Dissertations / Theses on the topic 'Rumen'
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Lynch, Jennifer Ann. "Rumen stability of two rumen-protected choline products." Connect to resource, 2008. http://hdl.handle.net/1811/32118.
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Bento, Maria Helena Lino. "The effects of condensed tannins on rumen and post-rumen digestion of nutrients." Thesis, University of Aberdeen, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.430272.
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Studies were conducted to evaluate the effects of tannins on in sacco disappearance in the rumen and post-ruminal digestion using the mobile bag and pepsin-pancreatin (in vitro) methods, and the tube-feeding technique in poultry. The treatment of Lotus pedunculatus with PEG increased in sacco disappearance compared with untreated lotus. Quebracho tannin (QT) reduced the disappearance of lupin seeds and soyabean meal. No effect of QT was found on the disappearance of chickpea, and an increase was observed for the disappearance of pea. Tannins increased the excretion of nitrogenous compounds and sialic acid, and reduced nutrient digestibility of most feeds tested, as measured by the4 poultry model. Tannins reduced the proportion of uric acid nitrogen in the excreta. Tannins in lotus reduced intestinal digestion of N as measured by mobile bag and in vitro methods. Nitrogen digestibility of soyabean meal and chickpea as measured by the mobile bag and in vitro methods was not affected by QT. Mimosa tannin (MT) inhibited the attachment of microbes to cellulose and decreased gas production. Polyethylene glycol completely restored the gas production from cellulose treated with MT. Pectin improved microbial attachment in the presence of MT, and the inhibition of the gas production from cellulose was partially restored. The gas production from maize shoots decreased with MT, and it was restored with the addition of PEG. Pectin did not improve the gas production from MT-treated maize shoots. The presence of both MT and pectin improved EMPS, but reduced the incorporation of 15N into microbial protein.
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Garrett, Jennifer L. "Varying rumen available carbohydrate and rumen available protein in diets of lactating cattle." Diss., This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-06062008-170400/.
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Wiryawan, I. Komang Gede. "Microbial control of lactic acidosis in grain-fed sheep." Title page, contents and summary only, 1994. http://web4.library.adelaide.edu.au/theses/09PH/09phw799.pdf.
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Bibliography: leaves 122-138. Investigates the use of microbial inoculants to prevent the onset of acidosis in acutely grain fed animals; and, the most effective combination of virginiamycin and lactic acid utilising bacteria (selenomonas ruminantium subsp. lactilytica and Megasphaera elsdenii) in controlling lactic acid accumulations in vitro.
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Snyman, Leendert Dekker. "Qualitative characteristics of selected Atriplex nummularia (Hatfield Select)." Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-04022007-162554.
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Embaby, Mohamed GalalEldeen. "EFFECTS OF UNCONVENTIONAL PLANT OILS AND RUMEN ADAPTATION ON METHANE GAS EMISSION AND RUMEN FERMENTATION CHARACTERISTICS." OpenSIUC, 2018. https://opensiuc.lib.siu.edu/theses/2353.
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The objectives of this work were to investigate the effects of unconventional oils rich in phenolic compounds and rumen adaption on methane (CH4) gas production and rumen fermentation characteristics under in vitro rumen conditions. For this purpose, two sets of trials were conducted. In the first trial, the effects of blackberry, blueberry, raspberry, pomegranate, black seed and hemp oils on CH4 production and fermentation were examined in three 24 h batch culture experiments. Treatments in each experiment consisted of control (no oil supplement), control plus corn oil, or control plus two of the unconventional oils. Oils were added to rumen cultures at 500 mg/L (equivalent to 3.3 g oil/kg of diet dry matter (DM)). After 24 h of incubation, CH4 production was not different between the control and the corn oil treatments. Of the six unconventional oils tested, only hemp and blueberry oils reduced (P<0.05) CH4 production by 9-16% relative to the control and corn oil treatments. No significant differences were observed between treatments in dry matter digestibility (DMD) or total volatile fatty acids (tVFA). Except for a reduction (P<0.05) in acetate concentration with the raspberry oil, and an increase (P<0.05) in valerate concentration with the pomegranate oil, all other treatments had similar VFA concentrations. In the second trial, the effects of adding oregano essential oil (OEO) to adapted and unadapted rumen cultures on CH4 production and rumen fermentation were evaluated under in vitro condition. Rumen cultures were obtained from continues culture fermenters fed a control diet or control diet plus OEO at 250 mg/day for 10 days. The addition of OEO decreased (P<0.05) ii CH4 production only in adapted cultures. Total VFA and acetate concentrations were greater (P<0.05) in the unadapted than adapted cultures and their concentrations decreased (P<0.05) with the addition of OEO particularly when added to the adapted cultures. Propionate concentrations were also greater (P<0.05) in the unadapted than the adapted cultures and concentrations decreased (P<0.05) with the addition of OEO. Dry matter degradability and total gas production decreased (P<0.03) with the addition of OEO in both cultures and total gas production tended (P<0.13) to be lower when added to the adapted cultures. In conclusion, our results showed that hemp and blueberry oils were moderately effective in reducing rumen CH4 formation without compromising rumen fermentation and digestibility. Oregano Essential oil addition negatively affected rumen fermentation in both adapted and unadapted cultures and the effect was greater in the adapted cultures. The greater effects of OEO on CH4 production in the adapted cultures most likely due to the lower fermentation efficiency in these cultures.
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Edwards, Nicholas John. "Nitrogen assimilation by rumen microorganisms: a study of the assimilation of ammonia by rumen bacteria in vivo and in vitro." Title page, table of contents and abstract only, 1991. http://web4.library.adelaide.edu.au/theses/09PH/09phe2657.pdf.
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Edwards, N. J. "Ammonia metabolism in rumen mirco-organisms /." Title page, contents and summary only, 1985. http://web4.library.adelaide.edu.au/theses/09AB/09abe26.pdf.
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Hillman, K. "Studies on metabolism in rumen protozoa." Thesis, Bucks New University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378375.
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Oyama, Linda Boniface. "Prospecting rumen bacteria for novel antimicrobials." Thesis, Aberystwyth University, 2015. http://hdl.handle.net/2160/648b4e03-b6d9-46b7-89d0-1b0d5d483219.
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Due to their broad-spectrum and bactericidal activity, antimicrobial proteins and peptides (AMPPs) are considered as future drug alternatives to combat the escalating problem of antimicrobial resistance in medicine. The community of competitive culturable and non-culturable bacteria in the rumen present a potential source for the discovery of novel bioactive compounds including AMPPs. Metagenomic and bioinformatics based techniques were used to prospect two rumen bacterial metagenomes for potentially novel antimicrobial genes (proteins) and peptide sequences. Novel short antimicrobial peptides (peptides 1-181) and eleven longer antimicrobial genes/miniproteins (Gene 6, 17A, 17B palG1 and palG2, H-G1, H-G2, H-G3, H-G4, H-G5) were identified. Eight of these (peptides 2, 3, 4, 5, 7, 8, 15 and palG1) were selected for further analysis. These antimicrobials displayed potent antimicrobial activity (minimum inhibitory concentrations ranging from 32 to 64 μg/ml) against both Gram positive bacteria strains (including Methicillin sensitive and resistant Staphylococcus aureus strains MSSA RN4220 and EMRSA-15, Enterococcus faecalis JH2-2 and Listeria monocytogenes NCTC 11994 (serovar 4b)), as well as Gram negative bacteria strains (Escherichia coli K12, Salmonella enterica serovar Typhimurium SL1344 and Pseudomonas aeruginosa (15692) PAO1 strain H103) in Mueller Hinton broth. No haemolytic activity against red blood cells was seen. Data obtained indicate that loss of cell viability is due to cytoplasmic leakage and there is some evidence of interference with the cell division mechanism. The rumen AMPPs identified in this study show great activity against clinically relevant human pathogens and to our knowledge are the first rumen AMPs identified using metagenomics. Overall, the data support the potential use of AMPs (2, 3, 7), AMPs (2, 3, 4, 5, 7, 8, 15) and the polypeptide palG1 in the treatment of S. aureus, E. coli and Ent. faecalis infections respectively in the future.
