Grazing Cereal

 

GRAIN & GRAZE:

With the increase in animal industries profitability. Consideration is being given to maintaining animal production while still keeping or increasing to a high cropping regime.

Early sowings are important for early winter and total fodder production. Early sowing is especially important to allow good growth before cold winter temperatures restrict growth. 

This has encouraged the research into grazing cereals and canola. Most of the major members of the Grower Group Alliance have carried out some research on into the application and the techniques required.

There is a major initiative sponsored by Grain & Meat Research and Development Corporations called Grain & Graze2 that combines research from the CSIRO and most State Departments of Agriculture.

Grazing cereal crops has included other benefits. Farmers are finding there is a disease control. Crops that may need 3 applications of fungicides only need 1.
With Forerunner and Massif Oats grazing stops these crops form getting so tall so they retain more leaf and the stalk is not as thick. While it is early days so far they hay has a higher feed value.
With wet spring Forerunner was grazed 4 times in th high rainfall regionwith out any decrease in hay production.
Caution is needed with crops that are for grain production overgrazing can decrease grain yield's. With expected price of grain this year the loss of 1t/ha of grain could outweigh the grazing benefits.
With long season grazing cereals they can be locked up in spring and the hay production will not be as effected. 

 

Check out Links under Massif Alliance for the websites that explain this research and outcomes 

Attached is a check list put out by NSW Agriculture.

Role of cereals in grazing

Forage cereals play an important role in most grazing enterprises by helping to overcome winter feed shortages. They have higher winter growth rates than most pastures (see Figure 1 for a typical example), and with their higher carrying capacity are able to ease the grazing pressure on pasture paddocks.

Figure 1. The estimated growth rates of oats and of annual grass / sub clover on the Central Tablelands

All cereals can be grazed but some have been specifically bred for grazing, with emphasis on dry matter (feed) recovery after grazing and in many cases also on grain recovery. Saving autumn growth from early-sown crops, particularly in high Rainfall areas, can be used to carry feed through into winter. Forage cereals can also play an important role prior to sowing a pasture by aiding in weed control and through paddock preparation.

 

Choosing a cereal

For overall forage production, oats will generally produce more forage than most other cereals.This has not been the case with Forerunner where in the 4 years it has been grown in WA it has produced more hay per hectare than oats.The total amount of feed available will be influenced by the type of crop, variety, disease resistance and sowing time.

Grain recovery is not so clear cut, with winter wheat’s and triticale often having yields comparable to those of oats. Where a grain harvest following grazing is required, specific dual-purpose varieties should be chosen.

Cereals that produce large awns can cause mouth injuries to livestock and should be avoided for hay production or where head emergence under grazing cannot be controlled. These cereals include barley, triticale, cereal rye and some wheats. This has been overcome by the introduction of lines like Forerunner.

Selecting crop types or varieties tolerant to root and/or leaf diseases will lessen the disease impact in susceptible situations . Where annual grass control (e.g. vulpia, soft brome, barley grass and rye-grass) has been poor in the winter/spring prior to sowing, cereal root diseases are likely to cause serious production losses, particularly on non-acid soils. Highly susceptible crops such as wheat and barley should be avoided; cereal rye has good tolerance, with oats the next best, followed by triticale.

Barley yellow dwarf virus is a serious disease. Large losses of both dry matter and grain production can occur when susceptible crops (especially oats and barley) are sown early. Tolerance to barley yellow dwarf virus will therefore influence crop and variety choice.

 

Quality tests 
On the forage of oats, wheat, barley, cereal rye and triticale, when grown under similar conditions, show no significant differences in levels of protein, energy and digestibility. Therefore a cereal with higher grain returns may be chosen as an alternative to oats.

Soil acidity will also influence cereal choice, as species and varieties vary in their tolerances. Even when highly acid soils are limed, acid-tolerant types may still need to be considered where the subsoil remains acidic.

 

Growth habits

A knowledge of the winter habit and maturing time of varieties will influence the choice of variety, sowing time and expected grazing performance.

