[Determination of the urea content of milk in general practice]

To determine the urea in milk and thus to get information on the feeding regimen, a method using colour stripes was developped for the extension service in Bavaria. The quantitative results are fairly exact and available within four minutes comparing the colour changes of the stripe with a four-colour-scale. The scale comprises a range from 15 to more than 40 mg urea nitrogen per 100 ml of milk. The resulting colour as a rule lies between two colour shadings. Udder diseases give uncorrect results. The pH values of the milk samples should be situated between 6.6 and 6.9. This test meets the requirements of the extension service in most cases. Thus disturbances of metabolism caused by feeding can be corrected without problems and immediately. The status of lactation seems to have no influence. Most important in this respect are a feed composition adapted to ruminants and a correct ratio between intake of energy and protein.