Relationship Between Feed Efficiency Measures During the Heifer Development Stage and Measures Taken During First Lactation in Purebred Angus—Final Report (Report to the American Angus Association, St. Joseph, MO)
Summary and Implications
Angus first-calf heifers were evaluated for feed intake utilizing the Feed Intake Monitoring System developed at ISU. Average dry matter intake for the feeding period was 3877 pounds with difference in dry matter intakes from the lowest to the highest intake female averaging 2143 lbs over the three years of the study. During the study an average difference between the lowest and highest consuming firstcalf heifer was 22.3 lbs daily to 38.4 lbs. Mixed model procedures identified significant components of a residual feed intake (RFI) model to be : initial metabolic body weight, female average daily gain, pounds of milk produced daily, days since lactation initiation, and the interaction between milk production and lactation initiation. The correlation between yearling and first-lactation RFI ranged from .44 to .77 for the three years with only one year being significant at less than the .05 level. However, when the Student T-test was conducted the conclusion was that a significantly positive correlation existed between yearling and first lactation RFI.
Iowa State University
Strohbehn, Daryl R. and Dahlke, Garland R.
"Relationship Between Feed Efficiency Measures During the
Heifer Development Stage and Measures Taken During First
Lactation in Purebred Angus—Final Report (Report to the American Angus Association, St. Joseph, MO),"
Animal Industry Report:
AS 658, ASL R2690.
Available at: http://lib.dr.iastate.edu/ans_air/vol658/iss1/22