Effects of Heat Lamp Output and Color on Piglets at Cool and Warm Environments

Piglets from birth to wean at 21 days of age were subjected to heat lamps with either constant power output (CO) of 175 W or variable power output (VO) from 175 W at birth to 100 W by weaning time. Each type of heat lamp had either clear or red radiant rays. The effects of lamp output and color on heat lamp usage (HLU) and average daily gain (ADG) of the piglets were examined for a cool air temperature of 18 ± 1°C (65 ± 2°F) and a warm air temperature of 27 ± 1°C (80 ± 2°F). Increase of air temperature from 18 to 27°C significantly reduced HLU (55% vs 9%; P < 0.05) and ADG (270 vs 231 g/day; P < 0.05). HLU or ADG was similar for both types of lamp output. However, replacement of CO lamp with VO lamp would yield an annual energy saving of $29 (assuming electricity cost of $0.10/kWh and 320 days or 88% of annual farrowing crate occupancy). Heat lamp color showed no effect on piglet behavior or performance. A practical, low-cost operant controller that operates the heat lamps based on the presence/absence of piglets in the heat zone should be investigated to achieve additional energy savings in creep heating.