Buying Dairy Cows
Some Suggestions for Beginning Dairy Producers
Wisconsin Department of Agriculture, Trade and Consumer Protection
Farm and Rural Services Bureau & Division of Animal Health
The financial success of a new dairy operation hinges on the quality and
productivity of its cows. “Cheap” cattle can be very expensive if they enter your herd carrying diseases or contagious mastitis that can potentially infect the
rest of your herd.
How $50 worth of testing could have saved one dairy operation more than $19,000
Susan and Jeff milk 100 Holstein cows in a tie stall barn. They are good managers; prior to
their problems last fall they had a rolling herd average of 22,000 pounds and a bulk tank
somatic cell count averaging 200,000. They treated one or two cows per month for clinical
mastitis, a manageable level in their minds. Over the years they received quality awards from
their milk plant. Due to a poor heifer crop two years ago, they decided to purchase 10 cows to keep their barn and bulk tank full. They bought some milking cows from a neighbor and some from an auction. None of the cows were tested for contagious mastitis pathogens nor did they have any information on somatic cell counts for the animals. Six months after they introduced the new cows to the barn their bulk tank somatic cell count had climbed to 450,000 even though
the cows never appeared sick. They were treating four or five cases of mastitis a month with limited success. Eight cows had to be culled for mastitis that would not respond to treatment.
Eight months later a bulk tank culture indicated moderate levels of staph aureus infecting the
herd. Individual cow culturing indicated that about 20% of the herd was infected with staph
aureus. Five of the purchased cows were infected with staph aureus and their monthly DHIA
somatic cell counts indicated that they were high from the time of purchase.
What did this purchase cost them on an annual basis because of poor milk quality?
Loss from infected cows not producing as much milk @ $13.50/cwt $ 6,700
Loss from unrealized milk quality premiums @ $.25/cwt $ 5,500
Loss from more cows being treated @ $90 per case $ 3,060
Loss from an increase in involuntary culls due to mastitis $ 3,900
Total opportunities lost from poor milk quality $19,160
Cost of doing individual milk culture for 10 cows $50.00
Purchasing Dairy Cattle --
General Guidelines:
Buy cattle from a single producer rather than individual animals from multiple producers.
However, buying multiple cattle from one source can amplify the impact if there is a problem in
the seller’s herd; it highlights the importance of testing cattle before purchase. Request the right to reject any animal for questionable health status, blank quarters, lameness, bad attitude, or other reasons.
Purchase cattle that are being managed in a way similar to how you intend to manage them.
Most, if not all, of the animals you purchase should have been sired by AI bulls and bred to
AI bulls.
Look for a herd that has been on a monthly veterinary herd health program. Ask for permission for your veterinarian to speak with the seller’s veterinarian. A herd that has been enrolled in dairy Herd Improvement (DHI) testing is preferred. Request vaccination records and health history for each animal you are purchasing. All animals should have:
� Calfhood vaccination for brucellosis
� Up-to-date J5 immunization against coliform mastitis
� 9-way vaccination
� 7-way clostridial vaccination
Before paying for the cattle, make sure that the seller has clear title and there are no liens
against them.
Prior to Purchase:
Visually inspect all animals for heel warts, ringworm, skin warts, active pinkeye, number of
teats, and condition of teats and teat ends. Ask to see forms, if available, filled out by the hoof
trimmer with the types of lesions treated during routine hoof trimming. If hairy warts are present
in the herd of origin, the purchased animals should be treated preventatively with an effective therapy.
Review bulk tank culture records for at least the past six months; take note of somatic cell count
(SCC), standard plate count (SPC) and preliminary incubation (PI) count. SCC gives you a sense of the milk quality of the cows; SPC and PI give you a sense of the management
quality of the seller. The average SCC should be less than 300,000 and preferably under
200,000. Standard plate count should be less than 5,000 and preliminary incubation count
less than 10,000.
