Holstein-Friesian calves selected for divergence in residual feed intake during growth exhibited significant but reduced residual feed intake divergence in their first lactation
KA Macdonald, JE Pryce, RJ Spelman, SR Davis, WJ Wales, GC Waghorn, YJ Williams, LC Marett, BJ Hayes
Journal of Dairy Science | ELSEVIER SCIENCE INC | Published : 2014
Residual feed intake (RFI), as a measure of feed conversion during growth, was estimated for around 2,000 growing Holstein-Friesian heifer calves aged 6 to 9 mo in New Zealand and Australia, and individuals from the most and least efficient deciles (low and high RFI phenotypes) were retained. These animals (78 New Zealand cows, 105 Australian cows) were reevaluated during their first lactation to determine if divergence for RFI observed during growth was maintained during lactation. Mean daily body weight (BW) gain during assessment as calves had been 0.86 and 1.15 kg for the respective countries, and the divergence in RFI between most and least efficient deciles for growth was 21% (1.39 and..View full abstract
The authors associated with DairyNZ and Livestock Improvement Corporation (LIC) thank the Ministry of Business, Industry and Employment (formerly Foundation for Research, Science and Technology; Wellington, New Zealand), New Zealand dairy farmers through DairyNZ Inc. (Hamilton, New Zealand), LIC (Hamilton, New Zealand), and Trade and Enterprise (Auckland, New Zealand) for funding, the LIC calf procurement team led by Katie Eketone and Jack Hooper, and the DairyNZ technical and farm teams at Hawera (New Zealand) for managing the experiments. The authors associated with the Department of Environment and Primary Industries thank the Gardiner Foundation (Melbourne, Australia), Dairy Futures CRC (Melbourne, Australia), and the Department of Environment and Primary Industries (Victoria, Australia) for funding and the technical groups at Rutherglen, Tatura, and Ellinbank (Victoria, Australia) for managing the experiments.