| an immunoprecipitin study of the incidence of influenza a antibodies in animal sera in the ottawa area. | a survey of over 600 'normal' sera from 14 animal species by immunoprecipitin tests in cellulose acetate using viron antigens revealed a high incidence of precipitating activity against a broad range of influenza a virus strains, particularly a2hhong kong/1/68 and /pr8. however, serum treatments trypsin-heat-periodate, naio4, v. cholerae receptor-destroying enzyme (rde), or kaolin eliminated most precipitating activity, which suggests that it was due to "non-specific" inhibitors of influenze vir ... | 1975 | 167931 |
| corynebacterium equi lymphadenitis in ontario cattle. | | 1979 | 466639 |
| the rates and patterns of survivorship and disease in a university dairy herd. | the rates and patterns of disease occurrence and survivorship were determined over a six year period in a university operated dairy herd. of the ten diseases selected for study, clinical mastitis occurred most frequently with an incidence rate of 10.1% and displaced abomasum occurred least frequently with an incidence rate of 4.4%. the occurrence of all disease except those of the ovary was associated with the age of the cow. mastitis, pneumonia and cystic graafian follicles tended to reoccur in ... | 1979 | 509376 |
| the gross and histopathologic lesions of maignant catarrhal fever in three captive sika deer (cervus nippon) in southern ontario. | the gross and histopathologic lesions of three captive sika deer (cervus nippon) with malignant catarrhal fever are described. lesions included those of the head and eye form and the more commonly described peracute form. one deer had been exposed to a wildebeeste (connochaetes gnou) and the other two to domestic sheep. | 1977 | 557117 |
| tissue pathology and comparative microanatomy of onchocerca from a resident of ontario and other enzootic onchocerca species from canada and the u.s.a. | the microanatomy of one male and one female specimen of a zoonotic onchocera sp in a fibrous nodule excised from the wrist of an ontario resident, two bovine onchocerca from saskatchewan and manitoba, canada, and o. cervicalis from the ligamentum nuchae of a horse in georgia, u.s.a., were compared. in dimensions and cuticular morphology, the three canadian specimens of onchocera shared certain features and closely resembled both o. cervicalis and o. gutturosa. the number of cuticular striae in s ... | 1977 | 596957 |
| the prevalence of serum antibodies to toxoplasma gondii in ontario mammals. | the prevalence of seropositive reactions to toxoplasma gondii was studied in farm animals, companion animals, wild rodents and birds. of the animals tested, 17% of cattle, 65% of sheep, 45% of pigs, 9% of horses, 33% of dogs and 20% of cats were seropositive by the sabin-feldman dye test. in addition 11% of mice (mus musculus), 5% of deer mice (peromyscus), 3% of rats (rattus norvegicus) and less than 2% of sparrows (passer domestcus) were seropositive. all samples from short-tailed field mice ( ... | 1978 | 667705 |
| brucellosis in ontario: a case control study. | data from cattle herds infected with brucellosis and from control (noninfected) herds were collected and analyzed using case control techniques. it appeared that herds located close to other infected herds and those herds whose owners made frequent purchases of cattle had an increased risk of acquiring brucellosis, particularly those who made purchases from other herds or from cattle dealers. infected herds had a lower level of vaccination than noninfected herds. however, the percentage vaccinat ... | 1976 | 826309 |
| bovine mastitis in ontario due to mycoplasma agalactiae subsp. bovis. | bovine mastitis caused by mycoplasma agalactiae subsp. bovis was first diagnosed in 16 of 55 cows in an ontario herd in feburary 1972. a total of 182 of 598 (30.4%) cows from 33 of 64 (51.5%) farms in widely separated areas of the province were culturally positive. herd incidence varied from 15 to 40% with one closed herd having an incidence of 61%. four herds were investigated culturally and serologically by the growth inhibition test for 15 months. in the acute phase the organism was present i ... | 1976 | 1000385 |
| insecticide and nutrient transport in water, related to agricultural land use of a stream basin in ontario, canada. | transport by stream water of insecticides and nutrients in big creek, norfolk county, ontario, canada, was examined by combining concentrations of substrates with flow data. big creek has its headwaters in dairy cattle country, its central basin area is mainly devoted to tobacco growing, and its lower reaches contain mixed farming, corn and vegetables, etc., before it flows into lake erie. three sampling sites were chosen to represent these 3 different land uses. generally concentrations of subs ... | 1976 | 1015861 |
| ddt in watershed draining the tobacco belt of southern ontario. | | 1975 | 1063713 |
| a survey of vertebral abscesses in domestic animals in ontario. | | 1975 | 1131789 |
