Porcine ear necrosis: characterization of lesions and associated pathogens

Porcine ear necrosis (PEN) is characterized by ulcerative lesions of the ear auricle. To investigate that problem, three farms with PEN in nursery pigs were included, and the study aim was to characterize PEN and the potential role of pathogens and mycotoxins. Within each farm, one batch of weaned piglets was included and the prevalence and severity of PEN were monitored for 6-7 weeks. Within each batch, 30 PEN-affected/non-affected animals were randomly selected. Blood samples were taken from these animals, to assess the systemic presence of pathogens and mycotoxins, as well as punch biopsies from the ear auricle for histopathological examination. From 10 animals, scrapings and swabs from the lesions were subjected to nanopore metagenomic sequencing and bacteriological cultivation, respectively. In all three farms, lesions appeared within 3-4 weeks post-weaning. The prevalence at the end of the nursery was 33%, 24%, and 46% for farms A, B, and C, respectively. Most affected pigs had mild to moderate lesions. Blood samples revealed low to very low levels of pathogens and mycotoxins. Different bacteria such as Staphylococcus, Streptococcus, Fusobacterium, Mycoplasma, and Clostridium species were identified by sequencing in the scrapings. The first two pathogens were also most often identified in bacterial cultures. Mycoplasma hyopharyngis was only found in PEN-affected pigs. Histopathological changes were primarily observed in the outer layer of the epidermis. The results suggest that PEN lesions develop by damage to the outer part of the skin e.g. by ear suckling or biting, followed by multiplication of opportunistic pathogens.

Validation of an ear tag-based accelerometer system for detecting grazing behavior of dairy cows

The objective of the study was to develop a grazing algorithm for an ear tag-based accelerometer system (Smartbow GmbH, Weibern, Austria) and to validate the grazing algorithm with data from a noseband sensor. The ear tag has an acceleration sensor, a radio chip, and temperature sensor for calibration and it can monitor rumination and detect estrus and localization. To validate the ear tag, a noseband sensor (RumiWatch, Itin and Hoch GmbH, Liestal, Switzerland) was used. The noseband sensor detects pressure and acceleration patterns, and, with a software program specific to the noseband, pressure and acceleration patterns are used to classify data into eating, ruminating, drinking, and other activities. The study was conducted at the University of Minnesota West Central Research and Outreach Center (Morris, MN) and at Teagasc Animal and Grassland Research and Innovation Centre (Moorepark, Fermoy, Co. Cork, Ireland). During May and June 2017, observational data from Minnesota and Ireland were used to develop the grazing algorithm. During September 2018, data were collected by the ear tag and noseband sensor from 12 crossbred cows in Minnesota for a total of 248 h and from 9 Holstein-Friesian cows in Ireland for a total of 248 h. A 2-sided t-test was used to compare the percentage of grazing and nongrazing time recorded by the ear tag and the noseband sensor. Pearson correlations and concordance correlation coefficients (CCC) were used to evaluate associations between the ear tag and noseband sensor. The percentage of total grazing time recorded by the ear tag and by the noseband sensor was 37.0% [95% confidence interval (CI): 32.1 to 42.0] and 40.5% (95% CI: 35.5 to 45.6), respectively, in Minnesota, and 35.4% (95% CI: 30.6 to 40.2) and 36.9% (95% CI: 32.1 to 41.8), respectively, in Ireland. The ear tag and noseband sensor agreed strongly for monitoring grazing in Minnesota (r = 0.96; 95% CI: 0.94 to 0.97, CCC = 0.95) and in Ireland (r = 0.92; 95% CI: 0.90 to 0.94, CCC = 0.92). The results suggest that there is potential for the ear tag to be used on pasture-based dairy farms to support management decision-making.

[Impact of the simultaneous implementation of husbandry procedures on suckling piglets]

OBJECTIVE

In addition to castration, further husbandry procedures are performed in piglets during the first week of life without anaesthesia. The aim of the present study was to investigate the pain-induced stress of the husbandry procedures castration, tail docking and ear tagging performed in piglets in combination in comparison with castration or handling alone. Furthermore, the effect of the presurgical administration of the nonsteroidal anti-inflammatory drug meloxicam alone or in combination with iron was investigated.

MATERIAL AND METHODS

The levels of pain and stress were evaluated based on cortisol and catecholamine concentrations, as well as from behavioural observations. The compatibility and the effect of combined drug administration were assessed, and the daily weight gain and blood iron level were determined.

RESULTS

When comparing the application procedures, the slight changes observed at the iron injection site were reduced by 40% when using the mixture. After performing all three husbandry procedures without administration of meloxicam (KSO group), higher cortisol concentrations were induced for up to 4 hours compared to the handling (H) and castration (K) groups. In piglets receiving meloxicam or the mixture of iron and meloxicam presurgically, the cortisol concentration was significantly reduced for 0.5 hours after castration and up to 4 hours following all three husbandry procedures when compared to piglets without medication (groups K and KSO, respectively).

CONCLUSION AND CLINICAL RELEVANCE

The results indicate that the blood cortisol concentration significantly rose due to multiple pain and distress when combining castration, ear tagging and tail docking. Application of meloxicam before performing these husbandry procedures reduced pain equally to its application before castration alone. The application of a mixed preparation of iron and meloxicam did not affect the efficacy of either drug and improved the local tolerance of the iron injection.