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81.
Chaffin MK Cohen ND Martens RJ 《Journal of the American Veterinary Medical Association》2003,222(4):467-475
OBJECTIVE: To identify farm characteristics as risk factors for the development of Rhodococcus equi pneumonia in foals. DESIGN: Prospective matched case-control study. ANIMALS: 2,764 foals on 64 equine breeding farms with 9,991 horses. PROCEDURE: During 1997, participating veterinarians completed paired data collection forms, 1 for a farm with > or = 1 foal with R equi pneumonia and 1 for an unaffected control farm. Matched data were compared by use of conditional logistic regression analysis. RESULTS: Farm characteristics found in bivariate analyses to be associated with increased risk for pneumonia caused by R equi in foals included > 200 farm acres, > or = 60 acres used in the husbandry of horses, > 160 horses, > or = 10 mares housed permanently on the farm (resident mares), > 17 foals, > 0.25 foals/acre, and the presence of transient mares (mares brought temporarily to the farm for breeding or foaling) and their foals. Affected farms were significantly more likely to be > 200 acres in size and have > or = 10 resident dam-foal pairs, whereas control farms were significantly more likely to have > or = 75% of their dam-foal pairs housed permanently on the farm. CONCLUSIONS AND CLINICAL RELEVANCE: Breeding farms with large acreage, a large number of mares and foals, high foal density, and a population of transient mares and foals are at high risk for foals developing pneumonia caused by R equi. 相似文献
82.
Influence of fibrolytic enzymes on the hydrolysis and fermentation of pure cellulose and xylan by mixed ruminal microorganisms in vitro 总被引:3,自引:0,他引:3
Colombatto D Mould FL Bhatt MK Morgavi DP Beauchemin KA Owen E 《Journal of animal science》2003,81(4):1040-1050
A series of in vitro studies was conducted to determine the effects of adding a commercial enzyme product on the hydrolysis and fermentation of cellulose, xylan, and a mixture (1:1 wt/wt) of both. The enzyme product (Liquicell 2500, Specialty Enzymes and Biochemicals, Fresno, CA) was derived from Trichoderma reesei and contained mainly xylanase and cellulase activities. Addition of enzyme (0.5, 2.55 and 5.1 microL/g of DM) in the absence of ruminal fluid increased (P < 0.001) the release of reducing sugars from xylan and the mixture after 20 h of incubation at 20 degrees C. Incubations with ruminal fluid showed that enzyme (0.5 and 2.55 microL/g of DM) increased (P < 0.05) the initial (up to 6 h) xylanase, endoglucanase, and beta-D-glucosidase activities in the liquid fraction by an average of 85%. Xylanase and endoglucanase activities in the solid fraction also were increased (P < 0.05) by enzyme addition, indicating an increase in fibrolytic activity due to ruminal microbes. Gas production over 96 h of incubation was determined using a gas pressure measurement technique. Incremental levels of enzyme increased (P < 0.05) the rate of gas production of all substrates, suggesting that fermentation of cellulose and xylan was enzyme-limited. However, adding the enzyme at levels higher than 2.55 microL/g of DM failed to further increase the rate of gas production, indicating that the maximal level of stimulation was already achieved at lower enzyme concentrations. It was concluded that enzymes enhanced the fermentation of cellulose and xylan by a combination of pre- and postincubation effects (i.e., an increase in the release of reducing sugars during the pretreatment phase and an increase in the hydrolytic activity of the liquid and solid fractions of the ruminal fluid), which was reflected in a higher rate of fermentation. 相似文献
83.
84.
The methanol extract of Butea monosperma seeds, tested in vitro, showed significant anthelmintic activity. 相似文献
85.
86.
Hypoglycemic activity of Nymphaea stellata leaves ethanolic extract in alloxan induced diabetic rats
The ethanolic extract of leaves of Nymphaea stellata given by oral route to diabetic rats at dose of 100 and 200 mg/kg/day for seven days reduced significantly by 31.6 and 42.6 % the plasma glucose level increased by intraperitoneal injection of 120 mg/day of alloxan. Moreover, the treatment significantly affected the plasma level of cholesterol and triglyceride. 相似文献
87.
The essential oil of Aristolochia indica, containing beta-caryophyllene and alpha-humulene as major constituents, was found to show a moderate antibacterial activity. 相似文献
88.
九龙山自然保护区黄山木兰群落结构特征及其优势种群结构 总被引:1,自引:0,他引:1
对浙江省九龙山国家级自然保护区黄山木兰(Magnolia cylindrica)的群落结构特征以及种群结构进行了调查研究。结果表明:黄山木兰群落植被具有热带向温带过渡的性质;群落主要伴生种为多脉青冈(Cyclobalanopsis multinervis);该群落具有明显的中亚热带常绿阔叶林特征,以高位芽占绝对的优势,叶的特征以中叶、纸质的单型叶为主;群落成层现象明显,可分为乔木层、灌木层和草本层;群落物种丰富度、多样性、均匀度都偏低;种群结构呈纺锤型,幼苗数量严重不足,种群有衰退的趋势;种群格局呈集群分布。 相似文献
89.
90.