 болни, оперирани с миниинвазивен достъп резекцията на ЩЖ е извършвана по разработена от автора методика, използваща аргон плазмен коагулатор - аргонплазмена тиреоидна резекция /АПТР/. Анализът на получените резултати показва, че тиреоидните резекции с миниинвазивен открит достъп съчетават предимствата на конвенционалните резекции на щитовидната жлеза и ендоскопските тиреоидектомии, като в същото време голяма част от ограниченията и недостатъците на двата метода се избягват. Техниката позволява да се минимизира хирургичната травма и да се подобри козметичният резултат, като същевременно се извършва необходимият обем на резекция. Достоверно е снижен следоперативният болничен престой. Разработен е практически алгоритъм за поведение при болни с тиреоидни възли, в които са намерили място нововъведените методи за оперативно лечение на тиреоидните възли.Thyroid nodules are the most common endocrine pathology encountered by surgeons. The main challenge for clinicians is the choice of adequate treatment behaviour and proper selection of nodules requiring surgical treatment. Modern principles and techniques of minimally invasive surgery were introduced in thyroid surgery at the end of the twentieth century. The aim of this thesis is to investigate, develop and implement in clinical practice minimally invasive open access thyroid resection and argon plasma thyroid resection within an optimized diagnostic and treatment approach for patients with thyroid nodules. Minimally invasive open access thyroid resection has been implemented by the author of this thesis in the operative treatment of thyroid nodules since the beginning of 2003. Within the period till June 2005, 237 patients were surgically treated. Within this same period of time 97 patients underwent conventional surgery, and 67 patients were operated with minimally invasive access. The thyroid gland resection was performed according to a developed by the author method using argon plasma coagulant – argon plasma thyroid resection (APTR). Analysis of the results revealed that minimally invasive open-access thyroid resections combine the advantages of conventional thyroid resection and endoscopic thyroidectomy, while at the same time many of the limitations and disadvantages of both methods are avoided. This technique allows minimization of the surgical trauma and improved cosmetic effect whilst the necessary resection volume is performed. The postoperative hospital stay is credibly reduced. A practical algorithm for patients with thyroid nodules has been developed where the newly introduced methods to be applied
Corresponding Author The Effects of Use Medicinal Plants on Rumen Fermentation Parameters in Ruminants
No full textABSTRACT Rumen is a persistent and specific ecosystem consists of bacteria, protozoa and fungus where feed fermentation takes place in it. Produced Hydrogen in rumen can be used in the synthesis of the volatile fatty acids and the microbial protein and its excess would be eliminated through the production of Methane by methanogenesis. Nutritionists have tried to find ways to decrease loss and energy and protein, increase synthesis of microbial protein and the ability of fiber digestion in the rumen through manipulating the rumen's fermentation processes. Hence, changing microbial ecosystem of the rumen by the use of proper feed additives could lead to the reduction of Methane and Nitrogen production and excretion and improve the performance of Ruminants. According to accomplished studies Ionophores increase the efficiency of the use of energy and the protein of feed effectively in rumen but with regard to antibiotic usage ban by European Union in January 2006 and public acceptability reduction of using these compounds in animal nutrition, animal nutritionists decided to use other alternative compounds, spending rumen microbial population control and creating proper changes in rumen fermentation. In recent years the use of herbs as growth stimulus is increasingly considered. The results of this study demonstrate that using of medicine plants effects positively rumen performance and pH, methane production reduction and ammoniac nitrogen concentration, protein metabolism and rumen microbial population improvement and volatile fatty acids production increase
The use of artificial neural networks for modelling rumen fill
