Influence of maternal thyroid alteration on fertility and hatchability in WLH birds.

摘要

The conditions of hypo- and hyperthyroidism were created by dosing drinking water with 0.02% methimazole or 3 mug/ml l-thyroxine, respectively, for 8 weeks. 100 White Leghorn hens were divided into 4 groups: (1) control, (2) hypothyroid treatment, (3) hypothyroid treatment for 3 weeks followed by withdrawal of methimazole, and (4) hyperthyroid treatment. The data collected were analysed separately for weeks 1-3 and 4-8. During weeks 1-3 there was no difference in percentage fertility between the groups, but fertility rates were lower for the hyperthyroxaemic group compared with the controls during weeks 4-8. Percentage hatchability of the hypothyroid group and controls did not differ. Lower hatchability was observed in hyperthyroxaemic group (weeks1-3, not significant; weeks 4-8, P<0.05) compared with controls.