Comparison of 6- and 10-day Collection Periods for Digestion Trials with Dairy Heifers

Abstract
Six digestion trials (3 animals/trial) were conducted in a study of oat hay rations. Coefficients of digestibility were determined on the basis of both 6- and 10-day collection periods, and coefficients of correlation were calculated for the 2 sets of values. Correlations for all nutrients except the ether extract fraction were significant at the 1% level of probability; the correlation coefficient for the ether extract fraction was not significant at the 5% level. When differences between values obtained at 6 and 10 days were analyzed by means of the "t" test, none were significant at the 5% level of probability. The largest loss of efficiency resulting from use of a 6-day collection period was -2.81% for the ether extract fraction. It appears that in this study there was little advantage in extending the collection period to 10 days.