Milk Analysis and milk testing

By: Lactolab  11-11-2011
Keywords: dairy, Milk, Dairy Industry



These parameters, in conjunction with milk volume, are used by the dairy farmer to determine the yield from a specific animal. Furthermore, milk buyers pay for milk using these parameters and it is therefore of utmost importance for the farmer that high producing animals are well maintained and the poor performers are identified. These parameters together with milk volume are the main price drivers.


When there is an infection in the udder the cow’s immune system respond by producing somatic cells to fight the infection. The higher these body cells the more serious the infection. The Somatic cell count is thus a very good indicator of how healthy the udders are. Not only do infected udders produce poor quality milk, but the production of milk is seriously affected. The health of the udder determines the quality and quantity of the milk.


Milk urea nitrogen content in the milk indicates the effectiveness of the feeding program. This value is of great importance to feeding consultants as it shows how effective the protein/nitrogen fed to the cow is converted into milk protein. The farmer will benefit economically by the effective use of nitrogen on the farm, as well as ensuring good animal health.


This is an instrumental analysis of the total bacteria content of raw milk, with the results available within 5 minutes. No preparation of samples is required by a laboratory technician. This method has the ability to count individual bacteria cells even if some grow in chains or pockets. It is more accurate than the traditional “colony forming unit” method where the assumption is made that one bacteria cell grows into a visible colony. The Bacto count is fast and accurate and the standard international method used to determine the total bacteria count in milk.

Dairy Standard Agency (DSA) Analyses

DSA plays a critical role in the dairy industry to ensure that all role players associated with the dairy industry produce milk quality that comply with at least legal standards and is safe for consumer consumption.

A standard set of 12 analyses are performed on all DSA milk samples:

  • Total Bacteria Count
  • Coliforms
  • Escherichia coli (E. coli)
  • Freezing point depression (Added Water)
  • Inhibitory Substances (Antibiotics)
  • Phosphatase Test (Pasteurisation efficiency)
  • % Fat
  • % Protein
  • % Lactose
  • Hydrogen Peroxide (H2O2)
  • Weight
  • Milk Ring Test (on raw milk)

Additional Tests

Testing Material

Sample bottles

Cost effective, leak proof, sterile sample bottles are supplied by Lactolab, with special care being taken that no leakage or opening of bottles occur during transport, especially by air.

Phosphotesmo M1

A rapid method to analyse the efficiency of the pasteurisation process. Without any preparation or reagents required, the Phosphatase test can be preformed in seconds with a high level of accuracy


This test is performed on the farm to ensure that milk of proper quality is loaded without taking any risks.


A preservative for raw milk that inactivates the metabolism of the bacteria. Azidiol will keep the sample stable for 5 days, ensuring that accurate bacterial counts are measured.

Quality assurance

We need to show competency regarding the analysis of milk samples. Results need to be accurate, repeatable and comparable to national and international standards. To obtain this we have specific controls in place.

1. UHT pilot

A UHT pilot sample is analysed on a daily basis to determine repeatability and reproduce-ability of results. The sample is very stable due to homogenisation. A deviation of no more than 0.03% is allowed.

2. Raw milk pilot

A raw milk sample with known values are analysed every 100 samples. If there is any build up in the instrument this will indicate it clearly. The allowed deviation is 0.05%.

3. Reference samples

Reference sample are prepared every month and are chemically analysed. They are tested at least once a week and any deviation of more than 0.03% on an average of 10 samples will be corrected.

4. International reference samples

Accredited reference samples from QSE Germany, are analysed monthly to ensure compliance to an international standard. Once again our limits are very strict and even though these samples are from a different part of the world it is still very comparable.

We also partake in a proficiency testing scheme of ERWAT, analysing milk for bacterial content and the phosphatase test.

Keywords: dairy, Dairy Industry, Milk, Milk Buyers, Phosphatase Test, Somatic Cell,