Getting cows off southern paddocks during winter does not need to involve building barns or pouring concrete. Anne Lee reports.
Farmers in Southland shouldn’t be pushed into thinking they have to put cows indoors to winter, Lincoln University veterinarian and fodder beet specialist Jim Gibbs says.
In areas where soil conditions and climate make wintering on crop difficult and where farmers prefer to keep animals close at hand rather than sending them off to graze outside the district he suggests they look to alternative beet feeding systems being developed by farmers in the southern regions.
“Getting them off paddock doesn’t mean putting cows indoors and building barns.
“From what I’ve seen that’s going to cost farmers $3000-$3500/cow and that’s just to build it.
“Wintering cows in barns requires a whole lot more capital to operate the system too,” Gibbs says.
There are numerous ways of setting up off-paddock systems that don’t require a roof and utilise existing winter crops farmers are able to grow and feed to cows cheaply, he says.
Fodder beet is successfully grown in Southland and Otago with good yields bringing the cost to grow the crop as low as 8c/kg drymatter (DM).
Farmers can use a beet bucket on the front of the tractor to scoop up the beet, leaves and bulb, so it can then be fed to cows, put out through a silage wagon on to an off-paddock, feed pad area.
In some cases, farmers will harvest it once a week and then stack it ready to put out daily.
If it’s bought-in as harvested beet – bulb only – it can be delivered onfarm at 23c/kg DM, he says. If farmers are using it bulb only then 30% of the diet should be grass silage rather than hay or straw because of the bulb’s low protein, he advises.
“Even if I put 35c/kg DM on silage and 25c/kg DM on harvested beet that’s still going to be a whole lot cheaper than using the types of feeds farmers are going to be using in a barn system.”
If cows are consuming bulb and leaf, once fully transitioned cows need only 10% of their daily diet – about 2kg eaten – to be a supplement with a good neutral detergent fibre (NDF) – hay or straw will suffice, he says.
He’s carried out repeated studies, one of which was published last year, and all show that on an ad lib diet rumen pH remains well above levels that cause acidosis throughout the day as cows self-manage their intake on the ad lib system.
The same published study showed restricting intakes with shorter feeding times caused rumen pH to drop. Overseas studies for 40 years had shown similar results with other sugar and starch feeds but the key message is that cows can’t be left to get hungry.
The rule of thumb on an ad lib grazing system is that by 5pm they should still have 20% of the crop left.
Farmers looking to get cows off paddocks through the winter don’t need to give up beet nor do they need to pour lots of concrete, he says.
One fit-for-purpose system he’s seen work effectively includes a river stone loafing area and a concrete feed pad area with a central feed bin where beet and silage (separately) can be brought to cows and fed under a wire.
The feed pad area is capable of holding 300 cows at a time.
A drainage system under the river stone area drains effluent and rainwater through to an effluent storage pond with the concrete feed pad area sloping so it, too, drains to a sump at one end which in turn drains to the same storage pond.
Gibbs says cows on the system he’s seen love the river stones, which hold heat from the sun but also drain freely so cows are able to lie down in dry conditions.
The stones can be washed.
Gibbs says these kinds of standoff and feed pad areas could also work well with sugar beet harvested and silaged.
For southern farmers this could allow them to sow the crop later, even into December, when they’re more likely to be able to get on to the paddock. The sugar beet crop could then be grown right through to October, ensiled and used in autumn and the following winter.
Gibbs says farmers have also been frightened off trucking cows out of the district to low rainfall areas by suggestions transporting cows is deleterious to their health or wellbeing.
“That’s one area where there’s been a huge amount of research especially overseas where they truck cattle very, very long distances.”
Gibbs says done right, transporting pregnant cattle causes no harm to the animals.
“There’s tremendous body of work around trucking animals and how safe it is. It’s a pernicious myth to suggest otherwise.”
Mycoplasma bovis is a risk but it is possible with good systems for large-scale operations to handle groups of animals from different farms without those animals coming into contact with each other, he says.
Those areas, like Central Otago are well set up, have great climates for wintering animals and the operators are able to crop and use tactics such as catch crops to reduce nutrient leaching.
• Southern dairy farmers interested in working with a new beet research project in these areas this year can contact Gibbs on Jim.Gibbs@fodderbeetclub.co.nz.
Investing in a 1000-litre calf milk replacer unit with a reticulated mixing tank can save time and make getting phosphorus on to straw a whole lot more efficient and effective, Gibbs says.
Cows need 50g of phosphorus a day if they’re being wintered on fodder beet, and it’s particularly essential they get that if they’re eating fodder beet and straw alone.
Gibbs says it’s best administered as DCP (di-calcium phosphate) mixed as a slurry and poured on to the dry feed such as straw or hay, or dusted on to wet supplement such as silage.
By applying it to the supplement – that farmers should be observing cows are eating – cows are most likely to get their daily requirement.
It’s not good enough and can indeed be dangerous to depend on licks put out in the paddock because that relies on all cows choosing to consume it and getting enough, Gibbs says.
For larger-scale wintering situations, particularly where straw is the fibre supplement of choice, mixing the DCP to a slurry in a 1000-litre calf milk replacer unit means the slurry can be applied to several days’ worth of straw at one time. The DCP is mixed with water – 50g DCP to 300ml of water.
A 200kg drymatter straw bale fed at 2kg DM/cow/day for 100 cows would require 5kg DCP mixed with 30l of water. Once they’ve mixed it in the larger tank they time how long it takes to fill a 30l bucket.
“They cut the top string of the bales so the bales feather out a bit and then they can drive along with the pod on the back of the tractor and pour the slurry on each bale, timing it to match the 30l bucket application rate.”
Sugar beet silage
Sugar beet, like fodder beet is a high energy crop that’s used commonly around the world, as a stock feed.
It’s being grown in New Zealand by both dairy and beef farmers, mainly for harvesting and feeding out.
It’s also been silaged successfully overseas and Gibbs says he’s working with farmers here on it this season.
Research has found a high walled, narrow pit is used with grass silage or something similar put in first as a 50-60cm layer.
The harvested beet bulbs, without leaf, are then piled in before another 50-60cm layer of grass silage is applied on top.
Gibbs says there’s no need to compress the bulbs as they compress over time themselves under their own weight, creating an anaerobic situation.
Care has to be taken to avoid an aerobic situation because the beet will quickly rot and produce leachate.
Higher drymatter varieties are used for the same reason.