Thyroid activity and growth rate in rapidly growing lambs.
1. This paper reports a study of the relationship between thyroid gland activity and rate of growth of lambs held in a controlled environment with feeding ad libitum.2. Thyroid activity was assessed by the rate of release of (131)I from the thyroid gland over a period of 1-2 weeks following injection. Growth rates were simultaneously recorded on a total of thirty-one lambs during forty-six measurements of thyroid activity.3. The results demonstrated a highly significant curvilinear correlation between growth rate and the rate constant for thyroid (131)I release (P < 0.001).4. Surgically thyroidectomized animals were demonstrated to have a much reduced rate of growth.5. It was concluded that thyroid activities considerably above or below the optimum have an adverse effect on growth rate.
D000704:Analysis of Variance; D000818:Animals; D001835:Body Weight; D005260:Female; D006128:Growth / Q000502:physiology*; D013006:Growth Hormone / Q000502:physiology; D007457:Iodine Radioisotopes; D008297:Male; D010902:Pituitary Gland / Q000502:physiology; D012756:Sheep; D013961:Thyroid Gland / Q000502:physiology*; D013965:Thyroidectomy
D007457:Iodine Radioisotopes; D013006:Growth Hormone