Effects of lighting conditions on regulatory mechanism of growth hormone secretion in cattle.

为了阐明光照对牛生长激素分泌的影响，测定了不同光照条件下生长激素的分泌模式。本研究表明，这种植物生长激素的分泌具有以6小时为间隔的超昼夜节律，光刺激可以改变其分泌节律。在畜牧业中，适当控制光照条件可能通过生长激素的分泌来提高牛的生产力。

To clarify the effects of light on growth hormone secretion in cattle, GH secretory patterns under various lighting conditions were determined. The present study showed that GH secretion has an ultradian rhythm with 6-h interval in this species and that photic stimulation can alter the secretory rhythm. It is possible that appropriate control of lighting conditions improves productivity of cattle via GH secretion in animal industry.