Fodder beet can be an excellent cost-effective winter feed for sheep and cattle especially if conventional forage is in short supply. It can either be grazed in situ in the field or lifted and stored in a clamp or pile before being fed to housed animals. Beet contains high levels of fermentable carbohydrates (so are high in energy) but are low in fibre, protein and minerals so it is not appropriate to feed fodder
beet as a sole diet without supplementation.

There are a number of health problems which can be associated with feeding fodder beet and care is needed over its use and introduction into the diet. When problems do occur they can affect very large numbers of animals in a short period of time, so it’s important to be aware of the potential pitfalls.

Fodder beet (especially the leaves) contains high levels of oxalic acid which can bind with dietary calcium and magnesium causing mineral imbalances leading to milk fever type symptoms of weakness and recumbency in animals of any stage of production and both males and females. Chronic exposure to oxalates can result in kidney damage and urolithiasis (bladder stones) so adequate access to water is very important. Gradual introduction of beet into the diet allows time for the development of oxalate-degrading bacteria into the rumen population and reduces the risk associated with oxalates.

Fodder beet is very high in rapidly fermentable carbohydrate and if it is not introduced into the diet gradually and with care it can result in carbohydrate overload. This can cause rumen acidosis, bloat and death, with the possibility of chronic complications such as liver abscesses in animals which survive the acute phase. Carbohydrate overload can even occur in animals which have been eating the crop for some time and it is important to offer additional forage such as silage or straw and not to allow them to become hungry and gorge on the beet.

Fodder beet is also relatively high in nitrate, especially after cold dry spells or when the plant is stressed, and this can cause problems. The nitrate is metabolised into even more toxic nitrites by the rumen bacteria which are readily absorbed into the bloodstream where they bind to red blood cells disrupting oxygen transport. Acute nitrate toxicity causes breathing difficulties, weakness and death. The rumen bacteria can adapt to process more nitrates over time so this problem can also be mitigated by gradual introduction of beet into the diet.

Grazing frosted beet can increase the risk of bloat, and cold weather may also increase the risk of problems with oxalates if access to water is restricted or water intake decreases. Frost-damaged beet will also spoil more quickly with the associated risks of rotting and microbial spoilage. Microbial spoilage can also increase the nitrate content. Frost damaged beet is unsuitable for feeding.

Like any solid feed (e.g. potatoes), large lumps of fodder beet have the potential to block the oesophagus resulting in bloat.

In bad weather conditions keeping animals outdoors grazing beet in-situ has the potential to become a welfare problem if there is inadequate shelter and ground conditions become excessively muddy. It’s important to have a contingency plan in case the weather becomes really bad and the ground becomes unsuitable.
To avoid these pitfalls it’s important to introduce fodder beet gradually into the diet to allow the rumen bacteria time to adapt to the high levels of carbohydrate and the presence of oxalates and nitrates. It’s really important to provide additional forage at all times (silage/straw/hay) particularly for cattle to prevent them from gorging on the beet. It’s also necessary to balance the diet for protein and minerals to prevent deficiencies occurring.