T HE phosphorus requirement of the laying hen has been studied by many research workers during" the last thirty years. Results reported during the period 1933 to 1953 appeared to indicate a higher requirement than suggested by several more recent reports, and these apparently divergent findings have stimulated additional research at a number of experiment stations. Because of the divergent results, it appeared desirable to review details of both experimental procedures and diet composition in recent and older studies for possible sources of the discrepancies. Among these details have been rate of egg production, length of experimental period, sources of phosphorus, effect of vitamin D level, calcium level, calcium:phosphorus ratios, total feed intake (net phosphorus intake), digestibility of the diet, whether the birds were housed on litter or wire floors, and adequacy of bird numbers and replication such that the results reported were reliable. Although several of these factors have been carefully considered by most workers, concurrent failure to consider others may have permitted conclusions which are of limited value.During egg production, the hen's need

Comparative data collected over two years are presented which refute the popular press claims that blue-shelled eggs of Araucana chickens have higher protein levels and lower cholesterol levels than market eggs. These comparisons were made between the eggs from the strains of Araucanas and those of White Leghorns and Sex-links. None of the differences found between test groups in % protein/g. albumen and % protein/g. yolk were shown to be consistently related to any one test group type. However, all Araucana test groups were significantly (P less than .01) lower in their total egg protein content than either control group by from 2.8--6.5%. This lower total protein content was the result of a consistent increase in the yolk/albumen ratio of the Araucana eggs over the market eggs. The Araucana eggs were consistently higher in their cholesterol levels on a mg./g. yolk basis than either of the market eggs. These increased concentrattions ranged from 2.0--6.9%.

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