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Thomson, Andrew Montgomery. "Gene transfer in rumen Bacteroides species." Thesis, University of Aberdeen, 1990. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU497422.
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Obligately anaerobic bacteria of the genus Bacteroides are important and abundant inhabitants of the rumen and hind gut of mammals. They are the most numerous group in the rumen and play a major role in fibre degradation with the rumen. They are phylogenetically remote from the better studied groups of facultatively anaerobic gut bacteria (eg. enterobacteria), but are closely related to the colonic Bacteroides. Interstrain conjugal transfer of a plasmid, pRRI4 (coding for tetracycline (Tc) resistance), from the multiple plasmid bearing B.ruminicola strain 223/M2/7 to F101, a rifampicin resistant mutant of B.ruminicola B 14, was demonstrated. pRRI4 was demonstrated to be self transmissible and carried the genes coding for TcR in B.ruminicola. Transformation of B.ruminicola F101 to Tc R with pRRI4 was achieved using electroporation at frequencies up to 106 per mug DNA. Four other B.ruminicola strains were not transformed with this plasmid nor was a strain of B.uniformis. Similar procedures gave transformation of B.uniformis strains, but not B.ruminicola strains, with the E.coli:Bacteroides shuttle vectors pDP1 and pE5-2 at frequencies up to 107 per mug DNA. A nuclease assay was developed to determine the nuclease activity of a number of rumen bacteria and high nuclease activity in all B.succinogenes and five B.ruminicola strains was demonstrated. E.coli and B.uniformis strains were also transformed using electroporation by the shuttle vector, pRRI207, which has been constructed from a cryptic B.ruminicola plasmid (pRRI2, 3.4kbp) cut with EcoRI *, an E.coli vector plasmid (pHG165, 3.37kbp) carrying the pUC8 multiple cloning site, and the 4.2kbp Cc-EmRTc R* EcoRI region of pDP1. pRRI207 is capable of transforming B.uniformis, B.distasonis and B.ruminicola to clindamycin (Cc) resistance and E.coli to TcR (only expressed aerobically), and was the only construct from eleven different constructs obtained based on pRRI2 able to do so.
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Segura, Carlos U. Häubi. "Use of the rumen simulation technique (RUSITEC) to model clinical and subclinical rumen acidosis in dairy cattle." Thesis, University of Reading, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.430925.
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Cersosimo, Laura Marie. "Rumen Microbial Ecology And Rumen-Derived Fatty Acids: Determinants Of And Relationship To Dairy Cow Production Performance." ScholarWorks @ UVM, 2017. http://scholarworks.uvm.edu/graddis/665.
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Rumen microbiota enable dairy cattle to breakdown fiber into useable energy for milk production. Rumen bacteria, protozoa, and fungi ferment feedstuff into volatile fatty acids (VFA), the main energy source, while methanogens utilize fermentation by-products to produce methane. Milk fat contains several bioactive rumen-derived fatty acids (FA), including odd-chain FA (OCFA) and branched-chain FA (BCFA), important for maintenance of human health. The overarching dissertation goal was to determine which factors affect rumen methanogen and protozoal community structures and their metabolism products, while defining relationships between rumen microbiota and animal performance. Results presented contribute to the goals of providing new knowledge to dairy farmers, maintaining ruminant health, and enhancing bioactive FA in milk.
The first objective was to use next-generation sequencing techniques to determine if lactation stage and dairy breed affect rumen methanogen and protozoal community structures and protozoa cell FA compositions in Jersey, Holstein, and Holstein-Jersey crossbred cows at 3, 93, 183, and 273 days in milk (DIM). A core methanogen community persisted by lactation stage and breed. At 3 DIM, methanogen 16S rRNA gene sequences formed distinct clusters apart from 93, 183, and 273 DIM, reflective of the dietary transition period post-partum. The starch-utilizing protozoal genus Entodinium, was more abundant in Holsteins than in Jerseys and Holstein-Jersey crossbred cows and positively correlated with milk yield. Jerseys had greater iso-BCFA contents in protozoa and milk and protozoa of the genus Metadinium.
The second objective was to determine if supplementation of mixed cool-season grasses with annual forages (AF) alters the forage, microbial, and milk FA contents during typical periods of decreased pasture growth in Northeastern US. In short-term grazing (21d) of AF, ruminal VFA and major rumen-derived FA were not altered in bacterial and protozoal cells, suggesting little alteration of biohydrogenation and maintenance of ruminant health. In spring, milk contents of iso-15:0 and 17:0 per serving of whole milk were greater in control (CON)-fed cows, while contents of 12:0 and 14:0 per serving were greater in AF-fed cows. Contents of de novo FA and OCFA per serving of whole milk were greater in summer AF-fed cows than CON-fed cows, while total contents and BCFA did not differ, suggesting post-ruminal FA modifications in adipose tissue and the mammary gland.
The third objective was to characterize and relate the rumen microbiota from CON- and AF-fed cows to animal performance. Rumen protozoal taxa were not altered, while less abundant bacterial taxa (< 5%) were different in both periods. The protozoal genus Diplodinium was positively correlated with feed efficiency and milk fat yield. In spring, AF-fed cows had greater abundances of the methanogen species Methanobrevibacter millerae, whereas CON-fed cows had greater abundances of the methanogen species Methanobrevibacter ruminantium, potentially as a result of differences in substrate availability.
In conclusion, the work presented identifies several factors that influence rumen microbiota, rumen microbial FA, and milk FA, while providing new information to dairy farmers, researchers, and consumers.
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Figueroa, Mario Raul. "Effects of Rumen Protein Degradability on Rumen Characteristics, Milk Production and Reproductive Performance in Holstein Dairy Cows." DigitalCommons@USU, 1992. https://digitalcommons.usu.edu/etd/4048.
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Three non-lactating Holstein cows fitted with rumen cannula were used to determine crude protein and dry matter rate of disappearance of two protein supplements: 1) soybean meal and 2) bypass protein blend by using the in situ bag technique. Rate disappearance (%/hr) was higher for soybean meal. Two collection periods were completed using 6 cows with a minimum of 21 d adaptation to the treatment top dressed on to the total mixed ration. Ruminal concentration of ammonia N, blood ammonia, and urea did not differ between treatments. Total concentration of volatile fatty acids was higher for bypass protein blend-fed cattle as well as percent molar concentration of propionate, butyrate, and valerate, while pH was lower. Total protozoa, and total and cellulolytic viable bacteria populations did not differ. Four of the cows received a dose of 5 ml of Prostaglandin F,a. Blood and cervical muc us samples obtained showed no difference in blood ammonia and urea concentration . Forty-six Holstein cows were assigned to one of the two treatments (top dressed on the t otal mixed ration), according to parity during the following 125 d postpartum. Daily dry matter intake and milk production were recorded. Feed, orts, and feces were sampled. Milk samples were collected weekly and analyzed for components. Percent lactose and solid non-fat showed higher for cattle fed the bypass prorein blend. Starting on day 10 postpartum, cows were observed for signs of estrus and bred at first estrus observed after 45 d postpartum. Cervical mucus and blood collected at first standing estrus, and first, seco nd, and third service, did not show a significant difference in urea concentration between rations. Twice-weekly collected blood samples showed similar monthly mean concentration of ammonia, urea, and progesterone profile for both treatment groups. Percent pregnancy, services per pregnancy, first service pregnancy and embryo mortality showed no significant difference. Motility and survivability of bull sperm were evaluated by incubating thawed semen in different levels of previously observed and/or ammonia. physiological There were no concentrations of urea significant treatment differences observed. Detrimental effects of treatment on sperm were not detected.
