Swine

Thermal Imaging as an Indicator of Pig Growth Efficiency

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Abstract

Optimizing feed efficiency is a critical goal in swine production to improve sustainability and to reduce costs. While traditional methods using feed stations provide accurate performance data, they are time- and labor-intensive. Infrared thermography (IRT) offers a non-invasive, real-time method to assess physiological indicators related to growth efficiency. This study evaluated the use of the Thermal Efficiency Index (TEI), calculated as mean surface temperature divided by body weight^0.75, as a potential selection criterion for sustainable pig production. A total of 10,071 Duroc pigs from a high-health nucleus herd were monitored for feed consumption and growth performance using conventional feed station technology for a 72-day period. An infrared thermal scan was performed on the animals at the end of the performance test by collecting automated dorsal thermal images and using these biometrics to measure a thermal phenotypic profile including TEI. Genetic parameters were estimated using mixed models, and genetic correlations between TEI and performance traits were assessed. TEI showed moderate heritability (0.22 ± 0.03) and strong negative genetic correlations with body weight (−0.78 ± 0.04), average daily gain (−0.78 ± 0.04), and feed intake (−0.67 ± 0.05), suggesting high-performance animals emit less radiant heat. Feed-efficient animals also showed higher TEI values, with genetic correlation of -0.24 ± 0.09 for TEI x RFI and -0.17 ± 0.11 for TEI x FCE. These findings highlight a trade-off: selecting for lower TEI could increase growth rates but may compromise feed efficiency. The negative correlations can be partially attributed to the thermoregulatory efficiency of feed-efficient animals, which helps maintain core body temperature, and consequently reduces surplus energy loss in the form of radiant heat to the environment. It reflects the biological principle that energy cannot be optimized simultaneously for both maintenance and growth, the same metabolic drive that promotes rapid growth can elevate total energy turnover, leading to higher intake requirements. From a breeding standpoint, this highlights the need to balance growth rate and efficiency. While targeting lower TEI may shorten production cycles, it could potentially raise feed cost, representing up to 70% of total expenses in intensive swine systems. EI is a quantifiable, heritable trait that captures key aspects of metabolic efficiency, thermoregulation and energy partitioning. Therefore, integrating TEI assessment alongside traditional feed station testing offers a comprehensive approach to selecting high-performance animals, it not only improves the understanding of an animal's overall growth potential but also ensures the sustainability of swine production systems.

Keywords: 2026

How to Cite:

Raidan, F., Charagu, P. & Huisman, A., (2026) “Thermal Imaging as an Indicator of Pig Growth Efficiency”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2295982. doi: https://doi.org/10.31274/wcgalp.24386

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