Doc’s Blog

Milk Fever

     Each incident of milk fever in dairy cows is estimated to cost the dairyman about $335.00. This figure does not include the cost of subclinical hypocalcemia, or  other often associated conditions such as dystocia, retained placenta, metritis, and displaced abomasum.  Milk Fever or peri-parturient hypocalcemia is caused by failure to maintain adequate levels of blood calcium at calving time.

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      Several recent internet articles dealt with strategies to lower the incidence of  milk fever in dairy cows.  All were written by University folks and all contained pertinent information. They all recommended the same old standard fixes: feed pre-fresh cows low calcium and low phosphorus rations and forages (limit pre-fresh cows to no more than 20 g/day of calcium and 80 g/day of phosphorus), feed anionic salts for 21 days before calving, and  treat affected cows as soon as any symptoms are noticed. 

     The common thread seems to be  to  micro-manage the mineral consumption of all animals to conform to commonly accepted parameters.  Given the variability of forages and feeds this may be difficult to implement on many farms.  One writer warned against allowing cows “selective consumption” of forages and advised to discontinue free-choice mineral feeding and to force feed all minerals.  This mind set disregards individual variation of needs. If all minerals are force fed in a TMR, some cows get too much, some get too little, and only a few get what they need.

     One author did point out that high levels of calcium and potassium in the blood caused the  'bone to blood pathways' of calcium mobilization to shut down.  After calving, it takes about 72 hours to reestablish this process—during which time the fresh cow is prone to milk fever. 

      I was disappointed no one mentioned the role of maintaining a proper dietary calcium/phosphorus ratio in the last three weeks of pregnancy.  Mineral balance is oft times more important than absolute amounts.

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      The ‘keystone concept’ they all missed is this. If dairy cows have free-choice access to separate calcium and phosphorus sources, they will self-adjust their individual Ca/P ratios and not disrupt the calcium mobilization pathway mentioned above.  When they calve they are less susceptible to milk fever.  

     I guess until dairymen, and nutritionists, discover the nutritional wisdom of cows  they will have to accept the current incidence of  milk fever—estimated to be 25 percent calving with clinical milk fever and another 25 percent calving with sub-clinical milk fever.

You might want to check out my article, “Addressing Milk Fever in Your Organic Dairy Herd.” —originally published in  Holistic Veterinary Practice  Dairy Herd Network   July 30, 2009.    

It can be viewed at:   http://www.dochollidaysblog.com/article-index/milk-fever.html

Earthworms - Nature’s Soil Builders

Other than for fishing, I first became aware of the value of earthworms back in the 1960s.  Many farmers were then  beginning to transition from harsh NPK fertilizers to more natural soil amendments—lime, gypsum, rock phosphate, and manure. With the renewal of health in the soil, great numbers of the dormant earthworm eggs hatched.  I recall one incident where the migration of newly hatched earthworms onto the roads bordering the fields resulted in slick roads as the worms were crushed by the traffic.

Some points to ponder about earthworms:

  • Earthworms are damaged by deep cultivation, drought, toxic fertilizers, heavy metals, and most agricultural chemicals. 
  • Populations of earthworms may vary from 30/m2 in intensively farmed fields to 450/m in organic soils.  250 per square meter equals about a million per acre. A thriving earthworm population is an indication of healthy soil.  Healthy soil contains more life under the surface than can be grown above the surface.
  • Earthworms replenish the soil with their excrement.  Earthworm castings—the little piles of poop on the soil surface—are estimated to be tons per acre. These castings contain 3 times more available Calcium; 2 times more available Magnesium, 5 times more available nitrogen, 7 times more available phosphorus, and 11 times more available potassium than the soil they inhabit.
  • Earthworms burrow through the top layers of soil to reach a stable, damp depth.   These burrows aerate the soil  and allow deeper penetration by  plant roots.
  • A healthy soil full of earthworms can absorb up to 150 liters of water per  square meter per hour thus helping to prevent soil erosion.
  • The common earthworm feasts on rotting, bacteria-rich plant matter it finds on the soil’s surface.  To encourage earthworm populations farmers  should leave some plant residue after harvest and use a cover crop such as grass during winter to provide food for the worms.   
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Nature’s soil builders and rejuvenators—earthworms—are under threat.  Their population continues to dwindle because of industrial agricultural practices. 

 

Protecting these unsung  heroes of the soil as they work unseen and underground   should be an agricultural goal.


A Timely Quote 

0923 WVgovt

"Cynics
do not contribute, skeptics
do not create, doubters
do not achieve."
Bryant S. Hinckley


Chewing On Wood

   A recent article in a popular equine magazine addressed a question about horses chewing wood.  A subscriber had written in wondering why her mare would chew on wood, and eat shavings and poop when her access to pasture was restricted.

  The author opined the problem was most likely low dietary fiber, because of  the low forage intake when not on pasture.  It was recommended to provide extra hay to compensate for the lack of pasture forage.

  Confinement, boredom, and lack of activity were also mentioned as possibly contributing to the problem. .  I have no doubt these factors—and probably others—are implicated in abnormal appetites for non-food items.

 I was dismayed that a lack of minerals was not considered as a possible cause.  Mineral imbalances are often associates with aberrant appetites if not the primary cause of many,  With today’s twin problems of low-mineralized feeds and limited access to pasture, most domestic animals need some extra mineral supplements. 

Stewart Jackie kw 1- edited 2-2-17 wk

In an earlier time, a phosphorus deficiency was thought to be the cause of chewing wood.  but with the decline in soil fertility  other deficiencies can also cause pica.  

   It is prudent for all horse owners to provide a supplemental source of minerals.  Given the choice of a variety of mineral formulas, horse will balance their mineral needs  and avoid at least one cause of chewing wood or eating dirt. As shown in the image, the feeder need not be elaborate. 

rjhdvm@gmail.com