Milk and Slaughter Withhold Times

If you have given a goat a drug, you may not sell their milk or meat until the drug is completely out of their system.  This to prevent people who eat the food or drink the milk, from getting resistant to antibiotics by being overexposed to them.  You must scrupulously adhere to withhold times, yet it is often difficult to know what they should be, since many drugs are labeled for other animals, and the withdrawal time for a goat may be very different.  

You should consult your veterinarian about withdrawal times, and if you vet does not know what the withhold time should be, he or she can get that information from FARAD (Food Animal Residue Avoidance Databank) at 1-888-us-farad, or go to www.farad.org.  

Many withdrawal times on drugs for goats can also be found in Scott Haskell's on-line manual entitled 

Testing the milk for antibiotics

Even if you know what the recommended withhold time is, you cannot be sure that a drug will leave the goat’s system when the withhold time says it will.  If an animal has been ill, it's whole system can be slowed down, and will not process the drug as quickly as it will in a well goat.  Make sure that you do not ship milk from a treated goat until a sample has been sent with your trucker and you get a call back that there are no antibiotics in the milk. (Haskell, Mastitis)  

Wisconsin Regulations regarding drug residues in meat: ATCP 55.07    Drug residues in milk: ATCP 60.19 and ATCP 97.23.

Common mistakes that cause antibiotic contamination in milk:

1. Milk from a treated goat was accidentally routed into the pipeline.

2. A “not completely dry” goat was given an intermammary antibiotic to prevent mastitis.  The farmer intended to move her to the dry goat shed, but somehow she was unintentionally milked with the herd.

3. The same milking unit was used to milk an antibiotic-treated goat before milking untreated goats.

4.  Lactating goats were purchased, and the new owner was unaware of recent antibiotic treatments given by the previous owner.

5.  One half of the udder was treated for mastitis and the producer didn’t ship milk from the treated half, but they did ship milk from the untreated half thinking it was safe.

6.  A minimilker, with milk from a treated goat, was tipped over, or overflowed, and some of the milk backed up into the system.

7. The farmer normally milked the antibiotic-treated goats last, removing the milk line from the bulk tank before doing it, but this time he forgot to remove the milk line.  

8.  Medicated feed meant for non-lactating animals was accidentally mixed into the lactating goat feed.

9.  Goats drank from a medicated footbath.

10. A goat in the dry goat pen is given a treatment to prevent mastitis.  She aborts.  The farmer forgets that the goat has antibiotics in her and milks her.

11. Severely ill goats were treated, and although the withhold time passed, the drug had not moved out of their body because they were so ill their system was not working properly. (Adapted from MDA)  

What to do if you think you milked a goat on antibiotics by mistake

If it is pick up day, do not allow the trucker to pick up milk that may have antibiotic in it.  If he arrives, ask him to test for antibiotics before he takes the milk.  If the trucker cannot test for antibiotics, then do not let him take the milk.  Instead, drive a sample to the trucking company headquarters or nearest testing facility and have a test run.  AgSource does not run tests on Saturday, Sunday, or holidays, but the trucking companies generally have one at their facility, and can run it any time. 

If the test positive, write down the amount of milk in the tank, then dump the milk and clean the tank.  Call your field man and tell him what happened.  Some of the cheese plants will pay for one dump per year.  If your company does not do this, then call your insurance agent and file a claim.  This is why you must always carry dairy protection insurance.

Consequences of shipping milk with antibiotics in it  

If milk is positive for antibiotics and you let it get picked up and mixed with the other milk in the truck, you are liable for all of the milk in the truck, as well as other expenses such as the cost of disposing of that milk, repeated testing, and any other costs incurred due to your negligence.  You should carry dairy protection insurance for this, as a truckload of milk is extremely expensive.   (Interview with Harvey Ziemer, Filed Man for Kolb Lena Cheese)  

  On-farm test kits for antibiotic residue:

According to the Ontario Ministry of Agriculture, Food and Rural Affairs, at http://www.omafra.gov.on.ca/english/livestock/goat/news/dgg0510a4.htm:.

"Currently, there are a variety of screening tests on the market suitable for on-farm testing. Each test has its own benefits and limitations in cost, speed and sensitivity. The major suppliers for the North American market are Idexx Laboratories, CHARM Sciences and DSM Food Specialties.

 

CHARM Sciences  ROSA MRL-3 Test http://www.charm.com/pdf/rosa_mrl3.pdf

 

IDEXX SNAP Testing, antibiotic drug residue training video and instructions for using SNAP test  http://www.idexx.com/dairy/training/howto.jsp

 

DSM Food Specialties http://www.dsm.com/en_US/html/dfs/dairy-products-tests.htm

Test kits are available for the ß-lactam, tetracycline and sulfa families. An important point to remember however, is that most of the tests were developed for testing bovine milk and it has been reported that these tests may give false positive test results when testing goat milk. This is primarily due to the difference in composition between goat and bovine milk. For this reason any positive result on a screening test should be confirmed using official methods." 

Goat milk production is an apocrine secretion. 

(Apocrine Secretion is a type of glandular secretion in which the tip of the secreting cell is released along with the milk.)

Cow milk production is an alveolar merocrine secretion.

Alveolar merocrine secretion is a type of secretion in which the honeycomb-type cells remain undamaged during the secretion of the milk, so only milk is released.

In other words, goat milk has cytoplasmic particulate debris and epithelial cells shed along with the milk.  Cow milk does not.  Therefore, if the somatic cell count of goat milk depends only upon counting numbers of cells, with no effort to sort out the type of cell, the goat milk will appear to have a higher somatic cell count than cow milk.  The debris and epithelial cells are about the same size as the white blood cells that appear where there is disease, and unless you have stains that differentiate between types of cells, you may have a falsely high somatic cell count. 

