The LKV Baden-Württemberg has determined methane values for 200,000 samples from the milk performance test in an extensive practical trial. With an average value of 404 g, the range was from 150 g to 650 g methane per cow and day. These values show a very good agreement with the values measured directly in climate chambers for dairy cows, as well as with values obtained using other, much more complex measuring methods.
Dairy laboratories all over the world use analytical instruments that work with medium infrared light. Light beams with these wavelengths are passed through the milk to be analysed. The milk absorbs parts of the mid-infrared light, resulting in up to 1,060 absorption values for a milk being tested. These values allow conclusions to be drawn about the milk ingredients with a high degree of accuracy. This photometric method is very fast and precise. Up to 600 milk samples per hour can be tested for fat, protein, lactose and urea content. This is done daily worldwide with the milk performance test samples.
The state control associations in Baden-Württemberg, North Rhine-Westphalia and Schleswig-Holstein are members of "European Milk Recording", the European association of organisations for milk performance and quality testing. Together they have worked on the determination of other milk constituents. In addition to important milk constituents such as milk fatty acids, acetone and BHB, which can be used to assess the health status of a cow, the characteristic methane was also worked on. In first experiments it was possible to draw conclusions about the daily methane production of a dairy cow with sufficient accuracy using the 1,060 absorption values of a milk sample. The method was developed in close cooperation between the Belgian research institution "Centre Wallon De Recherches Agronomiques" (CRA-W) and "European Milk Recording". Numerous research institutes, including those in Germany, Belgium, Scotland, Denmark, Ireland and Switzerland, supplied precisely determined quantities of methane from climate chambers that served as a reference for the values determined from the milk.
At present, German control associations and the German Association for Performance and Quality Testing (DLQ) are currently working together with the scientific community in the "ReMissionDairy" and "eMissionCow" projects funded by the Federal Ministry of Food and Agriculture and the Landwirtschaftliche Rentenbank to optimise the method for determining methane from milk. The influence of feeding on methane emissions is also to be investigated. The chances of obtaining reliable methane values from individual cows via milk performance testing are very good. In the future, the characteristic "methane production" can be successfully influenced both by breeding and by feeding measures.