Managing Health Risks when Introducing Cattle

Replacement or reentering livestock may introduce the following contagious diseases:

  • Contagious mastitis—Strep ag, Staph aureus, Mycoplasma (6 months)
  • Bovine viral diarrhea—illness/death, abortion, calf loss, weak calves (2 wks. to months), identify persistently-infected (PI) animals
  • Shipping fever—pneumonia complex (1 to 4 weeks)
  • Salmonella—acute illness including diarrhea, death or chronic carrier (days to months)
  • Salmonella dublin – severe respiratory disease in young animals with high death loss
  • Foot rot/heel warts—lameness, decreased production (weeks to months)
  • Johne’s disease—chronic wasting and diarrhea (months to years)
  • Bovine leukosis virus

Non-disease problems can include:

  • Digestive upset due to feed change
  • Injuries due to unfamiliar facilities, stall design, change in herd pecking order

Control Strategies Prior to Purchase

Assess the Potential Risks Prior to Purchase

  • Consider health, nutrition, management and immune status of resident herd
  • Consider the disease/exposure and immune status of incoming animals
  • Anticipate and develop strategies to prevent, identify and control problems
  • Compare costs of preventive measures to cost of potential animal losses and treatment

 Pre-purchase process

  • 4-6 weeks prior take health history, inspect, tape, pregnancy check, primary vaccination, deworm heifers exposed to pasture.
  • Enroll in the NYS Cattle Health Assurance Program Core and Expansion modules
  • Booster 3 weeks prior to movement 
  • Screening test: bulk tank culture and SCC 3 times prior to purchase.  Depending on home herd’s health status other testing might include: BVD-PI, Johne’s, BLV, Salmonella dublin.
  • Due to cost and limitations in test sensitivity, testing alone may not eliminate the risk of purchasing infected animals; therefore, post purchase management of incoming animals as well as management of the home herd are important control points.

Livestock Transport vehicles

  • Limit access to farm, utilize peripheral holding pens for pickups. Use only clean, disinfected, well-bedded trucks to move cattle to avoid introducing disease from manure on the truck and to avoid injuries during transport.

Sources of Replacement Animals

Listed from highest to lowest risk:

  • Single source purchase from a reputable herd with extra replacements to sell and where animals are inspected prior to purchase
  • Multiple source purchase from a cattle dealer—usually springing heifers are less of a risk than mature cows
  • Avoid weekly sale barn—too much exposure to sick cull cows.  Avoid purchasing any cull animals out of the cull pen.

Post Purchase Management of Animals

Identification and Segregations

  • Identify new arrivals and segregate 2-3 weeks. If possible, identify and segregate cows as a group for longer term monitoring
  • Booster vaccine, if necessary
  • Provide clean, comfortable housing with good ventilation
  • Consult nutritionist to develop transition ration. Change to new ration slowly.
  • Group foot treatment or inspection and treat any lame animals

Post-purchase monitoring

  • Plan and anticipate in advance
  • Identify which staff will monitor new animals
  • Train staff in monitoring techniques
  • Create written protocols for monitoring and treatment with criteria such as fever, signs of infection, lameness, off-feed
  • Aggressive monitoring is critical.  Early recognition is key to preventing spread of disease.
  • Consult with veterinarian to create testing scheme, which may include mastitis cultures, BVD, Johne’s, Salmonella dublin, BLV


In consultation with veterinarian, create treatment and cull plan prior to purchase. Important considerations include:

  • Isolation of sick animals. Decisions about treatment or cull.
  • Maintain treatment records.
  • Evaluate successes and evaluate failures. Diagnostic evaluations of problems are important.

Management of Resident Herd During Expansion

Optimize immunization of all resident groups on the farm

The purpose of a vaccination program is to build herd immunity, which requires a history, a plan, and healthy animals able to respond.  Work with herd veterinarian to design a program that will work for your farm and in your area. 

Proper management

Considerations include animal handling and density; nutrition; facilities; milking procedures and overall farm hygiene. 

Use general good management practices to prevent spread of infectious disease 

  • Avoid mixing manure and feed by using the same skidsteer, scraper, or shovels to clean and feed.
  • Prevent runoff of adult manure to calf rearing areas or contamination of feed fed to calves.
  • Provide a clean calving environment to prevent spread of Johne’s and Salmonella, to prevent calf scours, and to prevent fresh cow mastitis.
  • Segregate sick animals and keep the calving and hospitals pens separate.  Clean and disinfect any equipment used on sick cattle prior to use on healthy herd mates.
  • Milk any cows suspected of having contagious mastitis with a separate unit or last in the string.  Use adequate pre-milking udder preparation and post milking teat dipping and cow management to minimize spread of infection.
  • Active monitoring for disease, including diagnostics, i.e. health programs such as milk cultures—bulk tank cultures or somatic cell counts.
  • Segregation and handling by livestock production groups or stages.

Before expanding a cattle operation, many issues should be considered, including finances, labor, land base, feed availability and animal health.  An expansion plan should be created prior to buying cattle using resource people that can address the above concerns.  Enrolling in the NYS Cattle Health Assurance Program core and expansion modules can help reduce possible health risks.  To enroll in NYSCHAP contact your veterinarian.  For more information about NYSCHAP contact the Division of Animal Industry (518-457-3502) or the NYSCHAP Coordinator (585-313-7541) or visit our NYSCHAP website.