Should I Improve My Cooling System?

by Donald Gribble, PE

Dairy cows are cool weather animals. Loss of milk due to Heat Stress varies from 8 to 30% based upon various university studies of dairies in the southeast. Not only is milk lost, reproduction and overall herd health is affected by heat stress. When cows are heat stressed, respiration and sweating rates increase in an effort to dissipate heat; dry matter intake and milk production decrease.

Chart 1 shows the relationship between DMI and milk production.

  • Case 1 shows the increase in milk production and income based upon increasing the DMI of a cow from 40 to 50 lbs. This kind of improvement is easily achievable with modern barns, good ventilation, fans and cow soakers.
  • Likewise Case 2 shows what will happen if DMI is decreased from 50 to 40 lbs.

Most dairies in the southeast have invested in a cow cooling system. Barns with good natural ventilation, fans, cow soakers and controls are common. However these controls are usually very basic and inefficient. Most common is an interval timer that gives a fixed amount of water spray on and off time, typically 2 minutes on and 13 minutes off, started at about 75 deg. F. An even larger problem is maintenance on these systems. Often the controller is broken, turned off or not adjusted properly. Usually the dairy workers do not know how the cooling system works and the problems go ignored or unnoticed for long periods of time.

Suppose that a facility has decent ventilation, fans, cow soakers and controls. If we add the Agpro ProCool complete cow cooling system we can use water more efficiently, controller capabilities and reliability will be improved and the ability to quickly detect problems will result in the cow cooling system working more efficiently and reliably. This will result in more comfortable cows therefore more DMI and more milk.

  • Case 9 shows the impact on cash flow if DMI is increased from 40 to 50 lbs, or a 2% improvement. This can easily be achieved with the Agpro ProCool cow cooling system costing $35,700 for a 2000 cow dairy. Cash flow will be increased $380/day, payback will require only 94 days with $20 milk. Annual savings of about $10,000 in power can be achieved by shutting off the cooling system while the cows are milked. If this amount is accounted for in the cost analysis, the payback drops from 96 to 67 days!  Depending upon the condition of the existing control system, actual improvement may vary from .5 to 2 DMI. The payback time would vary from 188 to 47 days. Some dairies may have very poor cooling controls (DMI loss of about 5 lbs.) and the payback could be only a few weeks. This analysis accounts only for DMI change due to cooling the cows. The reduction of water and power use is not accounted for.

Milk Production Based Upon DM Intake And Income Gain/Loss

Case DMI 1 DMI 2 %change Feed 1 Feed 2 Prod 1 Prod 2 Milk Price Milk 1 Milk 2 Gain/Loss Dairy Size
lb/cow/day lb/cow/day $/cow/day $/cow/day lb milk/c lb milk/c $/100lbs $/cow/day $/cow/day $/cow/day 500 1000 2000
1 40 50 25.00% $4.40 $5.50 60 75 $17.00 $10.20 $12.75 $1.45 $725.00 $1,450.00 $2,900.00
2 50 40 -20.00% $5.50 $4.40 75 60 $17.00 $12.75 $10.20 -$1.45 -$725.00 -$1,450.00 -$2,900.00
3 48 50 4.17% $5.28 $5.50 72 75 $17.00 $12.24 $12.75 $0.29 $145.00 $290.00 $580.00
4 49 50 2.04% $5.39 $5.50 73.5 75 $17.00 $12.50 $12.75 $0.15 $72.50 $145.00 $290.00
5 49.5 50 1.01% $5.45 $5.50 74.25 75 $17.00 $12.62 $12.75 $0.07 $36.25 $72.50 $145.00
6 40 50 25.00% $4.40 $5.50 60 75 $20.00 $12.00 $15.00 $1.90 $950.00 $1,900.00 $3,800.00
7 45 50 11.11% $4.95 $5.50 67.5 75 $20.00 $13.50 $15.00 $0.95 $475.00 $950.00 $1,900.00
8 48 50 4.17% $5.28 $5.50 72 75 $20.00 $14.40 $15.00 $0.38 $190.00 $380.00 $760.00
9 49 50 2.04% $5.39 $5.50 73.5 75 $20.00 $14.70 $15.00 $0.19 $95.00 $190.00 $380.00
10 49.5 50 1.01% $5.45 $5.50 74.25 75 $20.00 $14.85 $15.00 $0.10 $47.50 $95.00 $190.00

