A system of grading ossification in limbs of foals to assist in radiologic interpretation.

Tetracycline-labeled bones of 23 foals from 52 to 104 days old were sectioned and macroscopically examined to assess the extent of ossification or fusion of ossification centers. A grading system was devised with which to record information about the ossification centers and growth plates. The objective was to define anatomic standards which could contribute toward obtaining an accurate radiologic interpretation. Labeled limb bones of 3 neonatal foals were similarly treated, but grading of these was limited to the consideration of whether each site was still cartilaginous or had commenced to ossify.     

Time-related responses of spontaneously breathing, laterally recumbent horses to prolonged anesthesia with halothane

Cardiovascular and respiratory functions were serially evaluated in ten healthy, fasting, spontaneously breathing, laterally recumbent adult horses during five hours of constant 1.06% alveolar halothane (equivalent to 1.2 times the minimum alveolar concentration for horses). Mean carotid arterial pressure was about 25% higher after one hour of constant-dose halothane than after 30 minutes of constant-dose (P less than 0.05), and remained increased throughout the study. Mean carotid arterial pressure peaked after 90 minutes, and was about 30% higher than at 30 minutes. Total peripheral vascular resistance initially increased (20% at one hour), then gradually returned to the 0.5-hour value over the next four hours. Cardiac output progressively increased with time (P less than 0.05; 20% by two hours; nearly 40% by five hours) because of an increase in stroke volume. An increase (P less than 0.05) in mixed venous PO2 accompanied the increase in cardiac output. Heart rate did not change significantly (P greater than 0.05). Some measures of ventilation changed significantly with time (P less than 0.05). After four and five hours of constant alveolar halothane, the PaCO2, inspired gas flow, and ratio of inspired vs expired gas flow were significantly higher than the 0.5-hour values. Inspiratory time significantly decreased, beginning at three hours. All horses recovered from anesthesia and recumbency without complications.     

Variations in the size of the soil biomass

In the surface 5 cm of a clay soil in 2 successive years the microbial biomass, as measured by a fumigation-respiration technique, was constant. The biomasses in two clay soils were approximately ten times greater than that in a silt loam. When straw from a preceding crop was chopped and left on the soil surface the biomass after 8 months was greater by a factor of two than that in soil where the straw had been burnt. Where soil had been kept in grass for 9 yr, the biomass was greater by a factor of three than that in soil of the same kind that had been in arable cultivation for the previous 4 yr. As the fumigation-respiration technique measured only the microbial and microfaunal contribution to the biomass, the total biomass can only be assessed by measuring the root contribution separately; when this was done the total biomass in the grassland was found to be greater by a factor of about six.     

A serosurvey of Borna disease virus infection in wild rats by a capture ELISA

For a serological diagnostic test for Borna disease (BD), we developed a capture ELISA with specificity and sensitivity based on detection of antibodies against BD virus (BDV) p40 protein. Using our capture ELISA system, the antibody response of rats inoculated intracerebrally with BDV at 4 weeks after birth showed a sharp increase from 1 to 4 weeks postinoculation (p.i.) and a steady level after 5 weeks p.i. To investigate prevalence of BDV infection among wild rats, we examined sera of Rattus norvegicus in Kami-iso town, Oshima district, Hokkaido, suggesting that rats in this area had not been infected by BDV.     