Full text linkArtificial Neural Network (ANN) and Random Forest models for predicting rumen fill of cattle and sheep were developed. Data on rumen fill were collected from studies that reported body weights, measured rumen fill and stated diets fed to animals. Animal and feed factors that affected rumen fill were identified from each study and used to create a dataset. These factors were used as input variables for predicting the weight of rumen fill. For ANN modelling, a three-layer Levenberg-Marquardt Back Propagation Neural Network was adopted and achieved 96% accuracy in prediction of the weight of rumen fill. The precision of the ANN model’s prediction of rumen fill was higher for cattle (80%) than sheep (56%). On validation, the ANN model achieved 95% accuracy in prediction of the weight of rumen fill. A Random Forest model was trained using a binary tree-based machine-learning algorithm and achieved 87% accuracy in prediction of rumen fill. The Random Forest model achieved 16% (cattle) and 57% (sheep) accuracy in validation of the prediction of rumen fill. In conclusion, the ANN model gave better predictions of rumen fill compared to the Random Forest model and should be used in predicting rumen fill of cattle and sheep.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
Effects of subacute ruminal acidosis challenges on fermentation and endotoxins in the rumen and hindgut of dairy cows
No full textThe effects of a grain-based subacute ruminal acidosis (SARA) challenge (GBSC) and an alfalfa-pellet SARA challenge (APSC) on fermentation and endotoxins in the rumen and in the cecum, as well as on endotoxins in peripheral blood, were determined. Six nonlactating Holstein cows with cannulas in the rumen and cecum were used in the study. A 3×3 Latin square arrangement of treatments with 4-wk experimental periods was adopted. During the first 3 wk of each experimental period, all cows received a diet containing 70% forages dry matter (DM) basis]. In wk 4 of each period, cows received 1 of the following 3 diets: the 70% forage diet fed during wk 1 to 3 (control), a diet in which 34% of the dietary DM was replaced with grain pellets made of 50% ground wheat and 50% ground barely (GBSC), or a diet in which 37% of dietary DM was replaced with pellets of ground alfalfa (APSC). Rumen pH was monitored continuously using indwelling pH probes, and rumen fluid, blood, cecal digesta, and fecal grab samples were collected immediately before feed delivery at 0900h and at 6h after feed delivery on d 3 and 5 of wk 4. The time for which rumen pH was below 5.6 was 56.4, 225.2, and 298.8min/d for the control, APSC, and GBSC treatments, respectively. Compared with the control, SARA challenges resulted in similar reductions in cecal digesta pH, which were 7.07, 6.86, and 6.79 for the control, APSC, and GBSC treatments, respectively. Compared with the control, only GBSC increased starch content in cecal digesta, which averaged 2.8, 2.6, and 7.4% of DM for the control, APSC, and GBSC, respectively. Free lipopolysaccharide endotoxin (LPS) concentration in rumen fluid increased from 10,405 endotoxin units (EU)/mL in the control treatment to 30,715 and 168,391EU/mL in APSC and GBSC, respectively. Additionally, GBSC increased the LPS concentration from 16,508 to 118,522EU/g in wet cecal digesta, and from 12,832 to 93,154EU/g in wet feces. The APSC treatment did not affect LPS concentrations in cecal digesta and feces. All concentrations of LPS in blood plasma were below the detection limit of >0.05EU/mL of the technique used. Despite the absence of LPS in blood, only GBSC increased the concentration of LPS-binding protein in blood plasma, which averaged, 8.9, 9.5, and 12.1mg/L for the control, APSC, and GBSC treatments, respectively. This suggests that GBSC caused translocation of LPS from the digestive tract but that LPS was detoxified before entering the peripheral blood circulation. The higher LPS concentration in cecal digesta in the GBSC compared with the APSC suggests a higher risk of LPS translocation in the large intestine in GBSC than in APSC
Molecular Monitoring and Isolation of Previously Uncultured Bacterial Strains from the Sheep Rumen
Full text linkTo estimate the contribution of uncultured bacterial groups to fiber degradation, we attempted to retrieve both ecological and functional information on uncultured groups in the rumen. Among previously reported uncultured bacteria, fiber-associated groups U2 and U3, belonging to the low-GC Gram-positive bacterial group were targeted. PCR primers and FISH probe targeting 16S rDNA or rRNA were designed and used to monitor the distribution of targets. The population size of group U2 in the rumen was as high as 1.87%, while that of group U3 was only 0.03%. Strong fluorescence signals were observed from group U2 cells attached to plant fibers in the rumen. These findings indicate the ecological significance of group U2 in the rumen. We succeeded in enriching group U2 using rumen-incubated rice straw as the inoculum followed by incubation in an appropriate medium with an agent inhibitory for Gram-negative bacteria. Consequently, we successfully isolated two strains, designated B76 and R-25, belonging to group U2. Both strains were Gram-positive short rods or cocci 0.5 to 0.8 μm in size. Strain B76 possessed xylanase and α-L-arabinofuranosidase activity. In particular, the xylanase activity of strain B76 was higher than that of xylanolytic Butyrivibrio fibrisolvens H17c grown on cellobiose. Strain R-25 showed an α-L-arabinofuranosidase activity higher than that of strain B76. These results suggest that strains B76 and R-25 contribute to hemicellulose degradation in the rumen
