Analysis of milk contents based on NIR spectroscopy
2011
Melfsen, A. | Haeussermann, A. | Hartung, E., Christian-Albrechts-Universitaet, Kiel (Germany). Institut fuer landwirtschaftliche Verfahrenstechnik
Determining milk-content characteristics can be helpful in monitoring the state of health of lactating dairy cows. Auxiliary variables such as cell count or fat/protein ratio provide important clues for the early detection of udder and metabolic diseases. Until now, milk composition (fat, protein, urea, lactose) and cell counts were usually recorded once a month within the framework of the provincial recording associations' milk-yield test. Basically, near-infrared spectroscopy (NIR) uses a non-invasive measuring method to enable a high-temporal-resolution recording of milk contents right on the farm, thereby directly providing the milk producer with information for improved herd management. The aim of the present investigation was therefore to gauge the potential of near-infrared spectroscopy (NIR) for determining the various contents of milk, as well as to determine animal- and lactation-specific influences on the calibration of the milk contents. For this, milk samples from 38 dairy cows were analysed via NIR spectroscopy. The samples were obtained on four different dates per week over a period of several months. The results of the chemometric spectral analysis as well as the comparison of the said results with reference analyses show promising possibilities for estimating the milk contents of fat and protein with a coefficient of determination of 0.9 and lactose with a high degree of accuracy. The urea and somatic-cell content in the milk could only be estimated with an average-to-low degree of accuracy. Factors influencing the accuracy with which all milk contents could be estimated were sample-presentation type and the quality of both the spectra and the calibration.
显示更多 [+] 显示较少 [-]