Preference for Lamp or Mat Heat by Piglets at Cool and Warm Ambient Temperatures with Low to High Drafts

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Xin, Hongwei
Zhang, Qiang
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Agricultural and Biosystems Engineering

Neonatal piglets (1.7 to 7.1 kg; 3.7 to 15.7 lb body weight) were allowed to choose at will a heat source (lamp or mat) in a wind tunnel at cool (20°C; 68°F) or warm (30°C; 86°F) air temperature coupled with various air velocities (0.05 to 0.45 m/s; 10 to 90 ft/min). The effects of original heat source in the farrowing crates on the choice of the piglets were included. At the cool temperature (20°C), piglets from heat lamp-equipped farrowing crates showed preference for lamp heat at 1.7 kg (3.7 lb) and similar usage of mat and lamp at 2.4 to 5.3 kg (5.3 to 11.7 lb). Piglets up to 5.3 kg from the heat mat-equipped farrowing crates generally did not show distinct preference for lamp or mat heat, except at the high draft condition (0.45 m/s; 90 ft/min) where preference for heat mat was exhibited. Piglets of 7.1 kg (15.6 lb) preferred mat independent of the original heat source type. At the warm temperature (30°C), piglets of 2.6 to 5.3 kg (5.7 to 11.7 lb) showed almost equal usage of mat and lamp independent of the original heat source type. Air temperature affected heat needs of the piglets. At 20°C, total (i.e., lamp + mat) heat usage (THU) by piglets of 1.7 to 2.4 kg (3.7 to 5.3 lb) averaged 98% of the exposure time for all air velocities tested. At 30°C, THU ranged from 24% for 2.6 kg (5.7 lb) piglets to 5% for 4.4 kg (9.7 lb) piglets. THU declined substantially as piglets reached 3.4 kg (7.5 lb), especially at the low air velocities. Piglets were more sensitive to drafts at the cool temperature. Drafts up to 0.45 m/s (90 ft/min) had little effect on THU at the warm temperature.


This is Journal Paper No. J-18222 of the Iowa Agriculture and Home Economics Experiment Station, Iowa State University, Project No. 3355. Financial support for this study was provided in part by the Iowa Energy Center and is acknowledged with gratitude. Mention of company or product names is for presentation clarity and does not imply endorsement by the authors or their affiliations, or exclusion of other suitable products.

This article is from Applied Engineering in Agriculture 15, no. 5 (1999): 547–551.

Fri Jan 01 00:00:00 UTC 1999