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Ambriz, Vilchis Virgilio. "Impact of dietary manipulation of rumen pH on health and productivity in dairy cows." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/22863.
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Current feeding strategies for dairy cows focus on meeting the energy requirements for high levels of milk production. However a major concern is the effect that these feeding regimes might have on rumen pH, which can have harmful effects on the cow and rumen microbial population. Several interventions have been used to counteract the effects of low rumen pH such as the use of probiotics e.g. yeast (Saccharomyces cerevisiae). However benefits have been inconclusive due to large individual animal variation in responses to treatment observed. The use of novel monitoring technologies can help assess the effect that different dietary interventions have on performance, rumen pH and rumen health. Data from three on-farm dairy cow trials (Trial 1 standard diet plus yeast; Trial 2 standard diet plus acidotic challenge plus yeast; Trial 3 cows grazing grass plus yeast) was used to evaluate the use of rumination collars (RC), rumen pH boluses, a whole cow dynamic mechanistic simulation model (SM) and the effect that different feeding strategies have on performance rumen pH dynamics and rumination time. No statistically significant differences between Control (no yeast) and Treatment (addition of yeast) diets were observed on any of the parameters measured. The lack of animal response to yeast supplementation observed in the three feeding Trials could be attributed to the stage of lactation, as the cows were passed peak lactation. Comparison of rumination time obtained with the RC and visual observations (obtained directly and from video recordings) suggest that the RC can be used to determine rumination time in housed cows. However its poor performance in grazing environments makes its use not advisable in cows outside at grass. The rumen pH boluses provided detailed and accurate data on circadian rumen pH. Highly varied individual responses to the feeding strategies were observed. This resulted in a diverse degree of risk of individual cows which experienced sub-acute rumen acidosis. The SM was able to accurately predict circadian pH, compared against the data obtained from Trials 1 and 2. The model provided pH values that were in agreement with those obtained with the rumen boluses. The use of new technologies to monitor cows individually could aid in whole-herd management, for example by setting thresholds for rumen pH and rumination time related to individual cow status, and then trigger appropriate interventions.
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Karnati, Sanjay Kumar Reddy. "Application of molecular techniques to assess changes in ruminal microbial populations and protozoal generation time in cows and continuous culture." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1164662405.
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Gnanasampanthan, Gnanapragasam. "Immune responses of sheep to rumen ciliates and the survival and activity of antibodies in the rumen fluid." Title page, contents and abstract only, 1993. http://web4.library.adelaide.edu.au/theses/09PH/09phg571.pdf.
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Videorecording has title: Effect of antibodies on the motility of rumen ciliates. Bibliography: leaves 197-259. Consists of a review of rumen ciliates, their implications in ruminant nutrition and a description of the research methods, the results and the conclusions drawn with regard to the prospects of establishing an immunological basis for the manipulation of rumen ciliates.
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Bernalier-Donadille, Annick. "Les champignons anaerobies du rumen : caracterisation et interactions avec les bacteries du rumen, dans la cellulolyse, in vitro." Clermont-Ferrand 2, 1991. http://www.theses.fr/1991CLF21281.
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L'isolement et la caracterisation de souches de champignons anaerobies du rumen nous a conduit a l'identification d'especes monocentriques precedement decrites et de deux nouvelles especes de champignons polycentriques. Malgre leur diversite morphologique toutes ces especes presentent une grande homogeneite de fonctions bien que les especes rhizoidales degradent plus efficacement les polymeres parietaux. Les associations entre especes monocentriques et les bacteries cellulolytiques majeures ont montre que fibrobacter succinogenes n'interagissait pas avec les champignons alors que ruminococcus flavefaciens liberait une proteine capable d'inhiber leurs cellulases et que l'activite cellulolytique de cette bacterie etait stimulee par s. Communis. Les bacteries fermentatives (selenomonas ruminantium et megasphaera elsdenii) inhibent la cellulolyse fongique du fait de l'accumulation dans la coculture d'un des produits de fermentation. Un transfert d'h2 entre les champignons et s. Ruminantium conduit a une deviation du metabolisme bacterien vers une production accure de propionate. En coculture avec une bacterie methanogene (methanobrevibacter ruminantium), l'activite cellulolytique des champignons est plus forte. Un transert d'h2 entre ces microorganismes conduit a une deviation du metabolisme fongique vers une plus forte production d'acetate concommittente a une augmentation de la croissance fongique. L'association d'une bacterie hydrogenotrope (eubacterium limosum) aux especes fongiques s'est egalement traduite par une deviation du metabolisme fongique, toutefois le mecanisme implique est plus complexe
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Yohe, Taylor Timothy. "Nutrient Impacts on Rumen Growth and Development." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/94558.
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Our collective knowledge of calf nutrition has evolved over the past 100+ years, but there are still areas of improvement that merit further scientific inquiry. The work described herein explored different aspects of calf nutrition with a central focus on rumen growth and development. The first study performed used 8 Holstein bull calves to determine if calf starters differing in starch and neutral detergent fiber (NDF) content would affect calf growth, intake, rumen metabolites, blood metabolites, and gross rumen measurements when fed along with milk replacer (MR). The experiment used completely pelleted calf starters consisting of ground and pelleted barley, wheat, and corn grains. Besides the high-starch starter resulting in lower rumen pH, the hypothesis that completely pelleted calf starter diets differing in NDF and starch level would alter intake, growth, rumen metabolism, and rumen measurements was not supported. However, calves fed the high-NDF starter were $5.71 less expensive per calf to raise. Findings suggest a form of feed effect in today's calf starter diets that might be of physiological and economic importance. The second study tested custom-built rumen infusion, sampling, and evacuation devices. The main objectives were to build and confirm the successful use of the devices in one Holstein bull calf at 62 days of age, which determined a liquid passage rate out of the rumen at 40.2% of ruminal fluid/h. The third and final study examined the effects of form of diet (MR only, n = 5; MR and starter, n = 6) on rumen growth and development. More specifically, isocaloric and isonitrogenous diets were fed to neonatal and ruminally cannulated Holstein calves for 6 week. The hypothesis of MR and starter calves having altered gross rumen measurements, epithelial stem and progenitor cell number, and epithelial proliferation status was supported, but hypothesized changes in volatile fatty acid (VFA) transporter abundance and VFA absorption rate were not supported. These results indicate that form of diet, even one that promotes rumen growth, does not equate to enhanced ability to absorb VFA, but there is an effect on rumen stem and progenitor cells as well as epithelial proliferation.PHD
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Hackmann, Timothy John. "Responses of Rumen Microbes to Excess Carbohydrate." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1364922613.
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Saluzzi, Liliana. "Ecophysiology of cellulolytic bacteria in the rumen." Thesis, University of Aberdeen, 1993. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU542848.
