14 January 2021
Grazing fodder beet can provide winter feed for all classes of dairy stock for as little as 5p/kg of dry matter (DM).
At half the cost of grass silage, it is a crop that could be a good fit for many Welsh dairy farms, suggests fodder beet expert Dr Jim Gibbs, a veterinarian and research scientist in ruminant nutrition at Lincoln University, New Zealand.
But, since fodder beet is such a high energy crop, transitioning dairy cattle onto the crop carefully is vital to prevent rumen acidosis.
Dr Gibbs told farmers listening in to a Farming Connect webinar run in conjunction with Field Options, KWS and Momont, that fodder beet can make up 80-90% of the diet of dry cows and heifer - the rest of the diet can come from a supplementary feed in the form of pasture, silage or hay.
He advised to transition dry cows or heifers over two weeks.
Despite popular belief, cattle don’t immediately love fodder beet – it takes a week or so for palatability to develop. It is therefore not uncommon to have 25-30% of a group that are slow to eat it in the transition phase, even cows that have been wintered on it for multiple seasons.
Dairy cows are more at risk of acidosis than any other stock class because they are trained to eat large volumes of fodder.
Acidosis is provoked when cows eat 2kg of DM of fodder beet more than they did the previous day therefore increase intakes of beet by just 1kg every other day until they are at the stage where they are leaving feed behind; this indicates that they have achieved maximum intakes.
Allow 1m of fence length for every animal and provide a large headland – six metres per animal.
To allocate it accurately, it is important to know what is in the crop so it is vital to correctly assess the actual DM in the leaf and the bulb.
On day one, provide 1-2kg of DM of beet and increase by 1kg every second day.
Provide 7-8kg of the feed supplement in the first week of transition, 4kg in the second and 2kg in the third and for the rest of the grazing season.
“To be fully fed, cows must have the rest of the diet provided in a palatable form, they won’t eat 7kg of straw,’’ warned Dr Gibbs.
Phosphorous might have to be given as a supplement as the bulbs have a relatively low level. Also, if the leaf area is poor, be mindful that phosphorous, calcium and protein levels could be poor.
But it is a myth that cows on fodder beet need a high protein supplement – at 12-13% protein, fodder beet is more than adequate in providing protein for dairy cows.
“High protein supplements are superfluous, they are not needed,’’ said Dr Gibbs.
Fodder beet can also be a useful winter feed for lactating cows in pasture-based systems.
Because production needs to be maintained during lactation, they won’t be as hungry as dry cows when they are introduced to the crop so transition will take longer – use their daily appetite cycle to your advantage, advised Dr Gibbs.
Start with 1kgDM from beet – and keep them on the crop beyond when they have eaten it, 1-2 hours from day one.
Instead of grazing, it can be lifted at this stage and sprinkled on pasture, smashed up with a tractor to make it easier to eat.
“Don’t let cows go onto the break in dribs and drabs, they must all be turned on to it together,’’ said Dr Gibbs.
Be mindful of mastitis as cows may need to walk through muddy gateways to get to the crop.
Dry cows and lactating cows don’t necessarily need to be vaccinated for clostridial diseases prior to being turned on the crop but Dr Gibbs pointed out: “Even the loss of one cow would cover the cost of the vaccine so it might be worth doing.’’
For growing heifers, it is vital to vaccinate for clostridial diseases.
Farm consultant Marc Jones, who grazes dairy heifers on fodder beet in Powys, was also a speaker at the webinar.
He said it was possible to graze 200kg liveweight heifer calves on fodder beet for five months from November to March.
Fodder beet can be grazed by heifers from six months old, Mr Jones advised.
For R1 heifers, allocate sufficient fodder beet to leave 25% of the crop behind the next day; this will maximise intake as they will go back and clean it all up. R2s can be grazed tighter.
R1 and R2 is a term that's more commonly used in New Zealand to classify the age of heifers but has recently been adopted here in the UK. R1 cattle are typically between 3-10 months of age whilst R2 cattle would be between 10-22 months of age.
Transition for younger cattle is slower – sprinkle beets onto pasture for a week and transition onto the crop for two weeks after that, increasing intakes by 0.5kg a day once all stock are eating the bulbs.