Finite Radiocarbon Dates of the Port Talbot Interstadial Deposits in Southern Ontario

Three new finite radiocarbon dates Suggest that (i) the thermnal maximum of the Port Talbot interstadial ocurred prior to 47,000 years before the present and (ii) the interstadial deposits were overridden by a glacial advance approximatels 44,000 years before the present. To facilitate correlaltions with other areas, new rock-stratigraphic names are proposed for the Port Talbot type section.     

A Hypoderma diana (Diptera: Hypodermatidae) infection in a horse

An infection with second-stage larvae of the warble-fly H. diana in a horse is described. The second-stage larvae were incapable of developing into the third stage, because horses are unsuitable hosts and because the infected horse was treated with an insecticide. Since the horse was used for dragging trees in the forests, the infection was likely contracted via contact with H. diana, a normal parasite of roe deer in the Netherlands.     

Effect of different methods of maintenance on the pathogenicity and infectivity of Babesia bigemina for the vector Boophilus microplus

Observations were made on the effects of five different methods of laboratory maintenance on the infectivity and virulence of Babesia bigemina for the tick Boophilus microplus. The original isolate was highly infective and virulent, causing premature death of engorged female ticks and reduced egg production. Maintenance of the strain by syringe passage in unsplenectomised calves at six to 10 week intervals reduced both its infectivity and virulence for ticks. When slow passages were preceded by a series of rapid passages in splenectomised calves, the changes to the strain were less pronounced. The other three procedures, rapid syringe passage in splenectomised calves and tick passage in either splenectomised or intact calves, had no statistically significant effect on the characteristics measured.     

Safety and efficacy of an oil-adjuvant vaccine against haemorrhagic septicaemia in buffalo calves: cross-protection between the serotypes B:2,5 and E:2,5.

The safety, efficacy and duration of immunity of an improved oil-adjuvant vaccine against haemorrhagic septicaemia, containing inactivated cells of Pasteurella multocida serotype B:2,5, were tested in young buffalo calves in Pakistan. For safety testing, five buffalo calves were vaccinated intramuscularly with twice the normal dose, and six weeks later with a normal dose. Except for a transient rise in rectal temperature at six hours after the vaccinations, no systemic reactions were observed. The buffaloes remained in good condition and had a normal appetite. No local reactions were observed at the injection site. For efficacy testing two trials were carried out. In the first, buffalo calves were vaccinated intramuscularly either with two doses two-and-a-half months apart, or with a single dose, or left unvaccinated. They were challenged subcutaneously with virulent P multocida after eight, 13 or 15 months. After challenge at eight months the four buffaloes given two doses and the buffalo given one dose were protected, whereas the control animal developed the typical signs of the disease. After the challenges at 13 and 15 months, the vaccinated animals were still protected whereas the control animals died. In the second trial, buffalo calves were vaccinated intramuscularly either with two doses two months apart, or with a single dose at two months or left unvaccinated. The buffaloes were challenged after eight or 14 months. After challenge at eight months the four control animals died, whereas three of the four buffaloes given a single dose were protected. After challenge at 14 months, the three control animals died, whereas four of the five buffaloes given two doses and both the buffaloes given a single dose were protected. To test for cross-protection against the heterologous serotypes E:2,5 and B:3,4, groups of mice were vaccinated once or left unvaccinated. Four weeks later, the vaccinated and control groups were challenged with a dilution series of the different challenge cultures. The vaccine appeared to induce protection against challenge with different strains of serotypes B:2,5 and E:2,5 but not against strains of serotype B:3,4.     

Sensitivity and specificity of the complement fixation test for detection of cattle persistently infected with Anaplasma marginale.

The complement fixation (CF) test commonly is used to identify cattle infected with Anaplasma marginale prior to interstate or international movement. Estimates of the accuracy of the CF test in detecting animals persistently infected with A. marginale vary widely. In this study, the sensitivity and specificity of the CF test for detection of carrier animals was determined using serum from 232 cattle previously defined as A. marginale positive or negative by nested polymerase chain reaction methods and hybridization. Considering results from 2 independent laboratories and interpreting a 1:5 suspect reaction as positive, the best estimate of CF test sensitivity was 20%, with a specificity of 98%. Using a 1:10 cutoff, sensitivity decreased to 14% and specificity increased to 99%. Results of this study indicate that the CF test is ineffective for identifying cattle persistently infected with A. marginale and thus is inadequate for anaplasmosis regulatory and surveillance programs.     

Equine piroplasmosis: a review.

This review focuses on equine piroplasmosis with specific reference to its distribution, diagnosis and clinical and pathological signs. The more common used drugs are discussed both with reference to treatment and chemosterilization. Areas requiring further research are also briefly mentioned.     

Exfoliative colpocytology: a method for the diagnosis of Capuchin monkey filariasis?

During vaginal fluid examinations (Papanicolaou) to study the physiological sexual cycle of Cebus sp., abundant Dipetalonema gracile microfilariae (110-160 microns x 4-5 microns, without a sheath) were encountered in the genital fluid, but not in peripheral blood. Considering the great difficulty in diagnosing this obscure parasitosis, exfoliative colpocytology was found to be an efficient diagnostic.     

Lelystad virus, the cause of porcine epidemic abortion and respiratory syndrome: a review of mystery swine disease research at Lelystad.

This paper reviews the laboratory investigations that led us to isolate the Lelystad virus and demonstrate that this virus causes mystery swine disease. We describe: 1) isolating the virus from the disease; 2) characterizing the virus as a new enveloped RNA virus; 3) reproducing the disease experimentally with the isolated Lelystad virus; 4) isolating the virus from the experimentally induced disease.     

Effects of growth curve parameters on cow efficiency.

Weight-age data from 50 Retinta beef cows from 8 to 97 mo of age located in southwestern Spain were fitted to von Bertalanffy, Brody, and Richards functions to determine the relationship between growth curve parameters and cow efficiency. Only cows having at least 31 weights were included in the analysis. Von Bertalanffy, Brody, and Richards functions were fitted to weights of each cow. Relevant parameters of the three functions are A and K, associated with the asymptotic mature weight and rate of maturing, respectively. Criteria for comparisons among the three functions were computing difficulty, goodness of fit, and lack of bias of A. Productivity indicators were number of calves weaned during the first five calving seasons (NC), average birth weight (BWT), average weaning weight (WW), and average weaning weight per cow per year (WWY). The von Bertalanffy function was selected as the most appropriate. Least squares means for A and K were 650 +/- 8.17 kg and .038 +/- .001 mo-1, respectively. The values of NC, BWT, WW, and WWY were 4.0 +/- .11 calves, 38.2 +/- .4 kg, 218 +/- 5 kg, and 172 +/- 5 kg, respectively. Regression analysis for A indicated a decrease in NC when mature weight increased (P less than .05). There was a nonsignificant trend for heavier cows (higher A) to have calves with heavier BWT or WW. The value of WWY increased (P less than .05) with increased maturing rate (K) of cows. No significant associations were found between K and BWT or WW.(ABSTRACT TRUNCATED AT 250 WORDS)