Broiler walking ability and toe asymmetry under harsh rearing conditions

Abstract

Morphological asymmetry has been described as a potential broiler welfare indicator, for interpreting the birds' ability to cope with the challenges that may affect its growth. The objective of this study was to evaluate the use of morphological asymmetry data to estimate broiler walking ability and welfare.dBroilers werefed diets supplemented or not with vitamin D. Toes were measured when birds were 42 and 49 days old using digital caliper.the left and right sides of the following four bilateral traits (tarsometatarsus length, outer toe length, mid toe length, and back toe length) were measured twice on intact alive birds by two different researcherh. Data from right and left sides were compared in the two treatments using the Student t-test, and Pearson's correlation was used to analyze the total asymmetry found as a result of the total sum of the differences in the measurements. Asymmetry data were comparedwith the total numberof leg lesions. Mid toe and tarsometatarsus asymmetry resultswere considered as actual fluctuating asymmetry, and presented normal distribution (Test of Kolmogorov-Smirnov, p >0.05). However, back toe and outer toe measurements were not normally distributed, as determined by the test of Kolmogorov-Smirnov (p <0.05), indicating anti-asymmetry; when comparing right with left limb,results were significantly different fron zero (t-Student, p <0.05) indicating directional fluctuating asymmetry.The welfare of broilers withwalking difficulty due to the presence of severe asymmetry in limbs is poor

Associations between welfare and ranging profile in free-range commercial and heritage meat-purpose chickens (Gallus gallus domesticus)

“…Walking difficulties in broilers with poor gait scores has been extensively studied ( Weary et al., 2006 ; Naas et al., 2009 ). Rapid growth rate is the main cause of locomotion problems ( Bessei, 2006 ) with the frequency of leg disorders increasing proportionally to body weight ( Baracho et al., 2012 ). However, continuous exercise has been shown to contribute to increased bone strength in poultry ( Bizeray et al., 2000 ).…”

“…Relations of toe damage and asymmetry with walking difficulties, reduced mobility, and reduced possibility to access resources exist ( Baracho et al., 2012 ). Although use of slower-growing broilers such as Sasso, as an alternative to fast growing hybrids, has shown to be more efficient in reducing many welfare issues, like leg weakness ( Bessei, 2006 ), heritage breeds of poultry like Green-legged Partridge seem to withstand production under organic conditions better regarding leg health.…”

Effects of different floor materials on the welfare and behaviour of slow- and fast-growing broilers

“…Hock-joint dermatitis was assessed using a five-scale score in accordance with RSPCA (2017) to levels 0: no discolouration or lesions present on hocks; 0.5: less than 25 % of the hock is covered with a lesion; 1: between 25 % and 50 % of the hock is covered with a lesion; 1.5: between 50 % and 75 % of the hock is covered with a lesion; 2: more than 75 % of the hock is covered with a lesion. Foot-pad lesions were scored according to five levels: a score of 0 indicated no lesion, 1 indicated a very small or superficial lesion, 2 indicated a mild lesion (minor superficial lesion), 3 indicated a medium-severity lesion (moderate hyperkeratosis), and 4 indicated a severe lesion (deep and large epithelial necrosis) (Welfare Quality Consortium, 2009;Butterworth, 2013;Pagazaurtundua and Warriss, 2006).…”

Walking Behaviour and Spatial Use of Broiler Chickens

“…Furthermore, their experiment showed that distance walked was affected both by physical ability and motivation [17]. In another very recent research, the use of morphological asymmetry data to estimate broiler walking ability and welfare was investigated by [18]. It was concluded that the welfare of broilers with walking difficulty due to the presence of severe asymmetry in limbs is poor [18].…”

“…In another very recent research, the use of morphological asymmetry data to estimate broiler walking ability and welfare was investigated by [18]. It was concluded that the welfare of broilers with walking difficulty due to the presence of severe asymmetry in limbs is poor [18]. In another research in 2013, the effect of different LED light colour on the behaviour and fear responses of broilers was investigated by [19].…”