The article on enterotoxemia in baby calves (January, page 46) brought a great deal of comment. Of the calls and letters that came in, producers primarily wanted advice; whereas veterinarians in most cases offered advice. The problem, however, is that while each veterinarian felt strongly about the recommendations offered ... advice from veterinarian to veterinarian differed and/or was contradictory.
That was not unexpected. In fact, the contradiction is why I wrote the article. I was attempting to generate interest in research so we could get some real answers. To date, there has been essentially no data on which to base practical management decisions.
In the article I used an incorrect term to describe serum taken from hyper-immunized animals. The correct term is anti-toxin, which is used to treat infected calves or at lower dosages to provide short-term immediate protection for calves at risk.
Toxoid, the incorrect term used, refers to vaccine designed to stimulate immunity for the toxin produced by the bacteria. I apologize for any confusion that may have caused. In retrospect, I should have had a veterinarian proof-read the article before publishing.
Need For Information Please understand, however, my intent was not to provide information, but rather to solicit information. This is a subject that is a thorn in the side of a great many cow-calf producers. Yet, there's virtually no research available on which to base recommendations.
There's a large camp of veterinarians who recommend vaccinating calves at birth. At the same time, however, there are other veterinarians who state that vaccination at birth can neutralize colostral antibodies, and thus be counter-productive.
In trying to research the subject, I found zero published studies addressing this specific problem. The available research concerns diseases other than enterotoxemia. So, the data available is highly variable.
With some diseases, vaccinating at birth resulted in little or no response. In other diseases such as brucellosis, where the dam provided no colostral antibodies, there was a small but measured response. To add to the confusion, some veterinary journals state that vaccinating a calf before its immune system is fully functional can retard response when vaccinated later on (i.e., body may not recognize the antigen as "foreign").
Most veterinary reference books recommend vaccinating cows with "anti-scour" type vaccines containing Clostridium perfringens C&D (to enhance antibodies in the colostrum). The problem, however, is there is no data to demonstrate how effective these vaccines are. Aside from effectiveness, another question becomes whether these vaccines work in harmony or conflict with vaccinating the calf.
There's even conflict over the use of anti-toxin. In my original article, I suggested that prophylactic use should be limited to herds with high incidence rates of enterotoxemia, due to cost and potential toxicity.
As can be seen in letters to the editor (pages 58, 60, 63), one veterinarian tells me I'm all wrong with respect to toxicity; and the other says I'm right.
The bottom line is that this is a perplexing subject that touches a nerve with just about everyone who has to deal with it. Veterinarian Ivan Nicholson with Boehringer Ingelheim Animal Health has contacted me and offered to cooperate in some ranch trials. Hopefully, we can generate hard data and put some of the controversy to rest.
David P. Price is a consulting nutritionist specializing in feedlot and range cattle. A number of his books and a subscription newsletter are available through BEEF magazine by contacting Marilyn Anderson at 800/722-5334, ext. #710.