Video: Advice on feeding fodder beet to dairy stock

Fodder beet is the largest-yielding fodder crop available and is high in sugar and metabolisable energy (ME), making it a direct replacer for cereal grain.

It fits dairy well because it provides a consistent ME – 12 MJ/kg dry matter (DM) – from spring planting right through the winter and into the next spring. It is also the highest ME forage available.

Except for grass, it is the cheapest feed on the whole farm, costing 5-8p/kg DM to grow.

See also: Fodder beet proves cost-effective for spring-calving herd

It can be used to rear dairy replacements through the winter when winter pasture has stopped growing. It can also be used to fill feed gaps in late and early lactation and for grazing youngstock.

On a recent Farming Connect webinar, Marc Jones, independent grass and forage consultant, who outwinters 350 dairy beef and 600 sheep on fodder beet, and Jim Gibbs, research scientist in ruminant nutrition at Lincoln University in New Zealand, gave advice on grazing dairy stock on fodder beet.

Watch Marc Jones’ video and read the full report below.

Setting up the paddock

Strip grazing provides good crop utilisation. Stocking rates depend on crop yields but vary from 25-40 cows a hectare for 70 days.

• Provide one linear metre a head of space along the fence to allow all cows access to the crop.
• Leave a 6m headland to provide space at transition. This can either be grass or lifted beet to prevent lighter or shy animals being pushed out by bigger animals, otherwise you get uneven intakes and difficulties in transition.

Measuring the yield

It is impossible to transition cattle well unless you know crop yields so you can allocate it accurately. Measure the yield and the DM:

• Mark out 5m linear runs (this equates to 2.5sq m in 50cm rows and 2.25sq m on 45cm rows) using measuring tape and pegs
• Pull all the beet from the row, cut the tops off, bag and weigh separately to the roots
• Repeat this process on four sites across the field, ideally
• Work out your fresh weights to 1sq m: divide by 2.5 for 50cm rows and 2.25 for 45cm rows
• Multiply the root and leaf freshweight by its dry matter (an analysis can be taken or you can assume variety average)
• Finally, multiply these weights by 10,000 to work out the DM yield/ha.

Transitioning

Transition is the critical three weeks of the whole season. A high sugar and water load means time must be given to allow the rumen, kidneys and cow intakes time to adapt to the fodder beet bulb’s rich sugar and low DM content.

Mixed-aged dairy cows are the most susceptible livestock class to transition acidosis. Acidosis is provoked if cows are eating more than 2kg DM than they did the day before.

• Lift and sprinkle beet out at grass for a week before grazing the crop
• Feed low amounts and build up slowly
• To keep the rumen fully fed, provide supplementary feed
• The supplement will initially need to be grass or silage and has to be palatable; cattle won’t eat 7kg of straw
• Cattle are not properly transitioned or safe from acidosis unless they are leaving beet behind (5-10% in a single day)
• Most important part of transition: teach animals their rate of intake so their rumen can handle it
• Lactating cows will take longer to transition. Watch out for poor eaters as you don’t want these to lose body condition or milk

Cautions with milkers

• Milkers can put on 0.25-0.5 of a full body condition score over 70 days, therefore it does need careful management
• Start milkers on beet while they are hungry and not full of grass
• Watch out for mastitis/increases in somatic cell count if conditions are wet

Feeding harvested beet with a beet bucket

This has the benefit of saving moving cows and reducing labour. It can work very well for lame cows to prevent them having to walk to paddocks. When feeding with a beet bucket:

• Spread it out well: provide 1m space per cow
• Be certain of your allocation: weigh and count it for the first time
• Break it up for one to two days to encourage intakes (run over it with a tractor)
• Wait until all cows are in the paddock to eat the beet to prevent gorging (for example, after milking).

Myth busting

1. All cattle will automatically take to fodder beet after grazing it in previous years.

• False. It is common to have 20-35% of the group that will be slow to take to the crop, even if it has been grazed by them before.

2. It usually takes a few days before you can be confident cows are eating the bulb, even if they have grazed it before.

• True.

3. There is no risk of acidosis after full transition providing intakes are adequate.

• True.

4. Restricted feeding is required.

• False. This alters intake behaviour, encourages competitive feeding and can provoke problems.

5. High protein supplements are superfluous for dry cows in a well-managed, well-grown crop (protein will be 11-13% typically).

• True.

6. Calcium supplements are never needed.

• True. Calcium is found in the leaf.

7. It does not affect tooth wear or cause gut damage or more disease.

• True.

8. Intake of soil does cause issues.

• False. Studies of fistulated cows showed any soil in the gut in the winter disappears by the spring.

9. Where the leaf is poor or there is not much phosphorus in the soil, it will need to be administered as a supplement.

• True.

10. Leaf oxalates are toxic in fodder beet.

• False. There is not a tremendous amount of oxalic acid in the leaf at maturity, and adaptation means rumen bugs detoxify this.

11. You should put animals on the crop for short periods of time and increase it.

• False. This predisposes small groups to acidosis because a lot will undereat and others will overeat. Allocation should not be done by time.

12. In very muddy conditions, animals can eat 1kg of soil/day or two-thirds of their bodyweight in a year.

• True.