Variation in residual feed intake in Holstein-Friesian dairy heifers in southern Australia
YJ Williams, JE Pryce, C Grainger, WJ Wales, N Linden, M Porker, BJ Hayes
Journal of Dairy Science | ELSEVIER SCIENCE INC | Published : 2011
Feed conversion efficiency of dairy cattle is an important component of the profitability of dairying, given that the cost of feed accounts for much of total farm expenses. Residual feed intake (RFI) is a useful measure of feed conversion efficiency, as it can be used to compare individuals with the same or differing levels of production during the period of measurement. If genetic variation exists in RFI among dairy cattle, selection for lower RFI could improve profitability. In this experiment, RFI was defined as the difference between an animal's actual feed intake and its expected feed intake, which was determined by regression of dry matter (DM) intake against mean body weight (BW) and ..View full abstract
The authors thank Taffy Phillips (DPI-Rutherglen, Victoria, Australia) and Marg Jenkin (DPI-Tatura, Victoria, Australia) for their technical expertise in the day-to-day running of the Rutherglen feed intake facility, the management of the calves, and data collation. The skilled assistance of other farm staff is also acknowledged. Melbourne University (Australia) master's student, Zibei Lei, is acknowledged for the initial analysis of feeding behavior data from cohort 1. Funding for this research was provided by Gardiner Foundation (Victoria, Australia) and Department of Primary Industries (Victoria, Australia). The authors thank Peter Moate (DPI-Ellinbank, Victoria, Australia) for his helpful comments during the preparation of this manuscript.