| a short incubation serum neutralization test for bovine viral diarrhea virus. | a three day serum neutralization (sn) test for the detection of antibodies to bovine viral diarrhea virus (bvdv), which is an improvement on the existing five day test, is described. the improved test results in a more rapid viral cytopathic effect and utilizes madin darby kidney (mdbk) cells, and horse serum as a medium supplement. a comparison of tests utilizing the nadl and the singer strains of bvdv and the use of either secondary bovine kidney cells with calf serum (bkcs) or continuous mdbk ... | 1992 | 1317246 |
| patterns of stillbirth and dystocia in ontario cow-calf herds. | the association between a number of individual animal and herd level factors and calving problems in beef cows and heifers were examined. data were from the 1987 calving season for a subset of 123 herds which maintained individual-animal records, from a sample of 180 randomly selected ontario cow-calf herds. the median herd dystocia rate was 5.8% and 24.4% of herds had no dystocias. the median herd stillbirth rate was 2.8%, and 33.3% of herds had no stillbirths. dystocias and stillbirths were mu ... | 1992 | 1586893 |
| culling practices of ontario cow-calf producers. | this study describes the distribution of herd culling rates for 123 ontario cow-calf herds maintaining individual animal records. associations between culling and factors at both the individual and herd level were examined. in addition, the relative importance of individual animal and herd level influences on culling were investigated. the following individual cow culling risk factors: nonpregnancy, age, weaning weight index, calf outcome, abortion, prolapsed vagina, prolapsed uterus, calving in ... | 1992 | 1586894 |
| associations between dairy production indices and lipoarabinomannan enzyme-immunoassay results for paratuberculosis. | data from an epidemiological study in ontario, involving 304 dairy herds, were used to identify associations between selected production indices and lipoarabinomannan antigen serological test results for paratuberculosis (lam-elisa). analyses were conducted at both the herd and individual cow levels of organization. after analytically controlling for management and cow factors in the respective regression models, positive serological paratuberculosis status (as defined by the lam-elisa test), wa ... | 1991 | 1790492 |
| prevalence of verocytotoxigenic escherichia coli in ground beef, pork, and chicken in southwestern ontario. | samples of ground beef (225), pork (235) and chicken (200) were randomly selected from meat processing plants in the southwestern ontario area. supernatants of broth cultures of the samples were tested for verocytotoxins using a vero cell assay. neutralization of cytotoxic activity using antisera specific for three types of verocytotoxin (verotoxin 1, verotoxin 2 and shiga-like toxin ii) was performed on positive samples. isolation of verocytotoxigenic escherichia coli (vtec) was attempted from ... | 1990 | 2200697 |
| pcb and dde residues in milk supplies of ontario, canada 1985-1986. | | 1989 | 2500993 |
| the associations between milk production, milk composition and salmonella in the bulk milk supplies of dairy farms in ontario. | the purpose of this study was to assess changes in dairy herd milk production and milk composition associated with changes in salmonella contamination of bulk milk on dairy farms in southwestern ontario. twenty-three dairy farms that had submitted milk filters for culture from which salmonella were isolated (cases) and 23 farms that submitted salmonella-negative milk filters (controls) were included in the study. the rolling herd averages for milk and fat of case and control farms for the months ... | 1989 | 2713783 |
| aspects of the epidemiology of nematode infections in a cow-calf herd in ontario. | on may 29, 1980, 108 cows and calves were placed on a 20 hectare pasture until october 26, except that from september 18 to october 2 they were in a barn. every two weeks during the total period, fecal samples were taken from 17 cows and 14 calves and herbage samples were collected from the pasture. parasite fecal egg counts were estimated using the cornell-wisconsin centrifugation technique and herbage infective larvae by a modified sandwich technique. daily maximum and minimum air temperature ... | 1989 | 2766154 |
| the frequency, distribution and effects of antibodies, to seven putative respiratory pathogens, on respiratory disease and weight gain in feedlot calves in ontario. | during 1983-85, 279 calves requiring treatment for bovine respiratory disease and 290 comparison (control) animals from 15 different groups of feedlot calves were bled on arrival and again at 28 days postarrival. their sera were then analyzed for antibodies to seven putative respiratory pathogens. on arrival, the prevalences of indirect agglutination titers to pasteurella haemolytica, p. haemolytica cytotoxin, mycoplasma bovis and m. dispar were greater than 50%, the prevalence of titers to bovi ... | 1989 | 2766158 |
| factors associated with the presence of salmonella spp. in dairy farm families in southwestern ontario. | | 1988 | 2856842 |
| bovine reservoir for verotoxin-producing escherichia coli o157:h7. | | 1987 | 2879192 |
