A Longitudinal Study to Identify the Causes of Mortality in Fayoumi and Rhode Island Red Chickens and the Immune Status of the Birds against Newcastle Disease
Keywords:Fayoumi chickens, Rhode Island Red (RIR) chickens, Newcastle disease (ND), Newcastle disease virus (NDV), Survival rate, Incidence rate, Haemagglutination inhibition (HI)
With a prospective longitudinal study undertaken between November 2005 and July 2006 survival rates and disease status of Fayoumi and Rhode Island Red (RIR) chickens, reared at a government poultry farm, Pahartali Zonal Poultry Farm (PZPF), were assessed. Immune status of these chickens against Newcastle disease (ND) was also determined by estimating the haemagglutination inhibition (HI) titre to Newcastle disease virus (NDV) in blood sera of the chickens. The results showed that, at the end of the 37 week, the survival rate of the Fayoumi and RIR chickens were 87 and 81% respectively. The difference of the survival rates between the two groups was significant (p <0.05). Among the diseases, coccidiosis was the predominant disease affecting both the populations. The incidence rate of coccidiosis, coccidiosis plus enteritis, salmonellosis, colibacillosis and heat stroke in Fayoumi and RIR chickens was 0.095 and 0.135, 0.064 and 0.057, 0.007 and 0.010, 0.006 and 0.012, and 0.017 and 0.016 respectively. The HI titre dynamics showed that, in case of Fayoumi (except 1st month), HI titre was always >log2 6.4, which was well above the protective threshold. Like Fayoumi, the highest level of HI titre (>log2 6.9) to NDV in the RIR chickens was recorded in the same month and almost identical ranges of HI titres to NDV were recorded in both Fayoumi and RIR chickens throughout the study period.
Keywords: Fayoumi chickens, Rhode Island Red (RIR) chickens, Newcastle disease (ND), Newcastle disease virus (NDV), Survival rate, Incidence rate, Haemagglutination inhibition (HI)
Bangladesh J Microbiol, Volume 24, Number 1, June 2007, pp 47-51