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131.
An acute afebrile paretic condition was diagnosed in 16 of 100 feeder pigs between eight to ten weeks of age. Nine pigs died acutely and seven pigs were euthanized. Macroscopic lesions in the ventral horns of the cervical, thoracic, lumbar and sacral segments of the spinal cord consisted of focal, bilateral, grey depressed areas. There was a bilateral symmetrical focal poliomyelomalacia histopathologically characterized by microcavitation, endothelial and glial cell proliferation and infiltration of eosinophils. Clinical and pathological findings resemble spontaneous and experimental lesions associated with acute nicotinamide deficiency and selenium toxicosis in swine. 相似文献
132.
Arthur L Hattel Daniel P Shaw Jenny S Fisher Jason W Brooks Brenda C Love Thomas R Drake Donald C Wagner 《Journal of veterinary diagnostic investigation》2007,19(3):334-337
The necropsy records of 65 elk ranging from 1 day to 13(1/2) years of age were reviewed to determine the primary cause of death of each animal. The animal carcasses were submitted from 22 separate Pennsylvania elk farms over an approximately 8-year period. The most common causes of mortality in animals in which the cause of death was determined were gastrointestinal parasitism (21 cases), pneumonia (7 cases), enterocolitis (5 cases), malnutrition (5 cases), and rumenitis/acidosis (5 cases). The cause of death was undetermined in 4 of the 65 elk. Nematode organisms (20 cases) were the primary parasites identified in cases of mortality owing to gastrointestinal parasitism. Arcanobacterium pyogenes (3 cases), Escherichia coli (3 cases), and Streptococcus sp. (2 cases) were the most commonly isolated bacteria from the lung in the cases of pneumonia. Fungal organisms, consistent with Aspergillus sp. were present histologically within the pulmonary lesions in 5 cases. Bacterial agents associated with enterocolitis included Clostridium perfringens (2 cases), E. coli (1 case), Salmonella Newport (1 case) and Salmonella Thompson (1 case). The majority (56.3%) of the death loss in elk of known ages occurred in animals 1 year of age or less, with 71.4% of the gastrointestinal parasitism, 60.0% of the malnutrition, 60.0% of the enterocolitis, and 57.1% of the pneumonia cases occurring in animals within this age range. In conclusion, gastrointestinal parasitism, pneumonia, malnutrition, enterocolitis and rumenitis/acidosis were considered the most common causes of death in captive elk in this study. 相似文献
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134.
A major problem for small farmers in the semi-arid tropics is the chronic shortage of fodder for draft animals. Leucaena leucocephala has improved productivity in many places in India and in various cropping systems, usually as either a pure crop or in a
hedgerow alley-cropping configuration. Mixed cropping with arboreal forms is seldom seen. For off-season fodder production,
hedgerows have the disadvantage of being open to unmanaged browsing when unfenced (as is usual). Arboreal forms are generally
far less vulnerable.
In this paper, the components of production of sorghum and arboreal Leucaena are measured under different intensities of canopy lopping. The most productive management system of those examined was pollarding
of the Leucaena at the time of under-sowing with sorghum. In a year with less than 50% of average seasonal rainfall, this system gave a yield
of 4.6 tonnes/ha/yr fresh wt fodder and 3.8 tonnes/ha/yr dry wt. of fuel harvests, while increasing the standing crop of wood
by 1.8 t/ha/yr and retaining a yield of sorghum grain equivalent to 46% of pure sorghum cropping; the LER of this system was
1.35.
Cash values of the alternative management systems were estimated, including the discounted Net Present Value of the standing
crop of timber. Maximum value was attained with unlopped pure crop Leucaena followed by pollarded Leucaena with sorghum; pure crop sorghum achieved a lower value.
These results demonstrate both the high productivity of Leucaena/sorghum based systems, and the stability of production even in poor rainfall conditions. Pollarding transferred the high
future value of Leucaena timber to the present value of sorghum grain and fuelwood. 相似文献
135.
Growth of trees and seasonal yields of understory crops were measured over a 5-year period for 4 crops grown under 17 tree
species at 8 × 8 m spacing in wetland rice fields. All tree species grew well in rice fields, at rates comparable to their
growth in forest plantations. Top and root pruning reduced average tree girths by up to 19% and average tree volumes by up
to 41%, depending on intensity of pruning. The crops monitored were Oryza sativa, Triticum aestivum, Corchorus olotorius,
and Lens culinaris. Crop yields under the trees averaged 93% of the corresponding yields outside the tree canopy. The most
important factor affecting the yields of undercrops was tree size (height and/or girth). Differences among tree species and
the interaction with species of undercrops were not significant after controlling for tree size. Pruning of roots and branches
significantly improved crop yields under trees by amounts proportional to the intensity of root or top pruning.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
136.
Association Between ETFA Genotype and Activity of Superoxide Dismutase,Catalase and Glutathione Peroxidase in Cryopreserved Sperm of Holstein–Friesian Bulls
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The aim of this study was to determine whether C/T missense mutation within the ETFA gene is associated with sperm antioxidant enzymatic activity. One hundred and twenty Holstein–Friesian bulls were genotyped by the PCR‐RFLP technique (MwoI). Commercial straws of frozen‐thawed semen were used to evaluate the activity of three antioxidant enzymes: superoxide dismutase, catalase and glutathione peroxidase. Among all bulls investigated, genotype CT was the most frequent (44.2%), in comparison with CC (42.5%) and TT (13.3%). Significant differences in glutathione peroxidase activity were observed between homozygous individuals (CC vs TT) with heterozygous CT having intermediate values. Dismutase activity was significantly associated with ETFA genotype, although only bulls with the CT genotype were significantly different from bulls carrying the CC genotype. The activity of catalase showed a similar trend (but was not statistically significant). In conclusion, we found that bulls with the ETFA TT genotype produce sperm with the highest glutathione peroxidase activity and can therefore be more efficiently protected from reactive oxygen. The mechanism of this interaction needs to be elucidated in future research. 相似文献
137.
138.
Calcium (Ca) spray materials improved fruit quality as measured by control of bitter pit, fruit finish (appearance), increased red skin color, reduced incidence of scald, increased juiciness, texture, and fruit firmness of ‘Red’ and ‘Golden Delicious’ apples (Malus domestica, Borkh.). Concentrations of Ca in leaf and fruit tissues were increased by Ca sprays, especially calcium chloride (CaCl2)‐containing spray materials. Improved fruit firmness and control of bitter pit occurred for either standard recommended or high rates of Ca spray materials. At high rates of application, the only significant difference that occurred between early and late applications of Ca spray materials was that less leaf injury occurred with the early applications. Unsprayed ‘Red Delicious’ fruit from M.7 rootstocks had greater fruit peel Ca concentrations and a lower incidence of bitter pit but smaller fruit than fruit from trees on M.26 rootstocks. The above information is strong evidence that Ca sprays are important for the improvement of apple quality. 相似文献
139.
140.