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United States Department of Agriculture

Agricultural Research Service

Title: Detecting Cmi Responses to Mycobacterium Avium Ssp. Paratuberculosis Infection in Calves Born to Naturally Infected Dams

Authors
item Robbe Austerman, Suelee
item Young, Sarah - IOWA STATE UNIVERSITY
item Oconnor, Annette - ISU/VDPAM
item Palmer, Mitchell
item Stabel, Judith

Submitted to: International Colloquium on Paratuberculosis
Publication Type: Abstract Only
Publication Acceptance Date: May 11, 2005
Publication Date: August 14, 2005
Citation: Robbe Austerman, S., Young, S., Oconnor, A., Palmer, M.V., Stabel, J.R. 2005. Detecting CMI responses to Mycobacterium avium ssp. paratuberculosis Infection in Calves born to Naturally Infected Dams [abstract]. International Colloquium on Paratuberculosis. p. 570.

Interpretive Summary: Our objectives were to evaluate the best age to use the skin test and INF-gamma ELISA for Johne’s disease in calves. Seventeen calves born from naturally infected Johne’s cows were used. At 4-6 months, 6-8 months and 12-13 months each calf was with the skin test and the INF-gamma ELISA. Calves were necropsied at 12-13 months of age and tissues were cultured. Ten of 17 calves were positive for Johne’s disease and 7 were negative. Of the ten calves the skin test identified 5 at 4-6 months of age, 4 at 6-8 months and 7 at 12-13 months. Of the ten Johne’s positive calves the INF-gamma ELISA identified 2 calves at 4-6 months of age, 4 at 6-8 months and 10 at 12-13 months. Of the seven Johne’s negative calves, all tested negative using the skin test except three animals at 12-13 months. The INF-gamma ELISA identified one calf as positive at 4-6 months of age, 6 as positive at 6-8 months and again at 12-13 months. In Johne’s positive calves the skin test and INF-gamma ELISA appeared best able to identify calves with Johne’s disease at 12-13 months.

Technical Abstract: Our objectives were to evaluate the age a CMI response could be detected in calves and the accuracy and reliability of the skin test and INF-gamma ELISA in MAP infected and non-infected calves. Seventeen calves born from naturally infected Johne’s cows were used. At 4-6 months, 6-8 months and 12-13 months each calf was tested for the presence of CMI response using the skin test and the INF-gamma ELISA. Calves were necropsied at 12-13 months of age and tissues were cultured. Ten of 17 calves were tissue culture positive for MAP and 7 negative. Of the ten MAP culture positive calves the skin test identified 5 at 4-6 months of age, 4 at 6-8 months and 7 at 12-13 months. Of the ten MAP culture positive calves the INF-gamma ELISA identified 2 calves at 4-6 months of age, 4 at 6-8 months and 10 at 12-13 months. Of the seven MAP culture negative calves, all tested negative using the skin test except three animals at 12-13 months. The INF-gamma ELISA identified one calf as having CMI response to MAP at 4-6 months of age, 6 as positive at 6-8 months and again at 12-13 months. In tissue culture positive calves the skin test and INF-gamma ELISA appears best able to identify a CMI response at 12-13 months. Even though the INF-gamma ELISA identified 6 of the 7 non-infected calves as positive, it may be the standard positive cutoff of 0.100 + control plasma is not adequate in young calves.

Last Modified: 11/27/2014
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