| an epidemiological study of selected calf pathogens on holstein dairy farms in southwestern ontario. | fecal samples from calves on 78 randomly selected holstein dairy farms in southwestern ontario were screened for salmonella, campylobacter jejuni/coli, enteropathogenic escherichia coli, rotavirus and coronavirus. based on the observed prevalence, 22% of farms had calves infected with salmonella, 13% with campylobacter jejuni/coli, 41% with enteropathogenic e. coli, 19% with rotavirus and 5% with coronavirus. these estimates can be modified, using a method developed by mullen and prost (1983) fo ... | 1986 | 3017528 |
| monitoring wood shaving litter and animal products for polychlorophenols residues, ontario, canada, 1978-1986. | | 1988 | 3130916 |
| the presence of listeria spp. in raw milk in ontario. | raw milk samples from bulk tanks in ontario were analyzed for the presence of listeria species. the overall incidence of listeria species in raw milk was 12.4%. listeria innocua was most frequently isolated and was found in 9.7% (43/445) of the raw milk samples, while l. monocytogenes and l. welshimeri were each found in 1.3% (6/445) of the samples. no other species of listeria was found. of five regions in ontario that were examined, the eastern region had a significantly higher incidence rate ... | 1988 | 3135930 |
| an epidemiological study of paratuberculosis in ontario dairy cattle: study design and lipoarabinomannan antigen elisa test results. | | 1988 | 3232609 |
| isolation of leptospira hardjo from kidneys of ontario cattle at slaughter. | kidneys from 117 cattle from 110 ontario farms were examined at slaughter for leptospires. leptospira hardjo (hardjo-bovis a) was isolated from 11 kidneys and l. kennewicki from one. the isolations were all made (12/89, 13.5%) from beef cattle from feedlots, no isolates being obtained from dairy or beef cattle from extensive farms (0/28). isolations were only made from cattle with antibody titers (greater than or equal to 20) against the serovars recovered. isolation was more sensitive than immu ... | 1987 | 3300922 |
| the prevalence, incidence, geographical distribution, antimicrobial sensitivity patterns and plasmid profiles of milk filter salmonella isolates from ontario dairy farms. | the prevalence, incidence and geographical distribution of salmonella on dairy farms in southwestern ontario were determined by culturing bulk milk filters from 511 randomly selected dairy farms. milk filters from 22 farms (2.9%) were salmonella-positive, with a cumulative incidence rate of 9.0% per year. positive farms were distributed throughout southwestern ontario, but were regionally clustered. the serotype, biotype, antimicrobial sensitivity pattern and plasmid profile of the salmonella is ... | 1988 | 3349397 |
| serosurvey on the occurrence of coxiella burnetii in ontario cattle. | | 1988 | 3355970 |
| infant feeding practices: 1984-85 versus 1977-78. | in 1979 and 1980 the canadian paediatric society's nutrition committee published guidelines for professionals counselling mothers of infants on feeding practices. the practices in 1984-85 of mothers in toronto were determined for comparison with the practices identified in a similar study conducted in toronto and montreal in 1977-78 to ascertain if practices had changed in favour of the recommendations. between july 1984 and february 1985, 404 metropolitan toronto mothers of infants were intervi ... | 1987 | 3567809 |
| a path model of factors influencing morbidity and mortality in ontario feedlot calves. | the principles of path analysis and causal modelling are discussed. path analysis was applied to three data sets to assess the relationship between group characteristics (number per group and "mixing" subgroups of cattle, feeding-management of the group and processing factors (vaccination and prophylactic antimicrobials) and subsequent morbidity and mortality in feedlot cattle. the major findings agree with previously reported results but the timing and pathways of the effects are elaborated. in ... | 1986 | 3742352 |
| the relationship among current management systems, production, disease and drug usage on ontario dairy farms. | the study involved 110 randomly selected dairy farms located in the ontario, canada counties of bruce, grey, huron, oxford, perth, waterloo and wellington. herds were classified as "intensive" and "extensive". on extensive farms, data were collected at the herd level only, while on intensive farms, data were recorded at both the individual animal and herd level. data collection continued for approximately two and one-half years. at each visit, technicians collected production data from the most ... | 1986 | 3742360 |
| susceptibility of psychrotrophic pseudomonads of milk origin to psychrotrophic bacteriophages. | a total of 47 psychrotrophic pseudomonads isolated from raw milk came from newfoundland (19 isolates), british columbia (6 isolates), ontario (19 isolates), and cork, ireland (3 isolates). the susceptibility of these was tested against 30 bacteriophages isolated from cold-storage beef. distinct lysotypes were observed with isolates representing different geographic regions. phages as agents in the control of bacterial populations in milk is discussed. | 1986 | 3954353 |
