With increasing use, we are getting a better understanding of the issues associated with feeding this crop. The key to successful use of fodder beet for non-lactating (dry) cow grazing is to follow good practice and not cut corners.
Transitioning cows on to fodder beet
- Have accurate yield and dry matter (DM) measurements, especially in the area to be allocated during transitioning - see Estimating Fodder Beet Crop Yield.
- Transition cows carefully by slowly introducing cows to fodder beet. Decrease the proportion of pasture/silage and increase the amount of fodder beet in the diet over 14-21 days.
- Start mature cows with 1-2kg DM fodder beet per cow per day and only increase by 1kg DM every second day to the required allocation. Do not continue to increase the allocation if all cows are not eating beet or bulbs are being left on previous days’ breaks. Start heifers and rising yearlings on 1kg DM fodder beet per cow per day and only increase by 0.5kg DM every second or third day once all animals are eating.
- Rising two year old heifers and rising one year old calves will be slower to take to eating the bulbs and will sometimes benefit from splitting bulbs (e.g. using a tractor wheel) to get them onto the crop.
- If transitioning onto unrestricted (ad libitum) fodder beet – do this over at least 21 days. After transitioning to 7-8 kg DM fodder beet hold this allocation for 7 days and then slowly increase the break line a little each day until the cows leave fodder beet behind to achieve ad libitum intake. These cows still require 2-3kg DM/day of a good quality fibre source (silage, straw, hay).
- Work out your break size accurately – measure the rows, yield and width of your paddocks. Remember cows can graze under the fence by up to 1 m so include this area in the allocation.
- Offer a wide enough face of fodder beet so that all animals in the mob can access the crop at the same time. In paddocks without a grass headland to provide additional space at the start of transitioning or very high yielding crops, harvesting the beets in the headland and using these for the first few days of transitioning is an option.
- Using a time based approach (i.e. a set amount of time on crop) is not recommended as a tactic for transition because cows can consume 1kgDM every 15-20mins (3-4kgDM/hr) directly after the fodder beet break is opened.
- Have good electricity on fences and have a second fence very close to the feeding fence in case of break out.
- Feed supplement prior to putting cows on crop to ensure a good gut fill. Long chop baleage, silage or hay fed at least 3 hours before beets are offered is best.
- Check cows frequently. Individual cows transition differently, so even with well-planned transitioning acidosis can occur.
- Farmers need to be looking for: cows that separate themselves from the mob, are not eating, dehydrated, scouring, ‘not doing well’, bloating, milk fever like symptoms, down cows or sudden death and contact their vet immediately.
Allocation and feeding levels
- Use the Winter Crop Allocation calculator to determine the feed requirements.
- Twice daily shifting of a long narrow break, feeding under the wire is considered best practice as this allows roots and plant tops to be consumed by all cows and minimises crop wastage.
- Break size is critical – given the range in crop varieties, it is best to analyse for DM rather than using book values. 1% DM difference equates to 1-2t DM/ha yield difference.
- The crude protein percentage of the crop may not meet cow requirements and it may be necessary to increase the percentage of pasture silage in the total diet.
- The phosphorous level in some crops is very low. This can result in metabolic issues, especially around calving time. This can be preventing using DiCalcium Phosphate (DCP) supplement. Discuss with your vet.
Estimating fodder beet crop yield
- Pull all the beets from at least three different 5 metre long sections of rows in the crop, chosen as a representative sample of the crop which the cows will eat first.
- Clean any dirt off the roots; cut the tops off and weigh the roots and tops separately
- Find the average weight per running metre of row for roots and average weight per metre for tops and multiply these numbers by 20,000 [in the case of a 50cm row spacing or by 22,222 in the case of a 45cm row spacing] to get a kg/ha wet weight for roots and one for tops
- Send a representative sample of roots and tops away for DM determination [a sample bag with instructions should be available from your rural supply store]. Cut an "average - representative" root into quarters lengthwise and seal in a plastic bag to minimise moisture loss. Check with your lab, they may want you to weigh the sample before sending it in.
- Multiply the wet weight kg/ha [step 3] of the roots and tops by their respective DM percentages, add these 2 numbers together to get the kg DM/ha yield.
- Repeat yield assessments every 2-3 weeks during the winter period as crops will continue to grow.