Forage Kochia Can Facilitate Pasture Bloat

Barry Perryman, Professor at the University of Reno, recently received a report of cows dying of frothy bloat after spring grazing on rangeland containing large concentrations of forage kochia. The following information should be shared in order to reduce/prevent any further incidents:

As we approach the fall season, the use of forage kochia as an important grazing resource increases. Although forage kochia is an excellent feed source for both wild and domestic grazing animals, it has a serious but little known negative characteristic. Forage kochia has a high potential for causing frothy bloat. At least four major mortality events have occurred since 2008. Other events occurred in fall 2012, 2014, and in the spring of 2015. With fall rains, forage kochia begins to grow rapidly and produces seed. Frothy bloat is a function of nutritional content and small forage particle size. Forage kochia has both of these characteristics, high protein content and very small stems, leaves, and reproductive parts including seeds. If forage kochia seeded areas have other grazeable forages like crested wheatgrass or cheatgrass, it will tend to lower the likelihood of bloat. However, when forage kochia is the only thing that is green and growing in a pasture, the likelihood increases. A few management actions can reduce the potential of bloat episodes and any associated mortality.

1) Avoid if possible, moving animals from dry feed conditions to areas where forage kochia is green and actively growing.

2) Avoid if possible, turnout of hungry animals into forage kochia seedings. Feeding hay or providing ample grazing forage just before the move should reduce the quick consumption of large amounts of green forage kochia.

3) Consider providing anti-bloat products, and/or provide free choice hay or other dry bulk feeds while the animals transition into forage kochia seedings.

These management actions cannot guarantee zero frothy bloat mortality, however they should reduce the risk.