A bulk tank sample should be collected prior to purchase and tested for staph aureus, strep ag, and mycoplasma. Keep in mind that it will take a week to get the results. If the bulk tank culture is positive for mycoplasma, do not purchase any cows from the herd. A staph aureus count of less than 50 cfm/ml in a bulk tank sample is considered to be acceptable. If the count exceeds that level, do not purchase from the herd. Individual culturing is not a reliable way to identify cows infected with Staph aureus.
Review the previous six month’s worth of DHI records. Only purchase animals with a somatic
cell count less than 200,000 for six consecutive months.
If DHI records are not available, test milk from all quarters of all animals using a California
Mastitis Test (CMT). Any positive results should be cultured. All animals should be pregnancy checked by a veterinarian and confirmed pregnant or normal. Animals should be blood-tested for bovine leucosis virus (BLV). Blood testing or an ear notch skin test should also be done to identify animals that are persistently Infected (PI) with bovine viral diarrhea (BVD). Fecal samples should be taken for Salmonella culture.
Johne’s Disease
Wisconsin has an implied Johne’s disease warranty written into its state statutes. If the seller does not test or reveal the classification of the herd, it is implied that these cows are not
infected with the Johne’s disease bacterium. If the purchased animal is later confirmed positive
for Johne’s disease with an official test, the seller can be held liable. Fecal culturing for Johne’s disease is the gold standard, but it can be time consuming. Positive results can be found in as short as two weeks but negative results can take up to four months.
� Purchase animals only from herds that have been Johne’s disease classified as either
management level A or B. Ask to see their classification certificate from DATCP. Get in writing the herd’s classification level. If the herd is not classified, the buyer should recognize that the animals carry maximum risk of carrying Johne’s disease.
� If purchasing from either a “maximum risk” or a B-level management herd, blood test (ELISA)
all animals over 36 months of age and fecal test animals younger than 36 months. Until
negative test results are obtained, treat these animals (and their calves) as high risk animals.
� If an animal has been vaccinated for Johne’s disease:
! It has come from a herd that has had Johne’s disease diagnosed.
! The farm is or has been working with a Johne’s disease certified veterinarian to manage the
disease following the protocol for the Voluntary Bovine Johne’s Disease Control Program.
! It does not necessarily mean that the animal will be Johne’s disease infected, but rather that
this animal may not develop symptoms of the disease or shed as many bacteria into her
environment.
! If vaccinated, do a fecal culture.
! Johne’s vaccination is not a bad thing, but caution should be exercised in interpreting what it
means.
! Johne’s vaccinates will have an official metal ear tag in the left ear and a tattoo in the same
ear.
After Purchase:
Keep purchased animals isolated from the rest of the herd for three weeks. During this isolation period, vaccinate with whatever vaccines the herd veterinarian recommends for the rest of the herd. To avoid transmission of infectious organisms between the existing herd and purchased
animals, a separate milking unit should be devoted for use only on the newcomers. Continue milking each of those cows separately until her SCC test shows less than 200,000; she can then join the main herd.
All purchased cows should have a milk culture performed immediately to check for the presence of contagious bacteria (staph aureus, strep ag and mycoplasma). Once they are confirmed negative, then they can be treated as a member of the herd, that is, “clean cow”. At minimum, all purchased animals should be quarter-sampled using the CMT and samples from any positive quarters should be cultured.
The Bottom Line:
Using these guidelines will slightly increase the initial cost of purchasing dairy cattle. You may
also encounter resistance from sellers or miss out on a herd you intended to purchase because
it is sold to a buyer who is less cautious than you. However, following these guidelines will
save you many dollars of veterinary expenses, lost production, and losses due to excessive
culling, not to mention the aggravation and frustration of dealing with unhealthy animals.
Wisconsin Department of Agriculture, Trade and Consumer Protection Farm Center
PO Box 8911, Madison WI 53708-8911
800-942-2474
August, 2007