<abstract xmlns="http://www.w3.org/1999/xhtml">

<sec id="j_jvetres-2022-0001_s_005">
<h3>Introduction</h3>
<p>Johne’s disease, caused by infection with <italic>Mycobacterium avium</italic> subsp. <italic>paratuberculosis</italic> (MAP), causes economic losses in dairy herds due to reduced milk production and premature culling. A test-and-cull strategy coupled with changes in calf rearing management preventing new infections has been introduced into infected herds to control MAP prevalence. This study appraised the effectiveness of these practice changes.</p>
</sec>
<sec id="j_jvetres-2022-0001_s_006">
<h3>Material and Methods</h3>
<p>In 19 large dairy herds (of a median 470 milk-producing cows), implementing MAP control measures for 3–7 years, a serum ELISA was used to detect infected cows in their dry-off period. The number of ELISA-positive animals per year (EPAY) was calculated and statistical analysis was used to test whether the EPAY total decreased during the control period and to analyse the EPAY in relationship to the duration of the control programme.</p></sec>
<sec id="j_jvetres-2022-0001_s_007">
<h3>Results</h3>
<p>Statistical support was found for a decrease of EPAY over time (P &lt; 0.01, odds ratio 0.756) and in 14 herds a significant fall in the percentages of EPAY during the test period (P ≤ 0.05) was noted.</p></sec>
<sec id="j_jvetres-2022-0001_s_008">
<h3>Conclusion</h3>
<p>Our results demonstrated the effectiveness of the control measures in place to reduce MAP infection in herds with initial EPAY ≥3.36%. The missing decreasing trend in the remaining five herds with low average initial EPAY suggested the need for additional measures to reduce the number of infected animals in these herds.</p>
</sec>
</abstract>

Introduction
Johne’s disease, caused by infection with Mycobacterium avium subsp. paratuberculosis (MAP), causes economic losses in dairy herds due to reduced milk production and premature culling. A test-and-cull strategy coupled with changes in calf rearing management preventing new infections has been introduced into infected herds to control MAP prevalence. This study appraised the effectiveness of these practice changes.


Material and Methods
In 19 large dairy herds (of a median 470 milk-producing cows), implementing MAP control measures for 3–7 years, a serum ELISA was used to detect infected cows in their dry-off period. The number of ELISA-positive animals per year (EPAY) was calculated and statistical analysis was used to test whether the EPAY total decreased during the control period and to analyse the EPAY in relationship to the duration of the control programme.

Results
Statistical support was found for a decrease of EPAY over time (P < 0.01, odds ratio 0.756) and in 14 herds a significant fall in the percentages of EPAY during the test period (P ≤ 0.05) was noted.

Conclusion
Our results demonstrated the effectiveness of the control measures in place to reduce MAP infection in herds with initial EPAY ≥3.36%. The missing decreasing trend in the remaining five herds with low average initial EPAY suggested the need for additional measures to reduce the number of infected animals in these herds.

Effective control of Johne’s disease in large Czech dairy herds

Journal of Veterinary Research

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

{"article-title":"Effective control of Johne\u2019s disease in large Czech dairy herds"}

Introduction
Johne’s disease, caused by infection with Mycobacterium avium subsp. paratuberculosis (MAP), causes economic losses in dairy herds due to reduced...

Herd	Number of lactating cows in the herd	Control period in years	Initial percentage of EPAY	Final percentage of EPAY	Average percentage of retested EPAY
1	470	4	12.86	3.88	16.84
2	284	6	0.82	0	0
3	330	6	9.42	1.11	0
4	432	3	2.20	2.96	0
5	535	4	3.36	2.00	8.33
6	920	6	7.65	2.32	3.20
7	423	6	2.53	1.53	4.79
8	390	5	7.04	1.90	8.23
9	435	6	10.04	0.90	8.16
10	570	4	2.90	1.24	23.67
11	590	4	7.34	2.76	41.31
12	600	7	10.66	0.20	22.28
13	730	3	3.80	1.73	0
14	613	3	11.42	4.65	21.17
15	550	5	8.11	2.20	27.33
16	760	6	2.05	1.95	13.13
17	188	4	9.22	1.49	9.40
18	110	7	17.20	3.45	29.21
19	220	7	23.05	7.57	36.39

Herd	Total number of tested animals	Total number of ELISA-positive animals	Percentage of ELISA-positive animals	Trend
1	1,425	117	8.21	P < 0.01
2	1,341	12	0.89	P > 0.05
3	2,271	88	3.87	P < 0.01
4	871	20	2.30	P > 0.05
5	1,922	47	2.45	P > 0.05
6	4,852	195	4.02	P < 0.01
7	2,764	59	2.13	P > 0.05
8	2,164	84	3.88	P < 0.01
9	2,463	113	4.59	P < 0.01
10	2,462	58	2.36	P < 0.05
11	3,032	130	4.29	P < 0.01
12	3,231	105	3.25	P < 0.01
13	2,168	54	2.49	P < 0.05
14	1,492	125	8.38	P < 0.01
15	2,357	100	4.24	P < 0.01
16	3,700	93	2.51	P > 0.05
17	736	30	4.08	P < 0.01
18	922	68	7.38	P < 0.01
19	1,960	189	9.64	P < 0.01

Total	42,133	1,687

Effective control of Johne’s disease in large Czech dairy herds

Pubblicato online: 25 mar 2022

Pagine: 61 - 67

Ricevuto: 24 ago 2021

Accettato: 20 dic 2021

DOI: https://doi.org/10.2478/jvetres-2022-0001

Parole chiave
dairy cattle, Johne’s disease, serum ELISA, MAP control

© 2022 V. Fichtelová et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig. 1

Characteristics of 19 studied herds and ELISA results during implementation of MAP control measures

Data and results of χ2 test for a trend of decreasing number of ELISA-positive animals tested per year during the control period

Effective control of Johne’s disease in large Czech dairy herds

Pubblicato online: 25 mar 2022

Pagine: 61 - 67

Ricevuto: 24 ago 2021

Accettato: 20 dic 2021

DOI: https://doi.org/10.2478/jvetres-2022-0001

Parole chiavedairy cattle, Johne’s disease, serum ELISA, MAP control

© 2022 V. Fichtelová et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig. 1

Characteristics of 19 studied herds and ELISA results during implementation of MAP control measures

Data and results of χ2 test for a trend of decreasing number of ELISA-positive animals tested per year during the control period

Parole chiave
dairy cattle, Johne’s disease, serum ELISA, MAP control