EFFECT OF DIETARY ASCORBIC-ACID SUPPLEMENTATION ON THE PERFORMANCE OF BROWN-EGG LAYERS AND EGG QUALITY

Five experiments were conducted to evaluate the effects of dietary ascorbic acid (AA) on the performance and egg quality of brown-egg layers. The trials were started during November and continued into September of the following year so that a range of environmental temperatures was involved. Egg production rates, body weight changes, and shell quality were not significantly affected by AA supplementation in any experiment. AA significantly increased the egg weight of hens at peak of lay in one of two experiments in which a low-protein diet was used. No other significant interactions between protein level and AA supplementation for other parameters were observed. Albumen quality, as measured by Haugh units, was significantly increased by AA (1000 mg kg-1) in only one experiment. It was concluded that supplemental AA for brown egg-laying strains has little practical value, at least when hens are kept under generally unstressful conditions. © 1990.