GoatDairyLibrary.org          A database of materials for the commercial goat milk producer
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Bibliography

Building/Planning  A-L

Building/Planning M

Building/Planning N-Z

Conformation  

Conversions

Definitions

Diseases A-B

Diseases C-E

Diseases F-K

Diseases L-O

Diseases P-Q

Diseases R-Z

Diseases Misc.

Forms

Grazing

Medical A-D

Medical E-M

Medical N-R

Medical S-Z

Milk Production  

Nutrition Categories

Nutrition General

Nutrition Grouping

Nutrition Links

Nutrition Rations

Plans

Producers Tips  

Reference

Reproduction 

Seminar Notes

Settng Up

Value Added.


Milk Production

Antibiotic Residue In Milk

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 
 Small Ruminant Clinical Diagnosis and Therapy,  http://www.rmncsba.org/SMALLRUMINANT.pdf
It is very slow to load, especially if you have dial-up internet service, but it is an excellent resource.
 
 See the medical section of this website if you have questions about extra-label drug use.

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:

"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/en/dairy/dairy-antibiotics.html), IDEXX SNAP Testing (http://www.idexx.com/dairy/training/howto.jsp antibiotic drug residue training video and instructions for using SNAP test,) DSM Food Specialties (http://www.dsm.com/le/en_US/foodspecialties/html/Products_Delvotest.htm).  Test kits are available for the -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."  http://www.omafra.gov.on.ca/english/livestock/goat/news/dgg0510a4.htm:.

Apocrine Secretion (Goat) v. Alveolar Secretion (Cow)

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.

Why is this important? 
Goat milk has cytoplasmic particulate debris and epithelial cells shed along with the milk.  Cow milk does not.  (see definition section below.)  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, especially if the testing company uses machinery calibrated for cows. 

As a practical matter, AgSource said, many small testing companies cannot afford to have a separate machine calibrated just for goats, so you  can expect higher counts.  The solution: ask your legislators to raise the test limits for goats in the state statutes.
 
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)
 

Average peak pounds of milk per day/goat
10-15 lbs. (at 8 lbs. per gallon, that is 1.25 to 1.875 gallons per day)
Dairy Practices Council “Guidelines For The Design, Installation, and Cleaning of Small Ruminant Milking Systems”  

Breeding for conformation, increased milk production and components

A Quebec study took 26 goat herds where farmers followed selection protocol-based traits that were balanced to 60% production and 40% conformation.  The traits were: Milk protein, fat yield, fat and protein percentage, 8 conformation traits of general appearance, leg strength, dairy character, body capacity, median suspensory ligament, front and rear attachment of the udder, and teat quality.  They made their selections of the young stock based on the performance of their mothers and other related does.  After 4 years there was an increase of 34.1-39.6 lbs of milk per goat per year, and annual average increase of 0.7-1.14 lbs. of butterfat and 0.7-1.10 lbs. of milk protein per goat.  This increased income by $1400-1600 per year per farm (minimum). http://www.uvm.edu/sustainableagriculture/SmRumNewsletterWinter2006.pdf

Colostrum

Colostrum will come for 2-3 days after birthing. The mother can be milked into a mini-milker at milking time in order to remove the colostrum from her body each day until the milk clears. You will know when the colostrum is ending because the milk will start foaming.  Any milk/colostrum from that point on should not be fed to a baby as colostrum, because it won't have enough antibodies in it, but it can be fed as heat-treated milk.   Do not put colostrum in the bulk tank. (Judy Remo)

Components: Butterfat and Protein

76% of dietary protein taken in by the goat goes to milk protein production, 14% to lactose production and 10% to butterfat production. (Dado et al, 1993)

For breed differences in butterfat and milk protein, see this chart::    Milk Fat and Protein Concentration By Breed (PDF)

Butterfat (also called milk fat)

Butterfat Normal values

Normal butterfat concentration of most European dairy goat breeds is 3.8% under temperate conditions.  Nubians traditionally give richer milk than other dairy breeds.(Smith, p. 485)

Milk fat synthesis is derived from palmitate, and palmitate is synthesized from acetate. (Baldwin, 1968) 

How to raise butterfat

Butterfat is increased by increasing the number, and protecting the conditions which are beneficial to cellulose digesting, acetate producing, bacteria in the rumen. 

 (1) Don't over feed supplement.  
Supplement should not exceed 50% of the diet. In their effort to make more milk, producers will often overfeed supplement.  This reduces butterfat, especially when the supplement to forage ratio approaches 2:1.  Concentrates are too quickly digested and with the correspondent drop in the need for saliva production, you get a drop in rumen pH, which is harmful to the microbes that produce butterfat. 
 
