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1.
Teeth from cattle, sheep, and horses that ingested various fluoride intakes and teeth from field studies of these species plus deer, elk, and bison were examined for abnormalities. Approximately 99,000 animals in 322 herds were examined for fluorosis. From field studies, 988 cattle of various ages and with different degrees of dental fluorosis were slaughtered and necropsied. The severity of fluoride-induced mottling, hypoplasia, and abnormal abrasion of paired permanent incisor teeth was correlated with abrasion of premolar and molar (cheek) teeth that form and mineralize at approximately the same age. Severe irregular wear of cheek teeth impaired mastication and resulted in poor utilization of feed and unthriftiness. Excessive amounts of fluoride during tooth formation and mineralization induce characteristic dental changes. Offspring from the fluoride-affected animals did not have discernible fluoride-induced lesions in the deciduous teeth.  相似文献   

2.
The objective of this study was to compare fatty acid weight percentages and cholesterol concentrations of longissimus dorsi (LD), semitendinosus (ST), and supraspinatus (SS) muscles (n = 10 for each) of range bison (31 mo of age), feedlot-finished bison (18 mo of age), range beef cows (4 to 7 yr of age), feedlot steers (18 mo of age), free-ranging cow elk (3 to 5 yr of age), and chicken breast. Lipids were analyzed by capillary GLC. Total saturated fatty acids (SFA) were greater (P < 0.01) in range bison than in feedlot bison and were greater (P < 0.01) in SS of range beef cattle than in feedlot steers. Muscles of elk and range bison were similar (P > 0.05) in SAT. In LD, polyunsaturated fatty acids (PUFA) were highest (P < 0.01) for elk and range bison and lowest (P < 0.01) for feedlot steers within each muscle. Range bison and range beef cows had greater (P < 0.01) PUFA in LD and ST than feedlot bison or steers, respectively. Range-fed animals had higher (P < 0.01) n-3 fatty acids than feedlot-fed animals or chicken breast. Chicken breast n-6 fatty acids were greater (P < 0.01) than for muscles from bison, beef, or elk. Elk had higher (P < 0.01) n-6 fatty acids than bison or beef cattle; however, range-fed animals had higher (P < 0.01) n-6 fatty acids than feedlot-fed animals in ST. Conjugated linoleic acid (CLA, 18:2cis-9, trans-11) in LD was greatest (P < 0.01) for range beef cows (0.4%), and lowest for chicken breast and elk (mean = 0.1%). In ST, CLA was greatest (P < 0.01) for range and feedlot bison and range beef cows (mean = 0.4%) and lowest for elk and chicken breast (mean = 0.1%). Also, SS CLA was greatest (P < 0.01) for range beef cows (0.5%) and lowest for chicken breast (0.1%). Mean total fatty acid concentration (g/100 g tissue) for all muscles was highest (P < 0.01) for feedlot bison and feedlot cattle and lowest (P < 0.01) for range bison, range beef cows, elk, and chicken. Chicken breast cholesterol (mg/100 g tissue) was higher (P < 0.01) than LD and ST cholesterol, which were lowest (P < 0.01; 43.8) for range bison and intermediate for the other species. Cholesterol in SS was highest (P < 0.01) for feedlot bison and steers, which were similar to chicken breast (mean = 61.2 vs 52.8 for the mean of the other species). We conclude that lipid composition of bison muscle varies with feeding regimen, and range-fed bison had muscle lipid composition similar to that of forage-fed beef cows and wild elk.  相似文献   

3.
Mycobacterium bovis infection in wild animals attracted little attention in Canada until the disease was almost eliminated from domestic livestock. Tuberculosis was endemic in plains bison and occurred in elk, moose, and mule deer in Buffalo National Park (BNP), Alberta during the 1920s and 1930s. Bison were moved from BNP to Wood Buffalo National Park (WBNP), where tuberculosis became, and remains, endemic in bison, posing a risk to efforts to restore bison in northern Canada. Tuberculosis was found in a white-tailed deer in Ontario in 1959, and in an infected elk near Riding Mountain National Park (RMNP), Manitoba in 1992. Intense surveillance has resulted in detection of 40 elk, 8 white-tailed deer, and 7 cattle herds infected between 1997 and 2008 in the RMNP area. The strains of M. bovis in the RMNP area are different from strains tested from cattle and bison elsewhere in Canada. Management of tuberculosis in cattle and wild animals is challenging because of uncertainty about the ecology of the disease in various species, difficulty in obtaining samples and population data from wildlife, lack of validated tests, overlapping jurisdictions and authority, and conflicting values and opinions among stakeholders.  相似文献   

