In most animals, both are equally potent. If inadequate levels of vitamin D are fed, induced calcium deficiency quickly results and egg production decreases.įeed grade vitamin D comes in two forms, D2 and D3.

Vitamin D is required for normal calcium absorption and utilization. Young birds should not be fed a high calcium layer diet because the calcium/phosphorus ratio will be unbalanced, resulting in increased morbidity or mortality. The consequence of feeding dolomitic limestone is induced calcium deficiency. Dolomitic limestone contains at least 10% magnesium and this complexes with calcium or competes with calcium for absorption sites in the intestines. However, dolomitic limestone (which is used in the steel industry) should never be used in poultry diets. Periodically, dolomitic limestone is offered to the feed industry. This means that the larger particles of the calcium source are released more slowly, and this may be important for the continuity of shell formation, especially in the dark period when birds do not ordinarily eat. Usually the larger the particle size, the longer the particle will be retained in the upper digestive tract. Particle size affects calcium availability. Birds on the ground or on litter floors recycle calcium and phosphorus through consumption of feces and do not have caged-layer fatigue.Ĭalcium can be supplied in the diet as either ground limestone or oyster shell.

The condition is known as caged-layer fatigue. In severe cases, hens are unable to stand. As calcium stores are depleted, bones become brittle. Hens store calcium in medullary bone, a specialized bone capable of rapid calcium turnover. Inadequate calcium consumption will result in decreased egg production and lower eggshell quality. The pullet's requirement for calcium is relatively low during the growing period, but when the first eggs are produced, the need is increased at least four times, with practically all of the increase being used for the production of eggshells. The eggshell is composed primarily of calcium carbonate. Birds deficient in chlorine are more nervous, showing increased sensitivity to sudden noise. Chlorine also plays a role in maintaining osmotic balance in body fluids. Hydrogen chloride (HCl) released from the true stomach (proventriculus) is important in digestion. Sodium deficiencies adversely affect utilization of dietary protein and energy and interfere with reproductive performance.Ĭhlorine is also an essential nutrient. A continuously low intake of salt can cause a loss of appetite. Sodium is an essential nutrient, playing a major role in maintaining body fluid volume, blood pH, and proper osmotic relationships. Cobalt iodized salt is often used in diets for swine and ruminants, and this can be used without any problems for poultry. Iodine is rarely added as a separate ingredient. Most animal feeds will contain added salt, usually in the form of sodium chloride. Feeding a salt-deficient diet will lead to increased feather pecking and a decline in egg production. Omission of Feed Ingredients SaltĪnimals have an innate desire to consume salt. Prolapse usually causes permanent damage to the hen and is fatal in many cases. Prolapse may occur when the bird is too fat and/or an egg is too large and the bird's reproductive tract is expelled with the egg. Many times these imbalances can cause other problems like oviductal prolapse. Feeding whole grains, scratch feeds, and table scraps will cause the birds' diet to become imbalanced and inadequate.

This is why it is so important to supply laying hens with a constant supply of nutritionally balanced layer food. Inadequate levels of energy, protein or calcium can cause a drop in egg production. Inadequate nutrition can cause hens to stop laying. Laying chickens require a completely balanced diet to sustain maximum egg production over time. In recent years, there has been a trend to extend the egg production period for an additional 15 to 20 weeks and not molt due to welfare concerns over molting. Poorer layers and older hens will molt more often and lay less consistently. Good layers will lay for about 50 to 60 weeks and then have a rest period called a molt. However, after two or three years many hens significantly decline in productivity (Figure 2). Noninfectious Causes Aging HensĬhickens can live for many years and continue to lay eggs for many of these years. Egg production can be affected by such factors as feed consumption (quality and quantity), water intake, intensity and duration of light received, parasite infestation, disease, and numerous management and environmental factors. Unraveling the cause of a sudden drop in egg production requires a thorough investigation into the history of the flock. Many factors can adversely affect egg production. A typical production curve for a laying flock.

Combining two flocks of chickens