Effect of kinetic activity on behaviour, productive performance, and carcase quality of different ECC-approved chicken genotypes

Increasing concern in the EU over animal welfare and food quality has strengthened policy pressure on broiler welfare standards and consumer demand for less-intensive systems. The European Chicken Commitment (ECC) promotes slow-growing genotypes to improve welfare, sustainability and sound rearing systems. This study compared two ECC-approved genotypes, slow-growing (SG, Kabir; 30–40 g/day) and medium-growing (MG, Ranger Gold; 40–50 g/day) with a conventional fast-growing genotype (FG, Ross 308; >65 g/day). One hundred chickens per genotype were divided into two treatments: control (C, no stimulation) and moderate exercise (EXC, 30 min/day at ∼4 km/h), all fed the same commercial diets. Growth traits of live chickens’ performance were measured, daily feed intake (DFI), daily weight gain (DWG) and feed conversion ratio (FCR). Behaviour was monitored via a computerised system (Noldus Technology); feather condition, footpad dermatitis (FPD) and sternal lesions were assessed. FG chickens exhibited the highest productive performance but also showed an increased incidence of FPD, sternal lesions, myopathies and reduced comfort behaviours. Conversely, SG birds expressed the greatest proportion of comfort behaviours, albeit with lower productive performance, whereas MG birds displayed decreased comfort behaviours and intermediate performance levels. Exercise elicited genotype-specific responses: in FG chickens, it reduced DWG and worsened FCR due to increased DFI and eating time, conversely MG and SG birds maintained stable performance. Exercise reduced carcase fat across all genotypes. Although both MG and SG strains are categorised as novel slow-growing ECC-approved genotypes, the observed differences between them highlight the need for genotype-specific management strategies.