Novel technologies for monitoring respiratory disease and health of pre-weaned calves

Health and welfare of farmed animals has become increasingly scrutinised in recent years, with farms increasing in size and the general public becoming more aware of where their food is sourced. High standards of animal welfare are seen throughout the EU, with farms being part of welfare accreditation schemes and increased levels of transparency to the general public. With the huge advancements in technology over the past 50 years, animal health and welfare can be further improved on farm, allowing animals to not only be more comfortable but also to have increased production parameters, a very important aspect to consider when feeding the growing world population. The aim of this thesis was to evaluate the use of novel technologies, specifically thoracic ultrasonography and circadian rhythm analysis, to monitor and predict animal health and production. A thorough literature review was performed. Preweaned calves were assessed on farms in Ireland during Spring 2019 and Autumn 2019. Calves underwent thoracic ultrasonography every 3 weeks as well as having clinical respiratory scores and weight measurements taken over the preweaning period. Some calves were also fitted with accelerometers on neck collars to collect movement records for periodicity and circadian rhythm analysis. Calves with chronically high thoracic ultrasound scores, suggesting consolidation of entire lung lobes, had the poorest growth rates. Calves were also able to improve in thoracic ultrasound score when identified and treated early, even with areas of consolidation. The results suggest that use of thoracic ultrasonography could improve calf health and welfare on a herd and individual animal level by facilitating earlier identification of cases for treatment, resulting in improved treatment success rates. The use of thoracic ultrasonography has the potential to reduce the amount of antibiotics used during the preweaning phase through the targeting of individual animals rather than group treatments. When looking at calf circadian rhythms, periodicity data was also able to detect changes in calf health in advance of more overt clinical signs, and also enabled monitoring of calves after husbandry changes or events, for example dehorning, and how long it took for a calf to recover. The use of new technologies for measuring calf health, such as thoracic ultrasonography and circadian rhythm analysis, are useful tools which can potentially aid veterinarians and farmers in the early identification, monitoring and treatment of sick calves resulting in improved health and welfare.