4.
As the campaign to eradicate bovine brucellosis (Brucella abortus) and tuberculosis (Mycobacterium bovis) in Canadian livestock nears completion, the importance of extraneous sources of these diseases increases. This review summarizes the literature on brucellosis and tuberculosis in Canadian wildlife species to determine existing and potential hosts. Canadian caribou (Rangifer tarandus) are reservoirs of Brucella suis biotype 4 which is pathogenic in caribou, humans and muskoxen but reportedly nonpathogenic in livestock. Bison (Bison bison) and elk (Cervus canadensis) are significant reservoirs of B abortus and M. bovis. The bison in and around Wood Buffalo National Park have both diseases and are the only wildlife reservoir in Canada. Free-ranging elk are important reservoirs of brucellosis in Wyoming, and captive elk initiated the recent outbreak of bovine tuberculosis in 20 American states which has also involved bison and cattle herds. If bison and elk ranching continues to develop in Canada, the industry will have to be monitored to prevent the introduction and spread of infectious diseases like brucellosis and tuberculosis. This requires the evaluation and / or development of effective diagnostic methods for use in these animals.  相似文献   

5.
In September 1988, 100 of 300 yearling dairy heifers developed blindness, tachypnea, foaming at the mouth, chewing, and facial fasciculations. Twenty-five animals died. Lead toxicosis was diagnosed based on the clinical signs and the presence of excessive concentrations of lead in whole blood, liver, kidney, and rumen contents of affected animals. The source of the lead was sudan grass silage that had been contaminated by soil that contained up to 77,000 mg/kg of lead. Lead concentrations were determined approximately 7 months after the acute episode of lead toxicosis. Whole blood and milk samples were obtained from heifers and a group of control cows 2 weeks prior to (blood only), at the time of, and 2 and 4 weeks after freshening. No lead was found in any of the milk samples (detection limit = 0.055 mg/liter). Animals that had been severely affected by lead toxicosis experienced a transient increase in whole blood lead concentrations at freshening that was not high enough to be considered toxic. No similar increases in blood lead were observed for control cows or heifers that had experienced milder toxicosis. These findings suggest that at parturition lead is mobilized into the blood of cattle previously exposed to excessive lead.  相似文献   

6.
Chronic ingestion of excessive amounts of fluoride from commercial fox food is associated with agalactia in vixens resulting in the starvation deaths of large numbers of kits in three fox herds. Evidence of infectious disease or poor management could not be found and a causal relationship between fluoride and high kit mortality is suggested.  相似文献   

7.
CASE DESCRIPTION: 2 juvenile (17 and 19 months of age) male American bison (Bison bison) were examined because of acute bilateral hind limb weakness and ataxia; 1 animal also had urinary incontinence. TREATMENT AND OUTCOME: Given the clinical signs and rapid deterioration in the condition of these 2 animals, obtaining a definitive diagnosis was considered essential to minimizing the risk of disease in the remaining bison herd and among other animals at the facility. Therefore, both affected animals were euthanized. At necropsy, no gross abnormalities were seen. Histologic examination of sections of the brains from both animals revealed mild to moderate multifocal aggregates of eosinophils and mononuclear cells in perivascular regions of the meninges and gray matter of the cerebrum, cerebellum, and brainstem. Systematic examination of multiple sections of brain and spinal cord revealed evidence of nematode sections and aberrant parasite migration. CLINICAL RELEVANCE: Findings suggested that CNS migration of Parelaphostrongylus tenuis in American bison may cause clinical signs. These findings have implications for the management of captive bison and free-ranging bison sharing ranges with white-tailed deer (Odocoileus virginianus), the definitive host, and elk (Cervus elaphus canadensis).  相似文献   

