What do we still not know about cow cooling?

Thank you for such a nice comparison among different the cooling systems. Do you have any picture of "reduced barn volume" to share?

Thank you, Israel and greetings (long time no se!), for such a comprehensive and forward-looking article. Your insights illuminate how much progress we’ve made in understanding cow cooling—and how many questions still remain.

One important contribution I’d like to offer comes from our experience in the Azores, where dairy farming is deeply rooted in a pasture-based system that coexists with a humid subtropical climate. While our region doesn't experience the prolonged extreme heat seen in some tropical areas, heat stress is still a silent productivity thief, especially when combined with high humidity and low wind. Unlike arid regions where evaporative cooling is highly effective, the persistent humidity in the Azores greatly limits the efficiency of indirect cooling strategies, such as misting or foggers.

This makes your point on knowledge gaps around cooling in high humidity regions especially relevant. In our case, cows are generally housed in simple facilities or remain on pasture for long hours, and bringing them in for cooling—if infrastructure even allows—is labor-intensive. That’s why context-specific studies, such as those you call for, are urgently needed.

Another layer of complexity lies in the balancing act between sustainability and animal comfort. As your article mentions, advanced systems with sensors and precision cooling are promising, but their feasibility must be tested in small- to medium-scale operations, which are common in island or mountainous regions like ours. The capital investment required often surpasses what producers can manage, despite clear long-term benefits. Thus, exploring low-cost, water-efficient adaptations to direct cooling—like shaded cooling zones integrated with pasture-based feeding or smart rotation systems—could provide practical solutions.

Lastly, I fully support your call to revisit air conditioning, particularly when tied to seasonal use in reduced-volume barns. However, in humid climates like ours, this may demand more than energy efficiency—it will require innovations in ventilation logic and layout, potentially inspired by greenhouse or maritime cooling techniques.

In sum, your article makes an excellent case for why “we don’t know enough yet.” I would encourage the research community to include underrepresented regions and systems in these studies—not just large-scale arid zone farms, but also the humid, pasture-based systems that account for a significant portion of milk production in regions like the Azores, Ireland, and parts of South America.

Thank you again for sparking this important conversation.

—
Alvaro Garcia, DVM, PhD
Dellait Animal Nutrition & Health
US. Grains Council
Santa Maria Island, Azores
ex Uruguay ex USA