Aim: A study was undertaken
to develop a forecasting model for predicting bluetongue outbreaks in North-west
agroclimatic zone of Tamil Nadu, India.
Materials and Methods: Eleven
bluetongue outbreaks were characterised by active and passive surveillances for
a period of twelve years and used in this study. Meteorological data comprising
of maximum and minimum temperatures, relative humidity, rainfall and wind speed
were collected and used as the multiple predictor variables in the multiple
liner regression model.
Results: A multiple liner regression model was
developed for the North-west zone of Tamil Nadu. Values of the dependant
variables were less than or greater than one, and indicated remote or greater
chances of bluetongue outbreaks respectively. The monthly mean maximum and
minimum temperatures, relative humidity at 8.30 h and at 17.00 h IST, wind
speed, and monthly total rainfall of 29.1 - 31.0°C, 20.1 - 22.0°C, 80.1 – 85.0%,
65.1 – 70.0%, 3.1 – 5.0 km/h and < 200 mm respectively, were identified as the
ideal climatic conditions for increased numbers of bluetongue outbreaks in this
zone.
Conclusion: Based on the values obtained from the prediction model,
stake holders can be warned timely through the media to institute suitable
prophylactic measures against bluetongue, to avoid economic losses due to
disease.
Key words: agroclimatic zone, bluetongue, forecating model,
multiple regression, sheep
