The declining rate of Cr concentration in faeces after the dosage of a Sodium dichromate treated protein supplement can be used as an estimate of the protein outflow; rate. The experiment reported was planned to show wheter the variation in the rate of decline of Cr concentration in faeces induced by level of feeding and processing of the diet reflect the variation in rumen outflow determined by the rumen dilution rate of the marker.

In a duplicate 3x3 square latin design, 6 mature ewes cannulated in rumen were fed a ground pelleted diet of ‘0.6 alfalfa hay and 0.4 barley grain at 1 or 2 x maintenance energy level (P1,P2) or the same proportions of chopped hay and -cracked barley offered in a loose mix at twice maintenance (Ch2). 50 g. of fish meal treated withsodium dichromate were given as a single dose after 15 days of adaptation period to the diet and faecal grab samples taken at 6,12,18,24,32,36,42,48,60, 72,96 and 120 h. A second dosage was given 7 days later and rumen samples withdraw-ned at 1,3,6,9,12,15,18,22,28,36,48,60 and 72 h.