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David Beck
Biology 1615
Sharyn Shelton
October 31, 2010
PRELIMINARY OBSERVATIONS ON
MYCOBACTERIUM SPP. IN DAIRY CATTLE
IN ECUADOR
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Table of contents
Abstract…………………………………….page 3
Introduction…………………..…………page 3
Research…………………………………..page 4
Results and discussion………………page 4
Conclusion and references……….page 5
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Abstract. This is a summary report on a study on mycobacterium spp. in dairy cattle in Ecuador.
The study was to evaluate bovine tuberculosis in dairy cattle and to determine if the herd size
of cattle was a causing affect to the number of cattle affected by this disease. This study was
also done to determine if programs needed to be put in place to manage this disease by ways
of cattle group sizing and more efficient early detection devises.
Introduction
Bovine tuberculosis is a disease caused by Mycobacterium bovis which is a slow-growing (16 to 20
hour generation time), aerobic bacterium and the causative agent of tuberculosis in cattle (known as
bovine TB) which is related to M. tuberculosis, “the bacteria which causes tuberculosis in humans”.
(Wikipedia)
The purpose of this research was to find out why the cattle in this region were dying from Bovine
tuberculosis “which was causing severe economic losses” and if it had to do with their size of herds and
lack of testing.
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Research
The methods used for the research were screenings of a single bovine tuberculin test in random cattle
from three different farms (large, medium, and small). Cattle that showed a positive reaction to the
bovine tuberculin test were then tested again with bovine and avian tuberculin. Organs from the
slaughterhouse that showed signs of the disease were studied in laboratories. In the cattle that showed
a positive result to the tests, a third comparative test was then implemented to eliminate any miss
readings. Many other tests were done with the organs from the slaughterhouses which included,
isolation of mycobacterium spp., In vitro culture and phenotypic identification, and Polymerase chain
reaction.
Results
The single tuberculin test in just over 1,000 cattle showed 44 positive reactors with more than half of
those in the large farm group and only 1 in the small farm group. Although these results might not
prove that this disease is more common in larger herd groups based on the fact that there are more
cattle in the larger farms. The results did find this disease in 39 of the cattle after a third test was done
after 60 days. Of the 125 specimens from the slaughterhouse only 5 showed a positive culture. The
cattle showed the strongest reactions from the avian tuberculin.
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Conclusion
Although there was a difference in the numbers of cattle infected based on the herd or farm size,
because of the limited number of cattle studied in this research, it cannot be concluded that the size of a
herd or farm can result in a higher percentage of diseases among the cattle. Much further research is
needed for herd size of farm size to be determined as a factor. What can be concluded is that “a
national control program is necessary and should be based on the detection of positive cattle by single
bovine tuberculin test in combination with a comparative tuberculin test.” (PRELIMINARY
OBSERVATIONS ON MYCOBACTERIUM SPP. IN DAIRY CATTLE IN ECUADOR)
Works Cited
(PRELIMINARY OBSERVATIONS ON MYCOBACTERIUM SPP. IN DAIRY CATTLE IN ECUADOR, 2006)
Mycobacterium bovis. (2010, October 5). In Wikipedia, The Free Encyclopedia. Retrieved
05:13, November 3, 2010, from
http://en.wikipedia.org/w/index.php?title=Mycobacterium_bovis&oldid=388873677
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