| correlation of bedrock type with the geography of leptospirosis. | leptospirosis occurs enzootically over most of southern ontario. leptospira pomona is the serotype most commonly found in outbreaks. antibodies to l. pomona occur frequently in the sera of deer in wilderness areas. the geographic location of leptospirosis presents a pattern which closely parallels the distribution of paleozoic bedrock. by contrast, l. pomona infection is absent from areas underlain by precambrian bedrock. comparisons of water chemistry, soil type, habitat, and host and pathogen ... | 1970 | 4246001 |
| trypanosomes in cattle in southern ontario. | trypanosomes were found in the blood of 155 out of 274 holstein cows of various ages from southern ontario. the incidence varied from about 8% in one herd to about 85% in another herd. two species of trypanosomes were found in cattle in the guelph area. one was trypanosoma theileri. the other was a much smaller trypanosome which morphologically resembles t. uniforme of the salivaria. this is the first report of such a trypanosome in cattle in north america. epimastigotes from blood agar slants o ... | 1970 | 4246837 |
| the isolation of trypanosomes from cattle in ontario. | a method for the recovery by blood culture of a t. theilieri-like flagellate from cattle is described. in ontario, 54% of 156 cows in 15 herds were found to have parasitemia. | 1971 | 4254891 |
| abomasal nematodes in cattle in ontario. | during 1970, 93 abomasa from cattle in ontario were examined, and from 63 of these abomasa nematode species of the genera ostertagia, haemonchus and/or trichostrongylus axei were recovered. the abomasa were from cattle six months to two years of age and were collected either from the postmortem room at the ontario veterinary college or from two abattoirs near guelph. the numbers of worms per abomasum were estimated and their genera were identified from a one-twentieth volume of the washings and ... | 1974 | 4272952 |
| overwintering of bovine gastrointestinal nematodes in southwestern ontario. | several steers, reared in isolation until approximately six months of age, were placed on a small isolated enclosed pasture from late spring to late fall of 1970, 1971 and 1972. the pasture was left vacant and unused during the winters and early springs. the pasture had been used in previous years by cattle, and in the late spring of 1970 was grazed by cattle know to be passing gastrointestinal nematode eggs in their feces. the steers were slaughtered periodically, and the prevalence of nematode ... | 1974 | 4272963 |
| epidemiological investigations on dictyocaulus viviparus (bloch, 1782) infection in cattle. | | 1970 | 4275423 |
| drug resistance among pathogenic bacteria from animals in ontario. | prevalence of antimicrobial drug resistance among over 3000 clinical isolates of animal pathogens in ontario during 1971-72 has been studied. a high number of multiple resistance patterns is prevalent among members of enterobacteriaceae, especially escherichia coli and salmonella typhimurium. the most common resistance pattern among bovine strains was against not less than six drugs in common use. among different animal species the bovine population was found to be the source of a high percentag ... | 1974 | 4277443 |
| infectious bovine rhinotracheitis--clinical, pathological, and virological aspects. | | 1966 | 4287716 |
| the veterinary requirements of the animal industry in ten years time. | | 1974 | 4434316 |
| ddt and dieldrin in watersheds draining the tobacco belt of southern ontario. | | 1974 | 4462708 |
| bovine tuberculosis in humans in ontario. the epidemiologic features of 31 active cases occurring between 1964 and 1970. | | 1972 | 4627829 |
| parasitisms in domesticated animals in ontario. i. ontario veterinary college records 1965-70. | | 1973 | 4688875 |
| gastrointestinal parasites in cattle in ontario. | | 1973 | 4699612 |
| disease trends in domestic animals and poultry in ontario 1971-72. | | 1973 | 4711498 |
| a survey of calves treated for calf diarrhea at the ontario veterinary college 1966-1971. | | 1973 | 4769615 |
| an outbreak of cysticercosis in feedlot cattle. | | 1974 | 4857011 |
| isolation of listeria monocytogenes from brain specimens of domestic animals in ontario. | | 1971 | 5005795 |
| left abomasal displacement: an epidemiological study. | | 1972 | 5016928 |
| case report. dermatophilus skin infection in nine-day-old calves. | | 1970 | 5463902 |
| infectious thromboembolic meningoencephalitis in ontario feedlot cattle. | | 1970 | 5464268 |
| serodiagnosis in q fever with special emphasis on the radioisotope precipitation test. | | 1968 | 5691056 |
| rabies today--man and animals. | | 1969 | 5812488 |
| case report. a mastitis problem in a dairy herd. | | 1969 | 5815591 |
| a note on selenium contents of two leguminous forage species collected in ontario and the possible incidence on selenium-responsive diseases. | | 1969 | 5816710 |
| serum transaminase activity in calves affected by nutritional muscular dystrophy in northern ontario. | | 1967 | 6068867 |
