Technical note: Relationship between infrared thermography and heat production in young bulls

Abstract

The traditional techniques to measure heat production (HP) are calorimetry (direct and indirect) and comparative slaughter. Both methods are expensive and require extensive amounts of time and infrastructure. Infrared thermography (IRT) could be a faster and less expensive alternative to estimate cattle HP. The objective of this project was to evaluate the use of the IRT technique as an indicator of HP in cattle. A total of 24 bulls (12 Nellore and 12 Black Angus) with initial BW of 380 ± 7 kg were used. Initially, 4 animals of each breed were harvested (baseline animals) and simple regressions were developed for each breed from these baseline animals to estimate the initial chemical composition of the remaining bulls. Eight animals of each breed were fed a silage/concentrate diet for ad libitum intake in individual stalls. On the 25th, 50th, and 75th experimental day, infrared thermal images (Fluke Ti 55ft; Fluke Corporation) were taken of each animal's face to access skin and ocular surface temperatures. A metabolism trial was conducted to estimate the ME intake (MEI). After 84 experimental days, the cattle were harvested and retained energy (RE) and HP were calculated. The data were analyzed using the MIXED and REG procedures of SAS adopting a significance level of 0.05. Angus cattle had a greater daily MEI, HP, and skin and eye temperatures than Nellore. We found significant correlations ( ≤ 0.005) between daily HP and maximum ( = 0.65) and average skin temperatures ( = 0.65) and maximum ( = 0.65) and average ocular surface ( = 0.69) temperatures recorded on d 50. Infrared thermography has potential to be used to evaluate HP in cattle.

Relationship between feed efficiency indexes and thermography, blood, and ruminal parameters in pre-weaning dairy heifers

“…In accordance with that, [ 11 ], did not observe differences in skin surface temperature between RFI groups, although finding greater heat production in HE RFI compared to LE RFI, measured by the face mask. Contrary to our findings, previous experiments reported greater skin surface temperature measured by infrared thermography in post-weaning LE RFI cattle [ 15 , 31 ]. Evaluations of thermography during the current study were executed in the animals’ own stalls in thermoneutral conditions for calves Gebremedhin.…”

“…To establish a constant area of evaluation, a figure was drawn on the image surface, and it was then dragged to the region of the skin located in the chosen area [ 15 ]. Only the maximum temperature within each delimited area was considered to reduce the interference of factors such as contamination by water, feces, urine, or contact with colder surfaces, which could influence the thermogram.…”

Differences in Beef Quality between Angus (Bos taurus taurus) and Nellore (Bos taurus indicus) Cattle through a Proteomic and Phosphoproteomic Approach

“…In another study, HSPA6 expression was strongly induced by heat, but it had no significant effect on protection of HEK-293 cells against heat-induced cell death [55]. These findings are interesting because in a parallel study evaluating the same animals used in the current study, there was higher metabolic heat production and higher body temperatures in Angus [56]. …”

Supplementation strategies affect the feed intake and performance of grazing replacement heifers

“…Infrared thermogenic photographs of each animal’s eyes were taken on d 60 and 100 at 1500 h to evaluate the effects of supplementation on heat production [19]. Body condition score (BCS) measurements were taken on the same d as the infrared thermogenic photographs by three trained individuals.…”