How New Zealand stock 45 dry cows on a hectare of fodder beet

In some parts of New Zealand fodder beet is yielding 44 tonne of DM/ha (>200t freshwieght) which is enough to carry 45 dry cows over 100 days of winter. The crop is successfully managing to run high numbers of sheep and cattle on modest areas of land at low cost per kilo of dry matter produced.

In the first eight years since developing beet grazing systems, the country has gone from 100 ha of fodder beet to over 70,000 ha

To find out more The Scottish Farmer caught up with Dr Jim Gibbs, a veterinary research scientist who developed such grazing systems in New Zealand 15 years ago. In the past six years, he has brought improved fodder beet growth around the world by working with groups in Latin America, France, the US, and here in the UK.

We caught up with Jim on his latest tour of the UK to find out how New Zealand manages to hit such astounding yields and animal growth rates. Critically we want to know if this is an option for farmers here in Scotland.

“The plant offer tremendous value for livestock farmers and we now have well established systems finishing thousands of cattle who graze fodder beet," said Jim.

"Annually there are around 4-5m sheep fed on fodder beet in NZ, which more than all the ewes in Scotland. There are a number of issues to overcome and hurdles which can derails its use. But once you get passed those issues, Scotland could have a very profitable winter feed for livestock.”

New Zealand has build up an entire new part of its beef sector which is exclusively finished or wintered on beet. Nearly all the cereals grown in the country are for human consumption, with livestock strictly kept on fodder-based systems.

Any additional concentrates need to be imported at a high cost which means farmers turn to forage and grass when working with a beef price hovering around £3.50/kg, nearly £1 less than the UK.

The cheapest way to feed fodder beet is to graze it in the ground which Jim said costs around 10p/kg DM – cheap compared to traditional concentrate, straw silage or hay, which he calculated at 40p/kg DM.

For wintering ewes, it can cost around £5-6/head compared to a full cost of £75/head for housed ewes with concentrates and hay, or silage. The crop can be used to maintain condition on dry cows and ewes or finishing young stock.

Steers weighing 270kg going onto a 100% beet diet regularly record growth rates of 1kg/day for 150 days and then use spring grass to a finished weight of 540kg at 16-18 months old.

Transition and diet management

Jim’s first advice in getting success with fodder beet is for growers to understand some counterintuitive learnings when animals are on the diet. The challenge is not just when animals are transitioning onto the diet, but also when grazing.

Transition to beet diets is only necessary in cattle, as sheep regulate their own beet intakes well. Typical sheep transition is to run them on to a beet break for a few hours for two days, then lock them on.

Cattle, however, must be slowly given increasing beet for about two weeks until they are eating as much beet daily as they want to and begin leaving some beet behind. Too much beet too soon and cattle get rumen acidosis, just as they do with grain diets.

The usual approach to transition is to start with 1kg DM of beet allocated by a 'hot' wire and the remainder of a full diet supplied by a roughage, such as silage. Once all cattle are comfortable eating the bulbs, then beet is increased by 1kg DM every second day, and the roughage is gradually decreased to 1-2kg DM daily.

It is important to give all cattle enough space to eat full intakes of beet – this requires 1m of hot wire for every cattle beast across the face. Less than this, and the shy and lighter cattle get squeezed out and then gorge later, causing problems.

Access to roughage supplement is similarly important, or cattle miss out and others get too much.

Once animals are fully onto fodder beet, Jim recommended farmers remain vigilant on the diet to ensure intakes are maintained. This is where it is vital to limiting supplementary feed when grazing a high beet diet.

A 12-month-old steer, or heifer starting grazing beet at 270kg will consume 4-5kgDM of beet and 1kg of DM of another feed, such as pasture, hay, silage or straw.

Jim added: “Limiting the supplement is vital to maintain an efficient rumen not to mention cost affective. Beet diets are unique in that too much fibre crashes the intake and corresponding growth rates.

"Fodder beet is high in water and can over hydrate animals by 300%, or 400%. This means water effectively replaces fibre in the gut and the rumen adapts to pass high volumes of water.

"Critically, if more than 1kg of roughages is fed to young cattle or 0.5kg to ewes then the rumen will slow down. This will crash fodder beet intake from a typical 7-8kgDM per day for a 350kg steer to 5-6kg/DM.”

Typical TMR diets for cattle would have a neutral detergent fibre (NDF) content of around 30%. When finishing cattle off fodder beet you want to keep the NDF level below 25% to maintain the rumen function.

