114
Mid-Infrared Spectroscopy to Predict Feed Intake and Efficiency in Lactating Dairy Cows
The aim of this study was to identify a rapid and inexpensive method of predicting feed efficiency of lactating cows. Morning and evening milk samples were analyzed using mid-infrared (MIR) spectroscopy and the resulting spectrum (from the morning, evening or combination of spectra from morning and evening milk) was used to predict residual feed intake (RFI), energy balance (EB) and energy intake (EI) in 378 Holstein-Friesian grass-fed cows. The correlation between true and predicted RFI, EB and EI was 0.59, 0.68 and 0.55, respectively. Each prediction equation was subsequently applied to 124,182 spectral records from lactating dairy cows and genetic parameters of true and predicted traits estimated. The heritability of true and predicted RFI was 0.10 (se=0.05) and 0.06 (se=0.01), respectively. The genetic correlation between true and predicted RFI, EB and EI was 0.78 (se=0.15), 0.61 (se=0.15) and 0.64 (se=0.14), respectively.
Keywords:
Mid-infrared-spectroscopy
Residual-feed-intake
Energy-balance