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The rumen microbial populations involved in the degradation of barley straw and clover/ryegrass forage during incubation in sacco were studied by the analysis of microbial phospholipids. The results suggested that the adherent populations differed from those in the liquid phase of the rumen contents, and that the microorganisms attached to barley straw differed from those attched to clover/ryegrass. In addition, the population adherent to barley straw appeared to change during the degradative process. The latter point was supported by observations using the electron microscope. When barley straw was incubated in vitro with Ruminococcus flavefaciens prior to incubation in the rumen, phospholipid analysis suggested that R.flavefaciens persisted during 72 h incubation in the rumen, although as a declining component of the mixed population. Ruminococcus flavefaciens was possibly displaced or other 'free' sites of attachment were occupied by different species. The in vitro incubation of Ruminococcus flavefaciens and Fibrobacter succinogenes on clover/ryegrass and barley straw showed that the presence of F.succinogenes reduced the population size of R.flavefaciens and the degradability of clover/ryegrass suggesting a competitive or antagonist interaction betweeen these species. The analysis of phospholipid marker components and viable counts showed that R.flavefaciens rapidly outgrew F.succinogenes. Ruminococcus flavefaciens and Fibrobacter succinogenes differed in the quantity and nature of the soluble plant components that accumulated in the culture liquids. After training Ruminococcus flavefaciens strain 17 to grow on different forages, adaptation through enhanced substrate degradation was detected when cultures were grown repeatedly on ryegrass. Significant increases in specific xylanase and beta-xylosidase activities were detected. It is concluded that the increase in dry matter solubilization and enzyme activities during prolonged subculture on ryegrass probably resulted from forward mutations.
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Lusweti, Francesca N. "Rumen undegradable protein in growing sheep diets /." free to MU campus, to others for purchase, 1997. http://wwwlib.umi.com/cr/mo/fullcit?p9842596.
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Cassiano, Eduardo Cuelar Orlandi. "Avaliação de anticorpos policlonais em bovinos adaptados ou não à dietas com alta proporção de carboidratos prontamente fermentescíveis após indução à acidose." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/10/10135/tde-17042014-100147/.
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O objetivo deste trabalho foi avaliar o efeito de um preparado de anticorpos policlonais (PAP) contra bactérias ruminais específicas, Streptococcus bovis e Fusobacterium necrophorum, em parâmetros ruminais da fermentação, em vacas canuladas, adaptadas ou não a uma dieta de alta proporção de carboidratos prontamente fermentescíveis, após indução à acidose. O delineamento experimental utilizado foi o quadrado latino 3X3 replicado em arranjo fatorial de tratamentos 3X2, sendo 2 aditivos alimentares (PAP na apresentação em pó - PAPP e PAP na apresentação líquida - PAPL) mais um grupo controle (CON) e dois manejos de adaptação à dieta, resultando em seis tratamentos. O primeiro quadrado latino foi submetido a um protocolo de adaptação à dieta do tipo gradual ou step-up: dos dias D0 a D4 os animais receberam 100% de forragem; do D5 ao D9, 30% de concentrados e do D10 ao D14, 60% de concentrados. O segundo quadrado latino recebeu 100% de forragem do D0 ao D14 (sem adaptação). Nos D15 e D16, todos os animais receberam dieta com 80% de concentrados. Para as análises foram coletadas amostras de líquido ruminal a cada 3 horas a partir da 0h antes da alimentação até as 36h (D15 e D16) durante o desafio com uma dieta de 80% de concentrados. Os dados foram analisados pelo procedimento Mixed do SAS com nível de significância de 0,05. Foi observada interação entre tempo e adaptação (P<0,05) para pH ruminal com diferença entre método de adaptação nas 0, 3, 6, 9, 12 e 36 horas pós alimentação, quando o grupo não adaptado teve valores maiores que o grupo adaptado, sendo que na hora 24 ocorreu o contrário. Para a concentração de ácidos graxos de cadeia curta (AGCC), nas horas 0, 3, 6, 9 e 36 pós alimentação o grupo adaptado obteve maiores valores comparado ao grupo não adaptado. Para proporção molar de acetato, a 0 hora o grupo sem adaptação obteve valores maiores comparado ao grupo adaptado. Já nas horas 24, 27 e 30 o grupo com adaptação que obteve maiores valores. Para a proporção molar de propionato o grupo sem adaptação teve valores mais altos em comparação ao outro grupo das 3 às 36 horas pós alimentação. Quanto à proporção acetato:propionato (Ac:Pr) às 6, 12, 24, 27, 30 e 36 horas pós alimentação, o grupo de animais adaptados teve valores mais altos que o grupo não adaptado. Na proporção molar de butirato, o grupo de animais adaptados obteve maiores valores nas horas 0, 3, 6, 9, 12, 33 e 36. Para os valores de nitrogênio amoniacal (N-NH3), às 6 horas pós alimentação, o grupo não adaptado obteve maiores valores que o grupo adaptado (26,1 vs. 19,3, respectivamente). Nas horas 9, 30, 33 e 36 ocorreu o contrário. Observou-se também interação entre tempo e aditivo (P=0,0430) para a proporção molar de butirato. Porém, quando a análise foi realizada por tempo, nenhum efeito foi observado. Para os valores relativos de protozoários mensurados (Dasytricha, Isotricha, Epidinium, Diplodinium e Entodinium) apenas o Entodinium apresentou efeito de adaptação (P<0,0236) tendo sua proporção maior no grupo adaptado. Os valores de haptoglobina também não foram influenciados nem por aditivo nem por adaptação. O preparado de anticorpos policlonais não foi tão eficaz quanto a adaptação gradual à dieta de alto concentrado para controlar alterações dos parâmetros ruminais.The objective of this trial was to evaluate the effects of polyclonal antibodies preparation (PAP) against specific rumen bacteria Streptococcus bovis and Fusobacterium necrophorum on rumen fermentation parameters in ruminally cannulated cows adapted or not to highly fermentable carbohydrates diets (HFC) after an acidosis challenge. The experimental design was two 3X3 Latin squares in a factorial arrangement of treatments 3X2 regarding two feed additives (PAP in powder presentation - PAPP and PAP in liquid presentation - PAPL) plus control group (CON) and two managements of diets adaptation, resulting in six treatments. The first Latin square had a step-up diet adaptation: from D0 to D4 100% forage; D5 to D9 30% of concentrates and D10 to D14 60% of concentrates. The second Latin square received 100% forage from D0 to D14. On D15 and D16, all animals received a diet with 80% of concentrates. For analysis, rumen fluid was sampled at 0 and every 3 h posfeeding totaling 36 h (D15 and D16) of challenge with a diet with 80% of concentrates. Data were analyzed by MIXED procedure with a significance level of 0.05. An interaction between time and adaptation (P<0,05) was observed for ruminal pH. At 0, 3, 6, 9, 12 and 36 h postfeeding, the non-adapted group had higher values compared to the adapted group and at 24 h postfeeding, the inverse was observed. For total short-chain fatty acids concentration, at 0, 3, 6, 9 and 36 h postfeeding, the adapted group had higher values compared to non-adapted group. For molar proportion of acetate at 0h postfeeding, the non-adapted group had higher values than the adapted group, and at 24, 27 and 30h, the adapted group had greater values than the non-adapted group. For molar proportion of propionate the non-adapted group had greater values compared to the adapted group from 3 to 36h postfeeding. For acetate:propionate (Ac:Pr) ratio at 6, 12, 24, 27, 30 and 36 h postfeeding, the adapted group had greater values compared to the nonadapted group. For butyrate molar proportion at 0, 3, 6, 9, 12, 33 and 36h postfeeding the adapted group had greater values than the non-adapted group. For ammonia nitrogen (NH3- N) concentration at 6h, the non-adapted group had greater values than the adapted group (26.1 vs. 19.3, respectively), however at 9, 30, 33 and 36h postfeeding, the adapted group had higher values compared to the non-adapted group. It was also observed an interaction between time and additive (P=0.0430) for butyrate molar proportion, but when the analysis was performed by time no effect was observed. For the relative values of protozoa measured (Dasytricha, Isotricha, Epidinium, Diplodinium and Entodinium) only Entodinium presented adaptation effect (P<0.0236) with a higher proportion in the adapted group. Haptoglobin values was also not influenced (P>0.05) by additive or adaptation effect. Polyclonal antibodies preparation was not as effective as the gradual adaptation to the diet high concentrate to control changes of ruminal parameters.
