Friday, March 20, 2020

Copper Toxicosis in Sheep

I had a question come up today about copper toxicity in sheep. Of all our domestic animals sheep are the most susceptible to copper toxicosis.
Copper is a required mineral in all species, but sheep have a narrow range between how much copper is adequate and how much is toxic. Most cases of copper poisoning in sheep occur when they are fed rations or minerals designed for other species that are more tolerant of copper.
When sheep are fed such diets over a period of time copper builds up in the liver because sheep do not excrete copper as efficiently as other animals. When the liver becomes saturated with copper, massive amounts of copper are released into the bloodstream resulting in tissue damage. This sudden onset is often triggered by some stressful event.
Note on the Mineral Wheel, that both molybdenum and sulfur act as antagonists to copper and have a protective effect if there is excess copper, The presence of these compounds bind with copper and prevent gut absorption and increase excretion of copper.
Sheep do well on ABC’s cafeteria-style mineral program and I have never encountered copper toxicosis in sheep on this program even though it does provide a free-choice source of copper. Animals will balance their own mineral needs if given the choice.

This item was originally posted to a previous issue of Doc' Holliday's Blog on 22 April 2015

Wednesday, March 18, 2020

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.
          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 all 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 often times more important than absolute amounts.
          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 may 
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

This item was originally posted to a previous issue of Doc' Holliday's   Blog on 27 February 2017

Tuesday, March 17, 2020

Liebig's Law of the Minimum

In 1840, Justus vonLiebig, a German chemist, published a book entitled. “Organic Chemistry in its Application to Agriculture and Physiology.” This book and succeeding revisions had a profound impact on agriculture. Liebig promoted the idea that chemistry could revolutionize the practice of agriculture — and it did.
A comprehensive discussion of Liebig’s many accomplishments as a participant in this cutting edge agricultural revolution are beyond the scope of this article. Here are some high points.


  • Liebig’s scientific investigation of the various aspects of the element carbon resulted in major contributions to agricultural and biological chemistry. Thus he is widely known as the Founder of Organic Chemistry. .
  • Liebig identified the chemical elements of nitrogen (N), phosphorus (P), and potassium (K) plus trace minerals as essential to plant growth. These recommendations fueled considerable criticism in some circles, which controversy persists to this day. Nevertheless, Liebig is known as the Father of the Fertilizer Industry.

In 1840, Carl Sprengel, a contemporary of Liebig, developed a principle of agricultural science known as the "theorem of the minimum”, which stated that plant growth is not determined by the total resources available, but by the scarcest available resource. Liebig popularized this concept and it became known as “Liebig’s Law of the Minimum.”
Later, a fellow named Dobenec illustrated the concept with a barrel composed of staves of varying length. Just as the capacity of a barrel is limited by the length of the shortest staves so plant growth is limited by the essential nutrients in shortest supply. This basic image became known as “Liebig’s Barrel”.
While this principle was originally applied to plant or crop growth it is also applicable to a multitude of other situations including biological populations and ecosystem models. It even applies to product manufacturing where production is limited by availability of raw materials.
I am amazed that a principle developed almost two centuries ago has as wide, or wider, application today as it did when originally proposed. Liebig’s Law of the Minimum is a perfect fit when applied to mineral nutrition in livestock.
The Liebig Barrel is compatible with the Mineral Wheel and adds a new dimension to the team player concept of balanced mineral nutrition.

All of the above begs the question:
“What is the shortest stave in your barrel?”

Wednesday, March 4, 2020

Treat the Cause, Not the Symptom

There is an article in a recent issue of Progressive Dairy Magazine. entitled Alternative medicine options for common ailments in cows." 
  It is a good article, well written, and certainly worth reading especially if you are interested in more natural treatments for your animals.  
That being said, I would like to remind readers the essence of holistic  thought is concerned more with finding and remediating the cause of illness rather than just treating symptoms. Obviously, the sick animal must be treated but not to the exclusion of dealing with the cause of the problem.
I was amused at the precautionary statement at the end of the article.  “Editor’s note: If you’re interested in any of the alternative medicine strategies described in the article, Progressive Dairy recommends working closely with your herd veterinarian to determine proper use and dosage.”   I realize it is a necessary PMA ploy to protect against lawsuits.  But give me a break!  That’s like referring a person with a common cold to consult with a heart surgeon!  Most mainstream Vets have little knowledge of or interest in alternative therapies. 
 Then too, their record of disease prevention in conventional dairy herds is not outstanding.  It is estimated that 50% of these cows freshen with either a metabolic or infectious disease.  Most do not complete two lactations. 

