A daily break of 5kg drymatter (DM) is easily achieved on almost every farm, because they will eat this in about 1.5 hours. Breakouts are rare, and, like in childcare, are easily avoided with common-sense management using plenty of feed and electricity. The issues are finding platform hectares, and in herds of more than 750 cows the additional walking distance created each day could lead to a lameness issue. This has been a real problem on some big farms, so talk to an experienced operator before you plant.
Lifted beet can be harvested in large volumes by single-purpose lifters, which leave only the bulb. Sugar beets are the best option for storage, because as a general rule the higher the DM%, the longer they last after harvest. The use of harvested beet is typically still cheap (about 5c/kg DM to lift) and the high DM sugar beet bulbs last in a windrow without the leaf for 3-6 months without any covers, even in warmer North Island areas. They should be kept in windrows, not stacks, because in the warmer New Zealand weather tall, deep storage can rot quickly, a very different scenario from the United Kingdom or Europe.
The harvested beets can be transported from the platform and don’t need chopping. This makes use quick and easy by putting them out through a standard silage wagon, equivalent to grass silage feeding, for a usual cost in total of less than 15c/kg DM if grown yourself. But it does mean the leaf DM – about 20% of the total DM yield – is lost, along with the protein and minerals in it. Up to 5kg DM daily, however, this isn’t a nutritional issue on pasture lactation diets. Harvested beet is especially effective on large farms where it can halve the cost of supplement.
Beet can also be harvested with a standard farm tractor and a beet bucket. This is the fastest growing use on dairy farms, and it can be very economical. The beet buckets scrape up whole beet, which are then fed out through a wagon, just like bulbs. Because the leaf doesn’t store well, it must be done at least weekly in warm weather, and at most monthly in cold weather, and is often done daily on farms that use it – straight into the wagon and fed out to avoid double-handling.
As a general rule, feeding a 1000-cow herd is about one hour’s work a day using the beet buckets. It adds about 2c/kg DM to the cost of grazed beet, but keeps the leaf and is cheaper than mechanical harvesting of bulbs, and it allows the farmer great flexibility to harvest, leave in wet weather, or grow the crop more. The disadvantage is it’s a constant task to be done across the feeding periods, lacking the ease of using harvested bulb from a windrow.
What goes wrong?
Most issues are caused by poor allocation or too little space and time, and those should be reviewed. However, there are a few specific problems worth discussing for grazed vs harvested beet use.
- In herds of more than 750 cows, longer walking distances in the shoulders will increase lameness, so pick your beet paddocks close to the dairy. A grazed paddock is another fixed point in the daily feed rotation, so further than 500m from the dairy has been associated with significant lameness issues in larger herds.
- Be careful not to switch rapidly between beet cultivars of very different DM%. If the cows are eating 5kg DM of a lower DM variety – say grazing Brigadier at 12% – and are then switched to a sugar beet (25%), they will eat it just as they did for the low DM% variety – effectively doubling intakes. If allocation is correct, this can be managed on a herd level, but potential for error is high, and there have been some notable, expensive stock losses doing this.
- Finally, a platform growing tip – plan your beet paddock ahead and irrigate well with effluent before sowing, and then from 60 days after sowing. For beet growing, every dairy farm in NZ has irrigation – it’s just sometimes called effluent. Because you won’t typically be growing large hectares of beet on the platform, effluent can be effectively used to target irrigate across the risk period of summer and early autumn, and can dramatically decrease cost and increase yields. Cows then eat the product and spread the minerals around the farm.
There are some great myths about lactation feeding of beet. Some of our favourites are:
1) “Beet is sugar – you need starch”. No, it is an ME source of 12MJ/kg DM. Your only real need when you hear this is a new nutrition consultant.
2) “Sugar beet is too hard”, or “the cows’ teeth wear out (or get tooth decay)”, or “it needs to be fed chopped in grass silage or they won’t eat it”.
3) “The dirt on harvested sugar beet fills up the rumen, or steals your topsoil from the paddock”. This one is great, since a seed company did a national roadshow a few years back spruiking this.
Both 2) and 3) are invented by folk who want to sell you something different to what you have or make you buy a chopper. They’re a sign from heaven that you should get them off the farm quickly before they cost you more money.
Terry Hughes and Jim Gibbs