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Yohe, Taylor. "Performance and Development of the Rumen in Holstein Bull Calves Fed an Aspergillus oryzae Fermentation Extract." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1397769968.
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Bottrill, Stephen. "Comparative studies of oxalyl-CoA decarboxylase produced by soil and ruminal bacteria." Title page, contents and abstract only, 1999. http://web4.library.adelaide.edu.au/theses/09ANM/09anmb751.pdf.
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Bibliography: leaves 139-167 The aim of this project was to identify an enzyme responsible for the metabolism of oxalate which would be suitable for degrading oxalate in the rumen, and clone and characterise that gene.
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Armato, Leonardo. "Yeast cell walls and live yeasts diet supplementation in beef cattle: effect on rumen fermentations and ultrasonographic rumen wall findings." Doctoral thesis, Università degli studi di Padova, 2017. http://hdl.handle.net/11577/3422409.
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The objective of this thesis was to determine the effect of yeast supplements on the performance and health of beef cattle during the receiving and finishing period. Furthermore, another aim of this study was to evaluate the applicability of rumenocentesis on beef cattle and the viability of transabdominal ultrasonography of the rumen mucosa as a suitable, non-invasive diagnostic tool to identify beef cattle affected by SARA. Three trails were conducted in order to do achieve that. Trail I and Trail II were conducted simultaneously using the same animals, while the third trail used a larger sample but always in the same herd. Trail I and II assessed the effect of dietary supplementation of yeast cell wall (YCW) and live cell yeast (LY) at different dosages on rumen’s metabolites. Sixty Charolaise steers were divided into two groups on the basis of their feeding phase: growing and finishing. Growing and finishing groups were each randomly divided into equal three subgroups (n = 10): no supplement (growing control), supplemented with YCW, and supplemented with LY + YCW, no supplement (finishing control), supplemented with LY and supplemented with LY + YCW. Ruminal fluid has been collected before, after 21 and 42 days of experimental period in order to evaluate the volatile fatty acids concentrations and pH values. Faeces samples were collected before (T0), after 21 (T1) and 42 (T2) days of the start of the study, which took place simultaneously and analysed for dry matter (DM), Ash, crude protein (CP), ethereal extract (EE), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL) and Starch detection. Dietary supplementation of LY and YCW increased (P<0.05) DM, ADF and ADL faecal concentrations in the growing phase; DM, ADL and Starch faecal concentrations in the finishing phase. T2/FC Diet showed a significant effect (P<0.001) of different diets respect to T2/FB in the finishing stage. The obtained results suggest that yeast supplementation do not have beneficial effects with all type of diet condition. Statistical analysis of VFA's data showed a significant effect of time (P < .05) on all studied parameters except iso-valeric acid both in growing and finishing groups. Changes among growing subgroups (P < .05) on propionic acid, acetic acid, iso-butyric acid and n-butyric acid were found, whereas no statistical significances were found among finishing subgroups. Trail III was conducted on 478 beef cattle of Charolaise breed, they were monitored three times during the livestock cycle in order to evaluating the rumen fluid pH and to assess the measures of the rumen wall: T0: 5±3 d after the arrival in farm;T1: 60±10 d after arrival; T2: 1 month before slaughter. Period effect (P<0.001) were found between the three periods after 10 days from the housing, rumen pH values were lower than the threshold value of 5.71 in T0 than in T1 and T2. Pearson’s analysis showed interaction between pH and total ultrasound thickness of rumen wall (-0.700; P<0.0001) and rumen mucosa (-0.7921; P<0.0001). Both differentiation efficiency of mucosal and submucosal layer thickness and rumen wall thickness between healthy and ruminal acidosis affected animals, as a result of ROC curve analysis, was excellent. Using a cut-off value of 5.4 mm, sensitivity was 96.30% and specificity was 91.60% on mucosal and submucosal layer. Using a cut-off value of 8.2 mm, sensitivity was 91.36% and specificity was 91.60 % on rumen wall thickness.
The study show that transabdominal ultrasonography of the rumen mucosa has the potential to be a suitable diagnostic tool to identify fattening bulls affected by SARA.L'obiettivo di questa tesi era di determinare l'effetto degli integratori lievito sulle prestazioni e la salute dei bovini da carne durante il periodo di ricevimento e finissaggio. Inoltre, un altro obiettivo di questo studio era di valutare l'applicabilità di ruminocentesi sui bovini da carne e la possibilità di utilizzare l'ecografia transaddominale della mucosa ruminale come uno strumento diagnostico non invasivo per identificare i bovini affetti da SARA. Tre prove sono state condotte al fine di fare raggiungere questo obiettivo. Trail I e II sono stati condotti simultaneamente utilizzando gli stessi animali, mentre per la terza prova utilizzato un campione più grande, ma sempre nella stessa azienda zootecnica. Trail I e II ha valutato l'effetto della supplementazione alimentare di pareti di lieviti (JWC) e lievito cellule vive (LY) a diversi dosaggi di metaboliti nel rumine. Sessanta vitelloni di razza Charolaise sono stati divisi in due gruppi sulla base della loro fase di alimentazione: accrescimento e finissaggio. Il fluido ruminale è stato raccolto al tempo zero e dopo 21 e 42 giorni del periodo sperimentale al fine di valutare le concentrazioni degli acidi grassi volatili e del pH. I campioni di feci sono stati raccolti prima (T0), dopo il 21 (T1) e 42 (T2) giorni dall'inizio dello studio, e sono stati analizzati per sostanza secca (DM), ceneri, proteina grezza (CP), estratto etereo (EE), fibra neutra detergente (NDF), fibra detergente acido (ADF), acido detergente lignina (ADL) e amido.I risultati ottenuti suggeriscono che la supplementazione di lievito non hanno effetti benefici con tutti i tipi di condizione di dieta. L'analisi statistica dei dati di VFA ha mostrato un effetto significativo di tempo (P <.05) su tutti i parametri studiati, eccetto l'acido iso-Valerianico sia nei gruppi di crescita e di finissaggio. 408/5000 Sono stati riscontrati cambiamenti tra sottogruppi crescita (P <.05) su acido propionico, acido acetico, acido iso-butirrico e l'acido n-butirrico, mentre non è stata trovata significatività statistica tra sottogruppi del finissaggio. Trail III è stato condotto su 478 bovini da carne di razza Charolaise, sono stati monitorati per tre volte durante il ciclo di bestiame al fine di valutare il pH del fluido ruminale e per valutare le misure della parete ruminale.Effetto Periodo (P <0.001) è stato riscontrato tra i tre periodi dopo 10 giorni dall'arrivo. Valori di pH ruminale erano inferiori al valore di soglia di 5.71 in T0 rispetto al T1 e T2. L'analisi di Pearson ha mostrato interazione tra il pH e spessore ad ultrasuoni totale di parete ruminale (-0,700; p <0,0001) e del rumine mucosa (-0,7921; p <0,0001). Lo studio dimostrano che l'ecografia transaddominale della mucosa ruminale ha il potenziale per essere uno strumento diagnostico adatto per identificare i tori da ingrasso affetti da SARA.
