Concurrent experimentally induced infection with Eimeria bovis and coronavirus in unweaned dairy calves.

Over a period of 3 summers, 21 colostrum-fed Holstein bull calves, 1 to 3 days old, were assigned to 7 replicates, each consisting of 3 calves. Within each replicate of 3 calves, 2 were selected at random, to be given 100,000 to 146,000 sporulated coccidia oocysts (principally Eimeria bovis) orally 60 hours after arrival at the college research farm. On the thirteenth day after coccidia inoculation, 1 of the 2 calves that had been given coccidia and the third calf that had not been inoculated, were given coronavirus by intranasal and oral routes. Calves were observed daily, and consistency of feces was scored visually. Nasal swab specimens for indirect immunofluorescent antibody testing for coronavirus and fecal samples for oocyst determination were obtained approximately every third day. Of 7 calves that were given only coronavirus, 3 developed diarrhea of short duration. Of 7 calves that were given only coccidia oocysts, 6 developed diarrhea. All 7 calves inoculated initially with coccidia and subsequently with coronavirus developed diarrhea. For 5 of 7 replicates, calves that were given coccidia and coronavirus developed diarrhea first. When overall severity, measured by fecal score and by blood in the feces, was compared, calves inoculated with coccidia followed by coronavirus were more severely affected (P less than 0.05) than were calves that were given only coronavirus. Calves that were given only coccidia oocysts appeared more severely affected than calves that were given only coronavirus, but differences were not significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Winter dysentery in dairy herds: electron microscopic and serological evidence for an association with coronavirus infection.

Faeces and, or, paired sera were collected from cows in six dairy herds with classical winter dysentery. Similar samples were collected from cows in three other dairy herds experiencing non-haemorrhagic diarrhoea during the survey period. Coronavirus was the only enteric pathogen identified by immune electron microscopy (IEM) in all six outbreaks, occurring in 26 of 29 (90 per cent) of the affected cows and in one of 11 normal cows from the same herds. Nineteen of 26 affected cows (73 per cent) developed greater than four-fold increases in neutralising antibody titres to the Mebus strain of bovine coronavirus, compared with two of eight normal cows in the same herds. No cows showed greater than four-fold increases in antibody titres to bovine virus diarrhoea virus. None of the cows from the three herds with non-haemorrhagic diarrhoea shed coronavirus in faeces detectable by IEM or developed greater than two-fold rises in coronavirus antibody titres in paired sera. No enteric pathogens were identified in two of the herds. However, two cows in the third herd shed a group B rotavirus detected by IEM. These findings provide additional evidence for a possible role for bovine coronavirus in the aetiology of winter dysentery. Furthermore, this is the first report of a group B rotavirus associated with diarrhoea in adult cattle.

Health and productivity of dairy cows fed polychlorinated biphenyls.

Holstein cows were studied through a complete lactation, a nonlactating period, and 42 days of a subsequent lactation for overt and subtle responses to a commercial mixture of polychlorinated biphenyls. Dosed cows (n = 4) received consecutive 60-day periods of daily dosing with 10, 100, and 1000 mg of Aroclor 1254. Control cows (n = 6) received daily sham doses. The following were recorded: daily milk production, feed intake, and health observations; weekly body weight, temperature, heart and respiratory rates and rectal palpation; semi-monthly clinical chemistry determinations; and monthly milk fat, microbiological culture of quarter foremilk samples, and composite milk somatic cell counts. Mean daily milk production (22.4 +/- 1.1 vs 24.8 +/- 1.0 kg) and net energy of a complete lactation (1.46 +/- 0.05 vs 1.45 +/- 0.03 Mcal/kg dry matter intake) were not different (p = 0.85) for control and PCB-dosed cows. Milk production during the first 42 days of the subsequent lactation was also similar for control and dosed cows. Occurrences of injuries, dysfunctions, and general infections were not related to polychlorinated biphenyl exposure. Intramammary infections were detected for both lactations with 51 and 32 infections detected in microbiological cultures, respectively, for the control and dosed groups. Environmental pathogens were most frequently isolated from cases of clinically apparent mastitis. The majority of quarter infections detected were due to Corynebacterium bovis. Only one animal (dosed, necropsy revealed left oviduct obstructed) failed to conceive with three to six services required before conception for the other control and dosed cows. Exposure to polychlorinated biphenyls resulting in maximal residues in milk fat, near 100 micrograms/g, had no apparent effect on health and productivity.

Identification by transfer blot of antigens reactive in the enzyme-linked immunosorbent assay (ELISA) in rabbits immunized and a calf infected with Cryptosporidium sp.

