• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 33
  • 13
  • 12
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 74
  • 74
  • 22
  • 19
  • 18
  • 13
  • 12
  • 11
  • 11
  • 10
  • 10
  • 10
  • 9
  • 9
  • 9
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Effects of feeding raw and roasted sunflower seeds on ruminal fermentation, nutrient utilization and milk production of dairy cows

Sarrazin, Pascale. January 2003 (has links)
No description available.
42

An appraisal of the equivalence of two media proposed for the isolation of cellulolytic rumen bacteria

Smith, Paul H. January 1955 (has links)
Two media proposed for the isolation of cellulolytic rumen bacteria were investigated. The inorganic medium containing rumen fluid gave greater total counts, greater cellulolytic counts, and a greater variety of morphological forms of cellulolytic rumen bacteria than the rich organic medium containing no rumen fluid. Cellulolytic bacteria were isolated in the inorganic medium which could not be subcultured in the rich organic medium. No cellulolytic bacteria were isolated in the rich organic medium which could not be subcultured in the inorganic medium containing rumen fluid. On the basis of the data obtained, it was concluded that under the conditions of the investigation the inorganic medium containing rumen fluid is superior to the rich organic medium for the culturing of cellulolytic rumen bacteria and for the culturing of the predominating fora of the rumen. / M.S.
43

Fermentation of uniformly labeled C14 glucose in vitro by micro-organisms of the bovine rumen

Newman, Jack Huff January 1959 (has links)
The present report describes a procedure developed for tracing C¹⁴ labeled glucose in rumen material in vitro. Twenty-five ml. samples of rumen fluid were incubated with uniformly labeled glucose for 1 1/2 hours in a closed system. The distribution of activity in both unfermented control samples and fermented samples was determined among protein and particulate material, ether extractable substances, amino acids and peptides, sugars and other neutral molecules, carbon dioxide, and methane. Samples were counted as barium carbonate following wet oxidation. Subsamples of the control and fermented samples indicated 80 to 85% recovery of C¹⁴. In these preliminary trials, additional losses were encountered among some individual fractions. Data indicated differences between fermentative activity of the two samples from different animals. In Trial I, 29% of 14 the fermented glucose C¹⁴ was recovered in the protein-particulate fraction, 15.6% in the carbon dioxide, and 10.5% in the ether extract. In Trial II, the ether extractable fraction contained 23.5% of the activity, 14.5% was recovered in the protein-particulate fraction, and 14.3% in the carbon dioxide. / M.S.
44

Ruminal degradability of subfractions of protein sources as determined by gel electrophoresis

Romagnolo, Donato 13 October 2010 (has links)
Degradability in the rumen of several protein sources was determined by suspending from 12 to 13 g of feedstuff in dacron bags into the rumen for 0, 2, 6, 12, 24, 36, 48, and 72 h. Rumen cannulated lactating Holstein cows consuming a diet of corn silage, alfalfa, soybean, and high moisture corn were used. Degradability of protein varied from 18.6% for corn gluten meal to 72.3% for soybean meal. Gel electrophoresis was used to monitor rates of degradation in the rumen of fractions of corn gluten (CGM), CORN, cottonseed (CSM), peanut (PM), and soybean meal (SBM) protein fractions. Fractional degradation rates in the rumen were determined from densitometric analysis of stained polypeptides bands on SDS-PAGE gels. Acidic subunits of soybean glycinin were degraded at a faster rate than basic subunits (.144 vs .104 h⁻¹). Rates of degradation of zein in corn and corn gluten meal were .026 and .015 h⁻¹, respectively. Protein degradability estimated by using B subfractional components did not differ from degradability measured using total B fractions. Lag phase associated with dacron bags suspension technique did not change effective degradability. Protein solubility in SDS-PAGE sample buffer was highly correlated (R²=.958) with in situ protein degradability of CORN, CSM, DBG, FM, PM, and SBM. Different rates of degradation of each fraction may directly influence protein and amino acid contribution to the animal. / Master of Science
45

Effects of ionophore antibiotics on rumen fermentation

Stucky, Steven Mark. January 1984 (has links)
Call number: LD2668 .T4 1984 S876 / Master of Science
46

RUMEN PASSAGE RATES AND FIBER DIGESTIBILITIES FOR WHEAT STRAW, ALFALFA HAY AND FLAKED SORGHUM GRAIN IN MIXED DIETS FOR STEERS

Poore, Matthew H. (Matthew Henry), 1959- January 1987 (has links)
No description available.
47

Avaliação de anticorpos policlonais em bovinos adaptados ou não à dietas com alta proporção de carboidratos prontamente fermentescíveis após indução à acidose / Evaluation of polyclonal antibodies in cattle adapted or not to diets with a high proportion of readily fermentable carbohydrates after induction of acidosis

Cassiano, Eduardo Cuelar Orlandi 17 December 2012 (has links)
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.
48

Quantificação de microrganismos ruminais de novilhos alimentados com cana-de-açúcar ou feno de tifton com diferentes relações volumoso:concentrado /

