Kinematic Analysis Quantifies Gait Abnormalities Associated with Lameness in Broiler Chickens and Identifies Evolutionary Gait Differences

Abstract

This is the first time that gait characteristics of broiler (meat) chickens have been compared with their progenitor, jungle fowl, and the first kinematic study to report a link between broiler gait parameters and defined lameness scores. A commercial motion-capturing system recorded three-dimensional temporospatial information during walking. The hypothesis was that the gait characteristics of non-lame broilers (n = 10) would be intermediate to those of lame broilers (n = 12) and jungle fowl (n = 10, tested at two ages: immature and adult). Data analysed using multi-level models, to define an extensive range of baseline gait parameters, revealed inter-group similarities and differences. Natural selection is likely to have made jungle fowl walking gait highly efficient. Modern broiler chickens possess an unbalanced body conformation due to intense genetic selection for additional breast muscle (pectoral hypertrophy) and whole body mass. Together with rapid growth, this promotes compensatory gait adaptations to minimise energy expenditure and triggers high lameness prevalence within commercial flocks; lameness creating further disruption to the gait cycle and being an important welfare issue. Clear differences were observed between the two lines (short stance phase, little double-support, low leg lift, and little back displacement in adult jungle fowl; much double-support, high leg lift, and substantial vertical back movement in sound broilers) presumably related to mass and body conformation. Similarities included stride length and duration. Additional modifications were also identified in lame broilers (short stride length and duration, substantial lateral back movement, reduced velocity) presumably linked to musculo-skeletal abnormalities. Reduced walking velocity suggests an attempt to minimise skeletal stress and/or discomfort, while a shorter stride length and time, together with longer stance and double-support phases, are associated with instability. We envisage a key future role for this highly quantitative methodology in pain assessment (associated with broiler lameness) including experimental examination of therapeutic agent efficacy.

Locomotion of commercial broilers and indigenous chickens

“…Comparing the gait of commercial strain and jungle fowl, Caplen et al (2012) found that broiler genetic strains present an unbalanced body due to the intense genetic selection for additional breast muscle (pectoral hypertrophy). Fast-growth birds develop compensatory gait adaptations to minimize energy expenditure that triggers high-lameness prevalence within commercial flocks.…”

“…This methodology of observing EC related to their stance behavior might not be sufficient to estimate bird welfare. It has been reported that birds with little genetic selection pressure have a more upright posture, while modern broilers present a larger pectoral muscle mass and increased meat yield, tending to bow forward during the stance phase (Havenstein et al, 2003;Schmidt et al, 2009;Caplen et al, 2012).…”

“…Fast growing broilers tend to become lame and bow forward (Almeida Paz et al, 2010). As a consequence of this unstable equilibrium condition, the angle from the center of the body mass toward the ground tends to become wider than normal, affecting the gait and deteriorating the welfare (Bessei, 2006;Caplen et al, 2012).…”

Effects of the level and duration of feeding restriction on carcass components of broilers

“…In fact, sudden death syndrome (Govaerts et al, 2000) and ascites (Kalmar et al, 2013;Wideman et al, 2013) are wellknown problems in these broilers, in addition to low immunity and disease resistance . Moreover, increased pressure on legs and hips leads to limb abnormalities, which reduces the ability to move (Caplen et al, 2012). Ultimately, mortality and welfare are also associated with broiler rapid growth (Leeson and Summers, 2001;Dawkins and Layton, 2012).…”

Diagnostic Application of Multirow Computed Tomography of the Hip Joint of Japanese Quails (Coturnix Japonica)

“…Multirow computed tomography scanners (MCT) and magnetic resonance imaging (MRI) have been significantly improved, and today enable the diagnosis of various types of diseases. The influence of these diseases on locomotion disorders of poultry have been studied using optical 3D techniques (Caplen et al, 2012).…”