(2) Feed roughage before you feed grain in the morning.
Again, having hay in the rumen first will slow down digestion, ensure adequate saliva production and keep the rumen pH at a favorable level for acetate-producing microbes.

(3) Take the total amount of supplement the goats need to eat during a day, and feed it in several small meals instead of giving it in only two larger meals at milking time.. Again, this optimizes the conditions beneficial to microbes.  It takes time to feed more often, so producers will have to decide how badly they want higher butterfat.

(3) Provide good ventilation, plentiful water and multiple smaller meals when it is hot outside.  Goats eat less when it is hot, so you will often see a drop in butterfat in the summer due to a drop in intake of feed..  Anything you can do to help them eat more will increase butterfat.  Increased intake increases the  heat of digestion in the rumen, and that in turn increases acetate production and raises the level of butterfat.
 
(4) Feed good quality forage.  If you have only poor quality forage, add buffer to the diet.
Low-roughage fiber intake lowers butterfat.  Supplement the diet with buffer at a rate of 4% of the amount of supplement fed per day to increase butterfat production when feeding poor quality forages.  (Note: many goats do not like buffer in their feed, and will completely refuse to eat the ration with it in there, but will take it readily when it is offered free-choice in the barn or lot.)
 
(5) Feed larger quantities of dried brewer's grain.
Research show that distillers grains contain yeast by-products that stimulate rumen cellulose digestion, which results in acetate formation, thereby increasing butterfat.  . 
 
(6) Breed for high butterfat as well as high milk production.
When selecting breeding stock, if you select for high milk production alone, don't pay attention to butterfat levels, you will gradually see decreased butterfat from one generation to the next..  
 
(7) Buy a couple Nubians.
Nubians give less milk than some other dairy breeds, but they add butterfat to the tank.

(Smith, 485)

Link: 

Variations in Milk Fat Composition: Why do my milk processor and DHIA tests not always agree? http://extension.usu.edu/files/publications/newsletter/pub__4960713.htm

Milk Protein

Milk Protein Normal Values: Average milk protein is 3.0.(Min)
 
Increasing the amount of supplement in the diet does not increase milk protein in goat milk as it does in cow milk.  (Min)
 
Fat supplementation does not decrease milk protein content in goat milk as it does in cow milk. (Min)

Plants That May Affect Milk Quality

Common Name

Scientific Name

Principal Toxin

White snakeroot

Eupatorium rugosum

Acetylbenzofurans (tremetol)

Rayless golden rod

Isocoma pluraflora

Acetylbenzofurans (tremetol)

Groundsels, senecio

Senecio spp.

Pyrrolizidine alkaloids

Rattle pod

Crotolaria spp.

Pyrrolizidine alkaloids

Hound's tongue

Cynoglossum spp.

Pyrrolizidine alkaloids

Fiddleneck

Amsinckia intermedia

Pyrrolizidine alkaloids

Comfrey

Symphytum spp.

Pyrrolizidine alkaloids

Heliotrope

Heliotropium spp.

Pyrrolizidine alkaloids

Viper's bugloss

Echium spp.

Pyrrolizidine alkaloids

Mustards, rape, cabbage

Brassica spp.

Glucosinolates*

Horse radish

Amoracia spp.

Glucosinolates*

Radish

Raphanus spp.

Glucosinolates*

Water cress

Nasturtium officinale

Glucosinolates*

Poison hemlock

Conium maculatum

Piperidine alkaloids (coniine)

Tobacco

Nicotiana spp.

Piperidine alkaloids (coniine)

Locoweeds

Astragalus, Oxytropis spp.

Indolizidine alkaloids (swainsonine)

Lupine

Lupinus spp.

Quinolizidine alkaloids (anagyrine)

Bitterweeds

Helenium, Hymenoxys spp.

Sesquiterpene lactones*

Bracken fern

Pteridium aquilinum

Ptaquiloside

Buttercups

Ranunculus spp.

Protoanemonins*

Onions, garlic

Allium spp.

N-propyl disulphide*

Autumn crocus

Colchicum spp.

Alkaloids (colchicine)

Avocado

Persea americana

Unknown toxin

Sage

Artemisia spp.

Monoterpenes, diterpenes*

Marijuana

Cannabis sativa

Cannabinol

* These plants impart an abnormal flavor to milk.


from Knight, A. P. and Walter, R. G.,  Plants Affecting the Mammary Gland,  http://www.ivis.org/special_books/Knight/chap10/chapter.asp?LA=1, accessed 6-20-07.

Links:

Lactation in the goat (videos)   http://www.goatbiology.com/animations/lactation.html
Anatomy of Lactation
Development of the Lactation System
Hormones of Lactation
Milk Production

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