There are many complex causes of disease.  But consider this, down through the ages scholars and scientists alike have affirmed that good health is dependent on good nutrition.  
  • Hippocrates  (460 -370 BCE)  — the Father of Modern Medicine, ““Let food be thy medicine and medicine be thy food.”
  • William A. Albrecht, PhD (1888-1974) —  the Father of Modern Soil Science, “It takes healthy soil to produce healthy plants, and healthy plants to produce healthy animals and people.”
  • Linus Pauling, Phd (1904-1994)   The only person to even win two unshared Nobel Prises,  “You can trace every disease and every infection to a mineral deficiency fr0om unequally yoked energy fields.” 
Thus, I think I am in good company when I point out that soil depletion has resulted in lowering the nutritional value of our feeds which impairs the immune systems thus setting the stage for disease in animals and humans. 

A basic principle underlying all this is that trace minerals are a key element in all enzymes and all metabolic function are regulated by enzymes. Any imbalance, deficiency or excess, of essential minerals may disrupt these natural chemical processes, resulting in  low production and greater susceptibility to disease.
Minerals are team players and interact with each other in complex ways.  (see Mineral Wheel).  If even one mineral is absent or deficient the team suffers. Whether it be team sports or mineral nutrition, to be successful you need all the appropriate team members on the field at the same time.


The goal of any mineral supplement program should be to balance mineral availability with mineral need for each individual animal. The best way to do this is  to provide individual sources of the full range of essential minerals.  This allows the animals to exercise their innate nutritional wisdom to self balance their mineral needs.  
Anyone who doubts that cattle can make valid nutritional choices needs to watch cows graze in a mixed pasture. They do not just mow grass like a lawn mower, but pick and choose each mouthful. minerals. Given the chance, they will balance their nutritional needs during each feeding period. They will do the same with minerals. 

If you would like to do a simplified trial on you own cattle, try this.  
  • Free-choice a basic mixed mineral with a 2:1 calcium-phosphorus ratio and another separate mix with a 1:2 calcium-phosphorus ratio. This allows them to self adjust the critical C:P ratio which influences many of the other minerals. (See Mineral Wheel.)
  • Free-choice a bicarbonate buffer.  Animals with incipient rumen acidosis may eat a lot of this ‘to put out the fire’!
  • Free-Choice kelp.  Most animals like kelp and will eat a lot.  If consumption remains high it may indicate low trace minerals in the diet. 
  • Always provide a free-choice source of plain white salt. 

I learned a lot by  paying attention to animal’s consumption of minerals, 
You can too!  
 If you have questions contact me at  rjhdvm@gmail.com.

Monday, March 2, 2020

Cafeteria-Style Mineral Research

Cafeteria-Style Mineral Research - Previously posted March 13, 2015

Research conducted at Cornell by water-quality expert Dave Beede has been published in the February Journal of Dairy Science. In the experiment, Beede and other researchers set up a series of water tubs cafeteria-style, so they could see which tubs the cows preferred based on iron concentrations in the water. Upon first exposure to drinking water, lactating dairy cows tolerated iron concentrations up to 4 mg/L (or 4 parts per million) without a reduction in water intake; however, water intake was reduced with concentrations of 8 mg/L.
They also indicated the direct livestock suitability water analysis used by some labs may underestimate the amount of iron in the water as some of the iron is chemically associated (bound) with other chemicals in the water and not analyzable. Therefore, what may appear as a favorable 2 mg/L level may actually be an inhibitory 8 mg/L level. 
Comment: Conventional nutritional opinion claims animals do not have the ability to balance their nutritional needs when given the choice. Yet, these researchers relied on the nutritional wisdom of these cows to set their own standards for acceptable levels of iron in their water by providing varying concentration of iron in water “Cafeteria-Style”.
Reading between the lines, this experiment also shows laboratory tests are not as accurate as an animal’s nutritional wisdom —“some of the iron is chemically associated or bonded with other chemicals in the water and not analyzable.” However, when given the choice, the cows didn’t have any problem choosing the level of iron acceptable to them.
And taking that one more step: maybe cows really are smarter than some scientists. Hopefully more researchers will begin to apply common sense in their research and the interpretation thereof.
Learn more: http://www.dairyherd.com/e-newsletters/dairy-daily/Keep-iron-levels-in-water-below-8-mgL-200473451.html