Cobalt Deficiency in Cattle
contributed article by Dr. Vince Collison, Collison Embryo and Veterinary Services,
Rockwell City, Iowa
Typically nutritional deficiencies are rare, but recently we had a case where cobalt deficiency was probably part of a problem. There is perhaps more to this case than just cobalt deficiency, but it is likely a major component to the problem. Over the last several years this herd had a history of Ostertagia, a parasite that can affect adult cattle. Treatment with injectable Dectomax would improve the symptoms, but it continued to pop up as a problem over time. There also was a history of Johne’s in this herd that started after the purchase of some bred heifer replacements. This herd had also experienced a significant drop in pregnancy rate to the AI program and overall decreased pregnancy rates after the bulls were turned out.
This past winter the owner had experienced a fairly high death loss in his cows due to loss of condition and some with some diarrhea. He had written some of this off initially due to his previously mentioned problems of Johne’s and parasites, but contacted us as the death loss became higher than normal. He also had previously purchased heifers that had originally come from Kansas.
Diagnostics included drawing 80 blood samples from the part of the herd that seemed to be experiencing the most problems. These cows were also wintered in a different field than the rest of the herd. We initially suspected Anaplasmosis with the high death loss and a history of purchasing cattle from Kansas which has more endemic Anaplasmosis than Iowa. The blood testing did not turn up much for Anaplasmosis or Johne’s disease. So, we had to re-evaluate what we were dealing with.
The next thing was to post a cow that had a rapid course of symptoms and died fairly quickly. This cow had a pyelonephritis, which is usually a poor prognosis and typically an incidental disease. To rule out the possibility of Leptospira we tested for this on 20 of the original 80 samples. This also came up with nothing.
At this point we spent several hours driving through the cows trying to examine and look for other clues. One noticeable finding was the cows had fairly dull haircoats along with a significant number with lower body condition. Lameness was also a problem. The impression was there was a deficiency occurring, potentially copper. This producer was feeding a custom mineral mix and when we looked at the label there was copper listed, but at lower levels than typically listed on most cow minerals. There was also nothing listed for cobalt.
Cobalt is a key component of vitamin B12 (cobalamin). B12 is essential for the formation of red blood cells and DNA. It also is important in brain function and nerve health. Lack of vitamin B12 can be responsible for a generalized condition of ill thrift in cattle. Symptoms such as anemia, poor growth, diarrhea, and poor haircoat can all occur with cobalt deficiency. Diseases that present similarly are Johne’s, parasitism, malnutrition, and deficiencies in copper. One other issue with vitamin B12 deficiency, is the cattle will be more susceptible to parasitism, which we had seen with this herd.
Vitamin B12 is manufactured by the microorganisms in the rumen. So, B12 deficiency is fairly rare in cattle, but if there is not enough cobalt in the diet it will become an issue. Supplementing with cobalt will improve symptoms within several days. In this case, the owner bought salt blocks containing cobalt and noticed a significant difference in the cattle within a couple days. The other thing that he did was change to a commercially available mineral for cows. He has reported continued improvement in the cows and also noticed the consumption of feed by the cows has improved dramatically.
Cobalt deficiency can also occur in areas where cobalt is deficient in soils or where pastures have had too much lime applied. Cobalt can also be antagonized by too much manganese, zinc, or iodine. In this case, it is probably a matter of being deficient in the diet.
Nutrition is a complex subject. There are many interactions between trace minerals that can cause problems due to antagonisms. When you buy commercially available mineral from a reputable source, there is a lot that goes into the formulation. Most of these companies have people with PhDs or masters in nutrition working on these products. If there is a suspected problem, work with your local nutritionist and veterinarian. Also, don’t hesitate to reach out to the company that provides the mineral product. They can offer some valuable assistance in trying to figure out the problem.
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Dr. Vince Collison is co-owner of Collison Embryo and Veterinary Services PAC
in Rockwell City, Iowa.