Coastal Sub-humid Zone

Figure

Typical Problems In This Area

1. The weather conditions are suitable for transmission of stomach and intestinal worms throughout the year, so worm numbers can be high.

2. Because of the high temperature and humidity, worm eggs develop to the infectious stages very quickly, so problems can build up rapidly.

3. There are high rates of Haemonchus, Trichostrongylus and Oesophagostomum.

4. Sites for transmission of liver fluke are common.

5. Both clinical and chronic worm infections are made worse by the presence of trypanosomiasis. Care is needed in deciding a cause for anaemia.

6. Mixed infections of fluke, roundworms and trypanosomes can occur.

7. SEVERE RISK OF ANTHELMINTIC RESISTANCE.

Features Of The Area That Can Help In Control

1. Due to the high temperatures, larvae do not survive very long on pasture.

2. If ground is kept completely free of animals for a period of four weeks it will be clean.

3. The presence of palm trees can help in providing evenly spaced tethering points for use in a rotational grazing system

Control Methods That May Be Useful

· Frequent observation of individual animals and treating only clinical cases.

· Rapid Rotation around a series of paddocks or tethering points.

· A Dose & Move system where all animals in the flock/herd are treated and moved onto clean ground.

· Medicated feed blocks can be made with locally available ingredients and provided to the animals overnight in the boma.

· Keeping local breeds of animals rather than exotics can lead to higher production at lower treatment costs (Genetic Resistance).

· GUIDELINES FOR USE OF ANTHELMINTICS SHOULD BE CAREFULLY FOLLOWED TO SLOW THE DEVELOPMENT OF ANTHELMINTIC RESISTANCE.