Efficiency of Feed Utilization in Relation to Body Weight and Egg Production

Titus (1928–29) has estimated that to produce a standard-weight egg, 40 grams of feed were required over and above that needed for maintenance, and in 1934 estimated that not less than 75 per cent of the total feed consumed by laying hens is used for body maintenance (Titus, 1934). Byerly (1941) calculated that the annual feed requirements for maintenance varies from 46.8 pounds for three-pound birds to 81.4 pounds for seven-pound birds and that for each standard-weight egg, 64.4 grams of feed were required over and above that needed for maintenance. Interesting observations were made by Bird and Sinclair (1939) on the energy required for maintenance, egg production, and changes in body weight of females kept in laying cages. A partial correlation coefficient revealed that the amount of ingested feed is positively and significantly correlated with body size, weight of egg material produced, and changes in body weight. They showed . . .