Supplemental lighting stimulates growth and lactation in cattle

Sixteen hours of light daily (114 to 207 lux) increased weight gains and milk yield 10 to 15% in Holstein cattle in comparison with cattle exposed to natural-length photoperiods (39 to 93 lux) of 9 to 12 hours. The weight gain was accomplished without increased consumption of feed. Manipulation of supplemental light may thus cause dramatic increases in food supplies from animals.