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Proceedings of the 10th International Colloquium on Paratuberculosis

Proceedings of the 10th International Colloquium on Paratuberculosis

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#79 Vaccinati<strong>on</strong> for <strong>Paratuberculosis</strong> in New Zealand farmed deer herds<br />

Peter Raym<strong>on</strong>d Wils<strong>on</strong>, Lesley Stringer, Cord Heuer, Kathy Goodwin-Ray, Jaimie Hunnam, Colin Mackintosh,<br />

IVABS Massey University, Palmerst<strong>on</strong> North, New Zealand; AgResearch Invermay, Mosgiel, New Zealand<br />

Aim: To evaluate Silirum ® in farmed deer.<br />

Method: Initial studies dem<strong>on</strong>strated 0.5, 1.0 and 2.0ml doses to three-m<strong>on</strong>th-old farmed red and red x<br />

wapiti deer (C. elaphus) were clinically safe, produced equivalent antibody and cellular immune resp<strong>on</strong>ses,<br />

and caused few significant injecti<strong>on</strong> site lesi<strong>on</strong>s. Subsequently, six commercial deer farms previously reporting<br />

≥5% annual incidence <str<strong>on</strong>g>of</str<strong>on</strong>g> clinical disease in young deer were selected for investigati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> efficacy and crossreactivity<br />

with bovine tuberculosis tests.<br />

In March-April 2008, 180 - 1120 deer/farm were randomised to vaccinati<strong>on</strong> (0.5ml Silirum ® , n=1671) and<br />

c<strong>on</strong>trol (n=1664) groups at 3.5 – 4.5 m<strong>on</strong>ths <str<strong>on</strong>g>of</str<strong>on</strong>g> age, and managed toge<str<strong>on</strong>g>the</str<strong>on</strong>g>r <strong>on</strong> pasture. Clinical disease, mortality,<br />

weight and slaughter data were collected, and 25 vaccinated and c<strong>on</strong>trol deer per farm faecal sampled<br />

for Map culture in November 2008. In January 2009, 180 vaccinated and 181 c<strong>on</strong>trol deer from three farms underwent<br />

a comparative mid-cervical test (CCT) for bovine tuberculosis, also interpreted as a single mid-cervical<br />

test (MCT).<br />

Results: By May 2009 when 95% <str<strong>on</strong>g>of</str<strong>on</strong>g> deer had been slaughtered, disease had been diagnosed in nine<br />

vaccinated and 22 c<strong>on</strong>trol deer <strong>on</strong> four farms, a tentative overall efficacy <str<strong>on</strong>g>of</str<strong>on</strong>g> 59% against clinical disease<br />

(p=0.02). Some injecti<strong>on</strong> site residual lesi<strong>on</strong>s were evident but did not affect carcass processing or value. Fifty<br />

nine (47%) vaccinates and 68 (55%) c<strong>on</strong>trols were faecal culture positive (p=0.2). Tuberculosis testing yielded<br />

44% vaccinates and 23% c<strong>on</strong>trols MCT positive, respectively, and corresp<strong>on</strong>dingly, two and three were CCT<br />

positive. Two c<strong>on</strong>trols remained positive to an ancillary Elisa test. Final data will be presented.<br />

C<strong>on</strong>clusi<strong>on</strong>: Despite <str<strong>on</strong>g>the</str<strong>on</strong>g> low incidence <str<strong>on</strong>g>of</str<strong>on</strong>g> clinical Ptb, <str<strong>on</strong>g>the</str<strong>on</strong>g>se data suggest that Silirum ® may aid c<strong>on</strong>trol <str<strong>on</strong>g>of</str<strong>on</strong>g><br />

clinical disease in young farmed deer. Fur<str<strong>on</strong>g>the</str<strong>on</strong>g>r data are now needed to better quantify efficacy. Tuberculin testing<br />

suggests that <str<strong>on</strong>g>the</str<strong>on</strong>g> risk <str<strong>on</strong>g>of</str<strong>on</strong>g> indistinguishable cross-reactivity is low in herds without tuberculosis.<br />