 

Winter habit

Varieties with a strong winter habit that are suitable for early sowing, as head initiation does not occur until there has been exposure to periods of cold temperature. This requirement is called vernalisation, and exposure can be cumulative. Once these requirements have been met, head emergence begins as temperatures rise and day length increases.

The degree of winter habit will depend on the genetics of the varieties. Varieties described as semi-winter types have a shorter vernalisation requirement to initiate heading.

 

Late maturing

Late-maturing cereals do not necessarily have a strong winter habit. Without the requirement for vernalisation, these types, when sown early in warm or long day conditions, will quickly initiate heads. These immature heads are concealed in the tiller, and removing them by grazing or cutting results in the death of the tiller. Regrowth is then significantly delayed and total forage production reduced as plants are forced into producing new tillers, a slow process that can take weeks.

Late-maturing types without a winter habit, when sown early, often require quick and early grazings to retard early growth and head emergence. This earlier-than-normal grazing will assist subsequent regrowth.

 

 Plant management

 

Sowing

Cereals used for either grazing or grain production will attain maximum production only if:

  • seed rates are kept high; and 

  • crop nutrition is adequate. 

Optimum seed rates will vary with climate and area of the state, and local advice should be sought. Optimum nutrition requirements will likewise vary according to climate, soil type and paddock history.

Wide row sowings should be avoided if maximum dry matter and grain yields are to be achieved. In an experiment on a light granite soil, a 25 cm row spacing was compared with the normal 17.5 cm row spacing. The 25 cm row spacing resulted in a reduction of nearly 12% in early dry matter yields of Coolabah oats. Wide rows, however, while reducing potential yield and increasing the risk of weed invasion, may aid in the reduction of leaf diseases by allowing better air movement through the crop.

 

Early sowings are important for early winter and total fodder production. Early sowing is especially important to allow good growth before cold winter temperatures restrict growth. 


Fertiliser

Fertiliser rates for grazing crops should generally be higher than for grain-only crops, owing to the longer growing season.

Phosphorus (P) rates in the range 15–25 kg/ha should be considered but this will depend on soil tests, paddock history, anticipated yield and soil type.

Nitrogen (N) application requires particular attention unless there has been a recent history of good legume growth. A good oat crop used for grazing and grain could be expected to use up to 100 kg/ha of nitrogen. Both pre-emergent and post-emergent applications of nitrogen can be used in nitrogen-deficient situations. With long-season dual-purpose cereals, split applications should be considered.


Insects

Red-legged earth mites and blue oat mites are the most widely occurring insects that attack grazing crops. Their chlorophyll-destroying effect is worse in moisture-stressed crops, and in these situations may require treatment. Adding an insecticide to the spring fallow herbicide can aid in their suppression.

Army worms can also attack crops, usually grain crops as they ripen. Chewed leaf margins and spikelets on the ground indicate their presence.

If insecticides have been used for insect control, the withholding periods must be observed before introducing grazing stock.

 

WARNING

 

Pesticide residues may occur in animals treated with pesticides, or fed any crop product, including crop waste, that has been sprayed with pesticides.

 

It is the responsibility of the person applying a pesticide to do all things necessary to avoid spray drift onto adjoining land or waterways.

ALWAYS READ THE LABEL

Users of agricultural (or veterinary) chemical products must always read the label and any Permit before using the product, and strictly comply with the directions on the label and the conditions of any Permit. Users are not absolved from compliance with the directions on the label or the conditions of the Permit by reason of any statement made or not made in this publication.

Weeds

Planning in the previous season to prevent annual weeds from seeding helps to reduce in-crop weeds and improves crop production. This is especially so for grass weeds. Control can be through pasture cleaning, topping or early fallow.

Herbicide usage can depend on crop type. Herbicides can be registered for use on some crops but not others, or the rates specified on the label may be different for different crops. For example, the maximum label rate for 2,4-D amine (500 g/L) on wheat is 2.1 L/ha, while on oats it is 1 L/ha. (See warnings.)

If herbicides are used for weed control, withholding periods must be observed before introducing grazing stock. Some grass herbicides have withholding periods of up to 60 days, which may affect grazing strategies.

Higher seeding rates help to compete against weeds, and maintaining crop canopy (bulk) will help discourage weed recovery.