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Holder, Vaughn. "The effects of specific Saccharomyces cerevisiae strains and monensin supplementation on rumen fermentation in vitro." Pretoria : [s.n.], 2008. http://upetd.up.ac.za/thesis/available/etd-08192008-131813.
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Rhéaume, John. "Rumen bacterial attachment to forage substrates and its relationship to digestibility and intake." Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63187.
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Singh, Nitin. "A model to predict fluctuations in rumen pH." College Park, Md. : University of Maryland, 2005. http://hdl.handle.net/1903/2568.
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Thesis (M.S.) -- University of Maryland, College Park, 2005.Thesis research directed by: Animal Sciences. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Serment, Amélie. "Dynamique et intensité de biotransformation dans le rumen." Phd thesis, AgroParisTech, 2012. http://pastel.archives-ouvertes.fr/pastel-00802657.
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La " biotransformation ruminale " est un concept qui regroupe l'ensemble des réactions se produisant dans le rumen (dégradation, synthèse et conversion). Ces réactions sont pilotées par trois forces motrices majeures : les lois de la cinétique chimique, de la thermodynamique et de la dynamique des populations microbiennes. Cette thèse a pour objectif d'étudier l'impact d'un facteur alimentaire (pourcentage de concentrés incorporés dans la ration, supplémentation en huile) sur le fonctionnement du rumen et la biotransformation ruminale des constituants alimentaires en termes de dynamique et d'intensité. Cette thèse a combiné trois types d'approches : un essai in vivo sur des chèvres en milieu de lactation, deux essais in vitro (méthode du gaz-test) et une approche de modélisation mécaniste. In vivo, les réactions de biotransformation ont été évaluées par un suivi de la dynamique postprandiale et des mesures de bilans duodénaux. De plus, nous avons étudié l'influence réciproque des phénomènes ruminaux et de l'animal-hôte (comportement d'ingestion, métabolisme, paramètres zootechniques, et qualité du lait) sur le long terme (6 semaines). Nos résultats sont en accord avec la plupart des études antérieures effectuées chez la chèvre ou la vache laitières. Les modifications du comportement d'ingestion observées après 6 semaines avec le régime riche en concentrés ont eu un effet sur les phénomènes digestifs ruminaux. Les flux duodénaux d'acides gras ont expliqué les profils en acides gras du lait. Les études in vitro ont donné des résultats très cohérents par rapport à l'in vivo lorsque les animaux donneurs recevaient les régimes incubés. Enfin, nous avons développé un modèle mécaniste de fonctionnement de rumen in vitro décrivant de manière spécifique les lois physico-chimiques expliquant les dynamiques d'évolution du pH et de formation de gaz. Ce modèle aboutit à des résultats satisfaisants et pourrait être intégré à un modèle de rumen plus complet. La modélisation semble être le meilleur moyen pour intégrer toutes les réactions de biotransformation observées lors d'expérimentations.
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Gilmour, Martin. "Lactate utilisation in the rumen bacterium Selenomonas ruminantium." Thesis, Heriot-Watt University, 1994. http://hdl.handle.net/10399/1379.
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Nam, In Sik. "Biohydrogenation of unsaturated fatty acids by rumen fungi." Thesis, University of Nottingham, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.431866.
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Ellis, Jayne Elizabeth. "Studies on the metabolism of rumen climate protozoa." Thesis, Cardiff University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305295.
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Newbold, Charles James. "Microbial metabolism of lactic acid in the rumen." Thesis, University of Glasgow, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235529.
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Eschenlauer, Sylvain Christain Pierre. "Lysosome in the rumen ciliate protozoan, Entodinium caudatum." Thesis, University of Aberdeen, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327592.
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Yakub, Guliye Abdi. "Energy sources and amino acids in rumen fermentation." Thesis, University of Aberdeen, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.408786.
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In a rumen simulation technique (RUSITEC), the availability and timing of energy (maltose) supply to amino acids/peptides from thawed (frozen) grass was examined in order to determine if continuous (synchronous), rather than transient (asynchronous, with maltose infused 6 h prior to, or 6 h after feeding RUSITEC with grass), availability of energy was required for optimum ruminal fermentation. The addition and pattern of energy supply (synchronous or asynchronous) did not influence either fibre (DM) degradation or microbial numbers, although there was an indication of increased total volatile fatty acids (TVFA) and acetate production in the continuous (synchronous) maltose supply. However, the supply of energy (maltose), irrespective of the pattern of supply, improved the capture of ammonia. The effects of amino acid supplementation on mixed microorganisms fermenting a range of substrates (maize and grass silages, barley straw, avicel and xylan) that usually form part of ruminant diets were examined using gas syringe incubations. Gas production, measured at 4, 6, 8, 12 and 18 h incubation, increased by 15.6, 18.7, 18.9, 15.0 and 5.4% respectively, in the xylan substrate, suggesting xylan fermentation was stimulated by amino acids supply. This implied xylanolytic organisms within the mixed population benefited more from the amino acids. A subsequent in vitro (syringe) experiment was conducted to identify amino acids that may be simulatory, using a deletion approach where individual amino acids were deleted from a complete mixture of all 20 amino acids normally found in protein. Amino acid additions, either as the complete mixture or with single amino acid deletions, stimulated microbial growth and fermentation rate compared to only ammonia as the N source. Although the individual deletion of aromatic amino acids (notably tyrosine and tryptophan), as well as leucine, seemed to decrease fermentation rate, microbial yield was not affected. The mixed microbial population achieved the highest growth rate and fermentation when complete mixtures of amino acid were provided.
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Morales, Silva Maria Sol. "Role of ionized calcium and magnesium in cellulose degradation by ruminal bacteria." Connect to this title online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1117564294.
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Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xvii, 163 p.; also includes graphics (some col.) Includes bibliographical references (p. 149-163). Available online via OhioLINK's ETD Center
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Mirza, Muhammad Aslam. "Laboratory methods of determining protein degradability in the rumen." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.319555.
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Carson, Mark T. "Diet, rumen fermentation pattern and butyrate metabolism in sheep." Thesis, Queen's University Belfast, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336040.
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Zhang, Jun Xian. "Genetic determination of xylanases in rumen bacterium ruminococcus flavefaciens." Thesis, University of Aberdeen, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317940.
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The xylanases and xylanase genes in the rumen cellulolytic bacterium Ruminococcus flavefaciens were studied in this thesis. Based on the experiments carried out in this thesis, the following conclusions can be drawn: At least seven multiple xylanases are revealed in R.flavefaciens strain 17 and strain 007, and nine in strain FD-1 by the method used here for activity detection in gels. A im54 kDa constitutive xylanase appears in both strains 17 and 007, but not in FD-1. Straw and xylan are the best substrates for production of most xylanases in R.flavefaciens. Sequencing one of the four xylanase genes isolated from R.flavefaciens 17, xynA, shows a 2862 bp open reading frame initiating from a TTG start codon which is preceded by a Gram-positive Shine-Dalgarno sequence (robosome binding site) of AAAGGAG. The enzyme encoded by xynA (XYLA) is predicted to have 954 amino acids including a probable signal sequence at the amino terminus. XYLA is novel in its structure having two dissimilar catalytic domains (domain A, 248 amino acids; domain C, 332 amino acids) linked by a highly repetitive region (domain B, 374 amino acids) extremely rich in asparagine and glutamine residues. The two catalytic domains can be active independently and act on xylan differently, with domain C producing smaller end products than domain A from oat-spelt xylan. Amino acid sequence comparisons with other enzymes show that domain A and domain C are related to two different families of xylanases, G and F, respectively. Therefore, this thesis provides the first evidence of a bifunctional hemicellulase comprising two different catalytic domains. Antibodies raised separately against domains A and C of XYLA recognize common enzyme bands in Ruminococcus, ranging in apparent molecular mass from 110 kDa to 200 kDa. This tends to confirm that XYLA is produced as a high molecular weight polypeptide in R.flavefaciens, as predicted from the sequence. R.flavefaciens has strong preference of codon usage for several amino acid residues, eg. glutamate (GAG); glutamine (CAG); and lysine (AAG).
