The Experts below are selected from a list of 27366 Experts worldwide ranked by ideXlab platform
Evan C. Titgemeyer - One of the best experts on this subject based on the ideXlab platform.
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Ruminal Acidosis in Beef Cattle: The Current Microbiological and Nutritional Outlook
Journal of Dairy Science, 2007Co-Authors: Tiruvoor G. Nagaraja, Evan C. TitgemeyerAbstract:Ruminal acidosis continues to be a common ruminal digestive disorder in beef Cattle and can lead to marked reductions in Cattle performance. Ruminal acidosis or increased accumulation of organic acids in the rumen reflects imbalance between microbial production, microbial utilization, and ruminal absorption of organic acids. The severity of acidosis, generally related to the amount, frequency, and duration of grain feeding, varies from acute acidosis due to lactic acid accumulation, to subacute acidosis due to accumulation of volatile fatty acids in the rumen. Ruminal microbial changes associated with acidosis are reflective of increased availability of fermentable substrates and subsequent accumulation of organic acids. Microbial changes in the rumen associated with acute acidosis have been well documented. Microbial changes in subacute acidosis resemble those observed during adaptation to grain feeding and have not been well documented. The decrease in ciliated protozoal population is a common feature of both forms of acidosis and may be a good microbial indicator of an acidotic rumen. Other microbial factors, such as endotoxin and histamine, are thought to contribute to the systemic effects of acidosis. Various models have been developed to assess the effects of variation in feed intake, dietary roughage amount and source, dietary grain amount and processing, step-up regimen, dietary addition of fibrous byproducts, and feed additives. Models have been developed to study effects of management considerations on acidosis in Cattle previously adapted to grain-based diets. Although these models have provided useful information related to ruminal acidosis, many are inadequate for detecting responses to treatment due to inadequate replication, low feed intakes by the Experimental Cattle that can limit the expression of acidosis, and the feeding of Cattle individually, which reduces Experimental variation but limits the ability of researchers to extrapolate the data to Cattle performing at industry standards. Optimal model systems for assessing effects of various management and nutritional strategies on ruminal acidosis will require technologies that allow feed intake patterns, ruminal conditions, and animal health and performance to be measured simultaneously in a large number of Cattle managed under conditions similar to commercial feed yards. Such data could provide valuable insight into the true extent to which acidosis affects Cattle performance.
G M Murphy - One of the best experts on this subject based on the ideXlab platform.
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studies on the pathogenesis of bovine ephemeral fever in Experimental Cattle iii virological and biochemical data
Veterinary Microbiology, 1992Co-Authors: M F Ure, T Sai D George, G M MurphyAbstract:Uren, M.F., St. George, T.D. and Murphy, G.M., 1992. Studies on the pathogenesis of bovine ephemeral fever in Cattle. III. Virological, and biochemical data in Experimental Cattle. Vet. Microbiol., 30: 297-307. In an attempt to define the nature of the response of Cattle to ephemeral fever infection, a number of indicators of inflammation were monitored during clinical disease. The total Ca, Zn, Fe, Cu, glucose and phosphate in plasma, together with blood ammonia, were assayed relative to changes in the rectal temperature. CaT levels fluctuated markedly and hypocalcaemia occurred in 4 of 8 Cattle. Plasma Zn and Fe values fell while plasma Cu levels rose markedly in all Cattle. Mean levels of serum NH 3 of 20-30/tmol 1- ' rose to a peak value of 56 #moll- '. Plasma glucose levels rose to a peak of 4.6 + 0.5 mMl- ~ and the plasma phosphate levels fell from 2.4 + 0.1 mM1- l to 1.17 + 0.2 mM1- ~ during fever. Values of pCO2 fell from a mean of 46.9 + 3.6 mmHg to 36.4 + 3.1 mmHg and coincided with a rise in pH. Virus was isolated 73 h ( + 23 ) after inoculation and persisted until 130 h ( + 21 ). The common role of these parameters in generalised inflammation and ephemeral fever is discussed.
Tiruvoor G. Nagaraja - One of the best experts on this subject based on the ideXlab platform.
