Pasture feed range needed for beef

Pasture consultant Peter Desborough says there are 10 key points to follow in establishing quality pastures for beef cattle.

01-05-2007 | Contributor

Pasture feed quality is well appreciated in profitable farming businesses. It is most important beef producers grow a range of pasture feed that suits the seasonal and dietary needs of their animals.

Bull finishing farmers management is now based on 80% production and 20% on control. They are growing more and higher qualify forage/ha and using it more efficiently.

Irrespective of whether a new pasture follows an old pasture or a crop, whether it is sown after conventional cultivation, direct drilled or aerially renovated, the real secret to successfully establishing new pastures is to do the job properly from start to finish.

There are 10 key points for pasture quality.

1. First it is essential to achieve total control of existing pasture sward. If difficult to kill species such as browntop are present it is better to double spray with Roundup either side of a summer or winter fallow.

Another consideration could be to spray top with low rates of Roundup in spring prior to seeding to control seed set of perennial and annual grasses.

Conversely with aerial oversowing gorse areas a two-spray strategy involving Trounce/Metsulphuron followed by fallow and a follow-up Roundup spray prior to seeding is recommended.

2. For direct drilling select a drill that can handle pasture residue and soil contour. Drill seed no deeper than 10-15mm (0.4 – 0.6 inch). More accurate seed depth control will be achieved with slower drilling speeds. Use covering device (harrows) if drill does not have press wheels. Retaining cover will help to conserve moisture and with over-sowing gives seed protection against elements.

3. Cultivated seedbeds should have all weed and crop residues buried and worked to a fine tilth then consolidated before sowing. There should be adequate soil moisture for seedling germination and emergence.

4. Pasture establishment by aerial techniques is becoming popular as a means of establishing grass/clover and winter feed brassica. Though there is greater risk of failure than ground sowing, if established guidelines are carefully adhered to the rate of success can be greatly improved.

5. The key to increased sheep and beef farm production lies in strategies that result in higher quality net pasture production, with improved animal performance. The more high metabolisable energy feed eaten the more rapid the stock turnover. For beef bull farmers heart of their feed production is rapid turn-round short term, quality fodder crops such as diploid and tetrapbid ryegrasses, fescue, chicory, brassicas.

On hill country ryegrass is the mainstay grass and serves farmers well when they grow good clover with it but summer growth is slower. Farmers would like more white clover in their pastures, because animals gain more liveweight on white clover than any other pasture species.

However drought, pests and diseases can reduce clover content to only 2-3% of pasture drymatter (DM) and that means a 95% plant loss.

Red clover has proved to be valuable in pastures for meat production, but it usually only lasts a few years. So it is probably better used with grasses that are also less persistent such as Italian and hybrid ryegrasses.

Plaintain is highly palatable to all livestock, establishes rapidly, is very drought and pest tolerant and has a high mineral content.

Cattle grazing chicory show excellent production as its forage is digested much more rapidly than normal pasture and this helps to account for high liveweight gains from chicory pasture and also helps animals to maintain good health.

Tall fescue is another perennial grass that offers more for meat production.

6. When using aerial renovation techniques use Prillcote technology to:

a) Improve penetration to the soil surface through increased seed weight.

b) Better absorb and retain moisture from the soil through improved seed/soil contact.

c) Improve nutrition of the seedling through placement of fertiliser around the seed.

7. Ensure all insect pests are controlled. Slugs, grass grub and porina are more likely to be a problem after direct drilling and aerial renovation because their habitat has not been destroyed during cultivation.

Plants can be protected from grass grub damage during establishment if either appropriate treated seed or insecticide is used. SusconGreen granules will give three-year protection against grass grub, while Ultra Strike grass seed treatment will give protection during establish phase.

8. Ensure an adequate level of soil fertility for the new, higher producing species being introduced.

Farmers should be soil testing paddocks due for pasture renovation six months in advance of sowing so pH and mineral deficiencies can be corrected well before the seed enters the ground.

Research has shown that average P levels in NZ have increased in the past 10 years from about 8-9 to between 15-20 so land has a better ability to grow a wider range of pasture species.

The challenge now is to mobilise what phosphate was already there rather than simply apply more. Availability of this phosphate is driven by bacterial activity.

It is particularly important with timing to correct soil pH because it can take three-six months for lime to be incorporated effectively into the soil.

A key part of a liming strategy could involve use of pelletised ultra fine lime to quickly achieve a quick response in pH lift. Optimise lime pellets could be used in tandem with agricultural lime and can be either aerially applied or applied through direct drill, placing them in direct contact with seed.

This may result in more rapid establishment and together with fertiliser ensuring good early root growth. All fertiliser programmes should include a liming policy.

Sowing seed into infertile soil along with fertiliser without raising the overall fertility of the paddock may give a good strike, but the new species will not spread out from the initial drill hole to form a thick sward.

The new species will then run out within a couple of years when the fertiliser applied with the seed has been used up.

Fertiliser is an investment, not a cost, and if you are not getting a return from it you shouldn’t be doing it.

9. If the pasture is being renovated by cultivation there is generally enough release of nitrogen (N) to meet the needs of the new pasture species from breakdown of the old sward.

However this will not be the case if it has been ploughed just before sowing when there will be a depression in N during the initial mineralisation creating a deficiency. If early ploughing is not possible it pays to apply N before sowing to meet the needs of the decaying pasture and the subsequent sward.

In the case of direct drilling into a sward sprayed with Roundup there will be no release of N from the decaying sward and a N deficiency can be expected.

In this case N is required to stimulate the new pasture. Care is needed with the use of N because it will stimulate grass growth and increase tillering in autumn and spring, but it is important that this extra grass growth does not cause shading of the clover.

Young grasses will respond to N very well for first four years.

10. Most farmers will be only too aware sowing new pastures is an expensive exercise.

Rotational grazing is best for all pastures in the first year. Tall fescue pastures require a different management from year one.

These pastures respond to some periods of hard grazing in spring which keeps reproductive growth to a minimum.

It is important to allow tall fescue pastures to have a spell in autumn, because this is the time when they generate new tillers for the following season.

Hard grazing in autumn will kill a lot of new fescue tillers.

Peter Desborough is a Dunedin-based economic pasture system consultant. Peter.m.desborough@xtra.co.nz

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