Bovine Tuberculosis Biosecurity Maria O’Hagan DAERA Veterinary Epidemiology Unit

Overview Results from 3 biosecurity related studies conducted in Northern Ireland 1. Bovine TB biosecurity study 2. Badger proximity study 3. An assessment of farmers’ understanding of biosecurity measures, the consequences of not applying biosecurity measures and their attitudes towards applying biosecurity measures when dealing with diseases Advice available from DAERA

Background bTB biosecurity study Minister of Agriculture requested an observational case-control study focussing on bTB biosecurity Study commissioned by DAERA and conducted by AFBI with DAERA input Objectives: To assess selected farm management practices as risk factors for bTB To assess the presence of badger related factors on the farm as risk factors for bTB To provide information on farmers’ current biosecurity practices with regards to bTB To assess farmers’ attitudes towards bTB and bTB control

Background analyses % of herds with confirmed disease: In total 60.6% of herds with ≥400 cattle had a confirmed bTB outbreak during 2008/2009 compared to 8.6% of herds with cattle

Observational study (no intervention) conducted comparing case and control herds in relation to the prevalence of exposure to a potential risk factor Case herds: Herds within the study area, that during 2008 or 2009 had a confirmed bTB breakdown or, if unconfirmed, 2 or more reactors. Control herds: Herds within the study area with no reactors or restricted herd tests in the period 2007 to Control herds were selected on a group matched basis by herd size category and DVO area

Study conducted in a high bTB incidence area 117 case farms (participation rate 37.4%) 75 control farms (participation rate 32.4%) Overall participation rate: 35.1%

Data sources Study conducted in Winter 2010-Summer 2011 Questionnaires completed by trained survey staff (face-to-face interviews with farmers) Badger sett surveys: > within a 250 metre radius of the farm buildings > validation of badger setts identified by farmers > within the farm boundary Farm boundary survey

Accuracy of sett identification by farmers Positive predictive value 81.4% Negative predictive value 49.3% Badger related risk factors investigated: - Observation of badgers or badgers signs by farmer - Observation of badger signs by field staff - Badger sett classification - Badger sett location - Badger sett accessibility for cattle - Badger sett density - Distance from the badger sett to the farm buildings

Farm management factors investigated: - Farm type - Area farmed/number of parcels - Cattle movements onto the farm - Cattle housing - Forage/grain/supplements/bedding used and stored - Drinking water resources - Grazing and slurry management - Membership of farm quality assurance schemes - Occurrence and control of other cattle diseases - Biosecurity measures - Contact with neighbouring cattle - Other animal species on the farm - Presence of deer on the farm

Multivariable analysis VariableAdjusted OR95% CIP Value LR Observation of live badgers Meal fed on top of silage Magnesium fed as supplement Accessible badger sett <0.001 Use of contractors to spread slurry/manure Purchase of store/beef animals Some of the risk factors identified:

Farm boundary survey Risk categoryDefinition 1No nose-to-nose contact possible (gap ≥ 3 metres) 2No direct nose-to-nose contact possible (gap<3 metres) 3Rare nose-to-nose contact possible 4Occasional nose-to-nose contact possible 5Frequent nose-to-nose contact possible What proportion of farm boundaries provided opportunity for nose-to-nose contact (i.e. category 3, 4 and 5)?

Farm boundary survey Risk categoryDefinition% of farm boundaries in category 1No nose-to-nose contact possible (gap ≥ 3 metres)33.2% 2No direct nose-to-nose contact possible (gap<3 metres)9.4% 3Rare nose-to-nose contact possible8.9% 4Occasional nose-to-nose contact possible24.2% 5Frequent nose-to-nose contact possible24.3% 57.4% of farm boundaries provide opportunity of nose-to- nose contact

Biosecurity measures

Biosecurity measures (purchasing cattle)

