FUNCTIONAL RESPONSES OF FIVE-CHICKEN GENOTYPES RAISED DURING DRY PERIOD IN HUMID TROPICAL CLIMATE

Abstract

The study was conducted to evaluate the effect of genotype and sex on the physiological responses of 5-chicken genotypes raised during dry period of the year in humid tropical environment. Five hundred chicks comprising 5 genotypes at 100 each were raised for eight weeks. Each genotype was further divided into two, based on their sexes and replicated 5 times at 10 birds per replicate. Physiological data via ambient and rectal temperatures, heartbeat rate, relative humidity and temperature-humidity index were collected to determine the health performance of the birds using appropriate statistical software. Results showed that the average relative humidity, ambient temperature and temperature humidity index (THI) during the experimental period were 62.43%, 23.57°C and 25.05 respectively. The heartbeat rate and rectal temperature were significantly (p<0.05) different amongst genotypes in the morning and evening while these values were higher in males than females in the morning. However, there was no difference in the physiological responses between the sexes in the evening. The study concluded that Arbor-Acre chickens performed better and possessed better innate thermoregulatory mechanisms for adaptability in tropical environment than the other imported genotypes. The birds should be considered in areas with high temperature humidity index. The result of this study may be used to design breeding plans for better adaptability and improvement in the health performances of avian species, especially the exotic stocks, when an unexpected rise in environmental temperature occurred.