Artificial light, as an environmental factor, is crucial for the release of hormones that play a key role in a bird's life, growth, immunity and reproduction. For laying hens, light plays an important role in the development and functioning of the reproductive system, significantly affecting the age of laying the first egg, egg-laying and productivity in general. The source of artificial light of the latest generation in poultry farming is LED lamps. Compared to incandescent and fluorescent lamps, LEDs have a longer service life, specific spectrum, lower heat output, higher energy efficiency and reliability, as well as lower maintenance costs, so they are increasingly used by manufacturers. LEDs are a special type of semiconductor diode that can give monochrome light. However, information on the effect of monochrome light with different wavelengths of light on the physiological state of the hens’ body is quite contradictory. Therefore, the aim of the work was to study the efficiency of egg production using monochrome light with different wavelengths. For this purpose, in the conditions of a modern complex for production of food eggs in a poultry house with an area of 2915 m2, 4 groups of hens of the industrial herd "Hy-Line W-36" were formed, each of which was kept in a separate poultry house similar in area and cage equipment. Each poultry house was equipped with cage batteries "Big Dutchman" (Germany), consisting of 1176 cages with an area of 40544 cm2 (362 × 112 cm). The differences between the poultry houses applied only to LED lamps. Thus, hens of the 1st group were kept using LED lamps with a peak light wavelength of 458 nm (blue color of the spectrum), the 2nd group – 603 nm (yellow color of the spectrum), the 3rd group – 632 nm (orange color of the spectrum) and the 4th group – 653 nm (red color of the spectrum). Every day, for 44 weeks of the productive period, the number of eggs laid by the laying hens of each group and the intensity of their laying were determined. The number of hatched hens (due to death and culling) was also counted daily and the number of livestock was determined. Once a week, the weight of eggs and live weight of laying hens were measured from certain labeled cages according to a sample. The European egg production rate on the basis of productivity was determined. It was found that for the maintenance of laying hens of modern white-egg crosses in 12-tier cage batteries of classical designs, it is advisable to use lighting with a peak wavelength of 653 nm, that is with red light. This makes it possible for the 44-week egg-laying period to receive an additional 4.8–18.8 million eggs from each poultry house (0.4–1.6 thousand eggs per 1 m2 of its area) at the highest level of the European egg production rate at 1.0–3.8 units The decrease in the peak wavelength from 653 to 632 nm, which was manifested by a change in light from red to orange, was accompanied by a decrease in the preservation of livestock by 0.7% (3.8% ˂ normal), body weight – by 0.6% within physiological norms, egg-laying per initial laying hen – by 2.9% (5.3% ˂ norm), which caused a decrease in the gross yield of eggs by 4.5 million eggs and egg mass – by 3273 tons from each poultry house, including 1.6 thousand eggs and 112.3 kg per 1 m2 of its area, with a decrease in the level of European egg production rate by 1.0 units. The decrease in the peak wavelength to 603 nm, that is the change in the color of light from red and orange to yellow, was accompanied by a decrease in the preservation of livestock by 6.0–6.7% (9.8% ˂ normal), body weight – by 1.0 –1.7% within the physiological norm, egg-laying per initial laying hen – by 6.6–10.3% (11.6% ˂ of the norm) and feed consumption – by 0.6–0.7% (7.5%) > norms), which led to a decrease in gross egg yield by 7.8–12.6 million eggs and egg mass – by 505.7–833.0 tons from each poultry house, including 2.7–4.3 thousand eggs and 173.5–285.8 kg per 1 m2 of its area, with a decrease in the level of the European egg production rate by 1.6–2.6 units. The decrease in the peak wavelength to 458 nm, that is the change in light color from red, orange and yellow to blue, is accompanied by a decrease in the preservation of livestock by 4.2–10.9% (14.0% ˂ normal), body weight – by 2,3–4.0% (0.2% ˂ of the norm), egg-laying per initial laying hen – by 5.6–15.3% (16.5% ˂ of the norm) and feed costs – by 2.0–2.7 % (5.3%> norms), which led to a decrease in gross egg yield by 6.1–18.8 million eggs and egg mass – by 365.3–1198.3 tons from each poultry house, including 2.1–6.4 thousand eggs and 125.3–288.9 kg per 1 m2 of its area, with a decrease in the level of the European egg production rate by 1.2–3.8 units.
Metabolic Obesity in People with Normal Body Weight (MONW)—Review of Diagnostic Criteria