This is a particular issue for fast growing steers and heifers destined for the abattoir. To combat this farmers, need to ensure that all animals have similar access to supplementary feeding.

Putting bales of silage out in a ring feeder is not the best option as a few bigger animals will bully the others and over eat in silage or hay. To combat this New Zealand farmers often use bail unwinders on the back of quads or ATVs to spread silage or hay on the ground.

Each animal needs around two hands worth of supplementary feed each per day, which means for a 100 head of cattle they typically only eat a single bale of silage a day.

Another approach is to wire off multiple bale feeders and simply let the stock in these for 30 minutes a day then chase them off.

Getting the agronomy spot on

The next challenge in grazing fodder beet is ensuring there is enough crude protein in the diet.

The bulb of the beet is filled with sugars and energy but is relatively low in protein at 4-9%. However, the leaf has good amounts of protein at 15-20% crude protein which averages out at 11-13% over the whole plant which is optimal for a finishing cattle diet.

The leaf often dies off in late autumn as frost damage turns springy strong greens to yellowy brown mush. But this does not always need to happen with New Zealand growers maintaining leaf on the plant well into winter even in sub zero conditions.

Jim said: “I have spoken across the world to farmers who all believe that their own farm has a unique climate which means they cannot grow a good leafy, balanced crop of fodder beet.

"But that is not true. On these farms, I have returned in following years and walked through strong crops with big bulbs and plenty of leaf which happens when the farmer gets the agronomy right.”

Maintaining leaf is vital to feeding fodder beet as without it, farmers will struggle to get protein into the diet any other way for growing animals. Adding supplementary feed, with additional protein, usually comes with additional fibre which will crash intakes and growth rates.

The only supplementary protein source which is regularly used in New Zealand is grass, which has a high enough water content to maintain the rumen’s balance. This is often incorporated into a system when finishing lambs with either strip grazing a field of one-third beet and two-thirds grass, or by lifting the beet and dropping it into grass paddocks for a two-day rotational system.

Maintaining leaf is one of the biggest challenges to producing a complete feed. Jim pointed out that many years of commercial use and specific research has demonstrated the leaf could be kept by feeding the plant a high level of nitrogen.

Traditionally, agronomy was based on sugar beet which wanted low nitrogen for easy sugar extraction. This meant that applications of N were usually around 100-120kg/ha – Jim advocated doubling that to get a strong crop that keeps its leaf into winter.

In 15 years of development, New Zealand farmers have proven that upping applications to over 200kgN/ha (similar to wheat) pays back in yield and especially leaf which can survive cold and wet weather. However, Scottish farmers will need to be mindful of NVZ requirements and the previous crop in the field before applying such high levels of N.

Jim added: “You can hold leaf in cold weather if you have strong plants. Our largest area where beet is grazed is in central Otago which is a high and dry plain which regularly gets hard frosts, down to -10°C.

"There, we have many units finishing 3000-9000 cattle annually on nothing but beet. We are getting crops of 44t DM/ha here and I would say Scotland would be achieving a typical yield of 10-17t DM/ha which is where we were 15 years ago. If the agronomy is right in Scotland, then you could regularly be achieving closer to 25-30t DM/ha.”

Fertiliser plan

A typical New Zealand agronomy plan would apply 100kg of DAP urea per ha when sowing, then put the rest on across three or four top dressings. The timing of the subsequent applications would be 40kg of granular urea before the canopy closed by the end of spring, or early summer, then two more applications in mid summer and late autumn.

Later applications of urea could scorch the leaves, so it is good idea to time applications with predicted rainfall. Jim said: “If you flip the hemispheres, then New Zealand farmers would be applying their last fertiliser in November. I am not sure you would be able to leave it that late, but certainly one month later than you would apply to grass and even into October further south in the Scotland.”

There is also a much bigger potential to get N into the soil before planting, with Scotland’s better access to shed muck, poultry litter and pig slurry compared to New Zealand.

He said: “We have been studying this for years now and we know if we have a 30t DM crop we will have 600kg N in that crop above the ground, given the protein levels of the plant. For a 20t DM crop, the plants will have 400kg of N out of the ground, so this crop will use the N if you provide it properly."

Jim advocated sowing as early as possible believing that any dieback from sharper planting is offset by faster growth once the warmth arrives. He also says tight rows, 300mm apart with 250mm seed spacing, helps speed up canopy closure which is the best deterrent to weed suppressant.

