Mathematical Modelling of Sleep Behaviour as an Indicator of Avian Welfare
PI: Dr Lorna Wilson, (Institute for Mathematical Innovation, University of Bath).
Co-Is: Prof Christine Nicol (Department of Zoology, University of Oxford); Dr Anne Skeldon (Department of Mathematics, University of Surrey)
Project Overview: The importance of a good night’s sleep is universally acknowledged to underpin good health and to promote effective mental functioning in human beings. Sleep follows a strong circadian rhythm and is controlled by internal clock-like systems and external cues. Some of these effects have been captured in mathematical models applied to humans and to other mammals, but there has been no work to describe sleep quality in birds. Like mammals, birds can sleep with both brain hemispheres simultaneously but unlike mammals, birds can also sleep with just half of their brain at a time, allowing the other half of the brain to remain active and alert.
The aim of this project is to develop a data-informed, mathematical approach to define and model sleep processes in birds, specifically commercially farmed laying hen chicks, under different on-farm rearing conditions. This will enable a preliminary decision about which rearing conditions lead to the best bird welfare.
The model will incorporate and quantify the uncertainty in this problem due to; the drivers of sleep-wake regulation in birds;how the sleep patterns are observed; variations between individual chickens; and variation in the stimuli that chickens receive. The model’s robustness and sensitivity to changes in the parameters – which will be input as probability distributions – will be tested. Monte Carlo simulations of the model with randomly sampled parameter ensembles, will be used to ascertain the extent to which individual bird differences affect the model output.
This project has an interdisciplinary approach at its core, and will bring together academic zoologists and mathematicians with farmers and consumer assurance schemes. These schemes enable producers and consumers to make better decisions with regards to animal welfare. This inter-disciplinary involvement is essential to better understanding the uncertainties described above as well as the uncertainty about how we should define “good” welfare.