12/16/2009

Beef Herd Biosecurity – protecting your herd

The Health/Biosecurity Program

Goal • To decrease likelihood of a devastating outbreak within a population of animals. • Effects are mild or subclinical in nature if a disease agent is present in the herd. Richard F. Randle, DVM,MS Extension Beef Cattle Veterinarian Veterinary Biomedical Sciences University of Nebraska, Lincoln

The Health/Biosecurity Program • Increase Immunity

The Health/Biosecurity Program

• Biosecurity • Reduces the likelihood of introducing a new disease from external sources.

• Limit or prevent transmission

• Biocontainment • Reduce or eliminate the agent

Biosecurity/Biocontainment Strategies Hazard Analysis and Critical Control Points

• Reduces the spread of infectious disease already on the farm. • Reduces the severity and economic impact of existing infectious diseases already present.

Biosecurity protecting your herd from Trichomoniasis

• Concept of HAACCP • understanding production cycles • understanding disease biology • recognize specific points to intervene • Certain strategies common • isolation, sanitation, stocking rates • Certain strategies specific • diagnosis, testing, treatment, culling

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• Trich is transmitted to cows by sexual contact with an infected bull.

• Cow to cow – via infected bull • A disease of naturally bred cattle as opposed to artificially inseminated cattle.

What happens to infected females? • Become infected when bred • Colonies of T. foetus grow and spread throughout reproductive tract

What happens to infected males? • No outward signs of disease • No effect on sexual activity or semen quality • Localizes in secretions (smegma) produced by penis and prepuce • Reside in crypts in the surface on the penis and sheath • Crypts become more prominent with age • Older bulls are more likely to become infected and stay infected.

• There is no effective treatment

End Result of Trichomoniasis Pregnancy Rate 70

• Open cows

60

60 50 % Pregnant

What is Trichomoniasis? • Trichomoniasis or “Trich” for short, is a venereal disease of cattle resulting in reproductive losses

40

40 30 20 10 0 Pregnant

Open

Pregnancy Histogram

• Reaction results in inflammation • Inflammation results in death of the fetus

40 35 30 25 20 15 10 5 0

35 30

% Pregnant

• Extended calving

15 10 5

1st 21d

Trich – Geographic Expansion?

2nd 21d

5

3rd 21d 4th 21d 5th 21d Cycle of Breeding Season

Open

Trichomoniasis Geopolitical issues

Traditional geographic range States now reporting Trich

http://www.fortdodgelivestock.com/pdfs/pdfs_for_beef/Trichomoniasis

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Trich in Nebraska • Spring 2008 – Trichomoniasis Health Committee

Trich in Nebraska

• NDA, NE Cattlemen, NE LMA, UNL, NE Dairy Assoc., NVMA • Draft proposal for voluntary Trichomoniasis Management Program • Improve reporting of Trichomoniasis in Nebraska

• Summer & Fall 2008 – Trichomoniasis Education • 12 regional cattlemen’s meetings • 3 veterinary educational meetings • Trichomoniasis educational material

• Fall 2008 – NVMA Ad hoc Trichomoniasis Committee • Review and advise Trich Health Committee on draft proposal • Proposed Trich education and certification for Veterinarians

Issued Jan 1, 2008: Amended Aug 8, 2008

Trich Reporting by County – NE only Reporting dates: Jan 1, 2008 – Dec 31, 2008 3810 total samples from 67 counties : 311 positives from 21 counties

Source: University of Nebraska - VDC

Trich Reporting by County – NE only

= At least one positive sample reported

Biosecurity – Guidelines for prevention

Reporting dates: Jan 1, 2009 – Dec 14, 2009

3706 total samples from 75 counties : 19 positives from 10 counties

= At least one sample submitted

• Females • Virgin heifers from reputable sources

• Males • • • • Source: University of Nebraska - VDC

= At least one sample submitted

= At least one positive sample reported

Virgin bulls or test negative bulls Do not loan, rent, or borrow bulls Use young bulls Perform annual Breeding Soundness Exams including semen check and Trich test

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Biosecurity – Guidelines for prevention

Manage by Breeding Groups

• Sound reproductive management strategy • Maintain short breeding season • Timely pregnancy diagnosis • Consider AI when possible • Avoid co-mingling • Maintain and manage by breeding groups • Maintain good records

Biocontainment - managing infected herds • Cull all open cows and “short breds” • These are the most likely carriers • Manage bulls to prevent ongoing transmission • Best –sell all bulls and replace with virgin testnegative bulls • Alternative –test all bulls and retain only young testnegative bulls from the herd • Cull cows and bulls should be sold for slaughter

Biosecurity protecting your herd from bovine Tuberculosis

300 cows 12 bulls

300 cows 12 bulls

95%

92%

100 cows 4 bulls

100 cows 4 bulls

65%

95%

800 exposed 721 pregnant 90% overall pregnancy rate

Biocontainment - managing infected herds • Segregate cows based on pregnancy status • ≥ 5 months pregnant • Most likely not infected or cleared infection • Cull cows that abort • < 5 months pregnant • Maintain separate and watch closely • Cull cows that abort • Open cows or cows with pyometra • Cull

What is bovine tuberculosis? • TB is a contagious, chronic progressive bacterial disease.

• Primarily affects cattle but can be transmitted to any warm-blooded animal including humans.

• Federally regulated disease.

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What happens if TB is discovered?

How is TB transmitted

• Initial herd is quarantined and tested.

• Spread by an infected animal through… • Respiration of TB bacteria aerosols • Contaminated feed or water from saliva or other discharges • Drinking raw milk from infected animal

• Herds with direct exposure to initial herd quarantined and tested. • Epidemiologic investigation • Trace back of animals leaving or entering initial herd

Biosecurity – Guidelines for prevention

TB in Nebraska • June 1, 2009, a beef herd in Rock county diagnosed with TB • Ongoing investigation with no additional infected animals found • At the peak of the investigation, 43 herds in 14 counties quarantined • Dec 13th, 9 herds in 8 counties quarantined • 19,800 cattle have been tested

Biosecurity

• Set of guidelines

• • • • • • • •

Maintain a closed herd Buy animals from an accredited TB-free herd Test new animals for TB Isolate for 60 days and retest Restrict contact between your herd and other herds Restrict on-farm visitors from contact with your herd Restrict contact with wildlife Test your herd

Questions?

• Reduces the likelihood of introducing a new disease from external sources.

• Assess your risks • Devise a plan • Consult your veterinarian

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