Whole-tract dry matter and nitrogen digestibility of lactating dairy cows selected for phenotypic divergence in residual feed intake
JB Thornhill, LC Marett, MJ Auldist, JS Greenwood, JE Pryce, BJ Hayes, WJ Wales
Animal Production Science | CSIRO PUBLISHING | Published : 2014
The objective of this experiment was to compare the whole-tract digestibility of dry matter (DM) and nitrogen (N) in Holstein-Friesian dairy cows selected for divergent feed conversion efficiency. The experiment used 16 primiparous Holstein-Friesian dairy cows selected based on their residual feed intake (RFI) measured as growing calves. The cows were housed in individual metabolism stalls and fed lucerne cubes ad libitum plus 6 kg DM per day of crushed wheat grain. Feed intake, milk yield, faecal and urine output were measured for 5 days. Rumen fluid was collected per os from each cow on one occasion. Milk production parameters and intakes of DM, organic matter, neutral detergent fibre, aci..View full abstract
The authors acknowledge the technical staff at DEPI, Ellinbank for their thorough management of the digestibility experiment. This work was funded by the Geoffrey Gardiner Dairy Foundation and the Department of Environment and Primary Industries.