Heat Stress in our Dairy Cows

Rosie cooling her heels

Summer time in the south!  It's hot.  Or as they say in Cajun French, "C'est chaud!"  It's hot for humans, but for cows?  Our poor Jersey cows are struggling mightily.  They just aren't built for this southern climate and don't deal with the heat well.  They get up early and slowly walk out to the pasture, battling mosquitoes, deer flies and horse flies.  They eat in the shade cast by the live oak trees against the rising sun in the east.  As the sun rises and the shade disappears, the cows slowly walk back and sit beneath the shade all day long until the process repeats but from the western side.

Here's the problem.  They are eating less and it puts them in stress.  Humans sweat and enjoy the evaporative cooling.  Jersey cows, on the other hand, do sweat, but much less than humans.  How do they handle the heat and cooling themselves?  Poorly.  They pant.  Their tongues hang out.  They drink lots of water.  Especially poor LuLu.  She's in milk since calving Betsy and that puts an additional load on her body.  We were splitting the milk with the calf by separating them allowing Betsy to get the milk all day and then after separating them in the evening, we milk first thing in the morning for us.  Well, we've stopped that temporarily until temperatures drop off.  It's been around 100 degrees for a number of days now.

We're doing a couple of things to assist LuLu.  First, in the early morning and late afternoon, we spray her down with a water hose.  She's taken a liking to this and eagerly walks to the spot by the hose in anticipation of the bath.  We're also making a drench with 1 cup of molasses, 1/3 cup of apple cider vinegar and 2 tablespoons epsom salt.  We mix this up and give her three 50cc drenches in a drench gun in the morning and the evening to give her an electrolyte boost.  Since she's not out eating as much due to the excessive heat, I'm picking sweet potato vines from the garden to supplement her minimal grass intake.  She loves sweet potato vines.  

I noticed Rosie (in the photo at the top of this blog post) standing in a puddle of water caused by the float valve not working properly because the water trough isn't level.  The water trickled over and caused a mud puddle before I caught it and shut the valve off.  Some say that cows will stand in the water to cool off their hooves and dissipate heat.  If that is beneficial short term, great!  It's generally not a good idea to have mud puddles as they are vectors for parasites and standing in water softens the hooves, making them susceptible to hoof rot and other foot ailments.  In this heat, however, that puddle will evaporate quickly and won't be a long term problem.

Tomorrow looks like we'll have a high of 97 degrees, but the days following look to have reduced temperatures down to a 'balmy' average of 94 degrees.  Not a huge drop but somewhat of a respite.  Hang in there, LuLu.  Cooler weather is coming.  In the meantime, we're doing everything we can to help her (and us) to cool off!