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Ruminal Acidosis in Beef Cattle: The Current Microbiological and Nutritional Outlook
Journal of Dairy Science, 2007Co-Authors: Tiruvoor G. Nagaraja, Evan C. TitgemeyerAbstract:Ruminal acidosis continues to be a common ruminal digestive disorder in beef Cattle and can lead to marked reductions in Cattle performance. Ruminal acidosis or increased accumulation of organic acids in the rumen reflects imbalance between microbial production, microbial utilization, and ruminal absorption of organic acids. The severity of acidosis, generally related to the amount, frequency, and duration of grain feeding, varies from acute acidosis due to lactic acid accumulation, to subacute acidosis due to accumulation of volatile fatty acids in the rumen. Ruminal microbial changes associated with acidosis are reflective of increased availability of fermentable substrates and subsequent accumulation of organic acids. Microbial changes in the rumen associated with acute acidosis have been well documented. Microbial changes in subacute acidosis resemble those observed during adaptation to grain feeding and have not been well documented. The decrease in ciliated protozoal population is a common feature of both forms of acidosis and may be a good microbial indicator of an acidotic rumen. Other microbial factors, such as endotoxin and histamine, are thought to contribute to the systemic effects of acidosis. Various models have been developed to assess the effects of variation in feed intake, dietary roughage amount and source, dietary grain amount and processing, step-up regimen, dietary addition of fibrous byproducts, and feed additives. Models have been developed to study effects of management considerations on acidosis in Cattle previously adapted to grain-based diets. Although these models have provided useful information related to ruminal acidosis, many are inadequate for detecting responses to treatment due to inadequate replication, low feed intakes by the Experimental Cattle that can limit the expression of acidosis, and the feeding of Cattle individually, which reduces Experimental variation but limits the ability of researchers to extrapolate the data to Cattle performing at industry standards. Optimal model systems for assessing effects of various management and nutritional strategies on ruminal acidosis will require technologies that allow feed intake patterns, ruminal conditions, and animal health and performance to be measured simultaneously in a large number of Cattle managed under conditions similar to commercial feed yards. Such data could provide valuable insight into the true extent to which acidosis affects Cattle performance.
M F Ure - One of the best experts on this subject based on the ideXlab platform.
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studies on the pathogenesis of bovine ephemeral fever in Experimental Cattle iii virological and biochemical data
Veterinary Microbiology, 1992Co-Authors: M F Ure, T Sai D George, G M MurphyAbstract:Uren, M.F., St. George, T.D. and Murphy, G.M., 1992. Studies on the pathogenesis of bovine ephemeral fever in Cattle. III. Virological, and biochemical data in Experimental Cattle. Vet. Microbiol., 30: 297-307. In an attempt to define the nature of the response of Cattle to ephemeral fever infection, a number of indicators of inflammation were monitored during clinical disease. The total Ca, Zn, Fe, Cu, glucose and phosphate in plasma, together with blood ammonia, were assayed relative to changes in the rectal temperature. CaT levels fluctuated markedly and hypocalcaemia occurred in 4 of 8 Cattle. Plasma Zn and Fe values fell while plasma Cu levels rose markedly in all Cattle. Mean levels of serum NH 3 of 20-30/tmol 1- ' rose to a peak value of 56 #moll- '. Plasma glucose levels rose to a peak of 4.6 + 0.5 mMl- ~ and the plasma phosphate levels fell from 2.4 + 0.1 mM1- l to 1.17 + 0.2 mM1- ~ during fever. Values of pCO2 fell from a mean of 46.9 + 3.6 mmHg to 36.4 + 3.1 mmHg and coincided with a rise in pH. Virus was isolated 73 h ( + 23 ) after inoculation and persisted until 130 h ( + 21 ). The common role of these parameters in generalised inflammation and ephemeral fever is discussed.
T Sai D George - One of the best experts on this subject based on the ideXlab platform.
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studies on the pathogenesis of bovine ephemeral fever in Experimental Cattle iii virological and biochemical data
Veterinary Microbiology, 1992Co-Authors: M F Ure, T Sai D George, G M MurphyAbstract:Uren, M.F., St. George, T.D. and Murphy, G.M., 1992. Studies on the pathogenesis of bovine ephemeral fever in Cattle. III. Virological, and biochemical data in Experimental Cattle. Vet. Microbiol., 30: 297-307. In an attempt to define the nature of the response of Cattle to ephemeral fever infection, a number of indicators of inflammation were monitored during clinical disease. The total Ca, Zn, Fe, Cu, glucose and phosphate in plasma, together with blood ammonia, were assayed relative to changes in the rectal temperature. CaT levels fluctuated markedly and hypocalcaemia occurred in 4 of 8 Cattle. Plasma Zn and Fe values fell while plasma Cu levels rose markedly in all Cattle. Mean levels of serum NH 3 of 20-30/tmol 1- ' rose to a peak value of 56 #moll- '. Plasma glucose levels rose to a peak of 4.6 + 0.5 mMl- ~ and the plasma phosphate levels fell from 2.4 + 0.1 mM1- l to 1.17 + 0.2 mM1- ~ during fever. Values of pCO2 fell from a mean of 46.9 + 3.6 mmHg to 36.4 + 3.1 mmHg and coincided with a rise in pH. Virus was isolated 73 h ( + 23 ) after inoculation and persisted until 130 h ( + 21 ). The common role of these parameters in generalised inflammation and ephemeral fever is discussed.
