Perinatal rib fractures in 18 calves delivered from Holstein dams

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We diagnosed rib fractures by palpation, computed tomography, and thoracic necropsy.

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For 163 symptomatic calves delivered from Holstein-Friesian dams on farms in Japan, 11.0% (18) showed rib fractures by palpation.

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Four of five calves that were scanned or necropsied presented with pneumonia despite not having tracheal stenosis.

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Rib fractures decreased sale prices at a livestock market and longevity.

Cranial rib fractures during dystocia and the ensuing callus formations in calves often cause tracheal stenosis. Rib fractures may affect the lung since ribs tend to fracture above the costochondral junction during delivery. Considering that calving assistance rates for dystocia are high, calves with fractured ribs may develop respiratory disease which results in economic loss. The objective of this study was to elucidate the contribution of rib fractures to economic loss through respiratory disease in calves. Of 163 sick calves delivered from Holstein-Friesian dams included in this study, a total of 18 rib fractured calves was found, giving an incidence of rib fracture in sick calves of 11.0%. There were significant differences in incidence by the rib involved, indicating the 2nd to 7th ribs tend to break. Many of the rib fractured calves showed dyspnea and pyrexia. In this study, four of five scanned or necropsied calves had pneumonia lesions despite the fact that these four calves did not have tracheal stenosis. Rib fractured calves sold at below market value with a median difference from average sale price of minus 64,861 yen. Survival analysis indicated an overall association between rib fracture and time to death. In this study, we demonstrated that rib fractures happened most frequently in the 2nd to 7th ribs, and these cases tended to cause pneumonia, which decreased sale prices and longevity. Farmers should work to reduce risks and rates of dystocia so as to lessen economic loss and poor welfare in calves due to rib fractures.

Pulsed-field gel electrophoresis in differentiation of erysipelothrix species strains

We report here the first analysis of Erysipelothrix spp. using pulsed-field gel electrophoresis (PFGE). Seventy strains of Erysipelothrix spp. were analyzed. SmaI, AscI, and NotI were tested for the ability to cleave the DNA extracted from those strains, and among them, SmaI was the most reliable enzyme. Sixty-three distinct PFGE patterns were produced, and no DNA degradation was observed, allowing the identification of all of the strains. Based on these results and on those of a previous analysis using randomly amplified polymorphic DNA and ribotyping, PFGE with SmaI might be considered to be more sensitive than those methods and to be the best method for epidemiological studies of strains of this genus.