Thermal comfort evaluation of three genetic lines of modern pigs using thermal images

T. M. Brown-Brandl, M. D. Hayes, G. R. Rohrer, R. A. Eigenberg

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

1 Scopus citations

Abstract

Previous ARS research found that heat production of growing-finishing swine is 6 - 41% higher than documented in the ASABE and ASHRAE standards. The smallest changes were noted at the lightest weight pigs. This change is most likely due to larger, faster growing genotypes used in modern swine production. As a result of this higher heat production, the ideal temperature the pigs are kept at has likely changed. Thermal comfort of the new genetics is critical to maximize production and well being of the modern swine. Measurements of posture, skin temperature, and ear temperature profile changes with temperature were evaluated for three modern pig genetic lines. A total 180 nursery pigs (30/sire - 3 different breeds: Duroc, Landrace, and Yorkshire) - with 2 sires for each breed) were acutely exposed (∼6-hours) to each of seven different temperatures (20°C, 22.5°C, 25°C, 27.5°C, 30°C, 32.5°C, 35°C) over a 13-day period. Both group (10 pens of 18 pigs each) and individual pig (12 pigs/sire line - 36 total) thermal images were captured at each of the thermal conditions. In addition, time-lapse images were taken on a 5-minute basis to document posture. First region of interest (ROI) was the average trunk surface temperatures; evaluated using an oval center of the trunk of the pig. Temperatures along the centerline of the ear were evaluated for each pig (12 pigs/sire line - 36 total) as the second ROI. Changes in the average trunk surface temperature were fit to two separate linear regression equations - Above and below the standard temperatures. The two regression lines were solved simultaneously to estimate the thermal comfort zone. The threshold temperatures were determined to be 26.1°C for Duroc sired pigs, 27.9°C for Yorkshire sired pigs and 28.8°C for Landrace sired pigs. Changes in ear surface proved to be a useful tool in evaluating thermal comfort. Based on the results of this study the standard set point of 27.5°C is appropriate for nursery pigs. These results demonstrate the ear is an ideal target for determining thermal comfort. Using current infrared temperature technology, an application could be developed to focused on the temperature of pig ears to ensure the building thermal environment is appropriate.

Original languageEnglish
Title of host publicationPrecision Livestock Farming 2015 - Papers Presented at the 7th European Conference on Precision Livestock Farming, ECPLF 2015
EditorsMarcella Guarino, D. Berckmans
Pages700-710
Number of pages11
ISBN (Electronic)9788890975325
StatePublished - 2015
Event7th European Conference on Precision Livestock Farming, ECPLF 2015 - Milan, Italy
Duration: Sep 15 2015Sep 18 2015

Publication series

NamePrecision Livestock Farming 2015 - Papers Presented at the 7th European Conference on Precision Livestock Farming, ECPLF 2015

Conference

Conference7th European Conference on Precision Livestock Farming, ECPLF 2015
Country/TerritoryItaly
CityMilan
Period9/15/159/18/15

Keywords

  • Genetics
  • Nursery pigs
  • Surface temperature
  • Thermal comfort

ASJC Scopus subject areas

  • Animal Science and Zoology

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