Effects of strain and sex on the behaviour of free-range slow-growing chickens raised in a hot environment

Behaviour is a good indicator of the well-being of chickens. The objective of the study was to compare foraging behaviour in males and females of three indigenous chicken strains under generally hot free-range conditions. Behavioural activities were monitored in 21-wk-old Potchefstroom Koekoek (PK), Ovambo (OV) and Naked Neck (NN) chickens. Birds were separated by sex and allocated to four pens of Chloris gayana. Three birds per pen were randomly chosen and marked with paint 20 min before observation. Temperature humidity index (THI) was calculated and main effects analysed using the general linear models procedure. Naked Necks spent more time walking than OV and PK. Strain did not affect other behaviours. Females spent more time foraging, while males dominated standing and walking. There was negative correlation between THI and time spent foraging. There was interaction between strain and sex on time spent standing. Foraging and drinking behaviours were more prominent in the morning (07:00 h) and late afternoon (17:00 h) compared to the 12:00-h period, whereas preening and dust-bathing were dominant around mid-day. Strain, sex and THI influence behaviour in free-range chickens. Breeding programmes should be cognizant of these attributes in order to produce hardier birds in view of worsening climatic uncertainties.