| approaches to immunization of infants and young children against gastroenteritis due to rotaviruses. | recent studies have shown that in developed countries rotaviruses are the single most important etiologic agents of acute gastroenteritis that requires hospitalization of infants and young children. although deaths from gastroenteritis are, in general, infrequent in the developed countries, an effective rotavirus vaccine would clearly be of benefit to reduce the heavy toll of morbidity from gastroenteritis due to rotavirus. in the developing countries the impact of diarrheal diseases is staggeri ... | 1980 | 6251528 |
| susceptibility of goats and calves after experimental inoculation or contact exposure to a canadian strain of mycoplasma mycoides subsp. mycoides isolated from a goat. | transmissibility of mycoplasma mycoides subsp. mycoides infection from experimentally inoculated goats to other goats and calves was studied. eight goats and six calves were housed in an 18 m2 room. six of the goats were inoculated endobronchially with strain d44 isolated from a natural case of polyarthritis in ontario. these six goats died within a week of mycoplasma septicemia. the two contact goats or the six calves never showed signs of disease and m. mycoides subsp. mycoides was not recover ... | 1983 | 6365296 |
| listeria monocytogenes infections in canada. | since its first isolation by murray in 1926 listeria monocytogenes has become recognized as a significant pathogen occurring worldwide and involving a wide range of wild and domestic animals including man. the first confirmed human listeriosis case in canada was published by stoot in 1951. a later survey based on records maintained at the laboratory centre for disease control, ottawa showed 101 cases detected over a 21 year period in nine provinces. the overall mortality was 30%. the most freque ... | 1984 | 6442654 |
| factors influencing morbidity and mortality in feedlot calves in ontario. | | 1983 | 6612961 |
| subclinical ketosis: prevalence and associations with production and disease. | cows in 32 southern ontario holstein herds were monitored for subclinical ketosis for a period of two and one half years. milk samples were routinely collected and the level of milk ketone bodies determined by the use of a commercial nitroprusside based test powder (reactions scored as negative, +1 or +2). approximately 92% of positive reactions were observed in the first 65 days of lactation and for that time period the prevalence of ketosis was 12.1%. based on this prevalence, the minimum poss ... | 1984 | 6713247 |
| fatal mastitis of dairy cows: a retrospective study. | the necropsy records of dairy cows with mastitis were reviewed from the provincial veterinary laboratory in guelph (44 cases of mastitis in nine years) and from the ontario veterinary college (168 cases in 14 years). mastitis was considered to be the primary cause of death in 167 of 212 cows (79%). of these 167 cases of mastitis, escherichia coli was involved in 107 (64%), klebsiella sp. in 12 (7%) and staphylococcus aureus in 11 (7%). bacteriology was not reported in 22 cases. coliform mastitis ... | 1984 | 6722641 |
| characterization of strains of corynebacterium bovis. | the biochemical and morphological characteristics of 104 strains of corynebacterium bovis isolated from bovine milk samples and the c. bovis reference strain were found to be uniform. valuable criteria for identification were presence of catalase and oxidase, production of acid from glucose and fructose and a requirement for enriched basal media. six strains of human and three strains of bovine origin were found to be inconsistent with the reference strain. | 1984 | 6722650 |
| antibody titers to pasteurella haemolytica a1 in ontario beef cattle. | indirect bacterial agglutination titers to pasteurella haemolytica a1 were determined in serum, thoracic, pericardial, or peritoneal fluid from cattle necropsied as part of the bruce county beef project in 1979-80 and 1980-81. antibody titers were also assayed in serum from 84 calves on entry to feedlots in the fall of 1979. titers on entry were low compared to antibody levels at necropsy. cattle which died with pneumonia, in particular those dying of fibrinous pneumonia (shipping fever), had lo ... | 1982 | 6756619 |
| evaluation of cow reproduction in the pureline foundation phase of the canadian national dairy cattle breeding project. | five reproduction traits--number of inseminations per cow, days to first estrus, days open, calving interval, and culling rate for infertility--were studied on dairy cows from a long-term breeding project of the agriculture canada research branch. five experimental farms maintained either holstein line, ayrshire line, or both. traits were analyzed within each line by a model in which station, year, sire group (paternal parentage), and bull (cow's mate) were considered. variation these factors ca ... | 1983 | 6682866 |
| somatic cell counts: associated factors and relationship to production. | factors affecting somatic cell counts and the association between somatic cell counts and milk production were evaluated. data were collected from 748 ontario dairy herd improvement corporation supervised herds that were on production and somatic cell count programs between april 1981 and march 1983. two data files were created; one, the lactation summary file, contained one record per cow on each of 9406 holsteins and the other, the test day file, included results of all tests during the comple ... | 1984 | 6478296 |