Adding identity to device-free localization systems
No full textThesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2017.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (pages 57-59).Recent advances in wireless localization systems show that by transmitting a wireless signal and analyzing its reflections, one can localize a person and track her vital signs without any wearables. These systems can localize with high accuracy even when multiple people are present in the environment. However, a primary limitation is that they cannot identify people and know who is the monitored person. In this thesis, we present a system for identifying people based only on their wireless reflection with high accuracy. We use a semi-supervised learning classifier to assign labels to each person tracked by the device-free localization system. We use recent advances in machine learning to leverage the big amount of unsupervised data that we have. A key challenge that we solve is obtaining labels that are used for guiding the classifier. To get labeled data, we devised a novel scheme to combine data from a sensor that people are carrying with data from a wireless localization system. We deployed and evaluated our system in people's homes. We present a case study of how it can be helpful to monitor people's health more effectively.by Rumen Hristov.M. Eng
Rumen morphology and volatile fatty acid production in the Blue duiker (Cephalophus monticola) and the Red duiker (Cephalophus natalensis)
No full textBlue duikers and red duikers have very similar rumen anatomy. In both species the rumen is a simple, plesiomorphic, sacculated S-shaped tube, while the ostia are large and the ruminal pillars weak. These specialisations facilitate rapid digesta passage. The rumens are densely papillated, and the fungiform papillae are highly vascular to aid absorption. Many of the adaptations are characteristic of concentrate selectors. Total concentrations of numeral fatty acids are lower in the red duiker than the blue duiker. Propionic and butyric acid concentrations are higher in the blue duiker than the red duiker while acetic acid concentration are greater in red duikers. Caecal concentrations of volatile fatty acids (especially acetic acid) are greater than those in the rumen of the blue duiker, but likely contribute less energy to metabolism because of the small size of the caecum relative to that of the rumenfinal article publishe
The role of dissolved carbon dioxide in both the decline in rumen pH and nutritional diseases in ruminants
No full textAbstractRumen pH has been central to theories of nutritional disease and nutrient digestion in ruminants for decades. In particular, rumen pH is the measurement of a physical phenomenon that describes the balance between bases and acids in a solution. Here, I take a closer look at rumen pH and suggest that its decline during acidosis is a sign of an increased concentration of dissolved carbon dioxide (dCO2), which is the acid in the main buffer system. Rumen dCO2 concentrations are thought to be constant and low, but modern feeding practices can lead to carbon dioxide (CO2) holdup, which is defined as a decline in CO2 fugacity due to changes in the physicochemical properties of the rumen liquor. Gas holdup might thus be responsible for increasing rumen dCO2 concentrations, with a concomitant pH decline. Dissolved CO2 is a biologically active molecule that directly influences bacterial metabolism and that, if found at high concentrations, might enhance rumen CO2 diffusion into the blood, leading to hypercapnia or high blood CO2 concentrations. Hypercapnia has known cellular and physiological effects that are closely associated with rumen acidosis. In this review, I discuss the implication of a high rumen dCO2 concentration for the onset of nutritional diseases and highlight the need to explore rumen acidosis from a physicochemical point of view and beyond pH decline
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