8.
The objectives of this analysis were to estimate historic (pre-European settlement) enteric CH(4) emissions from wild ruminants in the contiguous United States and compare these with present-day CH(4) emissions from farmed ruminants. The analysis included bison, elk (wapiti), and deer (white-tailed and mule). Wild ruminants such as moose, antelope (pronghorn), caribou, and mountain sheep and goat were not included in the analysis because their natural range is mostly outside the contiguous United States or because they have relatively small population sizes. Data for presettlement and present-day population sizes, animal BW, feed intake, and CH(4) emission factors were adopted from various sources. Present-day CH(4) emissions from livestock were from recent United States Environmental Protection Agency estimates. The most important factor determining CH(4) emissions from wild ruminants in the presettlement period was the size of the bison population. Overall, enteric CH(4) emissions from bison, elk, and deer in the presettlement period were about 86% (assuming bison population size of 50 million) of the current CH(4) emissions from farmed ruminants in the United States. Present-day CH(4) emissions from wild ruminants (bison, elk, and deer) were estimated at 0.28 Tg/yr, or 4.3% of the emissions from domestic ruminants. Due to its population size (estimated at 25 million), the white-tailed deer is the most significant present-day wild ruminant contributor to enteric CH(4) emissions in the contiguous United States.  相似文献   

9.
Serum samples from 2,539 cattle, 649 sheep, 123 goats, 413 pigs, 93 bison, and 56 elk from Montana were examined for antibody to Toxoplasma gondii in the Sabin-Feldman dye test or the modified agglutination test (MAT). Cattle, bison, and elk serum samples were treated with 0.2 M-mercaptoethanol before examination in MAT. In the dye test, 13.2% of sheep, 5.0% of pigs, and 22.7% of goats had antibody at a dilution of greater than or equal to 1:16. In the MAT, 3.2% of cattle, 3.1% of bison, and none of the elk were positive at a dilution of greater than or equal to 1:128.  相似文献   

10.
Foot-and-mouth disease (FMD) is caused by an RNA virus of the genus Aphthovirus; 7 immunologically distinct serotypes of the virus have been identified. Susceptible species are mainly domestic and wild even-toed ungulates, such as cattle, sheep, goats, pigs, bison, and deer. All body fluids of infected animals can contain the virus and are considered infective. The primary mode of transmission is animal-to-animal transmission through inhalation or ingestion of aerosols containing the virus. The virus can also be spread mechanically by contaminated organic debris and fomites and can survive for 48 hours on human oral and nasal mucosa and be spread to uninfected animals in this manner. There is a rapid progression of clinical signs after an animal becomes infected, and the virus spreads rapidly throughout a herd. Clinical signs include excessive salivation; fever; vesicles and erosions of the oral and nasal mucosa, coronary band, interdigital area, and teats; lameness; sloughing of claws; reluctance to move; anorexia; mastitis; decreased milk production; and abortion or weak newborns. In mature animals, FMD has high morbidity and low mortality rates. Infected animals can become inapparent carriers of the virus.  相似文献   

11.
氟对奶山羊红细胞影响的研究   总被引：1，自引：1，他引：0  
氟是机体所必需的微量元素，各种器官内均含有氟，大部分分布在硬组织如骨骼和牙齿中。但过量的氟吸收进入体内可引起多种组织细胞和器官的损害。红细胞作为机体血液循环含量最多的血细胞，有必要深入探讨过量氟化物对红细胞损害的机制，为揭示过量氟导致动物贫血及全身性损害提供有力的证据。  相似文献   

12.
Tissues (1 kg) from sheep, goats, cattle, moose, bison, or elk naturally infected with Sarcocystis species were fed to one to four Sarcocystis-free coyotes and the number of sporocysts in feces and intestines were counted. All 12 coyotes fed naturally infected tissues shed Sarcocystis in feces, with a prepatent period of 9 to 15 days. The four coyotes fed infected beef had 15, 25, 113, and 201 million sporocysts in their feces and intestines. The coyotes fed elk, moose, or bison had 2.5, 15, and 2.5 million sporocysts in their intestines, respectively. Sporocysts in feces of coyotes fed musculature of cattle, sheep, goats, and elk were structurally similar to those described previously from the feces of dogs. This is evidently the first report of the completion of life cycle of Sarcocystis species in moose and bison. Cross-transmission experiments indicated that one species of goat Sarcocystis completes its life cycle in both dog and coyote and that the ovine Sarcocystis is not transmissible to goats.  相似文献   

