Show layers require calcium to keep up production the south dakota agricultural cultural experiment station reports the results of five years experimental work in comparing several sources of calcium for or laying hens part ot of its conclusions from this work are as follows over a five year experimental period no significant difference was found in favor of any of the supplements ts used namely oyster shell clam shell black hills limestone limestone when results were judged by egg production egg weights weight and egg breaking strength A lack of calcium fed as a supplement to the ordinary complete ration either all mash or mash and grain markedly decreases egg production and causes a loss of egg shell st bength added calcium is absolutely necessary tor for maximum egg production added calcareous materials can stimulate the calcium secreting part of the oviduct in 24 hours after feeding when such materials had been previously y deni denied ed the hens |