Social facilitation between commercial broilers and Nigerian indigenous chicks and its effect on their welfare

This study was undertaken to investigate how social facilitation between two chicken breeds could affect their welfare. Sixty chicks each of a commercial broiler (CB) and Nigerian indigenous chicken (NIC) breed were used for this study. At four days of age, the birds were randomly assigned into three treatments namely: T1 – singlestrain CB (10 birds), T2 – single-strain NIC (10 birds) and T3 – mixed-strain (5 CB and 5 NIC) each having three replicates. Feed intake and weight gain were measured from the 1^st to the 4^th week of age. Behavioural observations were undertaken between 09:00 h – 10:00 h for three consecutive days per week from the 2^nd to 7^th week of age. At the end of the 7^th week, six birds per treatment were randomly selected for test of fear (tonic immobility) and level of stress (heterophil/lymphocyte ratio, H:L). Data collected were subjected to multivariate analysis using SPSS (version 21). A higher percentage (P < 0.05) of the CB displayed feeding, drinking and sitting compared to the NIC. However, higher percentage (P < 0.05) of the NIC displayed preening, foraging and standing behaviours compared to the CB. The percentage of birds drinking was greater in the mixed-strain (MS) compared to single-strain (SS). Also, there was a significant difference (P < 0.05) in breed × flock structure (FS) interaction on feeding and sitting behaviours specifically for NIC, where the percentage of NIC feeding was greater in the MS compared to SS. However, percentage of NIC sitting was greater (P < 0.05) in the SS compared to MS. CB were more fearful (P < 0.05) than NIC and chickens in the MS were less fearful (P < 0.05) compared to SS. The level of fear was reduced (P < 0.05) in the CB and NIC reared in MS compared to SS. H:L ratio was similar in CB and NIC reared either as SS or MS. Feed intake followed this trend T1 > T3 > T2. CB gained more weight compared to NIC. Body weight gain was similar in the SS compared to MS. In conclusion, MS management system had a positive influence on the welfare of both breeds.