As a general seed rate, he advised sowing at 100-130,000 seeds per ha, with greater numbers in the tighter rows. New Zealand farmers typically apply one pre-emerge and two post-emerge in their weed spray regime before canopy closure, which usually occurs at 75 days after planting.

On varieties, he recommended choosing one with a lower dry matter, this can seem counter initiative, but the plants will sit further out of the ground and will be more palatable to the animals. He also pointed out the colour of the bulb has never had a big difference in the performance of the animals.

Sheep on beet

So far, Jim has not managed to optimise lamb finishing systems on fodder beet.

However, beet is commonly used for tupping and wintering ewes and for holding lambs. Ewes are put onto beet at high stocking rates to allow covers in the rest of the farm to recover in autumn.

This allowed a bite of grass to be available in spring when feed is expensive. Further, the quality of the feed is high enough for flushing the ewes in the run up to the tup. The ewes can take a couple of weeks on the beet before the tups come in.

Lambs are another story. He said: “Lambs do terrible on beet. It is not a good feed for them. The crude protein is just not high enough and it is difficult to turn them over, so we tend to use beet for holding lambs – a bit like a ATM.”

Later-finished lambs often command a bigger price in New Zealand abattoirs. To get the timing right, thousands of lambs are held on fodder beet at modest growth rates, before being put onto finishing diets for the abattoir.

The lambs will be growing at 100g/day on beet and will be pulled off in batches for finishing on grass. Buying these lambs earlier and holding them onto beet to hit the market peak can make $20 to $25 and cost as little at $3 to feed.

They will typically go onto an Italian ryegrass, or some grazing cereal to finish for market. Jim explained: “We may lift the beet with a beet bucket and leave it in strips in the field. We would then break the field into a two-day rotation system with the lambs consuming a 50/50 grass and beet diet.

"The high water content of the grass prevents too much fibre crashing the rumen. This can give finishing growth rates of 250-300g DLWG with the lambs eating around 2.5-3% of the body weight per day in DM – this puts a typical 30kg lamb eating around 800g of beet and grass each day.”

Dry cow system

New Zealand has a lot of dry cows wintered grazing fodder beet which Jim says can be tricky to transition but doesn’t need as much fine tuning of the diet over the season.

He said: “You have to be disciplined. The cows will eat themselves to an early grave if you are cowboyish about it.”

This means, to move cows onto beet you need to apply carefully the rules on transition – adequate hot wire space, limited beet allocation, adequate roughage and a two week programme.

Once the cows have transitioned onto the fodder beet that would typically be supplemented with 1.5kg DM of hay, silage or straw to maintain condition for calving. Or the cows will have access to grass but due to this being winter feeding, farmers sould expect the animals to ‘monster the paddock’ as they say in New Zealand and destroy the grass.

The utilisation is of grass is poor by New Zealand standards at 70% but can drop to 50% if it is wet. Nevertheless, if there is a bumper crop over 40t DM/ha (200t fresh) then a 1 ha field can keep 45 dry cows in the run up to calving.

Finishing heifers and steers

Getting cattle to market specification is one of the success stories in the development of fodder beet in New Zealand.

With a typical fodder beet crop yielding 30t DM/ha, the field could be stocked with 35 270kg steers, or heifers. These animals would transition onto the beet, eating 4kg DM at 270kg then 8-9kg DM/day at 400kg after 150 days on beet.

These would then finish on spring grass for 90 days until finished fat at 530-550 kg liveweight. Typically, they will go onto the beet on April 15 (the equivalent of October 15 in Scotland) and be ready to go to the abattoir about late December in New Zealand (late June in Scotland).

Putting carbon back in the soils

The New Zealand system of growing beet is very hungry with N, which might not sit well with some of Scotland environmental and water quality goals. However, Jim pointed out that the crop takes up and holds above the ground 400-plua kg N at 20t DM/ ha, so in almost every case, there is a N deficit after growing big crops, so it is not an environmental negative.

When grazed, it also puts significant amounts of carbon into the soil due to the 3m roots of the plant and the very large yields which the root exudes to the soil far above that of most crops. Slurry from high stocking rates also contributes low N carbon sources back to the soil.

Jim explained: “If we have a crop of 30t DM/ha grazed, the total DM returned to the soil – from surface to 3m – can be 12-14t/ ha. This is far above alternative grazing crops and can be more than a tonne of carbon which is sequestered back into the soil.”