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Dewhurst, R. J. "Studies on energy and nitrogen metabolism in the rumen." Thesis, University of Bristol, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234566.
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Avornyo, Franklin Kennedy Kodjo. "Estimation of degradability of feed protein in the rumen." Thesis, University of Cambridge, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621652.
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Franklund, Clifton Victor. "Glucose Uptake by the Cellulolytic Rumen Anaerobe Bacteroides Succinogenes." Thesis, North Dakota State University, 1986. https://hdl.handle.net/10365/28338.
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Glucose uptake by the cellulclytic rumen anaerobe, Bacteroides succinogenes S85, was measured under conditions that maintained anaerobiosis and osmotic stability. This organism was found to possess a highly specific, active transport mechanism for glucose. Evidence for a phosphoenol-pyruvate:g1ucose phosphotransferase system was not detected. Compounds that inhibit electron transport systems (non-heme iron chelators, and sulfhydryl reagents) were effective inhibitors of glucose uptake. The strongest inhibitors were compounds (proton and metal ionophores) that interfere with maintenance of the proton motive force. Compounds which interfere with ATP synthesis also inhibited glucose uptake, but a role for ATP in energizing uptake could not be inferred from these results. Oxygen prevented glucose uptake (75% inhibition), reflecting possible active sulfhydryl centers (above) or autooxidation of electron transport components. The results suggest the fumarate reductase-coupled electron transport system of B. succinogenes can generate a proton motive force that is used to energize glucose uptake. Na+ and Li+. but not K+, stimulated glucose uptake and may partly account for the growth requirement of B. succinogenes for Na+. However, the data were insufficient to conclude that glucose uptake occurs by a Na+ symport mechanism. Spheroplasts of B. succinogenes transported glucose as well as whole cells, indicating glucose uptake is not dependent on a periplasmic glucose binding protein. A variety of sugars including the nonmetabolizable analog, [inversely proportional symbol]-methylglucoside. did not inhibit glucose uptake. Only cellobiose and 2-deoxyglucose were active and neither behaved as a competitive inhibitor. Metabolism of both sugars was probably responsible for the inhibition. Cellobiose-grcwn B. succinogenes showed a reduced ability to transport glucose compared to glucose-grown cells. This may indicate regulation of synthesis of the glucose carrier protein by cellobiose through a mechanism other than catabolite repression. Differences in the ability to transport glucose were detected between transition cells (transition from lag to log phase of growth) and log-phase cells. However, the differences were not due to different glucose transport mechanisms. Alterations in the structural integrity of the cell envelope, as reflected by osmotic- and cold-sensitivity features of transition and log cells, may have affected the glucose uptake abilities in these cell types.
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DEVILLARD, ESTELLE. "Enzymes fibrolytiques d'un protozoaire cilie du rumen, polyplastron multivesiculatum." Clermont-Ferrand 2, 2000. http://www.theses.fr/2000CLF22206.
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Le role des bacteries et des champignons dans la degradation des parois vegetales dans le rumen a ete largement demontre, mais celui des protozoaires n'a pu etre clairement etabli. Notre travail avait pour but d'etudier l'equipement fibrolytique d'un protozoaire cilie du rumen, par une approche moleculaire. Une banque d'adnc a ete construite, a partir de polyplastron multivesiculatum, et a ete criblee pour les activites xylanase et cellulase. Quatre clones ont ainsi ete isoles. Les adnc des clones xyna et xynd codent pour des xylanases de la famille 11. Le clone xynb exprime une enzyme constituee d'un domaine homologue aux domaines thermostabilisants et d'un domaine catalytique de xylanase (famille 10). Cela associe un domaine d'endoglucanase et un domaine de pectine methylesterase. Les 4 genes presentent les caracteristiques du genome des protozoaires (contenu en at tres eleve, usage des codons largement biaise). Xyna et xynb ont ete plus particulierement etudiees et l'origine de leur gene a ete prouvee. Des etudes phylogenetiques ont montre que xyna et xynb ont des homologies plus elevees avec les xylanases de bacteries a gram-positif qu'avec celles d'autres micro-organismes, suggerant un transfert horizontal de genes. Les parametres enzymatiques optimaux de xyna et xynb, exprimees chez e. Coli, ont ete mesures. Le domaine stabilisant de xynb ne participe que faiblement a la thermostabilite de l'enzyme, mais il deplace de 2 unites le ph optimal de l'enzyme et aurait un role dans sa stabilite au ph. Nous avons egalement montre que deux autres genres de protozoaires cilies du rumen expriment des genes homologues a ceux isoles de polyplastron multivesiculatum. Par ce travail, nous prouvons pour la premiere fois que les cilies du rumen possedent leur propre equipement fibrolytique et ont donc le potentiel enzymatique pour contribuer a la degradation des parois vegetales dans le rumen.
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Kinjet, Marc Philip. "Methane production from cows." Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273714.
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Aitchison, E. "A study of the removal of fibre from the rumen and voluntary intake of sheep eating hay diets." Thesis, University of Reading, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.353459.
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Batallas, Carlos Eduardo. "The Effects of Feeding a High Level of Rumen Protected Fat with Rumen Undegradable Protein With or Without Niacin on Rumen Fermentation Characteristics, Apparent Nutrient Digestibility, and Milk Production in the Early to Mid Lactation Holstein Cow." DigitalCommons@USU, 1992. https://digitalcommons.usu.edu/etd/4075.
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Forty high producing early to mid lactation Holstein cows were blocked according to stage of lactation and previous two-week milk yield (experiment 1) . Eight ruminally and duodenally cannulated nonlactating Holstein cows were used for experiment 2. The objective was to determine the effects of the ration's high fat content (11.53%) when rumen degradable or rumen undegradable protein is fed with or without added niacin. Cows received one of five treatments: 1) basal ration (TMR); 2) basal ration with added rumen undegradable fat (RUF) (1.6 kg); soybean meal (SBM) (1.73 kg), and niacin (12 g); 3) same as treatment 2, without niacin; 4) same as treatment 2 but replacing the soybean meal with undegradable protein (UIP) (1.9 kg ) ; and 5) same as treatment 4, without niacin. Rations and water were offered ad-libitum for 10 weeks. Intake for experiment 2 was limited to 18 kg TMR, 0 .76 kg RUF, 0 .88 kg SBM or UIP, and 6 g niacin. All cows in experiment 2 received the five treatments by the end of five collection periods separated by 21 d adaption. RUF increased dry matter intake (22.95 vs. 23 . 72 kg/d ) and mean body weight (607 vs. 637 kg ) , but decreased milk protein, lactose and SNF (proportion and yield); and 4% FCM without affecting daily milk yield. RUF, SBM, and N did not affect milk production. Milk protein percentage, protein yield, lactose percentage, SNF percentage, and yield were decreased by UIP supplementation. Niacin had a negative effect on milk fat percentage and yield, and milk protein percentage when fed with RUF and UIP . Supplements did not affect milk protein components. RUF increased plasma glucose (56.8 vs. 63.5). RUF addition increased AD and ND digestibility while decreased fatty acid digestibility. UIP improved ND digestibility in the lactation trial. For experiment 2, UIP increased rumen propionate percentage, thus reducing acetate to propionate ratio. Niacin increased total VFA production (128.6 vs. 114.3 umol/ml) . RUF, UIP, and niacin increased total bacterial population. RUF reduced cellulolytic bacteria in rumen fluid. Nutrient rate of passage and digestibility were unaffected by treatments except for dry matter and RUF digestibility that were reduced by RUF supplementation.
