Effects of Alcohol Ethoxylate and Pluronic Detergents on the Development of Pasture Bloat in Cattle and Sheep

¹ Alberta Agriculture, Food and Rural Development, 100, 5401 - 1st Avenue South, Lethbridge, AB, Canada T1J 4V6
² Research Centre, Agriculture and Agri-Food Canada, Box 3000, Lethbridge, AB, Canada T1J 4B1
³ Range Research Unit, Agriculture and Agri-Food Canada, 3015 Ord Road, Kamloops, BC, Canada V2B 8A9
⁴ Research Centre, Agriculture and Agri-Food Canada, 6000 C&E Trail, Lacombe, AB, Canada T4L 1W1

A series of studies was conducted to determine the efficacy and possible modes of action of a water-soluble mixture of alcohol ethoxylate and pluronic detergents (AEPD; Blocare 4511, ANCARE, Auckland, NZ) in preventing pasture bloat in ruminants grazing or fed freshly harvested alfalfa. Ten cannulated Suffolk wethers were offered freshly harvested alfalfa; five were given a daily intraruminal dose of 40 ml of 50% AEPD (vol/vol) 1 h 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. Treatment with AEPD did not affect dry matter (DM) intake, digestibility of DM, acid detergent fiber, or neutral detergent fiber, or N digestion and retention, implying that AEPD likely would not affect milk production. In a crossover 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 studies were conducted with cattle in Lethbridge, AB; Lacombe, AB; and Kamloops, BC. Treated animals received AEPD in the water (0.06%, vol/vol) and grazed vegetative alfalfa for 6 h daily. As it did with sheep, AEPD treatment effectively precluded the bloat observed in control animals. Consequently, AEPD may be a valuable tool for alfalfa pasture-based dairy production although further study is required to develop an integrated model for optimal administration under a variety of climatic conditions.

Key Words: bloat • alfalfa • grazing • pluronic detergent

Submitted on May 1, 2000
Accepted on August 10, 2000