Effects of alcohol ethoxylate and pluronic detergents on the development of pasture bloat in cattle and sheep

A series of studies was conducted to determine the efficacy and possible mo des of action of a water-soluble mixture of alcohol ethoxylate and pluronic detergents (AEPD; Blocare 4511, ANCARE, Auckland., NZ) in preventing pastu re bloat in ruminants grazing or fed freshly harvested alfalfa. Ten cannula ted Suffolk wethers were offered freshly harvested alfalfa; five were given a daily intraruminal dose of 40 ml of 50% AEPD (vol/vol) Ih before feeding , and five (controls) were dosed with water. Viscosity of ruminal fluid was reduced (P < 0.001) in AEPD-treated wethers, relative to the controls, for the first 2 h after feeding but not at 4 h after feeding and beyond. Treat ment with AEPD did not affect dry matter (DM) intake, digestibility of DM, acid detergent fiber, or neutral detergent fiber, or N digestion and retent ion, implying that AEPD likely would not affect milk production. In a cross over grazing study, five of the wethers were given AEPD in drinking water ( 0.1%, vol/vol); treatment with AEPD was 100% effective for preventing bloat in sheep grazing early-bloom alfalfa for 4 h daily. Replicate grazing stud ies were conducted with cattle in Lethbridge, AB; Lacombe, AB; and Kamloops , BC. Treated animals received AEPD in the water (0.06%, vol/vol) and graze d vegetative alfalfa for 6 h daily. As it did with sheep, AEPD treatment ef fectively precluded the bloat observed in control animals. Consequently, AE PD may be a valuable tool for alfalfa pasture-based dairy production althou gh further study is required to develop an integrated model for optimal adm inistration under a variety of climatic conditions.