The Potential Use of Dietary Salt Deficiency for the Force Resting of Laying Hens

Abstract

Two experiments using a total of 240 laying hens housed in individual cages were conducted to evaluate dietary salt deficiency as a potential tool for the force resting of laying hens. The control group of hens received the corn-soy diet with 0.25% added salt. Another group of hens received a basal corn-soy diet with no added salt for six weeks then was returned to the control diet. The third group was subjected to the force molting technique recommended by Wilson et al. (1969). The drinking water, given ad libitum, and the basal diet contained 26 p.p.m. and 270 p.p.m. sodium, respectively. Hen weight, feed consumption, egg production, egg weight and egg specific gravity were recorded throughout each experiment.Feed consumption and body weight of hens receiving the low salt diet (Treatment 2) or forced molted (Treatment 3) decreased significantly and egg production ceased during the molt period. The reproductive organs of hens fed the low salt diet regressed to about 25% of the original size. When hens were returned to control feed, recovery was complete with significant increases in egg weight and egg specific gravity for hens on treatment two. Egg production was significantly higher for both the hens which received low salt and those force molted, compared to the control birds during the post molt period.The results of the experiments indicated that dietary salt deficiency is effective for the force resting of laying hens.