J Vet Sci.  2023 Sep;24(5):e70. 10.4142/jvs.23111.

Comparison of blood parameters according to fecal detection of Mycobacterium avium subspecies paratuberculosis in subclinically infected Holstein cattle

• Ha S
• Kang S
• Jung M
• Kim SB
• Lee HG
• Park HT
• Lee JH
• Choi KC
• Park J
• Kim UH
• Yoo HS

• KMID: 2546802
• DOI: http://doi.org/10.4142/jvs.23111

Abstract

Background
Mycobacterium avium subspecies paratuberculosis (MAP) causes a chronic and progressive granulomatous enteritis and economic losses in dairy cattle in subclinical stages. Subclinical infection in cattle can be detected using serum MAP antibody enzyme-linked immunosorbent assay (ELISA) and fecal polymerase chain reaction (PCR) tests.
Objectives
To investigate the differences in blood parameters, according to the detection of MAP using serum antibody ELISA and fecal PCR tests.
Methods
We divided 33 subclinically infected adult cattle into three groups: seronegative and fecal-positive (SNFP, n = 5), seropositive and fecal-negative (SPFN, n = 10), and seropositive and fecal-positive (SPFP, n = 18). Hematological and serum biochemical analyses were performed.
Results
Although the cows were clinically healthy without any manifestations, the SNFP and SPFP groups had higher platelet counts, mean platelet volumes, plateletcrit, lactate dehydrogenase levels, lactate levels, and calcium levels but lower mean corpuscular volume concentration than the SPFN group (p < 0.017). The red blood cell count, hematocrit, monocyte count, glucose level, and calprotectin level were different according to the detection method (p < 0.05). The SNFP and SPFP groups had higher red blood cell counts, hematocrit and calprotectin levels, but lower monocyte counts and glucose levels than the SPFN group, although there were no significant differences (p > 0.017).
Conclusions
The cows with fecal-positive MAP status had different blood parameters from those with fecal-negative MAP status, although they were subclinically infected. These findings provide new insights into understanding the mechanism of MAP infection in subclinically infected cattle.

Keyword

Johne’s disease; subclinical infection; blood cells; blood chemical analysis; Bos taurus