Sequential Application of Lambda-Cyhalothrin on Cattle with the ElectrodynTM Method. Results Obtained in Togo in the Context of the African Animal Trypanosomosis Control

Abstract

Smallholders’ access to pour-on-type products was rendered difficult after the price increase of imported products, a consequence of the 1994 devaluation of the CFA franc. They thus turned to less reliable methods for the control not only of ticks, but also of African animal trypanosomoses (AAT) transmitted by tsetse flies or glossinae. To address this problem, the Animal Trypanomosis Control Project in Togo investigated the use of a new application method that combined pour-on method advantages and a lower cost: Electrodyn^TM (Zeneca). This method is based on the electrodynamic spraying of an insecticide formulation (Karate 2.5 ED^®) containing 1% lambda-cyhalothrin. The trial was conducted on 170 head of cattle in the village of Skriback in the north of Togo (304 head at the end of the trial). All the animals were treated between March 1996 and March 1997, and only half of them were treated between July 1997 and July 1998. Before starting the first treatment, preliminary surveys were carried over a one-year period (from February 1995 to February 1996) to obtain precise data on the area tsetse challenge, for before-and-after-treatment comparisons. Results showed that the system was very efficient within the study set-up. It helped reduce tsetse fly densities by 99.55%, and reduce AAT prevalence from 17 to 2% when used in combination with a trypanocide treatment. It also helped improve the herd mean packed cell volume from 27 to 32.5%, when used in combination with a regular anthelmintic treatment. The Electrodyn method is also cost-effective, its cost being a third of the traditional pour-on method. Furthermore, huge additional advantages can be obtained through the joint use of equipment in areas of intensive phytosanitary control. Handling of the applicator (fixed length) and the relatively high cost of batteries are the constraints that may affect acceptability of the technique.