Biological Systems Engineering, Department of


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Research Report. NPB #02-194


Used by permission.


Farm research trials were conducted in 2003 and 2004 to assess the effects of the type of zone heater and floor mat used in a wean-to-finish building on the thermal environment created for newly weaned pigs and resulting pig performance. Modulated LP gas-fired brooder heaters were compared to electric heat lamps, and floor mats made from farm-cut wood sheathing (3/8” oriented-strand board, OSB) were compared to commercial [unheated] rubber mats in a replicated 2x2 factorial experiment. No consistent differences in air temperature near the heating zone were found between either of the treatments, with treatment means within 1oF of each other in both trials. In pens having modulated gas-fired heaters, black-globe temperatures just outside the heating zone were consistently warmer (+2-2.5oF, P<0.05) than in pens with heat lamps. Black-globe temperatures were also warmer in pens with OSB mats (+0.5-2oF) than in pens with rubber floor mats. Conversely, the temperature of exposed mat surface area was warmer (93.9oF vs. 86.3oF on average, P<0.001) under the heat lamps than under the brooders. However, no significant difference was found in pig dorsal surface temperature. There was some evidence (P<0.10) that the temperatures of exposed mat surface areas were slightly warmer with rubber mats than with OSB sheathing (91.4oF vs. 88.9oF), but no corresponding difference in pig surface temperatures was found.

Overall, no statistically significant treatment differences in pig performance were found at the end of the zone-heating periods. Slightly higher rates of gain during the first week were found in pens using modulated gas-fired brooders than with heat lamps, but this advantage was not sustained. Time-lapse video footage helped document pig activity, but any differences that may have existed in pig activity did not noticeably influence performance. Daily energy consumption rates averaged 0.025 gal/pig/d for the LP gas-fired brooders and 0.40 kWh/pig/d for the electric heat lamps. For electricity prices ranging from 6 to 12 ¢/kWh and LP gas prices of $0.70-1.40/gal, annualized equipment & operating costs varied from $1.26 to $2.26 per pig place for electric heat lamps and $2.26 to $3.00 for the gas-fired brooders. Unless gas prices are low relative to electric rates, or some other financial benefit is obtained by using gas-fired brooders, heat lamps would appear to have an economic advantage for producers due to their lower unit fixed cost in equipment.