Dietary Energy Concentration Effect on Performance of White Leghorn Hens at Various Densities in Cages

Abstract

White Leghorn hens housed at cage floor densities of 660, 440, or 330 cm2 each (2, 3, or 4 per cage) were fed diets with 2,737, 3,003, or 3,322 kcal/kg of metabolizable energy from 21 to 73 weeks of age.As density of hens per cage increased, hen-day egg production and efficiency of feed utilization were reduced, whereas mortality increased. Final body weight decreased most with 4 hens per cage. Feed intake, energy intake, and egg quality characteristics were little affected.Dietary energy level did not significantly affect overall hen-day egg production. However, the highest dietary energy consistently resulted in the lowest egg production during the latter part of the experiment. This decrease was most noticeable with hens housed 4 per cage. This confirms our earlier conclusion with heavy, egg-type hens that high dietary energy is not conducive to sustained egg production with high density housing of hens in cages.Increasing the dietary energy level decreased feed intake and consequently increased efficiency of feed utilization. However, energy intake/hen was similar with all diets. Total mortality as well as that caused just by traumatic events increased as dietary energy increased. Egg quality characteristics were little affected by dietary energy.In agreement with our earlier study with heavy, egg-type hens, we conclude that increasing dietary energy level for White Leghorn hens will not reverse the downward trend in egg production that occurs as hen density in cages increases. The only depressive effect of increasing hen density in cages that was partly reversible by increasing dietary energy was the decline in body weight.