Show chickens need vitamin D to aid egg supply pullets which had no chonce at sunlight no cod liver oil or other sources of vitamin D laid ined an average of eggs from october I 1 tr t april 30 at the university of wisconsin last benr according to dr J G hatpin Hal pla similar pullets fed irradiated yeast laid eggs pullets receiving yeast not lr in radiated laid eggs then pen fed cod liver oil produced 1068 eggs and those allowed to run under tinder a mercury are arc tamp lamp wilc rave gave them ultra violet light 1 laid eggs professor R alpin recommends that houses should have windows framed and hinged so BO they can be opened on bright an days y a in the winter so liens hens may get direct rays of the sun windows having glass substitutes which admit the ultra violet light should be kept clean as the rays giving the liia min D cannot penetrate dirt |