Scientists and farmers actively seek the answer to the question whether changing of feeding conditions can affect edibility characteristics of chicken eggs. Russian researchers are now one step closer to finding the right answer.

Experiments with hens showed that despite concentrations of major nutrient elements in hen’s blood serum was subject to changes due to various external factors, these changes didn’t affect concentrations of calcium, phosphorus and magnesium in eggs of mentioned hens.

Scientists from Ural State Academy of Veterinary Medicine worked with ten laying hens, belonging to Loman white breed. All birds, participating in the experiments, were of the same age, lived in cage batteries at a poultry farm and ate same standard feeding mixtures. Researchers took one egg and blood for analysis from hens at eighteenth, twenty sixth, fifty second and eightieth week of laying eggs. After that, scientists measured concentrations of major nutrient elements in chicken blood, egg white and egg yolk.

During the process of laying eggs a hen loses calcium from its organism for building eggshells, and food is unable to compensate deficit of this essential nutrient. However, calcium content in chicken egg whites and yolks increases with time – studies show that concentration of this element in eggs during week 80 is much higher than that during week 18.

 

 

In an organism metabolism of calcium is tightly connected with phosphorus metabolism. When a hen gets older, calcium content in blood serum, as well as in egg components, slightly increases. Ratio between calcium and phosphorus content remains almost constant no matter when the egg was laid. As for magnesium, an essential nutrient, required for many enzymes and other important substances to function, it is always present in chicken food in sufficient amounts, but its concentration in blood serum is always low and constant in an egg, never depending on egg laying period.

Content of all three mentioned essential nutrients in blood serum is interrelated. Constant concentration of magnesium is supported by lowering calcium content, while concentration and balance of calcium and phosphorus strongly depend on how active parathyrin (a hormone of parathyroid gland, which secretion is regulated by magnesium) is. Parathyrin takes calcium from bones and elevates its concentration in blood.

Therefore, the time, when eggs are laid, has strong effect on concentration of such essential nutrients as calcium, magnesium and phosphorus in blood serum of hens. Concentration of the same nutrients in egg depends on nutritional requirement of a chicken embryo, but is no way affected by concentrations of these elements in blood serum. That is why feeding hens with mixtures, containing increased concentrations of calcium, magnesium or phosphorus, cannot make their eggs contain more nutrients. This information can save millions of rubles (or dollars, if you prefer) to farmers, which spend money for food, enriched in essential nutrients.