Evaluation of skin erythema by use of chromametry and image analysis of digital photographs after intradermal administration of histamine in dogs

OBJECTIVE: To investigate whether the degree of erythema during an induced erythematous reaction, the histamine skin test reaction, can be assessed objectively by use of chromametry and image analysis of digital photographs. ANIMALS: 9 pet dogs (6 Golden Retrievers and 3 yellow Labrador Retrievers). PROCEDURE: Histamine phosphate was injected intradermally, and erythema of the wheal reaction was evaluated during the hour that followed. This was done by use of clinical scores, chromametry, and image analysis of digital photographs. Method reproducibility was tested for visual evaluation of printouts of digital photographs and for image analysis of the same photographs. RESULTS: The coefficient of variation of the technically derived erythema values was < 10%. The reproducibility of image analysis was high and the range of agreement between observers narrow. Using chromametry, it was not possible to differentiate between various degrees of erythema intensity as visually perceived. In contrast, use of image analysis of digital photographs enabled discrimination of slight erythema from moderate and marked erythema. The dynamics of reaction measured by chromametry followed the clinical observation. CONCLUSIONS AND CLINICAL RELEVANCE: Chromametric values are comparable to those obtained by visual inspection. As the result of standardized conditions, chromametry is preferred over digital photography.     

Infrared skin temperature measurements for monitoring health in pigs: a review

Infrared temperature measurement equipment (IRTME) is gaining popularity as a diagnostic tool for evaluating human and animal health. It has the prospect of reducing subject stress and disease spread by being implemented as an automatic surveillance system and by a quick assessment of skin temperatures without need for restraint or contact. This review evaluates studies and applications where IRTME has been used on pigs. These include investigations of relationships between skin, ambient and body temperatures and applications for detecting fever, inflammation, lesions, ovulation, and stress as well as for meat quality assessment. The best skin locations for high correlation between skin temperature and rectal temperature are most likely thermal windows such as ear base, eye region and udder. However, this may change with age, stressors, and biological state changes, for example, farrowing. The studies performed on pigs using IRTME have presented somewhat discrepant results, which could be caused by inadequate equipment, varying knowledge about reliable equipment operation, and site-specific factors not included in the assessment. Future focus areas in the field of IRTME are suggested for further development of new application areas and increased diagnostic value in the porcine and animal setting in general.     

Locomotion scores and lying behaviour are indicators of hoof lesions in dairy cows

Locomotion scoring, lying behaviour and lesion recording during hoof trimming are all ways of evaluating hoof health in dairy cows. The objective of this study was to evaluate the relationship between these measures in a random sample of 1340 cows from 42 Danish dairy herds. The hypothesis was that locomotion scoring and/or the monitoring of lying behaviour could be used as tools to identify cows with hoof lesions, either of the horn or of the skin. Cows were locomotion scored, lying behaviour recorded and data on hoof lesions seen during hoof trimming collected. The results were analysed using logistic regression with hoof lesion as the outcome and locomotion score (1-5), mean duration of lying bouts, parity and lactation stage as explanatory variables. This analysis was undertaken for all types of lesions, for hoof horn lesions only and for skin lesions only. Odds of all hoof lesions and of skin lesions increased with increasing locomotion score and increasing mean duration of lying bouts. Odds of horn lesions also increased with increasing locomotion score, but there was no significant association between horn lesions and the mean duration of lying bouts. It was concluded that locomotion scoring and duration of lying bouts may be used as tools in the management of hoof health in dairy herds.     

Reproducible hairy root transformation and spot-inoculation methods to study root symbioses of pea

Pea has lagged behind other model legumes in the molecular study of nodulation and mycorrhizae-formation because of the difficulty to transform its roots and its poor growth on agar plates. Here we describe for pea 1) a transformation technique which permits the complementation of two known non-nodulating pea mutants, 2) a rhizobial inoculation method which allows the study of early cellular events giving rise to nodule primordia, and 3) a targeted fungal inoculation method which allows us to study short segments of mycorrhizal roots assured to be infected. These tools are certain to advance our knowledge of pea root symbioses.     

The development of skin,claw and teat lesions in sows and piglets in farrowing crates with two concrete flooring materials

Abstract

The aim of the study was to investigate lesions in sows and their piglets kept on two flooring materials – bare concrete and concrete coated with polyurethane containing sand. In total, 13 lactations on concrete and 11 on polyurethane were evaluated. The severity of skin lesions was scored and teat and claw lesions were recorded. The sand-filled coating was rougher compared to the concrete floor. Larger litter sizes were associated with a higher proportion of wounded teats in sows. Only seven of the 230 piglets had no skin lesions. The piglet skin lesions generally healed, since the number of more severe lesions decreased (p<0.001) and the number of less severe lesions (p<0.001) increased over time. Piglet lesions were associated with daily weight gain and litter size. The number of skin lesions on sows and piglets did not differ between animals kept on concrete and polyurethane-covered flooring. However, piglets kept on the latter flooring had more frequent claw lesions. On both types of flooring the majority of the piglets had skin lesions. Piglets had more claw lesions on polyurethane coating due to its roughness. In addition to the possibility of lower weight gains in piglets due to severe lesions, pig skin lesions are themselves a severe welfare problem in this type of housing system.     

Eliminative Behaviour in Preparturient Gilts Previously Kept in Pens or Stalls

The success of pens which provide pigs with a bedded resting area and an area for feeding, elimination and other activities depends on pigs' ability to show discrimination in elimination behaviour and thereby keep the resting area dry and clean. The eliminative behaviour of 16 gilts was studied during the last day of gestation when motivation for prepartum nest-building was high. During gestation the gilts had been housed in stalls (n=8) or in pens (n=8). Before parturition the animals were moved to farrowing pens with a peat and straw bedded resting area and a solid floor activity area. The gilts urinated and defecated significantly more in the activity area than in the resting area (P<0.001). However, significantly more gilts which had previously been stalled defecated in the resting area than gilts which had never been confined (P<0.05). Thus, previous housing experience may influence patterns of elimination in pigs.     

Variation in aggressiveness of Hymenoscyphus fraxineus genotypes amid the ash dieback epidemic

The ascomycete Hymenoscyphus fraxineus causes devastating damage to the European common ash (Fraxinus excelsior). The fungus originates from Asia, where it coexists with native ash species and completes its life cycle by sporulating on degrading ash leaf litter on the forest floor. Given this life cycle of the fungus, genotypes of H. fraxineus with varying degrees of aggressiveness may coexist in infected European ash forests. To test this hypothesis, we cultured 19 single-spore isolates from apothecia collected in a trial of heavily infected ash in Denmark and carried out stem inoculations on young ash seedlings. Microsatellite markers revealed that the 19 isolates were all genetically unique and did not show any genetic structure. High variation was observed among the 19 isolates in pathogenicity on young seedlings. The variation (assessed as necrosis development) was highly significant, but not correlated with the vigour of the fungal isolates when grown on culture media. The results support the hypothesis that aggressiveness of H. fraxineus may not be crucial for its fitness. In this sense, ash dieback disease may differ from other recent emerging infectious diseases on trees. We discuss the variation in aggressiveness of H. fraxineus in relation to durability of resistance and future management of the ash dieback epidemic. The findings of this study call for more research into natural variation in endophytic versus pathogenic behaviour of H. fraxineus on European ash.