Soluble and particulate fractions of Cryptosporidium sp. oocysts from cattle were obtained by homogenization and sonication. Electrophoresis of the soluble fraction in polyacrylamide gels with sodium dodecyl sulfate and silver staining revealed the presence of 41 bands. Enzyme-linked immunosorbent assay (ELISA) of sera from rabbits immunized with either fraction and from a calf 40 days after infection showed that the animals produced specific antibodies. Enzyme-linked immunoelectrotransfer blot tests revealed the presence of five antigens with the rabbit sera and nine with the calf serum. ELISA proved to be an appropriate test for diagnosis of cryptosporidiosis. Selection of reactive antigens may improve the quality of diagnosis and/or reveal the presence of protective materials in the parasite.

Experimentally induced coronavirus infections in calves: viral replication in the respiratory and intestinal tracts.

Eleven 3- to 50-day-old colostrum-deprived gnotobiotic calves and seven 25- to 63-day-old colostrum-deprived conventional calves were allotted into 3 groups. Each group was inoculated with a fecal isolate of bovine coronavirus via different routes: orally/intranasally OR/IN, No. 1 through 8, group 1 calves; OR, No. 9 through 13, group 2 calves; IN, No. 14 through 18, group 3 calves. Nasal swab specimens and fecal specimens were collected daily and were examined for coronavirus antigen by use of direct immunofluorescent staining (nasal epithelial cells) or by use of immune electron microscopy (fecal specimens). All but 4 calves (No. 11, 13, 17, and 18) were euthanatized on postinoculation days (PID) 3 to 7. Calves 11 and 17 became severely dehydrated and died at PID 5. Calves 13 and 18 were evaluated for nasal and fecal shedding of coronavirus through PID 14. Distribution of coronavirus antigen in the respiratory and intestinal tracts of the 14 euthanatized calves was evaluated by use of direct immunofluorescent staining. All calves developed profuse diarrhea by PID 2 to 4; however, calves did not develop clinical signs of respiratory tract disease before euthanasia or death. Inoculated calves shed coronavirus in their feces as detected by use of immune electron microscopy. Infected nasal epithelial cells were detected in all but 2 orally inoculated calves (No. 9 and 10). Route of inoculation influenced the sequence of initial detection of coronavirus antigen from fecal specimens or nasal swab specimens.(ABSTRACT TRUNCATED AT 250 WORDS)

Computerised tomography guided lumbar sympathectomy.

Fifteen patients had lumbar sympathetic block using needle localisation by computerised tomography. The technique has the advantage that the needle route to the sympathetic plexus can be accurately planned, avoiding damage to other organs. In this study, 13 patients out of 15 had significant benefit from the procedure.

Passive immunity to bovine rotavirus in newborn calves fed colostrum supplements from immunized or nonimmunized cows.

Colostrum was collected and pooled from each of five cows in three experimental groups: group I cows received intramuscular and intramammary inoculations of adjuvanted modified live Ohio Agricultural Research and Development Center rotavirus vaccine; group II cows were injected intramuscularly with a commercial modified-live rota-coronavirus vaccine; and group III cows were uninoculated controls. Pooled colostrum from group I cows had higher (P less than 0.05) enzyme-linked immunosorbent assay (ELISA) immunoglobulin G (IgG1) and virus neutralization (VN) rotavirus antibody titers (ELISA IgG1 = 2,413,682; VN = 360,205) than did colostrum from group II (ELISA IgG1 = 8,192; VN = 4,395) or group III cows (ELISA IgG1 = 5,916; VN = 2,865). The antibody titers of these last two colostrum pools did not differ (P greater than 0.05). Samples of these colostrum pools were fed as daily supplements (percent [vol/vol] in cow's milk infant formula) to 28 newborn, unsuckled, antibody-seronegative, male Holstein calves. Eight calves received no supplemental colostrum. The calves were orally challenged with virulent bovine rotavirus and monitored daily for diarrhea and fecal rotavirus shedding. Diarrhea and rotavirus shedding occurred in the eight calves fed no supplemental colostrum and persisted longest in this group. The pooled colostrum from group I cows protected eight of eight calves from both rotavirus diarrhea and shedding when fed as a 1% supplement. The pooled colostrum from neither group II nor group III cows protected 12 other calves against rotavirus diarrhea or shedding when fed at the same concentration (1%). Six rotavirus-challenged calves fed 0.1% supplemental colostrum from group I cows and two calves fed 10 and 50% supplemental colostrum from control cows displayed partial passive immunity, exemplified by delayed onset and shortened duration of rotavirus-associated diarrhea and virus shedding.

