Doc’s Blog

Epigenetics;  “… the ‘blood’ is still there.”

     In the early and mid years of the last century it was not uncommon for folks with lots of money to spend to buy a ranch and stock it with pure-bred cattle.  Many of these enterprises were successful and many were not.  Novice ranchers were prone to make mistakes in managing the care, breeding, and nutrition of their cattle. This usually led to a degradation of the appearance and productivity of the once fine looking breeding stock.  The end result was frequently a dispersal sale — selling the cattle at auction.

     My good friend and client, Evan, was a prominent  and successful    breeder of pure-bred polled-Hereford cattle in Missouri.  His knowledge of the bloodlines and families of Hereford cattle was unsurpassed.  Moreover, Evan was an innovative herdsman.  He fed his cattle well and was innovative in his approach to animal nutrition.  He was adding Wheat Germ Oil to the ration of his breeding a long time before livestock nutritionist recognized the value of Vitamin E. 

     If the dispersal sales mentioned above involved Hereford cattle with bloodlines compatible with those in his herd, and was located within a reasonable driving distance, Evan would attend the sale.  He rarely came home empty handed.

Evan would keep his new purchases separate from his main herd for a week or two just a precaution.  During the quarantine period he would call me to do a health evaluation.  The first time I did this, I was somewhat taken aback, as the new animals were not good specimen of the breed.  Evan noticed my dismay and said, “Yeah, I know they look like Hell, but they didn’t cost much and the blood is still there.”  He explained that by ‘blood’ he meant the bloodlines or genetics were intact and opined that good nutrition could build them back up.  I was not convinced.

     After some years, though, whenever I made a farm visit, Evan would p  oint out individuals in his herd that would have graced any Hereford show-ring.  With a grin on his face he would remind me, “Those are all direct 2nd or 3rd generation descendants of the animals you ridiculed years ago.” 

    Evan may not have understood the fine points of epigenetic as we now understand it, but he intuitively employed the basic concept of epigenetics decades before it appeared in the scientific press.  

   In simple terms, epigenetics is the study of changes in gene expression that occur without changes in the genetic code itself — genes are not set in stone as previously thought, but are like switches that can be turned off or on by various factors such as nutrition, stress, drugs, and sundry environmental factors — “and the ‘blood’ is still there.”

  The resulting change in genetic expression may persist for generations.  As one researcher noted, “If you are of reproductive age, whatever you take into your body— food, drink, drugs, air — may affect the health of your great grandchildren.”    These alterations can be good or bad — going down hill in the aforementioned mismanaged herds or climbing back uphill in Evan’s herd.  

Why D0 Nutritionists’ Reject Animal Wisdom?

 I have often wondered why more main–stream livestock nuritionists do not embrace the concept of animal nutritional wisdom and shun the use of cafeteria-style mineral feeding. 

      When questioned about this, many will opine, “Well, animals in the wild may have done this, but domestic animals have been bred-up to the point they have lost this ability.”

    Some will  point out our domestic animals often overeat grain or protein supplements. This is true because these feeds are not inherently natural to ruminants.  They rarely, if ever, overeat pasture or minerals. 

      Others nutritionists and dairymen give lip service to the need for a better way to quickly adjust for the ever changing mineral needs of animals but continue to reject self-select, cafeteria-style mineral feeding — possibly because of peer group pressure to conform to conve±ntional industry standards.

    I do not deny nutritionists are able to wring out a lot of milk from  a herd of cows – but at a huge cost when one considers the average dairy cow in our country is ‘burned-out’ at an early age and rarely completes even two lactations. 

      Modern nutritionists rely heavily on computer generated Total Mixed Rations (TMR). Using data from feed testing is entered into the ration balancing program. These figures may indicate chemical composotion bu not necessarily bio-availability.  A ration is then generated that conforms to the nutrient requirement tables published by the NRC (National Research Council). These recommendations may or may not be applicable to the situation at hand.  The computer ‘crunches the numbers’ and  spits out a recommended ration that purports to meet the nutritional needs of all the cows in the group. 

      Upon receipt of the print-out, the dairyman or his workers still must assemble the feed stuffs, properly measure and mix the ingredient, deliver the final ration to a feed bunk adequate to accommodate all the cows.  This series of steps is fraught with opportunities for mistakes.  What the cows actually get into their metabolism may bear little resemblance to the computer print-out,    Check out:  http://www.dochollidaysblog.com/docs-blog/what-are-you-really-feeding.html

     The problem is that a TMR fails to allow for variagion in individual nutritional needs. There is no such thing as an “average” cow.  With a TMR only a few cows may get precisely what they need – but some get too much of one thing or another and others get too little.   When thinking about averages consider this:  “If you have one foot in boiling boiling water and one foot in freeezing water—on the average your feet are comfortable.”

     The bottom line is there is no way to ascertain and correct the nutritional state of the animals unless and until obvious signs of malnutrition occur.  If I were a dairyman or a dairy nutrtionist I would insist on the presence of a full array of separate self-select minerals. 

    A properly installed and managed cafeteria-style mineral feeding system provides many benefits.

  • It is an excellent method to insue precise balanced mineral intake for each individual animals. It immediately adjusts for changes in the daily and seasonal needs of the individuals in the herd.  
  • It is a safety net and diagnostic tool that hi-lights problems associated with mineral imbalances caused by changing feed or environmental conditions.

    I think we should continue to use our accumulated scientific knowledge when compounding rations for animals, and also letting our animals exhibit  their nutritional wisdom to fine-tune the computer generated ration — thus combining the best of the two concepts.   

rjhdvm@gmail.com