#83 Prevalence reducing factors in <str<strong>on</strong>g>the</str<strong>on</strong>g> Danish c<strong>on</strong>trol programme <strong>on</strong> bovine paratuberculosis<br />

Søren Saxmose Nielsen, University <str<strong>on</strong>g>of</str<strong>on</strong>g> Copenhagen, Denmark<br />

A risk-based c<strong>on</strong>trol programme <strong>on</strong> paratuberculosis in Danish dairy cattle was initiated in 2006. In total, 1265<br />

herds (~28% <str<strong>on</strong>g>of</str<strong>on</strong>g> all dairy herds and ~40% <str<strong>on</strong>g>of</str<strong>on</strong>g> all dairy cows) were enrolled in <str<strong>on</strong>g>the</str<strong>on</strong>g> programme by April 2009.<br />

Cows are categorised as High-Risk or Low-Risk animals based <strong>on</strong> 3-4 annual milk antibody ELISA tests. High-<br />

Risk animals require management practices reducing calves exposure to milk and faeces from <str<strong>on</strong>g>the</str<strong>on</strong>g>se cows.<br />

Moreover, repeated test-positive cows are recommended to be slaughtered prior to next calving.<br />

The objective <str<strong>on</strong>g>of</str<strong>on</strong>g> this study was to assess <str<strong>on</strong>g>the</str<strong>on</strong>g> development in within-herd test-prevalences for different<br />

management practices.<br />

A questi<strong>on</strong>naire <strong>on</strong> management practices was distributed to all participating herds in January 2009. A<br />

total <str<strong>on</strong>g>of</str<strong>on</strong>g> 1075 (85%) herd-managers returned <str<strong>on</strong>g>the</str<strong>on</strong>g> questi<strong>on</strong>naire. Only <str<strong>on</strong>g>the</str<strong>on</strong>g> 679 herds that started in 2006 were<br />

included in <str<strong>on</strong>g>the</str<strong>on</strong>g> present analyses, because <str<strong>on</strong>g>the</str<strong>on</strong>g> effect <str<strong>on</strong>g>of</str<strong>on</strong>g> changes in management <strong>on</strong> prevalence would be expected<br />

at <str<strong>on</strong>g>the</str<strong>on</strong>g> earliest after 2 to 3 years.<br />

Results <str<strong>on</strong>g>of</str<strong>on</strong>g> univariable analyses showed that: a) culling <str<strong>on</strong>g>of</str<strong>on</strong>g> repeated test-positive cows reduced <str<strong>on</strong>g>the</str<strong>on</strong>g> testprevalence<br />

by 7%-points; b) cleaning <str<strong>on</strong>g>of</str<strong>on</strong>g> calving area subsequent to High-Risk cows’ calvings led to a reducti<strong>on</strong><br />

<str<strong>on</strong>g>of</str<strong>on</strong>g> 3%-points; c) separati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> High-Risk animals from Low-Risk animals resulted in a reducti<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> 2%-points;<br />

and d) use <str<strong>on</strong>g>of</str<strong>on</strong>g> colostrum from Low-Risk animals <strong>on</strong>ly, resulted in a reducti<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> 1.5%-points. Feeding practices<br />

using milk from High-Risk cows did not reduce <str<strong>on</strong>g>the</str<strong>on</strong>g> prevalence.<br />

The c<strong>on</strong>trol programme has been running for ~3 years in <str<strong>on</strong>g>the</str<strong>on</strong>g> herds included, and it is assumed that <str<strong>on</strong>g>the</str<strong>on</strong>g><br />

full effect will <strong>on</strong>ly be observed after 4-8 years. However, already after 3 years, reduced prevalences were observed<br />

due to changes in specific management practices. The reducti<strong>on</strong>s are not additive due to possible c<strong>on</strong>founding,<br />

which could not be assessed at this point in time because <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> distributi<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> management factors.<br />

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