The effects of choline supplementation in diets for laying hens (Dekalb White) were evaluated from 1 to 44 weeks-old. The experimental design was a 2x5 factorial arrangement (two choline supplementations from one to 16 weeks of age - with and without choline supplementation vs. five levels of choline supplementation from 18 to 44 weeks old. The choline level used in the diet for each group was 0, 200, 400, 600 and 800mg/kg). Choline supplementation used in birds with 1 to 16 weeks of age does not affect the performance of pullets and no gross and histological changes were observed in the liver during this phase. The effects of the choline supplementation levels in the laying phase on the hens' performance depend on the supplementation with this vitamin from 1 to 16 weeks old. The results of the experiment showed that birds reared for laying need a higher level of choline supplementation from 1 to 16 weeks old or birds reared for laying receiving higher levels of choline supplementation during 1 to 16 weeks old will need a higher level of choline supplementation in the laying phase.
choline; liver; hen; rearing phase; laying phase
