The effects of Newcastle disease and infectious bursal disease vaccines, climate and other factors on the village chicken population in North-Eastern Nigeria

Author: A. D. El-Yuguda, U. M. Dokas and S. S. Baba ^*

Received 29 August 2004, accepted 14 November 2004.

Abstract

The effects of viral vaccines, climate and other factors on the population of scavenging village chicken was carried out in four village units (designated A, B, C and D) in the North-Eastern Nigeria between the months of October, 1999 and February, 2000. Newcastle disease (ND), infectious bursal disease (IBD) and a combined ND and IBD vaccines were administered to birds in the villages A, B and C respectively, while the birds in village D served as the unvaccinated control. A gradual insignificant (P> 0.05) decline in the chicken population was observed over the study period within each village unit. However, marked decrease in population was observed in the control village D, indicating that the use of ND and/or IBD vaccines significantly reduced the losses in the flock of chickens in the vaccinated village units. In addition, the effects of the two vaccines on chicken population were comparable. A considerable decrease in the population of birds in all villages (significant at P<0.05 in village D) was generally observed between the months of November, 1999 and January, 2000 that coincided with the cold, dry harmattan season in the study area. The population of chicks was significantly (P<0.05) higher than those of growers, layers and cockerels within each village unit. In addition, within a village unit, significant proportion of pigeons and ducks are usually raised with chickens when compared to populations of Guinea fowls and doves. Besides ND and IBD virus infections, sudden death, slaughter, missing and sale of chickens are important factors in the reduction of chicken population in the study village units.