Practical measures for reducing risk of alfalfa bloat in cattle

Frothy bloat in cattle is a serious problem and is difficult to manage unde r field conditions as it progresses rapidly from early signs of distension to acute distress. Scientists at Agriculture and Agri-Food Canada centres i n Western Canada are committed to the development of bloat-free alfalfa gra zing systems, which may require feed additives or supplements. As well, a n ew cultivar of alfalfa (AC Grazeland), selected for a low initial rate of d igestion, will soon be available. In grazing trials the cultivar reduced th e incidence of bloat by an average of 56% compared with the control cultiva r (Beaver). Commonly accepted mineral mixes for the prevention of bloat wer e tested and found ineffective but we have confirmed that poloxalene (Bloat guard (R)) is 100% effective if it is given intraruminally at the prescribe d dose, However, under practical conditions, poloxalene can only be offered free choice and protection from bloat cannot be guaranteed. We have also s hown that the water soluble polymer, Blocare((R)) 4511, when used in the wa ter supply is 100% effective in bloat prevention. This product is not yet r egistered in North America, Other strategies for bloat prevention will be d iscussed, including the selection of growth stages and grazing schedules, a nd the reduction of risk by wilting alfalfa or combining it with tannin-con taining forages.