13.
A commercial feed concentrate and a mineral mix with excessive amounts of fluoride were introduced into a Holstein dairy herd with an average milk production well above national standards. Milk production decreased drastically, and during the following 6 years the deficit in milk production in the herd ranging from 52 to 120 milking cows was 1.5 million Kg (3 1/4 million lbs.). The tolerance levels set by the National Academy of Sciences for fluoride ingestion by lactating cow were found to be inadequate.  相似文献   

14.
氟是动物机体的必需微量元素,适量的氟有利于骨骼、牙齿的生长,过量的氟则会引起机体慢性全身性中毒,主要影响骨骼、牙齿的正常生长,另外对消化系统、生殖泌尿系统、神经系统、内分泌系统和免疫系统也产生中毒影响。作者从氟中毒机制的国内外研究现状和进展出发,就过量氟化物对动物机体的影响进行综述,以期为动物氟中毒病相关研究提供参考。  相似文献   

15.
In an attempt to establish a primate model of chronic cadmium (Cd) toxicosis, we ovariectomized cynomolgus monkeys and treated with CdCl2 by repeated intravenous injections for 13 to 15 months. The animals showed an increase in blood glucose from Month 10 and a decrease in blood insulin at Month 11of the Cd-treatment. Histopathological examination of the Cd-treated animals revealed islet atrophy with reduction in islet number and vacuolation of the islet cells, whereas there was no remarkable change in the acinar cells of the exocrine pancreas. In histomorphometrical examination, insulin-positive areas in the islets were significantly decreased, accompanying a relative increase of glucagon-positive areas. Large amounts of Cd accumulated in the pancreas, and metallothionein (MT), a Cd binding protein, was localized in the islets of Cd-treated animals. The present study demonstrated that the chronic intravenous injection of Cd to cynomolgus monkeys induced the accumulation of the metal in the pancreas, degeneration of islet B cells and the diabetic clinical signs. Therefore the islet B cell is one of the major targets of the chronic Cd poisoning in monkeys.  相似文献   

16.
Wildlife causes extensive crop damage throughout much of North America and these shared feeds are a key risk factor in the transmission of diseases between wildlife and livestock, including bovine tuberculosis (TB). Predicting wildlife use of agricultural crops can provide insight directed toward targeted disease mitigation at areas of potential indirect interaction. In this study, we quantified use of hay bales by elk (Cervus canadensis) during the winter in southwestern Manitoba, Canada using a database of 952 damage claims paid compensation from 1994 to 2012. We evaluated environmental factors predicted to determine risk of hay bale damage on each quarter section by elk using a Resource Selection Probability Function (RSPF) model. The most important variables (as measured for each quarter section and based on cumulative Akaike weights that scale from 0 to 1) were distance to protected areas (1.00), forest including a buffer around the quarter section (1.00), forage crop including a buffer around the quarter section (1.00), distance from streams (0.99), forage crop (0.92), cereal and oilseed crop cover including a buffer (0.85), and forest cover (0.82). We then developed an RSPF-based predictive map of damage to hay bales by elk that identified key areas with high probability of damage (RSPF ≥ 0.6), accounting for 3.5% of the study area. We then multiplied the RSPF values by the inverse of the proximity to known cases of TB positive elk and determined that 0.51% of the study area had an overall high combined probability of hay bale damage and proximity to TB positive elk (i.e. adjusted probability of ≥0.6). In the southern half of the study area where 164 hay yard barrier fences have been implemented since 2002, there has been a significant decrease in the number of annual claims. Barrier fencing around Riding Mountain National Park has been successful at reducing elk damage where it has been implemented. In our study area, prevalence of TB in both cattle (0.003%) and elk (0.89%) is very low, precluding conventional epidemiological analyses. In the absence of clear evidence of specific routes of TB transmission, we advocate that on-farm risk assessments and mitigation efforts should continue to address areas where elk cause damage to hay bales in winter using barrier fencing. Mitigation effort should especially focus on areas where TB positive elk have been identified, as these sites provide potential for indirect interaction between cattle and elk.  相似文献   

