Calibration of a remote early disease identification system for Australian feedlots

Summary

Diagnosing bovine respiratory disease (BRD) is challenging because, until now, it has relied on subjective assessments that aren't always accurate.

This project evaluated data from two Australian feedlots to determine potential associations between behaviour, lung condition (pleurisy) and carcase outcomes using the remote early disease identification (REDI) system.

Results show that there are several behavioural signs that indicate cattle are suffering from BRD. Early in the feeding period, these include spending more time in water and feeding areas early in the day and more time in the water zone at night. Cattle with BRD had decreased lung capacity, which also affected their overall performance, resulting in decreased carcase quality.

Objectives

The main objective of this project was to determine associations between animal behaviour, lung condition and carcase quality in feedlot cattle with BRD. This was achieved by using the REDI system to analyse data on:

• individual animal differences in activity and feeding patterns associated with BRD
• changes in behavioural patterns at the group (pen) level and associations between pen level disease risk and lung condition.

Key findings

Several key behavioural parameters were associated with sick or healthy cattle based on lung condition, treatment history and BRD outcomes.

• Cattle with BRD spent more time:

• at feed and water areas at an early stage of infection

• at water areas during the night

• in groups at an early stage, but then became more isolated after the first week of infection.

• Behavioural data confirmed sick calves are less active and spend more time by themselves and less time near feed and water.

• As feedlot cattle are housed in a group environment, understanding changes in population-level behaviour can be useful to identify groups of cattle that need further observation or intervention regarding BRD.

• The REDI system successfully used new algorithms that we were developed specifically for monitoring behaviour to identify BRD. This demonstrates the robustness of REDI algorithms and the ability of this technology to distinguish key health differences based on behaviour.

Benefits to industry

Misclassification of diseased cattle in feedlot industries and can lead to long term health consequences or unnecessary treatment. The REDI systems provides an opportunity to improve several areas of concern to Australian grainfed beef producers including:

• judicious use of vaccinations and treatments

• improved animal welfare

• increased labour efficiency

• understanding group and individual animal behaviour changes related to BRD status.

MLA action

MLA is currently evaluating the accuracy of the revised REDI algorithms developed in this project to identify acute and moderate cases of Bovine Respiratory Disease, compared to other veterinary diagnostics (e.g. thoracic ultrasound, lung auscultation, rectal thermometer). Results will be made available in late 2021.

Future research

The accuracy of the REDI algorithms varied regarding disease prevalence. Further adjustments may be beneficial to vary the algorithm to determine illness based on expected changes in herd healthy during feeding.