In order to evaluate an electronic method for determination of milk composition based on infrared determination, 48 raw milk samples from Holstein cows and five bulk tank samples were analyzed for fat, protein, lactose and total solids contents. Results for fat, protein, lactose, and total solids contents for raw milk samples were, respectively, 3.8%, 3.3%, 4.6% and 12.4% using the standard methods, and 3.8%, 3.3%, 4.5%, and 12.4%, using electronic equipment. For the bulk tank samples results for fat, protein, lactose and total solids contents were, respectively, 3.9%, 3.2%, 4.7%, and 12.6% using the standard methods, and 4.0%, 3.2%, 4.6%, and 12.6% using electronic equipment. No differences between values obtained from both analytical methods were observed (P>0.05). The quality of the American and Canadian standard samples was evaluated by determination of fat, protein, lactose and total solids contents, using the reference methods to compare the composition of the standard samples to the results of analyses issued by the supplier laboratory.
milk composition; infrared; reference samples; milk quality