Rapid, simple method of preparing rotaviral double-stranded ribonucleic acid for analysis by polyacrylamide gel electrophoresis.

A procedure for extracting rotaviral double-stranded ribonucleic acid (RNA) directly from fecal and intestinal specimens collected from calves and pigs is described. This procedure provides a rapid, simple, reproducible method of obtaining rotaviral double-stranded RNA preparations suitable for electrophoretic analysis in polyacrylamide-agarose composite gels. The rotaviral genome electrophoretic migration pattern produced by double-stranded RNA extracted directly from a specimen by this procedure was qualitatively identical to the electrophoretic migration pattern obtained with double-stranded RNA extracted from purified rotavirus derived from the same specimen. Direct extraction of specimens containing porcine rotavirus-like virus by this procedure gave preparations that had electrophoretic migration patterns similar, but not identical, to the characteristic electrophoretic migration pattern of the rotaviral genome. Sufficient rotaviral double-stranded RNA could be extracted from 6 ml of fecal or intestinal specimen by this procedure to permit 15 or more electrophoretic assays.

Intrafetal inoculation of swine with transmissible gastroenteritis virus.

Fetuses in 3 sows were inoculated (intramuscularly) with transmissible gastroenteritis (TGE) virus on 95th, 77th, and 74th days of the gestation. At 15, 14, and 37 days later (or days when pigs were obtained by hysterectomy), there was evidence of intestinal localization of virus, with villous atrophy and subsequent repair. All intrafetal-inoculated pigs became serologic-positive for TGE. A noninoculated pig shown to be seropositive for TGE at 15 days of age (after hysterectomy) was resistant to challenge exposure with virulent TGE virus given on the 32nd day, in contrast to 3 seronegative littermates that developed typical disease when challenge exposed.

Selenium/vitamin E: role in fertilization of bovine ova.

The effect of combined supplementation with selenium and Vitamin E upon fertilization of ova was evaluated in beef cattle maintained on either an adequate or inadequate nutrition. Fertilization of ova was 100% in those females receiving supplemental selenium/vitamin E and on an adequate plane of nutrition. Interaction between plane of nutrition and selenium/vitamin E was significant for percent fertility.

Influence of dietary protein on susceptibility to alert downer syndrome.

Fifty-three dry cows of the Ohio Agricultural Research and Development Center dairy herd were placed in one of four groups for the entire dry period. All received a corn silage-concentrate ration. Groups 1 and 2, however, were maintained on an intake of 8% crude protein while groups 3 and 4 received .65% of their dry matter as calcium and .29% as phosphorus while group 2 received .70% calcium and .70% phosphorus and group 4 received .66% calcium and .65% phosphorus. Animals were bled through the dry period at regular intervals and within 6 h postfreshening or prior to initiation of any therapy. In groups 3 and 4 metabolic disturbance occurred in 69.2% of calvings. These included eight alert downer cows, six of which died during treatment. In groups 1 and 2, the incidence of metabolic disturbance was 7.14% with no downer cows. Blood constituents showed no significant differences except between groups for urea nitrogen of plasma. Individual animals showed no significant changes in blood constituents indicative of a cause of the disorder. Dietary protein influences incidence of the disease. Dietary mineral imbalance and clinical expression of the downer condition were unrelated.

Porcine parvovirus: natural and experimental infections of the porcine fetus and prevalence in mature swine.

Antibodies against porcine parvovirus were detected in 17 of 116 prenursing pig sera. Antibodies against transmissible gastroenteritis or ECPO-6 (an enterovirus) were not detected in prenursing sera of the pigs tested. Seventy-seven percent of 129 serum samples from 23 Ohio farms and 82% of 96 samples from slaughter plants in Ohio were serologically positive for porcine parvovirus. Mummies or other abnormalities were not observed in newly born pigs exposed to porcine parvovirus by the transuterine route 101 days after gestation. Indirect evidence suggested that the virus had not spread to other fet uses following exposure after 101 days at least not in a sufficient amount of time to stimulate detectable antibody. Direct intrafetal exposure to porcine parvovirus (i.m. injection, transutero) after 62 days of gestation resulted in dealth and mummification of the two fetuses, and apparently in the subsequent spread of the virus, as five of nine live pigs born were serologically positive for porcine parvovirus and these five pigs had not been injected with the virus. Immunoglobulin G was detected in all newborn pigs irregardless of known antigenic stimulation or the presence of specific antibody. In general, the presence of immunoglobulin M or immunoglobulin A in fetal serum was correlated with a history of antigenic stimulation or the presence of detectable antibody.