Ribeiro Júnior, Carlos Stefenson. January 2014 (has links)
Orientador: Telma Teresinha Berchielli / Coorientador: Roberta Carrilho Canesin / Banca: Márcia Helena Machado da Rocha Fernandes / Banca: Ricardo Andrade Reis / Banca: Otávio Rodrigues Machado Neto / Banca: Maria Fernanda Soares Queiroz / Resumo: Objetivou-se com este estudo caracterizar as alterações na microbiota ruminal, parâmetros ruminais, consumo, digestibilidade das dietas e a eficiência de síntese microbiana, em novilhos Nelore confinados alimentados com diferentes relações volumoso:concentrado, utilizando como fontes de volumoso o feno de Tifton 85 ou cana-de-açúcar. Foram realizados dois experimentos, no experimento 1 utilizou a cana-de-açúcar como fonte de volumoso e no experimento 2 utilizou-se o feno de tifton 85 como volumoso. Em ambos os experimentos foram testadas diferentes relações V:C (70:30; 60:40; 40:60 e 20:80). Em cada experimento, utilizaram-se oito novilhos Nelore (331±8 kg PV), cânulados no rumen, distribuídos em duplo quadrado latino 4x4 balanceados para o controle do efeito residual. No experimento 1 (cana-de-açúcar), o aumento da proporção de concentrado na dieta reduziu a população de Fibrobacter succinogenes e Ruminococus flavefaciens, e aumentou a população de Selenomonas ruminantium e Megasphaera elsdenii, porém o CDFDN não foi alterado. O aumento da participação de carboidratos não estruturais na dieta favoreceu a síntese de proteína microbiana e reduziu a população de bactérias fibrolíticas. A cana-de-açúcar como fonte de volumoso em dieta com proporções crescente de concentrado pode otimizar a síntese de proteína microbiana sem alterar digestibilidade da fibra. No experimento 2 (feno de Tifton 85), o aumento da proporção de concentrado na dieta reduziu a população de Fibrobacter succinogenes, Ruminococus flavefaciens e Ruminococcus albus e aumentou a população de Selenomonas ruminantium e Megasphaera elsdenii e Streptococcus bovis e o CDFDN diminuiu com o aumento da proporção de concentrado na dieta. Feno de Tifton 85 em dietas com altas proporções de concentrado pode minimizar o risco de distúrbios ruminais em novilhos confinados / Abstract: This trial aimed to characterize the changes in ruminal microbiota, ruminal fermentation, intake, diet digestibility and microbial efficiency in Nellore steers fed with different forage:concentrate proportions, using as sources of forage Tifton 85 hay or sugar cane. Two experiments were conducted: in experiment 1 the sugar cane was used as forage source and in Experiment 2 the Tifton 85 hay was used as forage source. In both experiments were tested different F:C proportions (70:30, 60:40, 40:60 and 20:80). On each experiment were usedeight Nellore steers ( 331 ± 8 kg BW) cannulated in the rumen, in a double latin square 4x4 balanced to control the residual effect. In experiment 1 (sugar cane), increasing the proportion of concentrate in the diet reduced the population of Fibrobacter succinogenes and Ruminococus flavefaciens, and increased the population of Selenomonas ruminantium and Megasphaera elsdenii, but the digestibility of NDF has not changed. The increased participation of non-structural carbohydrates in the diet favored microbial protein synthesis and reduced the population of fibrolytic bacteria. The use of sugar cane as forage source associated with the increases of concentrate proportions in the diet can optimize microbial protein synthesis without change the fiber digestibility. In experiment 2 (Tifton 85 hay), increasing the proportion of concentrate in the diet reduced the population of Fibrobacter succinogenes, Ruminococcus albus and Ruminococus flavefaciens and increased the population of Selenomonas ruminantium, Megasphaera elsdenii and Streptococcus bovis and the digestibility of NDF decreased when increases the proportion of concentrate in the diet. Tifton 85 hay in diets with high proportions of concentrate can minimize the risk of ruminal disorders in feedlot steers / Doutor
49

The Influence of Various Energy Sources on Microbial Protein Synthesis From Biuret as Determined by Artificial Rumen Fermentation

Eggleston, Jenny 01 May 1971 (has links)
Barley, cornstarch, crested wheatgrass, glucose, molasses and solka floc were fermented with rumen fluid obtained from sheep that were adapted or unadapted to feed grade biuret (Kedlor) in their diet. Each rumen fluid and substrate combination was subjected to three nitrogen treatments: (1) control, (2) nitrogen added as feed grade biuret and (3) reagent grade biuret in a factoral arrangement of treatments. In vitro fermentations were terminated at 0, 12, 24, and 36 hours and the protein nitrogen insoluble in trichloroacetic acid (TCA) was determined. Molasses and cornstarch fermentation residues increased while barley, crested wheatgrass, glucose and solka floc decreased in TCA insoluble protein nitrogen. The average of all treatments decreased in TCA insoluble protein nitrogen during the first 12 hours and increased during the remaining 24 hours. Unadapted rumen fluid with simple carbohydrates from glucose and molasses and adapted rumen fluid with complex carbohydrates from barley, crested wheatgrass, cornstarch and solka floc gave the largest gains in TCA insoluble protein nitrogen. No significant differences occurred due to the addition of non-protein nitrogen.
50

Rumen microbial degradation of diaminobutyric acid, a non-protein amino acid : thesis submitted for the degree of Doctorate of Philosophy in the University of Adelaide, South Australia / by Hai Hong Peng.

Peng, Hai Hong January 2003 (has links)
"January 2003" / Includes bibliographical references (leaves 172-204) / xx, 204 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Science, 2003

Page generated in 0.1042 seconds