Farmers’ attitudes to bTB control Statement% agreement Bovine TB control very important81.3% Current controls adequate62.0% Enough information in relation to TB control Welcome additional advice Welcome an advisory visit 81.8% 57.6% 45.3% Biosecurity measures can make a difference67.7% Willing to take further biosecurity measures in the future68.2% Isolation of inconclusive animals essential80.2% Support greater use of the gamma interferon blood test64.6% In favour of the introduction of a pre-movement test Willing to pay for pre-movement test 52.6% 17.2%

Attitudes to badger-related control measures Preferences: Badger cull In favour of badger cull on problem farms81.8% Allow a badger cull on their own land79.2% Willing to pay for badger cull20.3% Concerned about public opposition to culling38.0% Badger vaccination In favour of badger vaccination in problem areas81.8% Allow badger vaccination on their own land89.6% Willing to pay for badger vaccination18.8%

Conclusions Biosecurity measures taken can be improved esp. in relation to badgers. Large herds are a major contributor to bTB breakdown rates in NI. Significant risk factors to bTB breakdown include: - the presence of badgers on the farm - farm management practices that would possibly attract badgers - purchasing cattle - the use of contractors to spread slurry/manure Majority of farm boundaries allow nose-to-nose contact with neighbouring cattle Although farmers find bTB control important and the majority is willing to put measures in place, very few are prepared to pay for these measures O‘Hagan, M.J.H., Matthews, D.I. Laird, C. McDowell, S.W.J. (2013): Bovine Tuberculosis Biosecurity study. Report to TB & Brucellosis Policy Branch, Department of Agriculture and Rural Development. Northern Ireland. ni.gov.uk/sites/default/files/publications/dard/tb-biosecurity-study.pdfhttps:// ni.gov.uk/sites/default/files/publications/dard/tb-biosecurity-study.pdf

Badger Proximity Study * in county Down * Sett surveys, bait marking, trapping, GPS collaring of badgers, motion activated cameras Aims: Quantification of the level of direct interaction between badgers and cattle at pasture Determination of frequency of badger visitation to farm yards/buildings

Badger Proximity Study Results: Mean territory size: ha ±11.28 ha Mean density: 3.62 badgers/km 2 Mean nightly movement distance: 1321 m ±34.5 m (max.:6541 m) Direct close-range interactions (≤2m) between badgers and cattle: how many interactions occurred? O'Mahoney, D.T. (2014): Badger-Cattle interactions in the rural environment: implications for bovine tuberculosis transmission. Report to TB & Brucellosis Policy Branch, Department of Agriculture and Rural Development. Northern Ireland.

Badger Proximity Study Results: No direct close-range interactions (≤2m) between badgers and cattle Great variation in badger visits between farm yards (0-16% of surveillance nights) Badgers positively selected feed stores and significantly avoided cattle sheds during visits to farm yards O'Mahoney, D.T. (2014): Badger-Cattle interactions in the rural environment: implications for bovine tuberculosis transmission. Report to TB & Brucellosis Policy Branch, Department of Agriculture and Rural Development. Northern Ireland.

An assessment of farmers’ understanding and attitudes toward biosecurity and disease control measures Study based on 20 minute postal/on-line survey (n=535) The majority of trading among cattle farmers is done locally Cattle farmers perceive a greater risk from imported animals compared to local sources On animal health checks, the majority of farmers only perform the minimum required by law; Bovine TB and brucellosis were the top priority diseases for cattle farmers Preferred sources of biosecurity advice were PVPs, DAERA Veterinary Officers and DAERA website

Farmers keen on more information/ training on biosecurity preferably “face-to-face” Disclosure of disease status of the farm to be traded with is considered useful by majority of farmers Larger farms are less likely to monitor/quarantine sick animals in comparison to smaller farms Least cost/labour intensive biosecurity practices are preferred option Speijers, M.H.M., Hartley, H., Lahuerta-Marin, A. Jack, C., Matthews, D., Finney, G. (2015): An assessment of farmers’ understanding and attitudes toward biosecurity and disease control measures. Report to TB & Brucellosis Policy Branch, Department of Agriculture and Rural Development. Northern Ireland. An assessment of farmers’ understanding and attitudes toward biosecurity and disease control measures

DAERA advice on bTB Biosecurity