Definitions:

Cytoplasmic particulate debris=debris particles from the protoplasm outside the nucleus of a cell

Epithelial cells make up the membranous tissue covering most internal and external surfaces of the body and its organs T

White blood cells are cells that contain a nucleus (have DNA) and cytoplasm and help protect the body from infection and disease.

Somatic cell: Any body cell other than a germ cell (Germ cells are ovum or sperm.)

Somatic Cell Count (SCC) is the number of body cells in a quantity of milk.

What we are looking for in somatic cell counts is evidence of infection (mastitis).  Where there is infection, you will find an increase in the number of white blood cells, since their duty is to protect the body from infection and disease.  Therefore, the perfect SCC test for goats would count only the white blood cells. The green stain, or direct microscopic (DMSCC) test is the only test that does that at this time.  

(Haskell, Caprine Milk Quality and Mastitis)

When stored under refrigerated and sanitary conditions, goat milk in farm bulk tanks met the grade A criteria for both SPC and SCC during 5 days of storage, but was of low quality thereafter. 

ZENG,  S., CHEN, S. , BAH, B. and TESFAI, F.  Research Note: Effect of Extended Storage on Microbiological Quality, Somatic Cell Count, and Composition of Raw Goat Milk on a Farm.  Journal of Food Protection: Vol. 70, No. 5, pp. 1281–1285.

Some goats will “milk through.” That is, they will continue to milk for long periods, even years, without being bred back.  If your herd is well established, and you have all the does you can handle so you don’t need new babies, consider not breeding the ones that milk the longest.  Let them milk through and keep the milk production up while the others are dry. (Considine)  

Link:

King, Tim. Milking Through: Dairy Goats can Produce Longer Than Normally Expected to Better Meet Owner Needs.  Dairy Goat Journal , Vol. 84 No.6, November/December 2006, p.15

When you get your milking parlor and equipment all set up, your dairy contractor should show you how to run and care for the system, and he should be present at the first milking or two to make sure everything works..  Tape record his directions, then write his instructions down, step by step, so you know exactly what to do and when to do it.  Put those directions in a plastic sleeve and hang them in the milk room.  At first you will use them every time you milk.  Later, you won't need to use them any more, but leave them in the milk room so that if you are hurt or have an emergency, someone else can fill in for you.  Make sure your family knows where the sheets are kept.  It's a good idea to hang them on the wall in plain sight. 

Sample milk room instruction sheet  (This one uses an acid sanitizer.)

Sample milk room instruction sheet.  (This one uses a regular sanitizer)

Standard plate count (SPC):

An elevated plate count indicates the presence of bacteria in milk.  If elevated, it indicates dirty udders, inadequate cleaning of equipment, a milk cooling problem, a water heater problem or other equipment failure. (AgSource)  Mastitis due to Streptococcus can also contribute to a poor test. (Haskell)

The recommended SPC should be 1,000-10,000/ml.  A sudden unexpected spike and then a quick return to normal indicates a one-time problem.  Prolonged high counts or increasing counts indicate a larger problem.  (Haskell, Milk Quality)  

Wisconsin Administrative Code ATCP 60.15 Milk Quality Standards, section 2:

(Summarized here.  To read the regulations in full, see ATCP 60)

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Grade A dairy:      Maximum plate count of 100,000/ml

 

ATCP 60.27: If two of the last 4 counts exceed the limit, DATCP will issue a warning to the producer.

While under a warning, if 3 of the last 5 plate counts exceed 100,000 the grade A permit will be suspended..

Grade B dairy: Maximum plate count 300,000/ml

 

ATCP 60.18(5)

If a bacterial count exceeds 750,000 per ml, DATCP will issue a warning to the producer.  They will confirm it with another test within 14 days.  If that also exceeds the limit, then the plant will reject the milk until they get a test under the limit of 750,000.  

 

ATCP 60.18 (under “Note” immediately following section(6)):

The department may suspend a milk producer’s license if bacterial counts continue to exceed the grade B standard of 300,000 per ml. (60.15(2))  They also may suspend the license regardless of whether any bacterial count exceeds the immediate response level of 750,000 per ml.  If 2 of the last 4 bacterial counts reported to the department exceed 300,000 per ml, the department will, at a minimum, send a warning notice to the producer.  

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Testing for Bacteria in milk

1) Required testing performed by a test lab for your milk company: 

Standard Plate Count (SPC) or Plate Loop Count (PLC) or raw count. Officially should be less than 10,000, but when things are done right in a dairy, it should be 1,000 -10,000/ml.

  2) Optional testing that the producer can have done to determine the cause of a high plate count:

Preliminary Incubation Count (PI):

Should be less than 20,000/ml.    

If the PI is 3-4 times higher than the SPC, then you have soil or water contamination.

Laboratory Pasteurized Count (LPC):

Should be less than 100/ml

Bacteria identification cultures for Strep Ag, Strep Non-ag and Coliform bacteria:

Strep Ag

Should be zero.

Presence of Strep Ag indicates that the elevated plate count is due to mastitis. Find the animal(s).  Treat them. Cull if mastitis recurs.

Strep Non-Ag

Should be less than 750/ml Presence of Strep Non-Ag indicates that the elevated plate count is due to poor cleaning, early fresh goats with mastitis, or inadequate cooling of milk

Coliform bacteria

Should be less than 100/ml

Presence of Coliforms indicates contamination.  If t