TY - DATA T1 - Physiological Responses of Slow-Growing Chickens under Diurnally Cycling Temperature in a Hot Environment PY - 2017/12/20 AU - T Mutibvu AU - M Chimonyo AU - TE Halimani UR - https://scielo.figshare.com/articles/dataset/Physiological_Responses_of_Slow-Growing_Chickens_under_Diurnally_Cycling_Temperature_in_a_Hot_Environment/5718487 DO - 10.6084/m9.figshare.5718487.v1 L4 - https://ndownloader.figshare.com/files/10039957 L4 - https://ndownloader.figshare.com/files/10039993 L4 - https://ndownloader.figshare.com/files/10039999 L4 - https://ndownloader.figshare.com/files/10040002 L4 - https://ndownloader.figshare.com/files/10040014 L4 - https://ndownloader.figshare.com/files/10040023 KW - Extensive KW - intensive KW - respiratory rate KW - heart rate KW - strain KW - temperature N2 - ABSTRACT Free-range chicken production has significantly increased in recent years and it often entails exposing birds to cyclic environmental conditions. The objective of the current study was to investigate the effect of bird strain and sex, and rearing system on the physiological responses of Potchefstroom Koekoek (PK), Ovambo (OV) and Naked Neck (NN) chickens reared in a hot environment. Body weight (BW), rectal temperature (RT), respiratory rate (RR) and heart rate (HR) were determined weekly for 4 weeks, in 3 slow-growing chicken strains under cyclic environmental conditions. A total of 288, 20-week old Potchefstroom Koekoek (PK), Ovambo (OV) and Naked Neck (NN) chickens were separated by sex and allocated to extensive and intensive rearing systems. Ambient temperature and relative humidity (RH) were used to compute a temperature humidity index (THI). A Proc MIXED model was used to analyze fixed effects and a linear regression model was fitted to test the relationship between THI and response parameters. All factors studied influenced (p<0.05) BW while none affected (p>0.05) RT. Higher BW (p<0.05) were obtained with OV in both rearing systems. Sex influenced (p=0.0021) HR but not RR (p>0.05). Week and rearing system affected (p>0.05) RR. THI showed significant correlation with RR and HR. THI was higher in intensive than extensive rearing. Physiological responses of PK, OV and NN are comparable under similar rearing conditions. ER -