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

摘要: Interest is increasing in the feed intake complex of individual dairy cows, both for management and animal breeding. However, energy data on an individual-cow basis are not routinely available. The objective present study was to quantify ability undertaken mid-infrared (MIR) spectroscopy analysis cow milk samples predict efficiency. Feed efficiency described by residual (RFI), which difference between actual used (e.g., production, maintenance, body tissue anabolism) or supplied from mobilization. A total 1,535 records intake, RFI, MIR spectral were available Irish research herd across 36 different test days 535 lactations 378 cows. Partial least squares regression analyses relate either coefficient correlation (REX) models RFI lactation ranged 0.48 0.60 external validation set; predictive was, however, strongest (REX=0.65) early (<60 d milk). inclusion yield as a predictor variable improved accuracy predicting (REX=0.70). measured balance 0.85, whereas balance, predicted spectrum, 0.65. Milk generated cows throughout and, therefore, prediction equations developed can be immediately (and retrospectively where have been stored) applied aid breeding decisions.