| Popis: |
Attempts to increase egg size and egg production through dietary manipulation of early-matured pullets were attempted. In the present study, 720 pullets were assigned to one of six treatments. Age to first egg was induced early (138.8 days) in the pullets on five of the six treatments; the remaining pullets were conventionally reared and began to lay at 152.4 days of age. The conventionally reared pullets (C-17) and one of the early-matured treatments (E-17) was given a typical 17% protein layer diet. Diets with increased concentrations of methionine, methionine and fat, protein, and protein and fat were given to the remaining early-matured pullets. Egg production, feed efficiency, mortality, and egg size were recorded from 18 to 66 wk of age. There were no significant differences in the hen-housed percentage production or in percentage mortality among the six treatments. Hen-day percentage production (HDP) was significantly depressed in E-17. Increasing the percentage of methionine in the diet of early matured pullets improved HDP to equal that observed for C-17. No additional improvement in HDP was observed by increasing fat, protein, or protein and fat. Pullets on E-17 required more feed to produce a dozen eggs than those on C-17. Improvements in efficiency of early matured pullets to equal that of C-17 were observed for the other treatments. Pullets on E-17 produced significantly fewer large eggs than pullets on C-17. Dietary manipulation of early matured pullets was without effect on egg size distribution. |
