Effect of genotype and sex on physiological response and haematological indices of four different strains of broiler chicken

Abstract

The experiment was conducted to investigate the effect of genotype and sex on physiological response and haematological parameters of Arbor Acre (AA), Arbor Acre Plus (AAP), Cobb and Ross. A total of two-hundred day- old chicks of mixed sexes were allocated at into five cells. Physiological parameters considered were Respiratory Rate (RR), Pulse Rate (PR), Rectal Temperature (RT), Skin Temperature (ST) and Heat Stress Index (HSI) which were measured at week 4, 8 and 12. Blood samples were collected via brachial vein and analysis of Mean corpuscular volume, Mean corpuscular haemoglobin, Mean corpuscular haemoglobin concentration Haematocrit (HCT), Platelet, Red blood cell (RBC), Haemoglobin, Packed cell volume (PCV), White blood cell (WBC) and its differentials were determined. There were significant (P<0.05) effects of genotype and sex on RR and PR across ages. Arbor Acre Plus exhibited lowest RR, PR and favourable haematology under heat stress with higher level of PCV and WBC. Males showed higher RR and PR, which suggested that male broilers experienced higher cardiovascular stress under heat stress. There was a significant (P<0.05) effect of genotype and sex on all haematological parameters except RBC and HCT. Based on the chicken superior heat tolerance and strong immune profiles therefore, AAP chickens are recommended for production in high ambient temperature environments.