Understanding My Results

Milk

Fat

The fat content of cow’s milk averages about 3.7% but varies from less than 3 to over 6 percent, depending on breed, stage of lactation, and a number of environmental conditions.

Protein
Fluid milk has about 3.5% protein. Amount vary according to breed, stage of lactation, and certain environmental situations.

Somatic Cell Count (SCC)
The somatic cell count (SCC) is commonly used as a measure of milk quality. Somatic cells are simply animal body cells present at low levels in normal milk. High levels of these cells in milk indicate abnormal, reduced-quality milk that is caused by a intra mammary bacterial infection (mastitis). The cell count for "normal" milk is nearly always less than 200,000 cells/ml. Higher counts are considered abnormal and indicate probable infection.

Lactose
Milk sugar. Lactose content of milk averages about 5%.

Other Solids
Lactose plus Ash (The residue remaining after complete combustion at -500 to -600 C of a feed or feed product during proximate analysis.)

Milk Urea Nitrogen (MUN)
Normal values are considered to be between 12 to 16 mg/dl. High MUN levels can be due to an excess of dietary and/or soluble protein, stress (including disease, exercise from grazing or extreme cold), or too little rumen available energy in the diet. Low MUN may be a result of an insufficient level of protein, too little degradable protein, or insufficient energy in the diet. As the non-fiber carbohydrate (NFC), crude protein ratio increases, MUN decreases. MUN also decreases as lactation progresses.

Johnes, MAP (Mycobacterium Avium Paratuberculosis)
Johnes is the chronic infection of the small intestine by the Mycobacterium Avium Paratuberculosi. This chronic infection can result in poor absorption of nutrient material, thus resulting in diarrhea and eventually emaciation of the cow. Death can occur in some instances.

All results for Johne's testing will come directly from the laboratory until further updates are made to reporting systems. Results can also be sent to your veterinarian for further applications.

Johne's is a reportable disease , so all results must be reported to the Board of Animal Health and the University of Minnesota for statistical and research purposes only. There will be no public record of results and no follow up on herds based on milk ELISA or serum results.

Bovine Pregnancy ELISA
The Bovine Pregnancy ELISA is designed to detect a subset of pregnancy-associated proteins (PAGs) in milk samples from cattle. Secretion of PAGs from the placenta begins at the time of implantation and circulatory concentrations generally increase throughout pregnancy, peaking just before parturition. Prompt detection of non-pregnant cows is critical to reducing days open and interval between services. The PAGs detected by the Bovine Pregnancy ELISA have a shorter half-life than other commercially available tests, allowing accurate determination of reproductive status. In milk samples, the assay can be used as early as 35 days post-breeding and 60 days-in-milk.

The Bovine Pregnancy ELISA quantifies the level of PAGs in milk. Results are presented in absorbance units (ELISA Score), which is directly correlated with the amount of PAG present in the sample.

In the current test, a sample with a value less than 0.10 units is considered ‘OPEN’, while a score of 0.25 or greater suggests the presence of a developing placenta, which is consistent with an active pregnancy. Therefore animals with a score of 0.25 units or greater are identified as ‘PREGNANT’. Samples with ELISA scores between 0.1 and 0.25 are interpreted as ‘RECHECK’, indicating either not enough PAG to confirm “PREGNANT” or too much PAG to confidently call the cow “OPEN”. These cows should be confirmed at a later date, either on the next vet check day or next DHI test day. Recheck results should comprise less than 4% of samples tested.

Milk: Sensitivity = 98.8%; Specificity = 97.7% A Sensitivity of 98.8% means there is a 1.2% chance of a false Negative. A Specificity of 97.7% means there is a 2.3% chance of a false Positive.

Stearns DHIA Laboratories
825 12th Street South, PO Box 227
Sauk Centre, MN 56378-0227
320.352.2028 · 800.369.2697
Fax 320.352.6163 · Email

 

Hours
Monday-Friday: 8AM-4PM
Front Entrance Drop-Off Open 24 Hours
Refrigerator Available for Water, Milk,
and Wet Feed Samples