Effects of heat stress mitigation strategies on feedlot cattle performance, environmental, and economic outcomes in a hot climate

Authors: MEJIA TURCIOS, SEBASTIAN - University Of California, Davis; Rotz, Clarence; MCGLONE, JOHN - Texas Tech University; RIVERA, CARLOS - Consultant; MITLOEHNER, FRANK - University Of California, Davis

Submitted to: Animal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/9/2024
Publication Date: 7/17/2025
Citation: Mejia Turcios, S.E., Rotz, C.A., Mcglone, J.J., Rivera, C.R., Mitloehner, F.M. 2025. Effects of heat stress mitigation strategies on feedlot cattle performance, environmental, and economic outcomes in a hot climate. Animal. 18(11). Artice 101257. https://doi.org/10.1016/j.animal.2024.101257.
DOI: https://doi.org/10.1016/j.animal.2024.101257

Interpretive Summary: Heat stress is a major concern in the cattle industry, and cattle on feedlots are particularly prone to suffer from high temperatures creating concerns for animal welfare as well as loss in productivity. Rising global temperatures are further exacerbating the problem of heat stress on cattle. An experiment conducted on a feedlot in Culiacan, Mexico used live animal data and life cycle assessment to determine the potential benefits of four types of shade structures used to mitigate heat stress. Structures included conventional shade, double conventional shade, a doom over the full pen surface, and the dome with fans to aid cooling. Compared to conventional shade, each alternative shade improved cattle growth performance and economic return while reducing carbon and nitrogen emissions per unit of body weight produced. Despite the large investment and electricity required, use of domed structures with fans provided the most economic and environmental benefit through greater animal gain. Further research should focus on elucidating the effects of the different shade structures on physiological response and behavior of cattle, as well as measurement of emissions from feedlots.

Technical Abstract: The increase in global temperatures presents a challenge for the beef industry, especially in the feedlot sector where heat stress is a major animal welfare and economic concern. Shade is one of the most practical methods to mitigate heat stress in feedlot cattle. Therefore, an experiment was conducted as a completely randomized design with 2,340 Bos indicus bulls (initial BW = 287 kg) where three shade structure types were used to investigate the effects of different heat stress mitigation methods on cattle growth performance, environmental, and economic outcomes using live animal data, and a partial lifecycle assessment (LCA) with the Integrated Farm System Model (IFSM). The live animal portion of the experiment was done once a year over a two-year period with three pen replications per treatment per year (n = 6 per treatment). Four shade structures used were: conventional shade (SC; steel shade 1.8 m2 of shade/animal), double conventional shade (DS; steel shade 3.6 m2 of shade/animal), dome structures without fans (DSA; 8.5 m2/animal with 98% solar radiation blocked), and domes with fans (DCA; three large sized low-speed fans). Each pen held 65 bulls in an area of 570 m2. Live animal data were analyzed as a completely randomized design using the GLM procedure of SAS (version 9.4) with shade type as a fixed effect, pen as the experimental unit, and repetition (year) considered a random effect. Cattle housed under DCA were 22 kg and 20 kg heavier final body BW (P < 0.05) compared to those housed under SC and DS, respectively. Final BW of DCA and DSA cattle were similar (P > 0.10). Average daily gain, feed efficiency, and hot carcass weight (HCW) were greater (P < 0.05) for cattle housed under DCA compared to the rest of the shade types. Dry matter intake was not affected (P > 0.10). When treatment results were extrapolated to the annual feedlot turnover of 209,700 animals, cattle in DSA and DCA versus SC and DS had reduced greenhouse gas (GHG) and ammonia (NH3) emissions in g per kg of HCW produced. Compared to SC, DCA increased profitability by $29.66/animal, followed by DSA and DS with profit increases of $5.79 and $8.90/animal, respectively. Overall, the implementation of advanced shade structures improved cattle performance and profitability while reducing the environmental impact of beef production