Five Common Ways Dairymen Lose Money Cooling Cows

  1. Too much water applied to cows. When cow cooling system starts, usually around 75 deg F, most dairies apply a fixed amount of water, about 2 minutes. During this phase too much water is applied and water is wasted.
  1. Not enough water applied to cows. As temperatures increase to the daily high, maybe 85 to 95, not enough water is being applied to the cows to maximize their comfort. Heat stress increases and milk production, conception rates, calf birth weights and herd health are reduced.
  1. Cooling system is broken or mismanaged. Often the controls have failed or have been disabled for some reason. The cooling system is left on continuously or worse, turned off. These conditions cost dairymen thousands or tens of thousands of dollars every year. Often the workers do not recognize or report problems and the cooling system is not managed.
  1. Cooling system is left on when cows are taken to the milk parlor. Every day, 2 or 3 times, the cows are removed for milking while the cooling system runs. Water, power and waste system costs are increased without need.
  1. Cooling system not adjusted for your particular climate conditions and utilities costs. Using just enough water to cool the cows with no waste is important for dairies with high water cost or waste system costs. Power costs also vary and can impact the cooing strategy. The most important consideration is the temperature and humidity effects of heat stress on your cows. Cooling strategies for dairies in Florida will differ from California or Kansas.

Cow Cooling The Agpro Way

Cow Cooling Cool Cattle DairyThe standard 3 minutes of cow soaking then 12 minutes drying time when dairy cow cooling is inefficient and wasteful. Cow cooling is required when temperatures reach about 74 degrees.  At these temperatures, a little soaker water is helpful to keep cows comfortable.  As temperatures increase, soak times should also increase. Humidity also affects the effectiveness of cow cooling and should be considered when determining soak and dry times.

Dairy ControlsThe Agpro® FanSoaker Cow Cooling System monitors both temperature and humidity. Based upon a preset user defined profile, cow wetting and drying times are calculated to provide optimum water usage. This eliminates wasted water and reduces heat stress potential for cows. The bottom line is more milk andless water and power usage.

In addition to providing water usage optimization the cooling system provides automatic starting and stopping of 2 banks of fans for each cow group. Normally, the first bank of fans start at 70 degrees and the second bank at 72 degrees. Fans turn off when temperatures drop below the set points.

The controller has one other unique feature. An external push button is available to Fan Soakertemporarily shut down all fans and cow soakers.  This allows the milkers to shut the cow cooling system off while cows are being milked or herdsmen can shut off the system when soakers and fans may annoy men performing herd health tasks. After a predetermined time the system returns to normal operation. This feature can save thousands of dollars per year in reduced electrical consumption, less water usage and less wear on fans.  The Agpro® FanSoakerTM system also reduces cow heat stress, a proven inhibitor of milk production. The FanSoakerTM system is used exclusively by Agpro® , the leader in dairy technology for over 40 years.

Check Out These Features:

  • Intelligent controller automatically monitors temperature and humidity.
  • Currently the only system using  Wireless communications modules between individual controllers that allow dairymen to sync settings and times between all controllers, which eliminates potential for error.
  • Wireless also allows you to place controllers as far apart as necessary, without running wires and cables between.
  • Rugged electronics are built from the ground up for the dairy environment.
  • Programmable on and off temperatures allow the dairyman to fully customize to meet his needs.
  • A weather-tight enclosure ensures the controller’s reliability in unprotected outdoor environments.
  • Manual controls add another layer of integrated redundancy, and allows the dairyman to turn fans and sprayers off when milking.
  • Distributed Industrial control system prevents system failure
  • First Modular Controller design that is plug and play, meaning that in the event of an individual unit failing, redundant  networked controllers will continue to operate all sprayers.
  • Only System to monitor both Temperature and Humidity, and base decisions on when to spray on both factors.
Dairy Barn Cooling