Grazing management

Grazing time

The earliest time to start grazing is when the plants are well anchored and reach the tillering stage (Zadok’s growth stage 21–29, see Winter Crop Variety Sowing Guide). For most grazing types under good growing conditions, this will occur 6–8 weeks from plant emergence, depending on variety.

With winter types, by deferring early grazing, more feed can be accumulated and saved for winter. For erect types, crops will usually be 20–25 cm high, and for prostrate types 10–15 cm high.

Varieties that do not have a strong winter habit but are sown in early autumn should be grazed even before tillering to retard growth and subsequent premature stem elongation and head initiation. When stem elongation occurs, immature heads are located just above the highest node (joint). If these are removed, tiller death occurs. While the plant is usually able to produce more tillers, forage production (and grain production) is severely reduced.

The latest time for grazing and the severity of grazing of crops intended for grain recovery or hay production should be governed by the position of the immature head in the stem. Some growers opt to graze late and remove these heads, particularly if the crop or variety is prone to lodging. These growers choose to accept lower grain or hay yields as a trade-off for having a standing crop at harvest.

Late grazing of semi-dwarf types can also greatly reduce crop height, causing subsequent harvesting problems in rocky or uneven paddocks.

 
Frost

Frost injury to grazed crops can be severe, particularly if crops are only a few centimetres high and the soil is loose and dry. Under severe frosty conditions, stock should be removed nightly. Damage occurs to the plants’ growing points and through the trampling of frost-covered leaves. Some crop varieties, particularly the oat varieties Blackbutt and Nile, have very low growing points, and therefore this type of damage is minimal.

 

Diseases

Diseases such as leaf rust on oats or powdery mildew on barley may also influence the timing and severity of grazing. By removing the canopy and opening up the crop, the incidence and severity of leaf diseases can be greatly reduced.

Barley yellow dwarf virus, sometimes a serious disease of early-sown susceptible crops, especially oats and barley, is best controlled by choosing tolerant varieties. When this is not possible, sowing in late autumn when aphid activity is lower will reduce the risk of infection.


Scouring

All cereals in the vegetative stage under good growing conditions are highly digestible and often contain 80%–85% moisture (15%–20% dry matter). The resultant scouring is normal when stock are grazing on highly digestible, high-moisture, green feed.

Adding hay or roughage to the diet will slow down animal performance as the animal substitutes the higher quality forage with the hay or roughage. In some cases this may be of benefit as it will extend the grazing life of the paddock.

Veterinary advice should be sought if abnormal scouring occurs, as this may be the result of internal parasites.


Stocking densities

Stocking densities will depend on specific animal production targets. Research has shown that continuous grazing of winter forage cereals gives better animal performance, as the best feed on offer will always be selected. This will only be achieved if stocking rates are balanced with crop growth rates and the feed on offer is not being significantly depleted (see Table 1).

* Calculated using GrazFeedTM for green oats at 2000 kg DM/ha, 20 cm tall, 73% DDM (digestible dry matter) assuming 25% spoilage rate.

† Assuming 30 kg DM/ha/day crop growth.

With continuous grazing, stock densities should be determined so as to leave plants with enough residual leaf material to enable both good regrowth and high animal performance. Benchmarks exist for both instances.

Residual plant heights of around 5–10 cm for prostrate types and 10–20 cm for upright types will correspond fairly closely to benchmarks of around 1000–1500 kg/ha for lactating ewes and fattening steers.

High stocking densities are used under rotational grazing but lower animal performances can be expected compared with continuous grazing. Rotational grazing can, however, be used to maximise the grazing value of a crop, by reducing wastage from trampling and/or frost damage or by the restriction of intake per head. Techniques such as strip grazing or limiting access times to the crop can be used for rationing feed.
Animal health disorders

 

Disorders can occur under certain growing conditions, and veterinary advice should be sought for animal treatment. The most likely disorders are:

  • enterotoxaemia (pulpy kidney) 

  • hypomagnesaemia (grass tetany) 

  • hypocalcaemia (milk fever) 

  • nitrate/nitrite poisoning. 

The possibility of these occurring should be considered when planning the grazing operation.