Influence of density and location on degradation of sustained-release boluses given to cattle
Riner, J.L.; Byford, R.L.; Stratton, L.G.; Hair, J.A.
American Journal of Veterinary Research 43(11): 2028-2030
1982
ISSN/ISBN: 0002-9645 PMID: 7181203 Document Number: 193299
Boluses with densities of 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, and 2.4 g/cm3 were given to 6 fistulated heifers. A minimum density of 1.6 g/cm3 was required to prevent regurgitation from the ruminoreticulum and a minimum of 2.0 g/cm3 for retention in the reticulum. Release of oxytetracycline from 2 boluses placed in the reticulum or in the rumen was measured in 12 fistulated heifers. Boluses retained in the reticulum had higher rates of release than those in the rumen. The smaller reticular compartment apparently caused greater contact between individual boluses and resulted in more rapid erosion.