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Broilers

Broilers

by Alberta Algriculture

What is ascites?

Ascites syndrome is a type of congestive heart failure seen mainly in young rapidly growing meat type chickens. It has become a major concern to the poultry industry around the world and it is extremely common in Alberta poultry flocks.

Ascites is an accumulation of protein rich fluid in the body cavity. Because of the high protein level, there may be clots of yellow, jelly-like material.

In birds, the right side of the heart is thin walled and the valve on this side consists of a flap pushed against the wall of the heart. As well, lungs of birds are different from those of animals. Bird lungs have very little ability to expand and the blood capillaries in the lungs are not able to handle increased blood flow or blood pressure.

When the right heart encounters increased blood pressure in the arteries of the lungs, it responds to increased workload, as other muscles do, by getting bigger. If the pressure remains high, the muscle continues to thicken until the valve no longer is able to completely close. This causes blood pressure to rise in the veins leading to the heart, especially from the liver. The result is an increased pressure in the liver with leakage of blood fluids, without the red blood cells, into the body cavity forming ascites.

What causes it?

  1. The genetics of meat birds has changed dramatically in the last ten years. Today's broilers grow much faster, eating less feed. The growth of the heart and lungs has not increased in size proportional to the increase in body weight and breast meat yield. The rapid growth of the bird means more oxygen demand, requiring more work out of the heart and lungs.
  2. Anything that limits oxygen uptake from the lungs is going to cause the heart to work harder. Diseases of the lungs and poor ventilation may be involved.
  3. Excess levels of sodium in the water or salt in feed leads to increased blood pressure in the lungs. Many well waters in Alberta have high levels of sodium. Levels of sodium over 400 ppm could cause problems in broilers.
  4. High altitudes have long been known to cause heart failure and ascites.
  5. Chilling is a common cause in small flocks. It causes an increased blood flow through the lungs.

Signs of the disease

Broilers with ascites look bluish because they are not getting enough oxygen in their blood. They have trouble breathing and often just sit and pant. They tire out easy and often die on their bellies. When it occurs within the first week of life, too much salt in feed or water usually is involved. Because the heart failure takes time to develop, most deaths begin at about 3 weeks of age.

Birds that die from ascites are quite easy to recognize. If their belly is opened as in proceeding to clean the bird, a cup or more of fluid or jellied material will pour out. Sometimes birds with the condition die from the effects of too much blood and fluid in their lungs before there is any significant amount of fluid in the body cavity.

Control

Ascites can be controlled by slowing the growth rate of the birds to reduce oxygen requirements. This can be done by restricting feed, feeding a mash diet, or using a less dense (lower energy and protein) diet. The other things causing ascites need to be controlled. If your water has high levels of sodium, consider using an alternate source of water that is better quality for the first 3 - 4 weeks. Take care to prevent chilling or overheating while at the same time maintaining proper ventilation.

Summary

As one can see, the cause of ascites is increased blood pressure in the lungs leading to a failing heart. The things that can lead to increased pressure and a failing heart are many. There is no one easy solution. Losses from the condition can be greatly reduced once problem areas are identified and eliminated.

Age in Days 24 hours light
0 - 4 24 hours light
4 - 7 18 hours light
6 hours dark
7 - 14 6 hours light
8 ½ hours dark
1 hour light
8 ½ hours dark
14 - 21 10 hours light
6 ½ hours dark
1 hour light
6 ½ hours dark
21 - 28 14 hours light
4 ½ hours dark
1 hour light
4 ½ hours dark
28 - 35 18 hours light
6 hours dark
35 days to market 24 hours light

Be sure to always have ample feeder space to allow all birds to eat at one time. If you feed your own grains after 3 ½ weeks, be sure to add one part 38% - 40% concentrate to three parts grain to ensure proper protein and vitamin level.


Age in Weeks  

0 - 3 ½

20% Medicated Chick Starter

3 ½  - 7

16% Medicated Poultry Grower

7 - Market

14 – 16% Plain Roaster Finisher

Broiler Growth & Feed Consumption Chart*

*These figures apply to broilers raised under industry standard condition

  Age in Weeks

LIVE WEIGHT (lbs)

 FEED CONSUMPTION (lbs)

End of Week

Weekly Gain

  Weekly

Cumulative

 1

 .33

 .25

 .30

 .30

2

.81

.50

.73

1.02

3

1.48

.67

1.15

2.17

4

2.28

.81

1.60

3.78

5

3.19

.93

2.10

5.87

6

4.18

1.00

2.58

8.45

7

5.20

1.03

3.13

11.58

8

6.28

1.09

3.42

15.00

9

7.37

1.09

3.75

18.74

By Alberta Agriculture

Also known as Acute Death Syndrome

Flip-over disease, or acute death syndrome, can cause a serious mortality rate in broiler chickens.