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Mackintosh, E. D. "The effect of monensin on in vitro rumen fermentation and in vivo rumen and total tract digestion and milk production in the dairy cow." Thesis, University of Reading, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265711.
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Gonçalves, Josemir de Souza [UNESP]. "Amido e fibra solúvel em detergente neutro em dietas para ovinos." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/104959.
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goncalves_js_dr_jabo.pdf: 576207 bytes, checksum: cfdaea1c27461a2cb51c7532f31b6d87 (MD5)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Os objetivos deste trabalho foram verificar os efeitos das relações amido:fibra solúvel em detergente neutro (FSDN) das dietas sobre os parâmetros ruminais, digestivos e de desempenho de ovinos Dorper x Santa Inês. As dietas foram caracterizadas pelas altas concentrações de amido (25%MS) ou de FSDN (25%MS) ou concentrações equivalentes destes nutrientes (18%amido+18%fibra solúvel na MS). No primeiro experimento foram utilizados seis borregos canulados ruminalmente, distribuídos em delineamento quadrado latino duplo (3 dietas x 3 períodos) para avaliação ruminal da concentração de amônia, pH e qualificação de massa microbiana. O segundo experimento avaliou o consumo, a digestibilidade total da matéria seca e dos nutrientes e os balanços de nitrogênio e energia das dietas experimentais, utilizando 15 borregos distribuídos em delineamento inteiramente casualizado. No terceiro experimento realizou-se um confinamento utilizando 24 borregos não castrados distribuídos em delineamento em blocos completos casualizados. Após 74 dias de confinamento os animais foram avaliados quanto ao ganho em peso, consumo, conversão e eficiência alimentar. Posteriormente foram abatidos e avaliados quanto ao peso de abate, características de carcaças e composição química do músculo Longissimus. Os valores de pH (6,29) não diferiam (P>0,05) entre as dietas enquanto que a maior concentração de amônia foi encontrada para a dieta com 25% de FSDN. Aproximadamente 60% dos microrganismos ruminais estavam associados a fase líquida, contudo as dietas não interferiram (P>0,05) na população microbiana ruminal. Elevados coeficientes de digestibilidade foram observados, independentementemente do tipo de carboidrato solúvel utilizado em maior proporção. O consumo de matéria seca foi menor para a dieta FSDN (1,075 kg) quanto comparado às demais dietas, afetando a maioria das variáveis...
The objective of this study was to evaluate the effects of dietary starch:neutral detergent soluble fiber (NDSF) relation on ruminal, digestibility and performance of Dorper x Santa Inês ram lambs. The diets were characterized by high concentrations of starch (25% DM) or NDSF (25% DM) or equivalent concentrations of these nutrients (18% starch +18% soluble fiber at MS). In the first experiment six lambs with ruminal cannula were used, distributed in Latin square design (3 diets x 3 periods) to assess ruminal ammonia concentration, pH and classification of microbes. The second experiment assessed intake, total digestibility of dry matter and nutrients and nitrogen balance and energy of diets, using 15 lambs distributed in a completely randomized design. In the third experiment ram lambs were distributed in a complete randomized block design. After 74 days of confinement all animals were evaluated weight gain, intake, feed conversion and efficience. Later were slaughter and evaluated by slaughter weight, carcass characteristics and Longissimus chemical composition. Average pH (6.29) did not differ (P>0.05) amoung diets while the highest concentration of ammonia was found for the diet with 25% of NDSF. Approximately 60% of ruminal microorganisms were associated with the liquid phase, however the diets did not affect (P>0.05) ruminal microbial populations. High digestibility coefficients were observed, regardless of the type of soluble carbohydrate used. Dry matter intake was lower (P<0.05) for NDSF (1.075 kg) compared to the other diets, affecting most of the performance variables. It is recommended the use of diets with 18% starch and 18% of fsdn to sheep fed high proportions of concentrate
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Lettat, Abderzak. "Efficacité et mode d'action des bactéries propioniques et / ou lactiques pour prévenir l'acidose latente chez le ruminant." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2011. http://tel.archives-ouvertes.fr/tel-00746197.
Full textAbstract:
L'acidose ruminale latente (ou acidose sub-clinique) est une préoccupation majeure pour la nutrition des ruminants à haut potentiel de production. Cet état se caractérise par une instabilité du microbiote et des fermentations ruminales qui s'orientent variablement vers le propionate et/ou le butyrate. L'une des stratégies de prévention de l'acidose latente consiste à distribuer dans l'alimentation des ruminants des probiotiques capables de rééquilibrer le microbiote et les fermentations ruminales (dans un sens favorable pour l'animal). L'analyse de la bibliographie montre toutefois que l'effet des probiotiques, et plus particulièrement des bactéries probiotiques (BP), est variable et parfois contradictoire ce qui serait probablement lié à l'instabilité du microbiote. Afin d'étudier la possibilité de prévenir l'acidose latente par les bactéries propioniques et/ou lactiques, nous avons émis l'hypothèse que leur efficacité dépend des orientations fermentaires dans le rumen. Des acidoses latentes butyrique et propionique caractérisées par des profils fermentaires et microbiens distincts ont été développées chez le mouton non productif et la vache laitière pour étudier l'effet et le mode d'action de la bactérie propionique P63 seule ou associée aux lactobacilles Lb. plantarum ou Lb. rhamnosus (P63, Lp + P63 et Lr + P63) sur le fonctionnement de l'écosystème ruminal et les performances animales. Chez le mouton en situation d'acidose propionique, les BP utilisées ont amélioré le pH ruminal via une réduction de la proportion en lactobacilles. Chez la vache laitière, la stabilisation du pH a été associée à une moindre disponibilité en hydrogène susceptible d'être transformé en protons, suite à une augmentation de la propionogenèse et/ou de la densité bactérienne, deux voies consommatrices d'hydrogène. Au cours de l'acidose latente butyrique, l'amélioration du pH n'a été observée que chez les moutons supplémentés avec Lp + P63. Cet effet semblait être dû à une diminution des acides gras volatils et de la proportion en S. bovis mais aussi à un pH initial faible (pH < 5,5) probablement optimal pour l'action des BP ; ce qui n'était pas le cas chez les vaches pour lesquelles le pH initial était compris entre 5,9 et 6,1. En revanche, l'efficacité digestive a été augmentée par l'association de P63 aux lactobacilles chez la vache laitière. L'association Lp + P63 a augmenté les activités fibrolytiques (cellulase, xylanase) et la digestibilité de la matière organique, tandis que Lr + P63 a amélioré la digestion des fibres et a diminué la production de méthane de 25%. Nous n'avons pas observé d'effet sur les performances zootechniques, ce qui serait probablement dû au dispositif expérimental en carré Latin qui n'est peut-être pas optimal pour mettre en évidence l'effet des BP. Nos résultats sont les premiers à démontrer l'efficacité des bactéries probiotiques pour sécuriser et/ou améliorer la digestion des rations et réduire la production de méthane chez le ruminant en acidose, et l'association de P63 avec les souches de Lactobacillus sont les plus efficaces. Enfin, nous avons validé notre hypothèse selon laquelle l'effet et le mode d'action des bactéries probiotiques pour prévenir l'acidose dépendent des orientations fermentaires dans le rumen.