Lipid metabolism and body composition in long-term producing hens

SUMMARY: The lifetime egg production capacity of laying hens (i.e. laying persistency) has increased tremendously in the last 50 years from 220 eggs in 1960 to 500 eggs in 2019. To improve and support laying persistency, nutrition is crucial to support the hen and provide the correct nutrients for egg formation. Several organs are involved in this long-term egg formation process. The follicles produced in the ovary need to grow and ovulate to initiate egg production. The liver needs to supply the nutrients, mainly lipids, for proper follicle growth and liver fattening must be prevented to maintain liver health and function. Adipose tissue has an important role in maintaining the body energy balance, functioning as a reservoir for fatty acids provided by the diet or produced by the liver. Additionally, adipose tissue might mediate in ovulation through adipokine (hormone) production. As such, body composition of laying hens might have an important role on laying persistency. This literature review discusses the interaction between these metabolic processes, the influence of diet and hormones and the effect on laying persistency.