Flip-over disease usually affects the larger, and rapidly growing, broilers that are between 2 and 12 weeks old. Most cases occur when the birds are between 3 and 5 weeks old. Although the percentage of birds affected is usually low, perhaps about one percent, in some instances it may be as high as 5 percent. The condition can also affect small farm flocks.

Small farm broiler flocks may be affected by the disease, but it is not usually a problem in these situations because the rations are often not conducive to rapid growth.

Signs

Birds that succumb to flip-over disease are often found dead on their stomachs with their legs stretched out behind them and their necks extended forward. Occasionally, a dead bird is fount on its back. There is rarely any sign of sickness prior to such deaths, but some people have observed a bird, which appeared to be perfectly normal, suddenly squawk, and make a small jump into the air and land on its back. The wings flutter, there are some convulsive movements and the bird is dead.

Cause

The cause of flip-over disease is still obscure. Heart attacks and enterotoxemia have both been suggested as causes, but neither theory has been substantiated.

Prevention

Decreasing the light intensity in commercial broiler barns, thereby slowing down the activity of the birds, appears to reduce the incidence of flip-over disease. Inhibiting the growth of the birds has also been reported to reduce the problem, but this is obviously not a practical approach. Apart from keeping the birds as calm as possible, there is very little that can be done to prevent flip-over in flock of broilers, or to prevent it from occurring in other flocks, until the cause of the condition has been determined.

By Miller Hatcheries

The raising of heavy meat birds can lead to leg problems due to the rapid weight gain of this particular breed of chicken. Over the years, this has become a great concern with the primary breeders and as yet, no one solution to this problem has been diagnosed. We have developed a few recommended methods which may help minimize this problem.

  • Chicks or turkeys should never be started on paper or any other slippery surface.
  • After your broilers are 10 days old, move the waterers near one end of the building and the feeders near the other end. This keeps your birds moving around and helps reduce leg problems.
  • It is very important that your birds feel comfortable.

  • We find that in over 90% of the cases where people encounter severe leg problems, they are cleaning their brooder house quite frequently. This is not recommended.
  • Until the birds are moved out, the original litter should be left on the floor and any fresh litter should just be added on top of the already existing litter. This existing litter can be dried out by the use of hydrated lime and frequent stirring
  • Never use white lights for lighting during the brooding period.

Be sure to always have ample feeder space to allow all birds to eat at one time.

If you feed your own grains after 3 ½ weeks, be sure to add one part 38% - 40% concentrate to three parts grain to ensure proper protein and vitamin level.

  • Always provide at least 1 gallon fount for water/50 baby chicks.

    NOTE: Watch chicks closely until they all get a good drink so they do not pile in the waterers.  

    • Do not use sawdust for litter·
    • Do not leave unattended for at least 30 minutes.·
    • Do not use warm water.·
    • Clean waterers daily and fill with fresh water.  
  • When using shavings, as litter be sure to provide feed in cardboard trays or 2 ½ dozen egg flats, etc. to provide easy access to the feed. Many feeder trays will prevent litter eating and lessen chances of losses.
     
  • We recommend using a 20% medicated chick starter or a 23% broiler starter. Keep the feed troughs full for the first three to four days.
     
    • Once the birds are four days old remove the feed troughs at night, leaving the waterers only. This allows the birds to rest and should help the livability without affecting the growth rate.

      NOTE: When you do this you must have enough feeder space so all birds can eat comfortably at one time. You should have a minimum of 2" feeder space per bird. For example: for 100 birds you would need 2 - 48" feeders.  

    • Continue to pull the feeders at night until you are off of chick starter at approximately 3 to 4 weeks.  
  • After 3 or 4 weeks you can switch to a 16% or 18% grower. You can now begin leaving the feeders in for longer periods of time. Once you take the brooding lamps away at night you no longer need to pull the feeders.

    NOTE: If you do not use a prepared grower but rather your own grains, be sure to mix approximately 1 part 38% - 40% concentrate to 3 parts your own grain.  

  • Birds require good ventilation without drafts in order to perform properly. Always try to provide ventilation high up on the walls to prevent any drafts on the birds at floor level.

    NOTE: Be sure birds do not become chilled at night or overheated. This will bring on a condition called ascites and can cause severe mortality from four weeks of age on. (Please refer to the ascites information sheet.)

NOTE: If you live in an area with a high amount of sodium in the well water, try to provide water from another source.

  • Refer to the approximate growth and feed consumption chart that should be a guide to you.
  • If you run into problems, call us for advice.