Metabolic Disease

Testing

       Many clinical metabolic diseases have been well controlled on our dairies.  The control programs are based on proper diets fed for maximum intake at the appropriate stages of the life and production cycle of cows.  The clinical diseases I am talking about are Milk Fever and Ketosis.  But the subclinical forms of these diseases, hypocalcemia and hyperketonemia, are common and have a major direct impact on longevity and productivity of the cows and indirect impact by predisposing to other problems such as metritis and digestive upsets, including displaced abomasum.  
       Let’s start with calcium.  Shortly before calving, “a dairy cow deposits 8 to 10 grams of calcium into her fetus, but when she calves, 20 to 30 grams/day are secreted into colostrum and milk.”  If the cow cannot quickly respond to this change on demand for calcium, clinical milk fever or subclinical hypocalcemia may develop.  The nutritionists have done a good job preventing milk fever.  But in many herds, hypocalcemia is still a problem.  To avoid problems with hypocalcemia, start by constantly monitoring and striving to maximize feed intake in the close-up pen.  With cows constantly leaving the pen after calving, this is not an easy task but worth the effort.  To monitor the status of your cows, start with weekly measurements of urine pH of cows in your close-up pen.  The cows to test should have been on the DCAD diet for at least 48 hours.  I like to test cows that are estimated to be within a week of calving.  “For Holstein cows, urine pH should be between 6.2 ad 6.8 (at least less than 7.0) and for Jersey cows between 5.8 and 6.3.  If the average urine pH is between 5.0 and 5.5, excessive anions are being fed (coming from both feed and water sources) and the diet needs to be reformulated to prevent a drop in dry matter intake.”  To monitor the results, measure the Day 2 serum calcium levels on a regular basis.  That is draw blood into a red top tube from cows that are 24 to 48 hours post calving.  Spin and separate the serum.  Send the serum to a diagnostic lab.  While there is debate about the exact cut point to use, it is generally accepted to be 8.0 to 8.5 mg/dl (2.0 to 2.2mmol/L).  If more than 20% or your fresh cows fall below this cut point, you probably should investigate the management and ration of the close-up pen.  If more than 50% are below 8.0 you should be dosing every fresh cow with a calcium bolus, like BoviKalc or Vitall, immediately after calving and again the next day.  Probably not needed for the first lactation cows.
        Subclinical ketosis, hyperketonemia, is a little more difficult but depends on the same management practices, keep the cows at the bunk, undisturbed, and eating as much as possible.  Stable social groups during the transition period probably has more impact on hyperketonemia than on hypocalcemia.  But again, the effort is worth it.  To monitor the results, test all fresh cows for BHBA levels in the blood.  This should be done twice on all cows that are from 3 to 9 days in milk.  Set up a schedule to test two days every week, say Tuesday and Friday.  Use a Precison Extra BHBA meter and test strips at cow side.  Cows that fall below 1.2 should be treated with 300ml of propylene glycol orally every day for 5 days and not tested again.  This is easy with Delaval robots that can be set up to test milk for ketones as needed.          As indicated by the test, the robot can then spray the feed pellets with propylene glycol when the specific cow enters the robot.  Cut gates can simplify the testing process without locking up the whole pen.  But the job can be accomplished if you commit enough people to get the job done without ever keeping the fresh pen locked up for more than an hour a day.  Otherwise you may be defeating the purpose. 
Testing transition cows for urine pH, calcium and ketones can be a precise way to monitor your close-up and fresh pen management.  The testing program can be used to identify cows that need preventive or therapeutic treatment before the transition battle is lost.  Winning that battle is critical to the health and well-being of the fresh cows and sets the stage for a successful lactation.