Kochia (Kochia scoparia L.) is a salt tolerant annual weed that grows well in road sides, around sloughs, and in cropland.
Reported yields are up to five tonnes per acre. When at the early bloom stage, nutritional value is similar to a high quality alfalfa grass hay. As the plant matures, quality declines and the accumulation of anti-nutritional compounds increase. This also occurs during periods of drought. Cattle are willing to eat kochia, but there are limitations to how much can be included in a beef ration.
Feed test results have shown that sodium (salt) can be as high as 0.7% (1.8% salt) which is well above the daily requirement of 0.097% sodium (0.25% salt). When sodium requirements are met by the forage that is consumed; animals are less inclined to eat a mineral product free choice. This can result in deficiencies of minerals such as calcium, phosphorus, and magnesium along with trace minerals and vitamins.
Sulfur can be high especially when the kochia was harvested around sloughs that have a salt ring. These areas can be high in sulfur and magnesium. When a ration exceeds 0.4% sulfur; the occurrence of polio encephalomalacia or polio can occur.
Nitrate accumulations can be high during of the growing season. Testing for nitrates should be done on forages that contain kochia. There are cases where animal deaths are attributed to high nitrate levels.
Saponins are a bitter substance that are present in kochia. They can reduce feed intake. When it is consumed, this molecule is broken down into glycosides. As it is digested, glycosides create foam that is stabile in the rumen, thus contributing to bloat.
Oxalates are also found in kochia. Oxalate levels increase as the plant matures. This compound impairs the absorption of calcium. It remains stable in cut hay or in silage. Additional calcium supplementation should be considered.
With all these possible limitations, kochia cannot be fed as the sole ingredient in a ration or consumed on pasture. It is recommended that the kochia not exceed 25-30% of the ration on a dry matter (DM) basis. Slowly introduce kochia into the ration. Step up the amount over 4 increments to get to the required feeding level.
For additional information about kochia in cattle rations, contact Barry at 403-741-6022 or bjyaremcio@gmail.com.