17.
Mycoplasma bovis was identified by a specific lesion, conventional bacterial culture, immunohistochemistry, and polymerase chain reaction in 2 feedlot bison found dead with severe, chronic, caseonecrotic pneumonia; polyarthritis; and laryngitis. On microscopic examination, pulmonary lesions were characterized by prominent, well-defined areas of caseous necrosis and bronchiectasis. Immunohistochemical analysis of lung exhibited staining in bronchiolar epithelium and in random areas of caseous necrosis. On gross examination, the laryngeal lesion observed in 1 animal was typical of changes seen in cases of calf diphtheria. Nasal swabs taken from 6 clinically ill bison from the same feedlot revealed 1 animal shedding M. bovis by the nasal route. No other pathogens were recovered from the pulmonary or laryngeal lesions; however, Mannheimia haemolytica was cultured from the nasal swabs of 2 clinically ill bison, although not from the animal found to be shedding M. bovis. Several other affected bison had swollen joints and exhibited lameness and a reluctance to move. Changes observed in dead and clinically ill bison from this feedlot are similar to what has been described in the literature as chronic pneumonia and polyarthritis syndrome in feedlot cattle caused by M. bovis. Based on the severity of the lesions, and the number of dead and affected animals, bison in a feedlot setting appear to exhibit sensitivity to infection with M. bovis.  相似文献   

18.
The effects of management practices on the spread and impact of parasites and infectious diseases in wildlife and domestic animals are of increasing concern worldwide, particularly in cases where management of wild species can influence disease spill-over into domestic animals. In the Greater Yellowstone Ecosystem, USA, winter supplemental feeding of Rocky Mountain elk (Cervus elaphus) may enhance parasite and disease transmission by aggregating elk on feedgrounds. In this study, we tested the effect of supplemental feeding on gastrointestinal parasite infection in elk by comparing fecal egg/oocyst counts of fed and unfed elk. We collected fecal samples from fed and unfed elk at feedground and control sites from January to April 2006, and screened all samples for parasites. Six different parasite types were identified, and 48.7% of samples were infected with at least one parasite. Gastrointestinal (GI) nematodes (Nematoda: Strongylida), Trichuris spp., and coccidia were the most common parasites observed. For all three of these parasites, fecal egg/oocyst counts increased from January to April. Supplementally fed elk had significantly higher GI nematode egg counts than unfed elk in January and February, but significantly lower counts in April. These patterns suggest that supplemental feeding may both increase exposure and decrease susceptibility of elk to GI nematodes, resulting in differences in temporal patterns of egg shedding between fed and unfed elk.  相似文献   

19.
A 1-month-old Jersey calf died of oxalate nephropathy. The calf had access to antifreeze (ethylene glycol) 3 days prior to death. Since ethylene glycol toxicosis had not been reported in cattle, the effects or oral administration of ethylene glycol were studied in 7 calves and 3 cows. The toxic dose ranged from 2 to 10 ml of ethylene glycol per kg of body weight. Clinical signs were increased respiration, staggering gait, paraparesis, depression and later, recumbency and death. Hemoglobinuria and epistaxis were seen at doses of 10mg/kg of body weight. Azotemia, hypocalcemia and neutrophilia were constant findings whereas acidosis, plasma hyperosmolality and hemolytic anemia were seen in the animals receiving the higher doses. A diagnosis of ethylene glycol toxicosis must be based upon a history of ingestion and the presence of calcium oxalate crystals in body tissues (especially the kidney and brain).  相似文献   

20.
SUMMARY Chronic fluoride toxicosis caused lameness, dental lesions and illthrift in an extensive beef cattle herd in northern Australia. Up to 15% of the herd was lame and the disease forced the culling of large numbers of cows. The source of fluoride was fertiliser-grade monoammonium and diammonlum phosphate fed as part of a mineral supplement. Large quantities of mineral supplement were provided to the cattle because lameness was attributed to phosphorus deficiency, which is endemic in the area. Most lameness developed in the late dry season in the post-lactation phase. Severe lameness was caused by fractured pedal bones.  相似文献   

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