| occurrence of "haemophilus somnus" in bovine semen and in the prepuce of bulls and steers. | haemophilus somnus was isolated from 40 of 79 unprocessed bovine semen samples, 14 of 23 preputial washings of bulls and three of eight preputial washings of steers. the results indicate nonvenereal colonization of the male urogenital tract. it is suggested that dissemination of h. somnus from the urogenital tract may be of significance in the epizootiology of h. somnus associated diseases. | 1982 | 7093816 |
| hyperbilirubinemia in sick cattle. | hyperbilirubinemia was present in 387 out of 1279 sick cattle admitted to the clinic of the ontario veterinary college. one hundred and ninety five of these had a total serum bilirubin of 17 mumol/l or greater. clinical records, laboratory data and when available, pathology reports from these 195 animals were examined in an attempt to explain the reason for the high bilirubin levels. the hyperbilirubinemia in 187 of these was mainly due to an increase in unconjugated bilirubin. jaundice, liver d ... | 1984 | 6478294 |
| factors associated with mortality and treatment costs in feedlot calves: the bruce county beef project, years 1978, 1979, 1980. | three years of data on factors associated with death losses and health costs in ontario feedlot calves were analyzed. the results support the previously reported findings; however, significant differences in the third year (1980-81) of the study were noted. calf groups that were "mixed" after arrival in the feedlot or had a larger than average number of calves (means = 142) had increased death losses and health costs. calf groups whose ration was changed from dry hay to hay silage or corn silage ... | 1982 | 7172100 |
| somatic cell counts, mastitis and milk production in selected ontario dairy herds. | somatic cell counts were performed monthly on bulk tank milk samples for all producers in the ontario counties of hastings, lennox/addington and prince edward throughout 1978 and 1979. other data were obtained via a structured questionnaire and from the records of the ontario milk marketing board. many producers have not adopted practices that have been advocated for the integrated control of mastitis. for example, 43.3% of producers surveyed used single service paper towels, 63.3% regularly use ... | 1982 | 7200385 |
| a field trial, of preshipment vaccination, with intranasal infectious bovine rhinotracheitis-parainfluenza-3 vaccines. | a total of 849 calves, 278 controls, 335 vaccinated intranasally with ibr-pi3/ts and 236 vaccinated intranasally with ibr-pi3/ptc were studied in a field trial of preimmunization. all calves were vaccinated in saskatchewan at least three weeks prior to shipment to feedlots. four hundred and twenty six calves were not sold within eight weeks of vaccination; however, seven of these died within four weeks of vaccination. treatment rates varied from 1.0% to 5.2%. there was no significant effect of v ... | 1983 | 6315194 |
| a mail survey of factors associated with morbidity and mortality in feedlot calves in southwestern ontario. | the design and results of a mail survey of a simple random sample of southwestern ontario feedlot owners are presented. the survey provided general data about management of feedlot calves and the association between a number of factors and disease and/or death rates. the number of calves purchased was related positively, in a linear manner, to mortality and morbidity rates. increased levels of morbidity and mortality were noted when the ration was changed to corn silage from dry-hay within the f ... | 1983 | 6309344 |
| reproductive efficiency and calf survival in ontario beef cow-calf herds: a cross-sectional mail survey. | a survey of the efficiency of production of ontario beef cow-calf herds was conducted using a stratified systematic random sample of ontario producers. in general, about 87% of females exposed to breeding produced a live calf and 6% of these died before reaching four weeks of age. the herd to herd variation in these rates was quite large, the coefficient of variation being about 17%. the stillbirth rate was 1.7% and the abortion rate 1.2%. in general, herds in northern ontario and herds whose ow ... | 1985 | 3986678 |
| incidence rates of cystic follicles in holstein cows according to 15-day and 30-day intervals. | cystic ovarian follicles occurred in 198 out of 1599 (12.4%) ontario holstein lactations. these occurrences were grouped by date of diagnosis into 15-day and 30-day intervals after calving, and only open cows were considered. the incidence rates for the 15-day intervals form zero to 150 days of lactation varied form 0.2% to 3.5%; the highest rate was 31 to 45 days. the incidence rates for the 30-day intervals from zero to 210 days of lactation varied form 1.4% to 6.8%, depending on the method of ... | 1981 | 7261593 |
