排序方式： 共有19条查询结果，搜索用时 0 毫秒
1.
D T Campbell J Maas D W Weber O R Hedstrom B B Norman 《American journal of veterinary research》1990,51(5):813-817
One hundred fifty Se-deficient, pregnant, crossbred beef cows were assigned to 1 of 4 treatment groups: group A, Se-deficient control; group B, 1 Se bolus at 0 and 119 days; group C, 1 Se bolus at 0 days; and group D, 2 Se pellets at 0 days. The Se bolus is an osmotic pump designed to release 3 mg of Se/d into the reticulorumen. The Se pellets weight approximately 30 g and contain 10% elemental Se, which is liberated in the reticulorumen. The Se bolus is designed to provide Se supplementation for 120 days and the Se pellets provide supplementation for up to 18 months. Cattle were maintained on Se-deficient pasture or forages prepared from these pastures for the duration of the experiment. Blood samples were collected from cows prior to treatment (time 0) and at 28, 52, 119, and 220 days thereafter and analyzed for blood Se (BSe) concentration. Body weights were recorded at each sampling time. Blood Se concentration of cows from all supplemented groups were significantly (P less than 0.01) higher than control values at all sample dates after treatments began. By the end of the 220-day study, treatment group-B cattle had significantly (P less than 0.01) higher BSe concentrations than any other group. Body weights of treatment groups fluctuated throughout the study, but did not differ (P greater than 0.05) between groups. One cow and 6 calves born to cows during the experimental period died. Necropsy of 5 calves provided no evidence linking these deaths to treatments.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
2.
3.
4.
Andreasen CB Hedstrom OR Allison P 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》1993,22(2):54-59
A 31-kg mediastinal mass from a 24-year-old horse is described. Cytologic imprints contained numerous spindle cells with indistinct cytoplasm and multiple foci of palisading nuclei. Histologic sections had these same characteristics and areas of central fibrillar material between palisading nuclei (Verocay bodies). Within histologic sections, spindle cell cytoplasm had positive immunoreactivity for vimentin and S-100, whereas immunoreactivity was not detected for desmin and cytokeratin. Cytologic, histologic, and immunochemical evaluation confirmed a diagnosis of solitary schwannoma. 相似文献
5.
Turkey poults were fed a vitamin D-deficient diet and examined for clinical signs and structural changes of bone and parathyroid glands. Vitamin D-deficient poults developed ricketic changes during days 10 to 14. Control poults (deficient diet plus vitamin D) did not develop rickets. In deficient poults, lengths of proliferating-prehypertrophied zones of growth plates increased significantly in the proximal tibiotarsus but were only slightly elongated in the distal tibiotarsus. Unmineralized hypertrophic chondrocyte zones increased in length rapidly in conjunction with a decrease in the length of mineralized hypertrophic degenerative zones; this occurred more rapidly in proximal than in distal tibiotarsus. Other ricketic changes included decreases in bone ash, total femoral bone ash (calcium, phosphorus, magnesium), bone length, and body weight. Plasma alkaline phosphatase was increased, calcium was normal, and phosphorus was normal or elevated. Parathyroids were hyperplastic and had foci of degeneration. Vitamin D3 metabolites 25OHD3, 1,25(OH)2D3, and 24,25(OH)2D3 were rapidly depleted. Increase in bone ash Ca/P ratios in deficient poults suggests that phosphorus may be selectively released from ricketic bone. Low 25OHD3 and 1,25(OH)2D3 of control poults early in the experiment suggests that 1,400 IU of vitamin D3/kg of feed may not be an adequate level of vitamin D3 for growing turkey poults. 相似文献
6.
Aloisio C.D. Bueno Med Vet MS Barbara J. Watrous DVM Jill E. Parker VMD Olaf R. Hedstrom DVM Phd 《Veterinary radiology & ultrasound》2000,41(6):551-553
A 5-year-old Hereford cow was donated to Oregon State University, College of Veterinary Medicine. Two weeks before presentation the cow was treated by a left-flank laparotomy to correct a uterine torsion that revealed an excessive amount of abdominal fluid and a full term dead fetus. Ultrasonographic evaluation of the right cranioventral thoracic cavity was performed owing to physical examination (muffled heart sounds, areas of silence) and thoracocentesis findings suggestive of pleuritis. Ultrasonography revealed hypoechoic pleural effusion and a mass of mixed echogenicity visible within the right atrial lumen extending into the cranial vena cava. A diagnosis of cranial vena cava thrombosis was demonstrated at necropsy. The clinical, ultrasonographic, and pathological features of this less common condition (cranial vena cava thrombosis) in cattle are discussed. 相似文献
7.
A 2.5% mortality rate was observed in a flock of 19,000 commercial one-day-old broiler chicks that had been placed 24 hours previously on litter treated with ferrous sulfate heptahydrate. Ulcerative ventriculitis and severe hepatopathy were the primary lesions observed grossly and microscopically. Pooled digesta contained 6854 ppm iron. Lesions identical to those found in the field case were reproduced experimentally. 相似文献
8.
B D Hultgren E G Pearson E D Lassen B J Watrous O R Hedstrom 《Journal of the American Veterinary Medical Association》1986,189(7):797-798
A conifer twig was responsible for severe fibrinopyogranulomatous adhesive pleuritis and pneumonia in a horse. At necropsy, the twig was found in a terminal bronchus and extended into the lung parenchyma, through the pleura, and into the accumulated exudate. Inhalation of plant material may be a more common cause of pleuritis than previously recognized. Meticulous examination at necropsy would be necessary to make the diagnosis. 相似文献
9.
M. C. Marra A. S. Kezis S. M. Goltz W. E. Hedstrom R. D. Hews 《American Journal of Potato Research》1987,64(5):249-260
The economic value of potato yield and quality response to supplemental irrigation were shown to be dependent on the potato cultivar and the market destination. The results of on-farm tests in Aroostook County, Maine indicate the value of this response ranged from — $257.18 to $1057.46 per hectare in 1985. The annual variable and ownership costs, excluding the value of management time, of center pivot irrigation systems were estimated to be from $226.67 to $387.02 per hectare in 1985 and were found to be dependent on the long-term system plans of the producer as well as on the standard components of cost. The managers’ time commitment was found to be quite large both in the planning stages and in the first year operation of the systems. 相似文献
10.
High mortality in 1-week-old commercial turkey poults was attributed to the accidental substitution of dicalcium phosphate in the diet for corn. At necropsy of the affected birds, lesions were observed in the upper gastrointestinal tract, suggesting acute ingestion of a caustic substance. Mortality and gross and microscopic lesions were reproduced experimentally in turkey poults fed diets similar to the diet fed in the field case. The cause of these lesions was attributed to increased pH due to the phosphoric acid content of the diet. 相似文献