Year of Publication


Degree Name

Master of Science (MS)

Document Type

Master's Thesis


Agriculture, Food and Environment


Animal and Food Sciences

First Advisor

Dr. Joao H. C. Costa


Heat stress abatement is a challenge for producers in the United States, especially in the southern states. Dairy producers could benefit by having a simply metric to measure heat stress abatement strategies with the goal of motivating improvement in heat stress management. Managing heat stress is key to ameliorating the effects on dairy cow performance. A study was performed to explore the use of a heat stress metric called the Summer to Winter performance ratio (S:W ratio), to quantify and compare farm performance variables among regions of the United States. Summer to Winter ratios were closest to 1.0 in the northern regions and furthest from 1.0 in the southern regions for all performance variables other than milk fat and protein percentage. This suggests that summer performance varies by region and shown using the S:W ratio. A second study compared S:W ratios among Southeast states and then applied the performance ratio to heat abatement strategies in Southeast states. The S:W ratio varied by performance measure and heat abatement strategies but tended to be best for herds implementing cow cooling strategies. The studies in this thesis demonstrated S:W ratios can identify heat stress differences by region and heat abatement strategies by herds.

Digital Object Identifier (DOI)

Included in

Dairy Science Commons