With cows on the farm year-round, fodder beet has been used successfully for many seasons as a winter crop to reduce the amount of pasture taken out of the milking platform.
However, offering enough high quality grass in the spring has become a problem, especially as the farm increased its six-week in-calf rate from about 60% to 70%.
“This clearly increased demand in the critical early part of the season yet our pasture growth wasn’t increasing at that time by nearly enough,” Southland DairyNZ consulting officer Nathan Nelson said.
“The farm’s management team wasn’t overly excited about putting in more palm kernel or crushed barley into the system because of the cost of the feed but also because we would have had to put a significant investment into infrastructure to feed the 3-4kg needed per-cow per-day and it wasn’t achievable in our view.”
So they gave SugaBeet a go.
SugaBeet is a new sugar beet variety with a bulb drymatter (DM) of 23-26% so it can be lifted and stored for long periods of time. Uniform bulb size and crown height aids lifting. Bulbs consistently have 12 megajoules of metabolisable energy (MJME)/kg DM. Planted in mid-October, it is lifted twice a year, in March and August when weather conditions are right, yielding about 18 tonnes DM/ha in the autumn and 22t DM/ha in the spring.
Lifting costs $1050/ha and the unwashed beet is stored on concrete. The leaves are left in the paddock and eaten by the cows with about 10% wastage.
The SugaBeet is fed to the cows, unchipped and mixed with silage, in a feed wagon on to pasture starting with 1kg DM/cow/day offered and no more than 5kg DM/cow/day at peak feeding.
“Feeding it out is like being at a lolly scramble for kids,” farm manager Barry Bethune said.
Offering it with silage lessens the effect of the low-protein beet.
“All beets have very low fibre and phosphorus and high sugar so anything above 5kg a day and you would probably see the cow health and production affected,” Nelson said.
Autumn feeding has the added advantage of doubling as transitioning on to the fodder beet winter crop on the farm. Beet needs 10 to 14 days of transitioning and if not done correctly can cause rumen acidosis, resulting in rumen damage and death.
On the downside, it’s a 15-month crop, taking 12 months to grow and another three months until new grass planted in the spring can be grazed.
“Paddocks selected for SugaBeet are growing towards the bottom of our pasture recorded dry matter yields at 9-10t DM/ha/year which would be about 11-11.5t DM/ha for the 15 months so the SugaBeet is giving us a net gain of 11t DM/ha,” Nelson said.
Spraying the old pasture, cultivating, fertiliser, pre-emergent spray and two post-emergent sprays, and seed costs $3265/ha for the demonstration farm.
If the second post-emergent herbicide spray is not needed, it’s reduced to $2750/ha.
Including lifting, Nelson says the true cost of the SugaBeet crop in energy for the cows was 3c/MJME which compares with 2.9c for palm kernel ($240/t on the farm), 4c for silage (34c/kg DM in the stack) and 4.3c for barley ($440/t DM).
Nelson said with lifting the crop a quarter of the cost of the feed, the farm had considered feeding the SugaBeet where it was grown but utilisation would be lower.
“There is also the added cost of damage to the soil structure, nitrogen and phosphorus losses and possible cow lameness.
“It’s a high-yielding crop and feeding any high-yielding crop has all of these problems when it is fed where it’s grown.”
The farm might plant a winter Italian annual or winter oats on paddocks where the Suga Beet has been lifted in the autumn instead of waiting until late spring to sow permanent pasture.
“This would mean the overall yield for this land would be higher and so the figures would look a lot better,” Nelson said.
“We’re still learning.”
