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By Alberta Agriculture

About Blackhead Disease [Histomoniasis]

Blackhead disease, or more correctly, histomoniasis, is primarily a disease of young turkeys. Chickens are more resistant to the effects of the infection but may act as carriers of the disease-causing organism. Histomoniasis is caused by a microscopic protozoan called Histomonas Meleagridis. The name blackhead is a poor descriptive term because the heads of the birds infected with this parasite are not dark. The protozoan causes considerable damage to the liver and ceca of infected turkeys, and the untreated birds usually die.

Histomoniasis can cause considerable losses in farm turkey flocks. It is a disease commonly seen in these birds at veterinary diagnostic labs in Alberta. It is less common in commercial turkeys because their rations contain low levels of histomoniasis preventing agents.

Life History of the Disease

Histomonas meleagridis is most often transmitted to turkeys in the eggs of a second parasite, the cecal worm, commonly found in both chickens and turkeys. The eggs of the cecal worm may remain infective in the soil for three years of longer and could transmit the blackhead-causing protozoan during this period.

H. meleagridis may also be transmitted by earthworms that accidentally eat the cecal worm eggs. The cecal worm larva released from the egg and the blackhead parasite within that larva may remain in the earthworm for a year of more. When chickens or turkeys eat infected earthworms, the cecal worm larvae containing the blackhead parasites are released and a blackhead infection may result.

Turkeys may acquire the blackhead organism directly from the droppings of infected birds. However, meleagridis found free in the droppings and not protected by a namatode egg die quickly, particularly during warm dry weather.


A decrease in feed consumption and loss of weight may be the first signs observed. Sick birds appear dull and depressed, and often stand by themselves with dropping trails, ruffled feathers, and a sleepy appearance. Sulphur colored yellow droppings may be observed. If birds are not treated, or if treatment is delayed, mortality may be very high. Birds dying of histomoniasis have characteristic enlarged livers with circular depressed areas and enlarged ceca containing a rather dry cheesy material (Figures 1 and 2). Recovered birds may show swollen hard and scarred livers at the time of slaughter.


The drug Dimetridazole can be used in the drinking water or feed to control outbreaks oh histomoniasis. Other drugs occasionally are used for treatment but are better used as preventatives. Sick birds should be isolated from the main flock and treated separately. Dead birds should be burned or buried deeply. All equipment used by an infected flock should be thoroughly cleaned and disinfected.

Prevention and Control

The protozoa-causing blackhead may remain infective within the eggs of the cecal worms in the soil for nearly three years; therefore each flock of new turkeys should be raised on new uncontaminated ground. Young turkeys should never be reared near older turkeys or with chickens that may carry the infection. In addition to domestic chickens, various wild birds such as pheasant and grouse may serve as reservoirs of infection for domestic turkeys.

The periodic moving of feeders, waterers, and roosts will help prevent the local buildup of infective organisms. Good sanitation and litter management will help prevent transmission of the cecal worm as well as the blackhead organism. Many histiostats or preventative drugs are available and they are commonly included in commercial turkey rations. Because of the very serious nature of blackhead in turkeys, it is advisable to develop a regular program of preventative drug treatment.

Information prepared by:

  • Poultry Disease Section
  • Animal Health Division


"CEVA Laboratories expresses appreciation to World Poultry Magazine, published by the Farmers Publishing Group, England, for permission to reprint portions of the article which appeared in the March 1986 issue of World Poultry Magazine. The author, Derek Jee, is Deputy Editor of the magazine. CEVA has taken the liberty of changing certain British English terms to American English for this article."

Day old turkeys have been described as suicides looking for somewhere to happen. More than any other species of poultry, getting them through the first days of their lives is absolutely critical, whether they are stock destined for breeding or fattening.

They need what is described as tender loving care (TLC), which includes thorough preparation of the house, correct preheating, proper lighting and the provision of adequate feeders and drinkers.

Any signs of poults huddling together and you have a potential disaster on your hands, but get them over the first six to eight days of their lives and half your problems are over. A specially designed brooder house is essential, preferably one with a controlled environment.

Temperature at day old should be 102 - 104°F for the house. After the first seven days the temperature can be reduced by 5ºF per week.

All drinkers, feeders, lighting and ventilation equipment should be thoroughly checked well before the poults arrive, and house temperatures should be at the correct level at least 24 hours before delivery is due.

Cardboard Guards

Use Cardboard brooder guards to protect poults from drafts and make sure lighting is adequate - - as bright as possible for the first few hours.

Additional feed should be put in the poult feeder lids for the first week and all feeders adjusted so that the lip is at poult beak height. Use supplementary drinkers for the first two weeks, by which time the young turkeys should be fully accustomed to using the automatic feeders and drinkers.

Poults should be eating and drinking regularly within 48 hours of delivery - - less than that if they have had a long journey. If they are not, starveouts will begin to arise at 5 days of age.

Lighting should be continuous for the first 36 - 48 hours, although within the first 12 hours it is a good idea to give the flock a short dark period - - maximum of and hour - - to get them used to it. From then on cut light back fairly rapidly until 14 hours (or natural day length) is reached by five days of age.

To help the poults find feed and water, light intensity should be at its maximum for the first 24 hours. Cut this back to about 60 per cent of maximum thereafter to prevent vent and wing pecking. Poults are not normally beak-trimmed before seven days of age, often later.

Looking after poults is mainly common sense. But such is their apparent death wish you will need to spend time with them just watching their behavior. The key signs to impending disaster are huddling and proportion of the flock failing to find feed and waters.

