Relationships between multiple welfare indicators measured in individual chickens across different time periods and environments

Abstract

The assessment of animal welfare requires the collection of multiple indicators of welfare but quantification of their associations in different contexts is lacking. Previous studies have examined correlations between a few indicators, but not relationships between many different indicators, or between indicators taken from the same individuals in more than one environment. We housed 60 hens for six sequential 35-day phases in different pen environments. During each phase, a series of behavioural and physiological measures was taken for every bird: body and plumage condition, surface body temperature, behaviours observed in the home pens and during test periods, tonic immobility, physiological blood profiles, and faecal sample composition. Most variation in nearly all measures was not explained by either individual bird or grouping effects but varied across phases within the birds. Acknowledging this, we examined correlations between all parameters at the phase within-bird level, selecting a conservative P-value. A consistent set of correlations showed that a slow approach response and alert behaviour in the novel object test was associated with higher bodyweight, lower body temperature and lower acute phase protein, heterophil: lymphocyte ratio and blood glucose level. A cluster analysis confirmed these correlations. Other important parameters known to be linked to the hens’ environmental preference (eg comfort behaviour) were independent of the set described above. We conclude that statistical techniques can reveal patterns of independence and redundancy in the collection of behavioural and physiological measures of welfare.

An analysis of the welfare of fast-growing and slower-growing strains of broiler chicken

“…Castellini et al (2016), recorded many indicators, but some, such as back and wing feather condition, may have been redundant (essentially measuring the same trait) (Nicol et al, 2011) and an agreed indicator profile for future research would be constructive. Bird affect is a key component of broiler welfare which can be accessed via behavioural assessment (Nicol et al, 2011;Abeyesinghe et al, 2021) but has often been neglected. Behavioural recording was approached in many different ways by those source studies that employed it in this review.…”

Review of the influence of farrowing and lactation housing and positive human contact on sow and piglet welfare

“…Non-human animals are not capable of verbal speech to communicate to humans how they feel, and therefore scientists are reliant on behavioural and physiological indicators of animal welfare. Furthermore, as we will discuss later, because there is no one absolute indicator of good or bad welfare, it is increasingly argued that a broad range of behavioural and physiological indicators of welfare should be used to assess animal welfare (Dawkins, 2008;Fraser, 2008a;Nicol et al, 2009;Nicol et al, 2011). In reviewing the literature on sow and piglet housing and handling, we will utilise two broad conceptual frameworks used by scientists in studying animal welfare, the biological functioning and affective state frameworks.…”

“…Each of these two conceptual frameworks to assess animal welfare are not perfect: they have advantages and disadvantages. Animal welfare science is increasingly seen as a multidisciplinary exercise (Nicol et al, 2011;Siegford, 2013;Hemsworth et al, 2015) and we have previously proposed that biological functioning is taken to include affective experiences and affective experiences are recognised as products of biological functioning, and therefore a better knowledge of the dynamic interactions between the biological functioning and affective state frameworks is fundamental to our understanding of and thus managing and improving animal welfare (Hemsworth et al, 2015).…”