The Effect of Ultraviolet Radiation on Egg Production of Hens

LIGHT is generally thought of as being radiation that is visible to the human eye, that is, the electromagnetic radiation spectrum from a wave length of about 4000 to 8000 angstrom units. Immediately below this visible range is the ultraviolet radiation which, although not perceptible to the human eye, produces such marked effects as the killing of bacteria, causing sunburn and the fluorescing of certain materials. These invisible ultraviolet radiations may be separated into three general regions in a manner similar to division of visible light which is classed in its three primary colors: red, blue, and yellow. These ultraviolet regions are: Bactericidal, which ranges from about 2000 to 2800 angstrom units. Erythemal or suntan, which ranges from about 2800 to 3200 angstrom units. Blacklight, which ranges from about 3200 to 3800 angstrom units. Radiations from the erythemal band 2, which peaks at about 2967 angstroms, activate . . .