Temperature fluctuation and control in avian welfare

A PhD project with the University of Plymouth
Temperature fluctuation and control in avian welfare

Background

Does giving animals’ control of their own thermal environment improve welfare?
In animals, thermal environment in early life can shape behavioural, cognitive and physiological development. This sets individuals on different lifelong welfare trajectories. While mechanisms for thermogenesis mature, neonate birds (‘chicks’) are dependent on the parent for brooding. A better understanding of the thermal preferences of commercial species, and the consequences of these for downstream welfare, offers scope to inform fine-scale environmental control in farms. This is increasingly tractable within Precision Livestock Farming (PLF), and has scope to improve not only welfare, but energy efficiency, with direct economic and environmental benefits. 
In nature, chicks of precocial poultry and game species call to elicit brooding by the parent amongst bouts of activity. Consequently, they have 1) experience of varying temperatures in early life and 2) scope for behavioural control of thermoregulation. This is in contrast to commercial systems, where whole-house heating is usually applied and optimised on a daily temperature informed by flock-level production data (e.g. growth rate, mortality). These optima are necessarily based on the average chick, and may not capture thermal requirements of those at the extremes with different energetic costs (e.g. smaller size, poorer health status, higher stress). Given the choice of a thermal gradient, naturalistic thermo-temporal patterns emerge: chicks rest in higher temperature zones and move into lower temperature zones during activity/foraging. This suggests potential energetic and welfare benefits of a more naturalistic thermal regime. This may either be via experience of temperature fluctuation per se, or by affording the animal greater control.
However, the downstream impacts of temperature fluctuation are under-researched. Each year, 800 million chicks (chicken, turkey, geese, game) in the UK, and over 17 billion around the world, may therefore live in sub-optimal thermal environments.
<p>Figure 1: A chick being recorded using a thermal imaging camera<br></p>

Figure 1: A chick being recorded using a thermal imaging camera

Methods

The aim of this project is to explore whether 1) experience of varying temperature and 2) scope to choose temperature are important to welfare and production. The project will entail short, laboratory trials while chicks are thermally non-independent. The candidate will develop a thermal gradient arena and an approach, using thermal imaging (see Figure 1) and animal-mounted sensors, to describe the thermo-temporal profiles. They will compare welfare outcomes between chicks that are reared with more or less control of their thermal environment, and in naturalistic versus commercial contexts. Throughout the project, the candidate will use established, and develop new, non-invasive welfare (behavioural, cognitive, and physiological) indices. They will also measure production outcomes (e.g. growth, feed conversion, survival).

Student training and experience

We are looking for a candidate with a degree in biological sciences (or similar) and an interest in understanding the impacts of early life environment on behavioural, cognitive and physiological development, and ultimately welfare.
The successful candidate will benefit from the interdisciplinary nature of this project, applying infrared thermography and sensor technology to challenges within production, sustainability and animal welfare science. This will include a significant experimental design component, to develop a bespoke set up to remotely manipulate thermal environment during behavioural trials. The candidate will develop key skills in experimental and enclosure design, welfare/production assessment, and animal handling and husbandry. They will be supported to develop a network of both academic collaborators and stakeholder contacts. Enthusiasm to learn and develop this diverse set of skills and engage with different audiences is therefore important. On completion they will be well-placed to seek academic positions in e.g. thermal physiology and behavioural and welfare science, and industry positions in the growing field of PLF. 
If you wish to discuss this project further informally, please contact Dr Mark Whiteside and co-supervisors, Dr Katherine Herborn and Dr Sarah Collins .

Key papers by supervisory team

1. Knoch, S., Whiteside, M. A. et al. Hot-headed peckers: thermographic changes during aggression among juvenile pheasants (Phasianus colchicus). Philosophical Transactions of the Royal Society B 377, 20200442 (2022)
2. Whiteside, M. A.et al. Diet complexity in early life affects survival in released pheasants by altering foraging efficiency, food choice, handling skills and gut morphology. Journal of Animal Ecology 84, 1480-1489 (2015).
3. Herborn, K. A., Jerem, P., Nager, R. G., McKeegan, D. E. & McCafferty, D. J. Surface temperature elevated by chronic and intermittent stress. Physiology & behavior 191, 47-55 (2018).
4. Herborn, K. A. et al. Spectral entropy of early-life distress calls as an iceberg indicator of chicken welfare. Journal of the Royal Society Interface 17, 20200086 (2020). 
5. Collins, S. A., J. A. Archer, and C. J. Barnard. Welfare and mate choice in zebra finches: effect of handling regime and presence of cover. Animal Welfare 17 (2008): 11-17.

Supervisory team