What Is Fatty Liver Syndrome (FLS) And Explain The Signs And Lesions Of FLS?

Fatty liver syndrome (FLS) is found in both light-breed and heavy-breed chickens, generally more often in cage layers than in those on the floor. If FLS occurs in floor pens, the chickens are more likely to be of the heavy breed.

Signs: After chickens reach their peak of production, a decline of 10% to 30% in the rate of lay may occur. The decline generally comes after the chickens which have been in production for a few weeks. At the time the FLS problem is recognized, feed consumption is usually very low. Chickens going out of production appear unthrifty but may not show sickness. Mortality, however, is greater than normal.

Lesions: A variety of excessive fat areas may be evident, beneath the skin and in the body cavity.  A typical yellow liver showing extreme infiltration of fat is seen in most affected chickens. A normal liver seldom contains as much as 25% fat, but in affected chickens, the liver may contain as much as 70% fat. It lacks the firm texture of a normal organ and may be soft and mushy.