Caged Layer Fatigue

Cage layer fatigue is a condition that is unique to hens that are in a high state of egg production, primarily caged layer hens. The cause of the condition is thought to be associated in an imbalance of minerals/electrolytes in the body.

Rickets and abnormal bones in adult birds is commonly present. In layers under thirty weeks of age, the cause is usually a temporary calcium deficiency when egg production reaches eighty percent or higher. If intake of calcium does not satisfy the need for egg production, the hen will remove calcium stored in the bones. Ultimately, osteoporosis develops, bones become soft and hens are subject to bone fractures. Crippled and unable to stand, the hen suffers from the caged fatigue symptoms.

Many hens show spontaneous recovery if removed from the cages and allowed to walk normally on the floor. This indicates that a lack of exercise may be a partial cause. Cage layer fatigue is more prevalent in single-hen cages than in multiple-hen cages. When two or more hens are caged together, they get more exercise because of competition for feed and water.

Supplementation of the diet with phosphate, calcium and vitamin D3 is usually helpful. Adding calcium to young birds by top-dressing the feed with twenty pounds of oyster shell or limestone per one thousand hens will often help the condition. In older hens, calcium deficiency is less likely than phosphorus or vitamin D3 deficiencies. Recommended treatment in these birds is to remove the hens from cages and top-dress feed with equivalent level of dicalcium phosphate. Adding a vitamin/electrolyte supplement to drinking water is recommended in any age bird suffering from this condition.

Flocks that do not respond to the above therapy should be submitted to a poultry disease diagnostic laboratory to determine the cause of the problems. Several diseases can cause symptoms similar to caged layer fatigue. Flock treatment for the condition can be prescribed after diagnosis is completed.
Fatty Liver Hemorrhagic Syndrome

Fatty liver syndrome is a condition that affects only hens. The basic cause is thought to be excessive dietary energy intake. Hereditary tendencies vary among various strains of egg production stock, but heredity is not the entire cause for this malady. Laying hens housed in cages are most often affected since they are less able to get sufficient exercise and dispose of the extra dietary energy.

Birds within a flock that are most often affected are the high producers. This indicates that physiological energy metabolism and production are closely associated with this condition. Mortality varies considerably among flocks but can become excessive in some cases. Lesions include accumulation of large amount of abdominal fat; enlarged, easily damaged liver and presence of blood clots that indicate that hemorrhages have occurred prior to death. Death usually is caused by a fatal internal hemorrhage originating in a portion of the liver. This hemorrhage is often caused as the hen is straining to lay her egg and the enlarged, friable liver is more vulnerable to injury. When a large blood vessel ruptures, sufficient blood is lost to cause death of the hen.

The primary treatment for this condition requires an alteration of the diet or amount of dietary energy consumed. Replacement of some of the corn in the diet with lower energy feedstuffs like wheat bran can provide a lower energy diet. If a complete layer ration is being fed, addition of vitamins can be of benefit. If grains are the primary feedstuff, it is suggested that the birds be switched to a complete layer diet. Control of body fat is the only successful remedy for this condition and is best accomplished by regulation and reduction of total energy intake.