Identifying Cool Profits

Identifying Ways to Keep Cows Cool Will Turn Up the Heat on Profits

Article contributed by Dr. Chet Rawson

With an abatement program, by 300 DIM, 92% of cows were recorded as pregnant compared to just 84% without cooling.
A report from Western Dairy Management Conference

June, July and August of 2005 made for one of the hottest summers over the last 25 years in an area from Vermont to South Dakota and south to Kentucky. It was up there with 1988 and 1993. Reviewing reproductive records for those months showed depressions in conception rate that ranged from 10% to 70%. Milk flows were down from 3 to 20 lbs. Estrus detection rates were down as much as 50%. For the cows that were going through transition in this period, early lactation cull and dead rates increased. The peak milk for these cows was down and their subsequent lactational performance has been negatively impacted. There was also an accelerated loss of body condition.

Observations:
Summer heat had the largest negative impact where;

• 1. Little or no heat abatement was in place
• 2. Bunk space and or cow space were compromised, for example 4-row versus 6-row barns.
• 3. Pen densities were higher than prudent.
• 4. Segregation of 1st lactation animals from 2nd and greater lactation animals was not practiced.
• 5. Transition management was less than optimal.
  • a.Proper ration formulation and feed delivery
  • b.Three feet of bunk space was not allowed pre-fresh animals for at least three weeks and there was not a bed for every animal.
  • c.Postfresh animals were not allowed at least 2.5’ of bunk space and a bed.
  • d.Adequate cooling was not in

It all points to the importance of planning ahead and preparation for potential issues.

• 1. A greater number of pregnancies created last fall will lead to increased pressure on transition facilities and management this summer.
  • a.How will we manage that increased pressure?
  • b.Will we be able to meet the ideal requirements for transition?
  • c.Will we be able to adequately cool these animals?
• 2. Improved facilities and management strategies developed over the next months will help minimize the negative effects of future environmental insults.

We don’t know what the summer of 2006 will bring, but it’s easy to predict that those with a heat abatement program in place will experience less of a downturn on production and repro performance.

Cow Cooling Quick Tips

Cooling fans:

• Post spacing of 24-30 feet – One 36-inch fan per post
• Post spacing of less than 20 feet – One 48-inch fan every other post
• Place fans over both the free stalls and feed line (Field trials at Kansas State University have indicated a 5-6 pound milk production response when fans are placed at both locations versus just one )
• Mount fans such that air flow is with prevailing winds and as close to cow height as possible
• Fans should be set on thermostat to operate when barn temperature is greater than 70°F Adding fans provides little benefit unless a good soaking system is installed first

Soaking Systems:

• System capacity should be approximately .33 gallons per cow/cycle
• Soaking system set on thermostat to operate when barn temperature is greater than 70° F
• Duration will depend on nozzle size and will generally be 1 to 2 minutes
• Frequency: 70-80° F(every 15 minutes) 81-90° F (every 10 minutes) > 90° F (every 5 minutes)
• Mounting height – 6 to 12 inches above headlocks or 5 to 6 feet above floor
• Pressure in distribution line should be 15 to 20 psi
• Nozzle spacing should be every 6 to 8 feet

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Posted Jun 27th

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