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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Animal Genomics and Improvement Laboratory » Research » Publications at this Location » Publication #412930
Research Project: Improving Dairy Cow Feed Efficiency and Environmental Sustainability Using Genomics and Novel Technologies to Identify Physiological Contributions and Adaptations

Location: Animal Genomics and Improvement Laboratory

Title: Impact of heat stress on dry matter intake in mid-lactation Holstein cows

Author
item NASCIMENTO, BARBARA - University Of Wisconsin
item CAVANI, LIGIA - University Of Wisconsin
item PARKER GADDIS, KRISTEN - Council On Dairy Cattle Breeding
item Baldwin, Ransom - Randy
item SANTOS, JOSE - University Of Florida
item KOLTES, JAMES - Iowa State University
item TEMPELMAN, ROBERT - Michigan State University
item VANDEHAAR, MICHAEL - Michigan State University
item WHITE, HEATHER - University Of Wisconsin
item PENAGARICANO, FRANCISCO - University Of Wisconsin
item WEIGEL, KENT - University Of Wisconsin

Submitted to: Journal of Dairy Science
Publication Type: Abstract Only
Publication Acceptance Date: 3/6/2024
Publication Date: 6/25/2024
Citation: Nascimento, B.M., Cavani, L., Parker Gaddis, K.L., Baldwin, R.L., Santos, J.E., Koltes, J.E., Tempelman, R.J., Vandehaar, M.J., White, H.M., Penagaricano, F., Weigel, K. 2024. Impact of heat stress on dry matter intake in mid-lactation Holstein cows [abstract]. Journal of Dairy Science. 107(Suppl. 1):17-18(abstr. 1139).

Interpretive Summary:

Technical Abstract: Studying the effects of heat stress on feed consumption, and consequently milk yield, can provide valuable information to identify more efficient and thermotolerant dairy cows. The goal of this study was to estimate genetic parameters of dry matter intake considering heat stress in mid-lactation Holstein cows. Data consisted of 530,046 daily dry matter intake records from 6,710 cows collected on 8 research stations in Florida, Iowa, Maryland, Michigan, and Wisconsin between 2007 and 2023. Heat stress was assessed using the maximum or average daily temperature humidity index (THI). Multi-trait repeatability test day models with random regressions on functions of THI values were used to estimate variance components for dry matter intake, considering the first three lactations as different traits. The models included cohort (trial-treatment) and DIM effects as fixed, and general and thermotolerance additive genetic and permanent environmental effects as random. Heritability estimates for dry matter intake ranged from 0.19 to 0.30 for average THI and from 0.20 to 0.26 for maximum THI and decreased across parities. These results suggest that there is an important genetic variability underlying feed intake under heat stress conditions. Estimated genetic correlations between thermoneutral and thermotolerant additive effects ranged from -0.08 to -0.44 for average THI and from -0.12 to -0.34 for maximum THI. These results indicate an unfavorable relationship between cows’ ability to consume feed under thermoneutral vs. thermal stress conditions, suggesting that continued selection without consideration of genetic variation in thermotolerance may lead to greater susceptibility to heat stress.