Remote Identification of Sheep with Flystrike Using Behavioural Observations.

Emily P Grant,Sarah L Wickham,David W Miller,Anne L Barnes,Patricia A Fleming,Fiona Anderson

doi:10.3390/ani9060368

Emily P Grant, Sarah L Wickham + Show 4 more

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https://doi.org/10.3390/ani9060368

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Abstract

Simple SummaryFlystrike in sheep is a common condition in Australia where parasitic flies lay eggs on soiled wool or open wounds; and the resulting maggots feed off the flesh. Identification of ‘flystruck’ individuals is crucial for treatment; but requires labour-intensive physical examination of every animal. The aim of this study was to investigate the behaviour of sheep; while they remained in the paddock; to try and visually distinguish those suffering from flystrike. Observers who were blinded to the flystrike status of the sheep were asked to score the animal’s body language from video footage. These scores were then compared with the condition of the wool and whether the sheep were flystruck. The observers found that the flystruck sheep exhibited behavioural characteristics that corresponded to the flystrike severity and the condition of the wool around the tail (breech) of the sheep. We therefore conclude that behavioural monitoring of sheep in the paddock could be used to identify animals that had flystrike.Flystrike is a major problem affecting sheep in Australia. Identification of ‘flystruck’ individuals is crucial for treatment; but requires labour-intensive physical examination. As the industry moves toward more low-input systems; there is a need for remote methods to identify flystruck individuals. The aim of this study was to investigate the behaviour of sheep with breech flystrike within a paddock setting. Video footage of sixteen Merino sheep; eight later confirmed with flystrike and eight without; was collected as they moved freely within the paddock with conspecifics. Quantitative behavioural measurements and a qualitative behavioural assessment (QBA) were conducted and compared to their breech conditions (i.e., faecal/urine staining; flystrike severity). Both qualitative and quantitative assessments indicated behavioural differences between flystruck and non-flystruck animals. Flystruck sheep had a behavioural profile characterised by restless behaviour; abnormal postures and reduced grazing time (p < 0.05). Furthermore; flystruck sheep were scored to have a more ‘exhausted/irritated’ demeanour using QBA (p < 0.05). The behavioural responses also corresponded to the flystrike severity scores and condition of the breech area. We conclude that remotely assessed behaviour of flystruck sheep diverges markedly from non-flystruck sheep; and thus could be a low-input method for identifying and treating affected animals.

Highlights

Flystrike, or cutaneous myiasis, is a major health and welfare problem within the Australian sheep industry
The diagnosis of flystrike is usually straightforward based on physical examination of individual sheep, but there is an obvious need for a non-intrusive method of identification that does not involve the gathering and individual handling of all animals
Such a method would allow for the targeted or selective treatment of animals, reducing costs and minimising labour as it would involve only the gathering, handling and treatment of flystruck animals rather than all stock. We applied both quantitative and qualitative methods to study the behaviour of breech-flystruck sheep in a paddock setting to identify potential indicators of flystrike

Summary

Introduction

Cutaneous myiasis, is a major health and welfare problem within the Australian sheep industry. The disease of flystrike is caused by the chemical and mechanical effects of blowfly. Onset of disease is rapid [5,6], and is characterised by cutaneous lesions, pyrexia (fever), inflammation and the severe irritation of the skin [4,7]. Infested sheep can experience reductions in feed intake, body weight, wool production and lamb losses [6,8]. More important is the risk of death from bacterial and/or systemic toxaemia in severe or untreated cases [8,9]. It stands to reason that, when not properly managed, flystrike represents a debilitating disease that raises significant welfare concerns

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