Guard Against Dehydration in Your Dairy Herd

 By Bruce Derksen

 An old-timer once told me during a discussion on different breeds of cattle that a cow is a cow, meaning there is really no difference among them.  Although technically true, there is always more to every story.  Whether discussing a beef or dairy herd, the fact does not change that food, water and shelter are vitally important basics of life.  But when discussing hydration in particular, just like with a beef herd, there can be many potential causes, including introducing new cows and heifers not aware of the routines and locations of water sources, dominant bully cows that guard water supplies and most importantly, the overall health of the herd but additionally with dairy cows, there is a greater loss of fluids and water due to milk production.

For reference, let’s look at some facts about dairy cattle and water.  Approximately 60 percent of the total body weight of a cow is fluid, plus water accounts for about 87 percent of all the milk produced by each cow.  Depending on environmental conditions, a dairy cow will ingest between 30 and 50 gallons of water per day, of which 50 to 60 percent will be consumed immediately after milking sessions.  Their regular day consists of only 20 to 30 minutes drinking, supplying 60 to 80 percent of their daily water as opposed to 4 to 5 hours per day eating, making up the remainder of their moisture requirements.
Obviously, a large quantity of available good quality water is extremely important.  If the previously mentioned obstacles exist, dehydration may set in.  In early on-set a cow is able to maintain a disguise of normalcy and health by drawing on the natural reservoir of the rumen to maintain an average fluid balance, but as this reservoir becomes depleted, her body weight will shrink and if untreated a severe life threatening clinical dehydration can develop.
Beyond the noticeable symptoms of dehydration including dull, sunken eyes, dry tacky mucus membranes, and slow responding skin tenting, dairy producers need to be aware of depressed immune functions, higher than normal reproductive issues including conception failure and early embryonic death or abortions.  Watch for digestive upsets or scouring in younger replacement animals.  Early recognition of dehydration allows a highly successful response strategy such as timely immune treatments along with fluid drenching by the use of a stomach tube.  In extreme cases, use intravenous fluids or consult your veterinarian if necessary.  
There are important preventative measures that should be put in place to fight against dehydration.  As a dairy cow prefers to drink over half of their daily intake immediately after milking, provide access to moderate temperature supplies of fresh clean water upon exiting the milking parlor.  If using a trough, allow at least 2 feet of perimeter space for 15- 20 cows.  Cows are happy to drink standing side by side as long as they have a comfortable space and room to back away when finished.  If using water bowls, there should be at least 2 per pen but do not place them in dead end areas making it tempting for dominant cows to guard them.
Just as important as the amount of water sources is the flow and volume available.  Cows prefer to submerge their muzzles in at least two inches of water.  A lower level than this can deter them from drinking proper amounts.  If water lines are too small and do not offer enough volume and flow, cows will lose interest, especially if there is congestion and jostling of position for the existing supply.
Always keep water bowls and cups clean and maintained properly.  Stray electric voltage can be deadly.  
Lastly, have the water sources tested regularly by reputable labs with experience handling livestock and dairy operation samples for valid results.
By using well designed facilities with sufficient numbers of water supplies that offer proper flow volumes, combined with diligent monitoring of your herd’s health and regular lab testing of your water’s quality, you can do your part in making sure dehydration is not a problem for your dairy.  Be sure to consult your veterinarian if issues beyond your control arise.  With ease of access to this most basic essential of life, your dairy cows will happily contribute to your successful operation.