Bahamas Farmer Information System

Connecting Farmers, Growing Futures in the Bahamas
Poultry Bulletin 7

How to get the BEST from your Hens

Bulletin #7

Common problems affecting Laying Hen Production

Managing Parasites on your farm

  1. External Parasites

Significant problem affecting table egg production in Jamaica. The tropical fowl mite is a blood sucking arthropod (Ornithonyssus bursa) that can exist both on and off the host. It lays its eggs along the feather shaft and has a life cycle of 4 days. Detecting and monitoring the mite population level is an important factor for effective control. A minimum of 10 randomly selected birds should be examined for mites weekly. Infestation levels can be estimated by parting the bird's feathers to expose the skin and counting the mites that are immediately seen.

The following index can be used to estimate mite infestation levels:

 5 mites counted =       Bird may be carrying from 100 to 300 mites

 6 mites counted =      Bird may be carrying from 300 to 1,000 mites (light infestation)

7 mites counted =      Bird may be carrying from 1,000 to 3,000 mites - small clumps of mites seen on skin and  feathers (moderate infestation).

8 mites counted =        Bird may be carrying from 3,000 to 10,000 mites - accumulation   of mites  on skin and feathers (moderate to heavy infestation).

9 mites counted =         Bird may be carrying 10,000 to 32,000 or more mites – numerous large clumps of mites seen on skin and feathers; skin pocketed with scabs (heavy infestation).

  1. Internal parasites,What to look for
  • Body Weight Loss & Poor Flock Uniformity
  • Diarrhoea (Enteritis) & Anaemia
  • Increase in Cannibalism through vent pecking due to straining
  • Reduction in egg production, egg Size and egg quality
  1. Treatment Options
  • Prevention (Biosecurity program)
  • Medicate flocks once every 6 weeks
  • Calculate dosage based on flock weight
  • Rotate worm medicines to prevent worms acquiring resistance to them.
  • Plan a treatment schedule and record treatment dates
  1. Dosage calculation Example
  • Flock Size : 1000 hens
  • Average Hen Wt: 1900 Grams.
  • Product: Parasitol ® (100 grams/Pack)
  • Dosage: 100 grams per 3500 Kg
  • Calculation: 1000 * 1.9 Kg = 1900 Kg
  • Parasitol® Required = (1900/3500)*100 grams = 54 Grams or (1/2 Pack)
  • Mix in amount of water consumed in 1 Day

Record Keeping

Keeping a record of all flock mortality and where possible the cause of death, medication used and treatment duration, observed symptoms, environmental conditions e.g. temperature and the result of veterinary intervention should be kept. These records will assist in troubleshooting flocks exhibiting poor performance.