The Interaction Between Dietary Calcium and Protein for Laying Hens

A GREAT deal of information is available on the calcium requirement of the laying hen. Much of the recent work in this field has been reviewed by Mehring (1965) and although there are some differences of opinion most workers are in agreement that a dietary calcium level of 2.5–4.0 percent is required for egg production-type birds depending on the conditions. There are also many reports in the literature concerning the protein requirement, and the factors influencing the protein requirement of laying hens. Differences in protein requirements due to strain have been reported by Harms and Waldroup (1962), age and environmental temperature by Reid et al. (1965), dietary amino acid balance by Bray (1965), and dietary energy level by Lillie and Denton (1965). It is apparent that any factor which influences feed intake will affect the requirement of layers for protein and calcium when the requirements are expressed as a …