Table Birds

Having gotten the flock through its poult stage and into growing quarters at perhaps five weeks of age, management will then show wide variations depending upon whether they are reared as breeders or as fattening birds and, if the latter, at what age they will be killed.

All turkey feeds should be crumbled (starter ration) or pellet form. Most feed companies offer a very high protein (27%) super-starter ration for use to four weeks of age, followed by a lower protein starter (23% protein) to be fed to around nine weeks.

Birds suitable for killing at 12-13 weeks would then be put on a special early finisher (20% protein) but those destined for further growth would be transferred to a rearer feed (19% protein).

Flocks for slaughter at around 17 weeks of age would go from this to a "super" finisher (18% protein) at 14 weeks, while the real heavy-weights for killing at over 21 weeks and then be transferred to a "standard" finisher (14% protein) until slaughter.

By Miller Hatcheries

Temperature - Temperature - Temperature

  • Chicks require 90E to 92E F at the floor.
  • Turkeys require 95E at the floor
  • For the first 10 days keep chicks and poults confined to a smaller area close to the heat source, food and water.
  • Provide 3" to 4" of fluffy dry litter. Never start chicks or turkeys on paper or any other slippery source.
  • Until birds are moved out, the original litter should be left on the floor and fresh litter should be added to the top. The existing litter can be dried out by the use of lime and frequent stirring.

Use Proper Feed
Chick Feed for Chicks - Turkey Feed for Turkeys

  • For meat birds, once they are one week old try to regulate how much they eat by feeding smaller portions more often.
  • When feeding farm grains, always provide the proper amount of supplement to give the birds the nutrition they require to perform to their potential.


I. Turkey Introduction

Turkey poults have been described as suicides looking for somewhere to happen, especially day-old poults. More than any other species of poultry, getting them through the first days of their lives is a challenge to producers. Today's turkeys have a tremendous potential for growth; the aim of the grower should be to provide an environment which, through thorough cleaning and preparation of the house, correct preheating, proper lighting and provision of adequate feeders and drinkers, will encourage efficient consumption of feed and allow the poults to express their growth potential.

II. Clean Out & Disinfection/Sanitation

Prior to placement, the brooder house and all equipment to be used should be thoroughly cleaned and sanitized.

III. Setting up the Brooder House & Placing the Poults

A. Brooder Rings: After the house has been cleaned and dried, and 3-5 inches of new litter is spread, brooder rings should be set up. These serve several functions:

  1. To prevent drafts.
  2. To prevent pile-ups of poults.
  3. To keep the poults near food water and heat.

Prior to poult placement, the temperature directly under the brooder should be 95 - 100 degrees Fahrenheit (35 - 38 degrees Celsius), while the temperature at the perimeter of the ring should be 90 - 95 degrees Fahrenheit (24 - 30 degrees Celsius).

Once the poults arrive, use their behaviour to adjust the brooder temperature and height. See Figure 1.

Between 3 and 5 Days after placement, gradually extend the brooder guards/rings. Between 6 and 14 days, reduce brooder temperature approximately 5 degrees Fahrenheit (3 degrees Celsius) per week and gradually raise the height of the brooder. If the temperature is correct, the poults will locate feed and water sooner, which will help prevent dehydration and mortality.

B. Feed: Feeder space recommendation is 1.5 linear inches (4 cm) per poult. Feed troughs or pans should be no more than 1.5 inches (4 cm) above the litter. For the first 2 to 3 days, feed provided in egg flats or meat trays improve feed consumption. Replace these gradually with feed troughs. Feed troughs and trays should be kept as clean and as full as possible, and should be distributed so that poults can eat at whatever temperature is comfortable to them.

C. Water: Provide 0.5 linear (1.25 cm) per bird. Keep in mind the smallest bird when placing waterers and feeders. Birds will consume about 2 to 2.5 times as much water as feed.

D. Water Quality Guidelines: Poults, above all other species, are susceptible to high sodium levels in the water. Maximum recommended should be 300 - 350 ppm; at higher levels than this, the sodium level in the diet needs to be adjusted.

E. Waterers and Feeders: Waterers and feeders should be cleaned daily for the first week to keep them as fresh as possible. Water drinkers may require daily cleaning (emptying and scrubbing) for a longer period, depending on water quality.

F. Lighting: On days 1 and 2, poults should receive 24 hours of light with intensity of 60 - 70 lux (6 - 7 foot candles) at poult eye-level. This high intensity during the first two days will keep poults active, eating and drinking.

IV. The First Weeks/Grow-out

A. Air Temperature: The goal is to drop temperatures about 2 degrees Celsius per week, getting to 22 degrees Celsius (75 degrees Fahrenheit) at the end of the fifth week.

B. Ventilation: A successful ventilation program should:

  1. Supply adequate oxygen necessary for birds' respiration.
  2. Maintain air temperature at a level which will be comfortable for the birds, while not wasting energy (fuel and/or feed) doing so.
  3. Remove moisture from the house and maintain good litter conditions.
  4. 4. Minimize dust and air-borne contaminants.

B. Grit: The feeding of insoluble grit aids the bird's digestion. The following chart is a guideline for providing grit to turkeys.

Age in Weeks Amount/1000 birds/day Size of Grit
0 - 5 5 kg (11 lbs) Starter (#1)
6 - 12 7 kg (15 lbs) Grower (#2)
13 - market 11 kg (24 lbs) Adult (#3,4)