Semakula J.,National Agricultural Research Organization Secretariat |
Lusembo P.,Mukono Zonal Agricultural Research and Development Institute |
Mwesigwa M.,Mukono Zonal Agricultural Research and Development Institute |
Ssennyonjo J.,Mukono Zonal Agricultural Research and Development Institute |
And 3 more authors.
Livestock Research for Rural Development
Data were collected on the health performance of indigenous chickens in two districts of the Lake Victoria Crescent Agro-ecological Zone (LVCAZ) of Uganda with the aim of determining the infectious causes of mortalities. A total of 240 chicken keeping households were engaged in the longitudinal study in which survival and mortalities were monitored in a longitudinal study for one year. During the study period 6,226 mature birds, which belonged to different sex categories,were found dead as a result of disease occurrence. Organ samples were taken from every dead bird for laboratory analysis. Additional data were collected on health history and post-mortem findings for birds which died. The incidence rate of mortality was 0.230 per mature bird-months at risk. Of the total deaths 90% were diagnosed coming from single or mixed type of infections. Whereas in the baseline survey, responses based on farmer observed clinical signs ranked the infectious causes of chicken death as Salmonellosis (37%), Newcastle Disease (ND) (28%), mixed infections (16%) and Coccidiosis (14%) related infections in order of commonality and importance in the study areas, post-mortem and laboratory findings showed a slight deviation. Newcastle disease had the highest proportional mortality rate (46%) followed by mixed infections (30.3%). The proportional mortality caused by Salmonellosis, Coccidiosis fowl cholera, fowl pox and undiagnosed cases were 7.02 %, 4.58%, 0.321%, 1.27%, and 10.36%, respectively.Vaccinated birds were 3.7 times more likely to survive (P < 0.01, χ² = 306) during the scourge. Chicken mortality was also significantly linked to seasonal changes (P <0.05, χ² = 157) with critical times (March to May and October to late November) which are the two wet seasons, showing the highest mortality rates. Time between last vaccination against ND and disease outbreak incidence significantly (P < 0.01) affected mortality of chicken. A logistic regression model of last vaccination (against ND) time prior to incidence with the proportion of the death was significant (P < 0.01, χ² = 121.06). The model indicated that the shorter the last vaccination times prior to occurrence of incidences the higher the survival of flocks. It was concluded that the main infectious causes of death in scavenging flocks were treatable (Bacterial and Coccidial) and immunizable Newcastle Disease, strategic control of which could help minimise mortalities considerably. © 2015, Fundacion CIPAV. All rights reserved. Source