A note on the use of chromium sesquioxide as a marker in nutritional experiments with dairy cows

Abstract

ABSTRACTThe faecal recovery of chromium sesquioxide (Cr203) was examined in four experiments with non-lactating Ayrshire cows. In the first experiment Cr203-paper was given intraruminally twice daily to cows receiving a diet of hay. The mean recovery of the marker was 0·829 (s.d., (Mil, no. = 12). In the second experiment the marker was given as Cr203 powder to cows receiving a diet of hay and ground barley. The powder was mixed with the barley part of the diet and given in 24 hourly meals per day. The mean recovery of the marker was 0·944 (s.d., 0·079, no. = 8). In the third experiment cows receiving a hay and barley diet were given Cr203 powder suspended in ground-nut oil administered twice daily through a cannula in the duodenum. The recovery of the marker was 0·980 (s.d., 0·027, no. = 3).In the fourth experiment ground straw impregnated with Cr203 was used as a marker in cows receiving a hay and barley diet. The marker was mixed with the barley and given in eight meals per day. The faecal recovery of Cr2()3 was 0-941 (s.d., 0·022, no. = 7). It is concluded that when Cr203 is used as an indigestible marker in studies with dairy cows its recovery in faeces may be variable and low due to retention of the marker in the stomach. In digestion studies with cows there are considerable advantages in favour of the use of Cr2()3-impregnated straw rather than Cr203 powder or Cr203-paper.