Mid-infrared spectrometry of milk as a predictor of energy intake and efficiency in lactating dairy cows

• Published in: Journal of dairy science 2014-09, Vol.97 (9), p.5863-5871
• Main Authors: McParland, S., Lewis, E., Kennedy, E., Moore, S.G., McCarthy, B., O’Donovan, M., Butler, S.T., Pryce, J.E., Berry, D.P.
• Format: Article
• Language: English
• Subjects: Animals; biomarker; Breeding - methods; Cattle; Dairying - methods; Energy Intake - physiology; Energy Metabolism - physiology; feed efficiency; Female; Ireland; Lactation - physiology; Least-Squares Analysis; mid-infrared spectrum; Milk - chemistry; Models, Biological; predictor; Spectrophotometry, Infrared - methods; Spectrophotometry, Infrared - veterinary
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.2014-8214

Interest is increasing in the feed intake complex of individual dairy cows, both for management and animal breeding. However, energy intake data on an individual-cow basis are not routinely available. The objective of the present study was to quantify the ability of routinely undertaken mid-infrared (MIR) spectroscopy analysis of individual cow milk samples to predict individual cow energy intake and efficiency. Feed efficiency in the present study was described by residual feed intake (RFI), which is the difference between actual energy intake and energy used (e.g., milk production, maintenance, and body tissue anabolism) or supplied from body tissue mobilization. A total of 1,535 records for energy intake, RFI, and milk MIR spectral data were available from an Irish research herd across 36 different test days from 535 lactations on 378 cows. Partial least squares regression analyses were used to relate the milk MIR spectral data to either energy intake or efficiency. The coefficient of correlation (REX) of models to predict RFI across lactation ranged from 0.48 to 0.60 in an external validation data set; the predictive ability was, however, strongest (REX=0.65) in early lactation (