1- FLHS Is a metabolic or nutritional disease with great economic important in long life birds , It’s characterized by general obesity with an enlarged, liver that becomes soft and friable , production drops 5 -10 % below standard , mortality varies 5 to 30 % and is often caused by sudden death characterized with internal hemorrhage due to rupture of the liver cells usually appears in the second phase of production as high feed calories cumulative problem or after viral or bacterial infections which affects the liver in rearing or production phases appears usually in cage houses with high stocking density and low feed space , Physiological feed back mechanisms allow laying hens to eat according to the first limiting nutritional factor, which is usually dietary energy. So, differences in dietary energy levels must have implications

*     The Main Causes :

2- Over nutrition and its mainly refers to excess energy in the feed when the energy in the feed is high and the protein is low, too much energy is stored in the form of fat in the laying hen, especially in the liver. If the fat could not be transported out of the liver in time, they will accumulate in the liver cells, resulting in fatty liver.

3-   Lack of nutrients such as Choline or Choline Chloride, Betaine , Methionine  , A.A and Vitamins in feed as they help in the synthesis of Lipoproteins to carry fat out of the liver .

4-   Cage system Houses has greatly limited the movement ability and reduced energy consumption of layers and breeders .

5-    Hormone effect  as the high-production and continuous breeds genetic selection makes the birds more physiologically sensitive to fatty liver syndrome , Because the level of egg production is related to the activity of estrogen and estrogen promotes the synthesis and deposition of fat in the liver.

6- The impact of toxins , Aflatoxin mainly is also considered to be trigger that causes fatty liver hemorrhagic syndrome in laying hens ( reduce the ability of the liver to synthesize lipoproteins, there by reducing the ability to transport fat out of the liver, allowing fat to deposit in the liver).

7- Environmental Stress ( Poor housing conditions – Sudden changes in diets – Overcrowding and high stocking density – Low Feeding space – Temperature fluctuations – High Humidity ) .

*       Diagnosis by Post Mortem examination :

8-     The liver is usually pale , yellow , enlarged , and friable, showing varying amounts of hemorrhage , The abdominal cavity often contains large amounts of oily unsaturated fat. The ovary is usually active, at least in the early stages of production , Pale head, wattles, comb, or skin shows hypovolemic anemia.

9-   Fatty liver disorder also impairs calcium metabolism in the bird, thus affecting skeletal integrity and leading to poor egg shell quality interference with the formation of active Vitamin D (1, 25, (OH2) D3) which is vital in egg shell formation process .

10– Prevention and treatment of fatty liver syndrome :

1. Keep the stocking density and feeding space as recommended standard guide ( Birds have selective feeding behaviors and almost 90% of farms in middle east supply feed mash so they will compete for the whole or partial grains of corn which is high caloric content )
2. Keep the amount of energy consumed dietary as standard feeding stage and revising for the feed formula and specifications as every stage in rearing and production as breeds requirements and recommended standard guide .
3. Remove aflatoxin contaminated feed immediately, Max 20 PPM as the effect is cumulative in laying birds .
4. Adding Choline chloride , Betaine to feed as a treatment (1-2 KG ).
5. Adding selenium and minerals from organic Source .
6. If calcium deficiency is suspected, adding large particle calcium to feed 3-5 MM in up to 100% coarse in production
7. Reduce environmental stress specially in hot climate areas as in Middle East, Stick to fully controlled houses , Reduce stocking density , Keep feeding space as standard breeds guides.
8. Lipotropic nutrients are feed ingredients that promote healthy liver function and the export of fat from the live, Methionine, chlorine, Inositol, Vitamin B12, biotin, L-tryptophan, carnitine , Vit E , Vit C, and Biotin , and all A.A% which are essential for proper liver function and fat metabolism.
9. However, Good bio security measures , Body fat control , Standard feed Formula , High quality raw materials ,  are the only successful ways of fatty liver control .

Dr. Ahmed Hamdy

Poultry Breeds Consultant

Technical Veterinary Manager Ommat Co. Saudi Arabia – GCC