Efficiency of conventional versus marker technique for shortening the time in digestion trials.

Investigation was carried out to determine the digestibility of the main nutrients (DM, CP and energy) in digestion trials using some roughages in order to reduce the collection period and to study the suitable time of the marker technique and its application. This study revealed the following results: (1) The average recovery of chromic oxide in feces were 99.71 +/- 3.75% in the 3rd day (after administrating the marker), 95.17 +/- 1.03% in the 5th day and 96.53 +/- 2.35% in the 7th day. It could be concluded that this marker is indigestible and could be used as an ideal one. (2) There were no significant differences between the digestibility values with the conventional method and those of the two short-period techniques (the first three days and the first five days collection periods). The percentage differences were not exceeding 6% except some deviations with CP digestibility in one trial (hay : rice straw mixture). These two methods seemed to be reliable in practice. (3) The same differences were found between the digestion coefficients, which conducted from the conventional method, and those of the marker technique using three times for collection except high deviations were found with one trial in the last two procedures. Using marker technique appeared promising from the 3rd day up to the 7th day after its administration.