Brazle, F.K.2010-10-152010-10-152010-10-15http://hdl.handle.net/2097/6361Two studies were conducted to determine the effect of feed additives on the transit shrink of yearling cattle. In Trial I, 146 mixed-breed heifers were offered a mineral mixture containing either Terramycin® or Bovatec®, or without additive while grazing native grass pastures. Shrinkage after 300 miles in transit was lower (P<.09) for Bovatec-fed heifers than the other groups. In Trial II, 60 mixed-breed heifers were offered free choice prairie hay, plus soybean hulls without additive or containing either Aureomycin ®, Rumensin, or Bovatec®. Both ionophores tended to reduce live weight shrink following a 10-hour withholding of feed and water, but treatment differences were not significant (P>.05). The small shrinkage differences observed in these two trials would not justify changes in the weighing practices of feeder cattle.BeefShrinkAntibioticIonophoreFeeder cattleConference paper