| a mail survey of the efficacy of prophylactic medication in feed and/or water of feedlot calves. | a mail survey of feedlot owners was conducted to evaluate the efficacy of prophylactic antimicrobials, given in the water, or in the ration at preventing illness and/or death. one hundred and twenty-seven farmers from southwestern ontario collaborated in the study. the percentage of calves requiring individual antimicrobial treatment, for any reason within 28 days of arrival was 22.6% (median 17.8%) and 0.6% (median 0.2%) died in that period. the use of medicated starter rations was not associat ... | 1985 | 3986676 |
| an evaluation of screening programs for the detection of brucellosis in dairy herds. | data were collected from approximately 1000 dairy herds, initially blood tested for brucellosis in 1977, in each of southeastern and southwestern ontario. these data were used to evaluate three brucellosis screening programs, the area recertification program, the market cow program and the milk test program. the milk test program was the most efficient program at detecting brucellosis, 29.5% of the herds tested were classified as infected, but lacked the ability to detect a large proportion of " ... | 1980 | 7397599 |
| mechanobullous disease in a belgian foal in eastern ontario. | | 1995 | 7497429 |
| prevalence of bovine parvovirus infection in ontario dairy cattle. | studies were conducted to determine prevalence and dynamics of bovine parvovirus (bpv) infection. dairy cows from 29 randomly selected herds in southwestern ontario were tested twice, one year apart, for the presence of hemagglutination inhibition (hi) antibodies against bpv. fifty-one percent of 1141 cows tested had bpv-hi titers > 1:32. one year later, the seroprevalence was 83% in 1131 cows from the same farms. the herd mean seroprevalence was 49% and 86% for the year-1 and year-2 samples, re ... | 1995 | 7648531 |
| like father, like son. | | 1994 | 7730114 |
| bovine viral diarrhea in a dairy herd. | | 1995 | 7757928 |
| campylobacter fetus in artificial insemination unit and slaughterhouse bulls in ontario. | preputial fluid samples were collected from 90 bulls in two ontario artificial insemination units using a penial glove swab technique previously developed by one of us for use in donor bulls. no campylobacter fetus organisms were identified from the prepuce or from samples of semen collected at the same time from these bulls. the distal genitalia of 200 bulls were collected at a slaughter house. one isolation of a campylobacter fetus subspecies venerealis was obtained on a culture from the forni ... | 1985 | 3893662 |
| rate of campylobacter spp. isolation in three regions of ontario, canada, from 1978 to 1985. | isolation rates of campylobacter spp. were analyzed for an 8-year period, 1978 through 1985. three laboratories of the ontario ministry of health examined 146,842 human feces samples for bacterial pathogens, including campylobacter jejuni and campylobacter coli. campylobacter spp. were isolated from 5,580 specimens (3.8%), with monthly isolation rates ranging from 1.1 to 7.4%. the data showed a seasonal distribution of isolations, with peaks during the summer months (june to september). most inf ... | 1986 | 3771774 |
| seroprevalence and association with abortion of leptospirosis in cattle in ontario. | sera were collected using a systematic random sampling from 348 cattle herds in ontario, in proportion to the cattle population in different areas. one cow in five from 296 dairy herds and one in three from 52 beef herds were sampled. the sera were analyzed for prevalence of antibodies to leptospira interrogans serovar grippotyphosa, hardjo, icterohaemorhagiae and pomona using the microscopic agglutination test. herd seroprevalence (one or more animals with titer greater than or equal to 80) in ... | 1988 | 3370556 |
| evidence of direct transmission of escherichia coli o157:h7 infection between calves and a human--ontario. | | 1994 | 8038753 |
| five-year follow-up of hancock pericardial valves: management of premature failure. | the durability and function of bovine pericardial valves are dependent upon design, preservation, patient factors (age, sex), and site of valve implantation. in 1983, a shelf recall of all hancock bovine pericardial valves (hpv) was instituted by the manufacturer. this report represents the results of an organized 5-year follow-up in a hospital prosthetic valve registry of 129 hpv implanted in 122 patients (79 males, 43 females) between may 1982 and april 1985 using echo doppler and careful clin ... | 1988 | 2980043 |
| a serological survey for bovine immunodeficiency-like virus in ontario dairy cattle and associations between test results, production records and management practices. | a chemiluminescence western blot analysis (wba) for detecting antibovine immunodeficiency-like virus (biv) antibodies, had good repeatability. the test was subsequently applied to a bank of serum samples from 928 adult cows from 265 herds in ontario; the number of cows sampled within each herd ranged from 1 to 13. the overall prevalence of anti-biv antibodies among cows was 5.5% with a 95% confidence interval of 4.2% to 7.2%. in contrast, 18.1% of herds had at least one reactor among cows tested ... | 1994 | 8143251 |
