A trial was undertaken to determine whether a bloat drench containing copper (Cu), cobalt (Co), selenium (Se), and iodine (I) would by#x2010;pass the reticulo#x2010;rumen (rumen) of cows. Six rumen#x2010;fistulated cows were fed pasture at a range of intakes so that there was an 8#x2010;fold range in rumen dry matter (DM) pool size, and the Cu in the drench was used as a marker. The extent to which the rumen Cu pool size increased as a consequence of drenching was used to indicate the fate of the drench. The increase in the rumen Cu pool with drenching showed 30#x2013;100 of the drench (mean 71.3 #xB1; SE 5.15) remained in the rumen 25#x2013;30 min after administration and recovery was not affected by rumen fill or saiety. It is suggested that the low and variable recoveries could be the result of a slow dispersion of drench in the digesta, so that drench which was concentrated in the cranial reticulo#x2010;rumen passed rapidly to the abomasum. The drench did not appear to elicite a closure of the oesophageal groove.
展开▼
