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Ms Joanne Edgar

BBSRC Future Leader Fellow: Emotion, cognition and social behaviour in farm animals

BBSRC Future Leader Fellow

The aim of this BBSRC funded fellowship is to use the study of fundamental maternal care to improve welfare and production for farmed laying hens.

For a domestic chick, the mother hen is an important role model; chicks learn a great deal from their mother about what to peck, when to rest and how to behave when there is a threat.  However, in large farms, allowing hens to rear their own chicks is not commercially viable and so commercial domestic chicks are hatched in large incubators and reared artificially, without a mother hen. Chicks reared without a mother are more fearful and more likely to develop behavioural problems, such as pecking the feathers and skin of other chickens; a highly prevalent and serious welfare concern.  Since natural brooding is not an option on commercial farms, the aim of this project is to artificially simulate a number of important features of maternal care that result in healthy, less fearful, higher welfare chickens.  

To develop these artificial simulations of maternal care, we will first observe how effective mother hens behave by identifying features of maternal care that result in less fearful, higher welfare chicks. After pinpointing the most effective features, small scale studies with non-brooded chicks will allow us to assess whether artificial simulation of these features is feasible and effective in improving chick welfare. Finally, candidate artificial features of maternal care will then be rolled out onto commercial laying hen farms to determine whether the welfare benefits can be replicated on a large scale and persist until the end of the production period. This project will not only provide fundamental new insight into avian maternal behaviour, but will result in practical and effective animal welfare solutions.

Further information about Dr Joanne Edgar can be found here.

Research findings

Our work has shed light on mother hens’ roles in modifying their chicks’ responses to a stressor. In particular, we have shown that individual differences in maternal responses to apparent chick distress affect the chicks’ behavioural response. Mother hens respond to their chicks’ distress with a suite of behavioural and physiological responses, including increased heart rate and stress-induced hyperthermia (Figure 1, top right). This ‘socially-mediated arousal’ directly increases the chicks’ behavioural responses to a stressor - indicated by a decrease in ground pecking and preening. Furthermore, we demonstrated that mother hens act as social buffers for their chicks - reducing their chicks’ responses to a stressor, indicated by an upwards return towards baseline levels of ground pecking and preening – but only when the individual mothers show low levels of 'socially-mediated arousal' in response to their chicks’ distress (Figure 1, bottom right).

 

Fig 1. We have developed sensitive non-invasive measures of stress in chickens. Top left (Photo credit: Anna Davies): Hen habituated to wear a heart rate monitor. Top right: Heart rate and eye temperature of mother hens prior to and during their chicks receiving an air puff (arrow = onset of air puff) Error bars = SE. Bottom left: Thermal imaging can detect stress-induced hyperthermia, with hens and chicks showing reduced eye temperature in response to stressors. Bottom right: Individual mother hens’ arousal in response to chick stress (y axis - socially-mediated arousal) is negatively correlated with the chicks’ behavioural response to their mother’s presence during a stressor (x axis - social buffering)