MMN March 2025 – Fodder Beet in Milking Rations

Fodder beet has surged in popularity for outwintering livestock, providing one of the highest yielding energy crops (65-90T of bulb and leaf yield/ha). While the crop may only be around 18-20% dry matter, fodder beet has an energy content of around 12 to 13.5MJ/kg DM depending on variety, making it comparable with cereals and other concentrate feeds. Fodder beet is often used to outwinter heifers, but it also has a place in the milking ration, even for high yielding housed cows, where it can help drive intakes and performance. If you are thinking about fodder beet as a crop for lifting and feeding to the milking herd, there are a few things to consider from variety choice to storage and how to incorporate it into the ration.

Variety

If you plan to lift the beet and not graze in situ, there are varieties more suited to lifting, for example, smooth skinned varieties and those with a lower dirt tare (less soil contamination of the lifted crop). Grazing varieties will tend to have more bulb above the soil surface and lifting varieties will sit lower in the ground, have a higher dry matter and be lighter in colour e.g. white.

Medium to high dry matter varieties are recommended for lifting. They tend to sit further into the ground and have a higher dirt tare and so may need washing before feeding. Their root is also slightly harder than lower dry matter varieties and should be chopped before feeding. However they will tend to keep better over the winter once lifted, being less prone to cracking in frost and more winter hardy than lower dry matter varieties. Low dry matter varieties are much softer and should only be used for grazing.

Paddock selection will be important as undulating terrain will be more difficult for a specific beet lifter to operate. Sowing with a precision drill with 500mm row spacing is recommended when using a beet lifter at harvest, however some growers are planting at 350mm to enhance yield. Alternatively, a beet bucket could be used to lift beet.

Think about when you might lift the beet for feeding, if late on, the variety must have a good frost tolerance. In theory, the green tops of the beet can be fed once wilted and are high in protein – around 15-25% on a dry matter basis, compared to the bulbs which are just around 6% protein. However, many modern lifters take the leafy top off which is left in the field, as removing the moisture from the leaf will help with storage.

Storage

The crop can be stored in either indoor or outdoor clamps but can be susceptible to frost. Frosted beets can cause digestive upset. The beet pile can be covered with straw to provide some insulation against frost. It can also be ensiled but should be washed and chopped beforehand. Feeds such as sugar beet pulp or soya hulls can be ensiled with the crop at a ratio of 1T to 5T of fodder beet, helping soak up the effluent.

If lifted and stored correctly, the crop can last for six months. It is recommended to wait at least four days between lifting and feeding, due to the high nitrate levels post-harvest.

Feeding

If dirty, the beet may have to be washed and it is best chopped to reduce the risk of choking. Like any new feed, it should be introduced gradually and can be fed at up to 15kg/head/day to milking cows. Start with no more than 5kg/head and then increase by 3-5kg/head every four days until the target level is reached. The roots are low in calcium, so it is worth reviewing whether current mineral supplementation is meeting requirements for milk production. If not, limestone can be added to the ration to make up the shortfall.

It is best to consult a nutritionist on inclusion to ensure the diet is properly balanced, especially if the fodder beet is there to replace another feed. However, depending on the inclusion rate, there may be little substitution needed, with a higher overall dry matter intake. It can be used as a direct replacement for cereals, with around 4.25kg of fodder beet replacing the same amount of dry matter of 1kg of dried barley. As it raises the sugar content in the ration, a great feed source for rumen bugs, it may have a positive effect on fibre digestion and hence butterfat.

For information establishing and growing fodder beet, see the following technical note: https://www.fas.scot/downloads/tn694-alternative-forages-sheep-fodder-beet/

lorna.macpherson@sac.co.uk; 07760990901