Comparison of radiographic assessments of the tibial plateau slope in dogs

OBJECTIVES: To evaluate the accuracy of 2 radiographic methods used to assess tibial plateau slope (TPS) in dogs and evaluate effects of film digitization and radiographic beam placement on TPS measurements. SAMPLE POPULATION: 16 hind limbs from dog cadavers weighing > 20 kg. PROCEDURES: Radiographs of tibiae were made with the radiographic beam centered over the stifle joint and midshaft of the tibia. Tibiae were collected, the femorotibial contact area was determined, and slope of the medial tibial condyle in relation to the tibial shaft was measured. Radiographs were digitized. Slope of the medial tibial condyle was measured on printed and digitized radiographs read in random order by 6 examiners unaware of anatomic measurements. Three examiners used a conventional measuring technique, and 3 examiners used an alternative measuring technique. RESULTS: Anatomic measurements were significantly higher than radiographic measurements made by use of the conventional interpretation method but did not differ from radiographic measurements made by use of the alternate method. Measurements from printed radiographs were lower than measurements from digitized radiographs for the 4 most experienced examiners. CONCLUSIONS AND CLINICAL RELEVANCE: Measurements made by use of a line tangential to the cranial, linear portion of the medial tibial condyle at the femorotibial contact point were accurate measurements of the anatomic TPS. Measurements made by use of the conventional TPS measurement method underestimated the anatomic TPS. Measurements made on digitized radiographs were typically more accurate than measurements made on printed radiographs.     

Risk factors of contamination of pig farms in the Netherlands with pig diseases and agents thereof: a review of the literature

Part of the project 'Clean pigs' an extensive study of literature was made of the risk factors related to the introduction of pathogenic micro-organisms in pigfarms in the Netherlands. On the basis of this study of literature and in close cooperation with the experts of the steering group of the project 'Clean pigs' a number of risk factors relevant for the Dutch pig farming were estimated. The impact of these risk factors on the introduction of the most important pig diseases/-agents in Dutch pig farming was quantified for three different levels of preventive measures. It is shown that many risks can be reduced or even be neglected by the biosecurity measures already applied on pig farms. For most diseases, including list A and B diseases of the OIE list, introduction of new animals is regarded as the main risk factor, but this risk can be reduced in several ways. Besides this, aerogenic transmission and introduction by rodents and pet animals need the most attention. Through specific actions and measures several important risk factors can be diminished or even eliminated.     

Influence of ante- and peri-mortem factors on biochemical and physical characteristics of turkey breast muscle

Summary The course of post-mortem breakdown of glycogen and ATP in turkey pectoralis major muscle was markedly influenced by several ante- and peri-mortem variables. Application of a proper stunning procedure was highly effective in preventing peri- and post-mortem muscle stress reactions. The physiological level of glycogen and ATP was not significantly affected by road transportation covering 260 km. Birds which rested for 24 hrs following transportation had lower glycogen and ATP levels at the moment of slaughter than non-rested birds. According to the changes in the rate and extent of post-mortem biochemical reactions, several meat characteristics such as water-holding capacity, colour, and tenderness were significantly changed. Furthermore, the results also indicate that turkey breast muscle is susceptible to a PSE-like condition as described in pork.     

Destruction of Trichinella spiralis spiralis during the preparation of the "dry cured" pork products proscuitto, proscuittini and Genoa salami

Genoa salami, proscuittini and proscuitto were prepared from pork carcasses that were heavily infected experimentally with Trichinella spiralis spiralis. Genoa salami was prepared with salt concentrations of 2.0%, 2.75% and 3.3%. Proscuitto was prepared by two procedures approved by Agriculture Canada. At various times postpreparation, samples of the various cured products were taken and examined by pepsin digestion and rat bioassay for the presence of viable trichinae. Water activity and pH of the cured meat were also determined. Curing of the various products was shown to destroy the Trichinella larvae. Pepsin digestion revealed that larvae progressively became loosely coiled, uncoiled and more subject to digestion (ghost larvae) during the curing process. Rat bioassay revealed the presence of viable trichinae in the proscuitto prepared using a sodium chloride salt mixture at day 34 but not at day 48 postpreparation. All other bioassays carried out on Genoa salami between 13 and 42 days postpreparation, on proscuittini between days 27 and 69 and on proscuitto between days 34 and 69 were negative for viable trichinae. Under the conditions of this study, preparing Genoa salami with salt concentrations as low as 2% did not appear to affect the destruction of Trichinella larvae.