| forensic application of repetitive dna markers to the species identification of animal tissues. | highly repetitive dna markers have been used for determining the species origin of animal tissues in cases of illegal commercialization and poaching of game animals. this approach has been used in cases involving white-tailed deer (odocoileus virginianus), moose (alces alces) and black bear (ursus americanus). digesting the dna with various restriction enzymes, agarose electrophoresis and staining with ethidium bromide revealed unique banding patterns for each species. these patterns have been u ... | 1994 | 8195749 |
| highly presumptive identification of bacterial isolates associated with the recent canada-wide mastitis epizootic as nocardia farcinica. | a highly presumptive identification of nocardia farcinica was made of 47 bacterial isolates. fifteen isolates from alberta, 9 from ontario, and 2 each from new brunswick, newfoundland, and nova scotia were from clinical cases involved in the canadian mastitis epizootic. seventeen additional isolates from alberta were recovered from farm milk bulk tanks from herds found to have cows involved in the epizootic. all isolates were shown by high-performance liquid chromatography to possess mycolic aci ... | 1993 | 8364799 |
| dynamics and regulation of bulk milk somatic cell counts. | somatic cell count (scc) in milk is inversely related to dairy cow productivity and milk quality. in an effort to improve product quality, and indirectly farm productivity, regulatory limits on somatic cell counts have been established by many of the major dairy producing countries. the purpose of this paper was to assess the impact of regulations on bulk milk somatic cell counts in ontario and to assist producers in meeting regulatory limits through development of prediction models. through the ... | 1993 | 8490807 |
| cadmium levels in bovine liver and kidney from agricultural regions on and off the canadian shield, 1985-1988. | | 1989 | 2804412 |
| update on bovine virus diarrhea in ontario. | | 1996 | 8681292 |
| trends in bovine abortions submitted to the ontario ministry of agriculture, food and rural affairs, 1993-1995. | | 1996 | 8705972 |
| control of bovine leukemia virus infection in dairy herds by agar gel immunodiffusion test and segregation of reactors. | canadian cattle intended for export, in future, may have to originate from herds which are serologically negative for bovine leukemia virus, in addition to being negative individually by the agar gel immunodiffusion test as currently required. in this study, agar gel immunodiffusion testing of herds and segregation of reactors were examined. the results demonstrated that bovine leukemia virus infection could be controlled when three groups: 1) bovine leukemia virus-positive, 2) bovine leukemia v ... | 1989 | 2536579 |
| bovine anthrax in eastern ontario. | | 1996 | 9111696 |
| associations between farm management practices, productivity, and bovine leukemia virus infection in ontario dairy herds. | the objective of this study was to investigate the associations between herd-level bovine leukemia virus (blv) status and herd-level management and production variables. the study population consisted of 1330 cows sampled from 102 ontario dairy herds. the individual-cow prevalence of blv infection in the population (based on agid testing) was 23%, with 69.6% of herds having one or more positive animals. the herd-level explanatory variables were divided into two datasets containing winter housing ... | 1997 | 9234445 |
| evaluation of a bulk-milk elisa test for the classification of herd-level bovine leukemia virus status. | the results of a commercial bulk-milk enzyme-linked immunosorbent assay (elisa) test for herd-level bovine leukemia virus (blv) status were compared to results obtained from individual agar-gel immunodiffussion (agid) testing on sampled cattle. a positive herd was defined as a herd having one or more agid-positive animals. the estimated true herd status was based on the sensitivity and specificity of the agid test and the number of cattle sampled per herd. ninety-seven herds were used, with a me ... | 1997 | 9234446 |
| use of test day milk fat and milk protein to detect subclinical ketosis in dairy cattle in ontario. | serum beta-hydroxybutyrate (bhb) levels were determined for 1333 dairy cows in various stages of lactation and parity on 93 dairy farms in ontario. the data were collected in a cross-sectional manner, as part of the 1992 ontario dairy monitoring and analysis program. the median serum bhb was 536 mumol/l for all cows, with a range of 0 to 5801 mumol/l. when subclinical ketosis was defined as a serum bhb level of 1200 mumol/l or higher, the prevalence of ketosis for cows in early lactation (< 65 d ... | 1997 | 9360791 |
| persistence of escherichia coli o157:h7 in dairy cattle and the dairy farm environment. | the persistence of escherichia coli o157:h7 in cattle and the farm environment was investigated on eight ontario dairy farms positive for e. coli o157:h7 in a longitudinal study commenced one year previously. faecal samples from cows, calves, humans, cats, rodents, wild birds, a composite fly sample and numerous composite and individual environmental samples were cultured and tested for verotoxin-producing e. coli (vtec). vtec isolates were serotyped and e. coli o157:h7 isolates were phage typed ... | 1997 | 9363025 |