Using standing crops to finish lambs and protect paddock health

Alison Frischke, BCG

Take home messages

• Standing crops are a nutritious and profitable feed source to use later in the season for
weaning and finishing lambs on.

• They provide excellent groundcover and reduce the risk of summer soil erosion, benefiting
soil health.

Want a good source of paddock feed to look after your lambs? A ‘standing crop’ can be used to
wean and finish off lambs in spring and early summer, while providing benefits to ground cover and
soil health.

Mixed farmers have grazed crops for a long time, however, crops are usually grazed when they’re
green and vegetative during the growing season, or remnant grain and stubble is grazed following
harvest. It is not common to graze a crop during its reproductive phase and maturity unless it has
failed.

Once pastures turn off in late spring, there can be a feed gap of a few weeks before harvest stubbles
are available. For a system that is growing autumn/winter drop lambs with genetic potential for
growth rates >300g/day, the timing of this coincides with the stage that lambs should start to be
finished, i.e. high growth rates should be maintained to achieve target sale weights for marketing.
If finishing is later and stubbles can be used, once sheep have grazed the unharvested heads or spilt
grain the paddock feed value falls. Large paddocks also mean animals need to walk longer distances
to search for grain. Nutrition can then fall short of requirements, and the growth potential of lambs
may not be realised unless supplemented.

A ‘standing crop’ is a crop that has been held as a fodder bank for grazing later in the year, from
head emergence and into grain fill. It can be used for high quality feed to wean lambs onto, and to
finish lambs between three to six months of age. The standing crop can be a cereal, or a combination
of a cereal with a legume or grain supplement which delivers higher protein for growing lambs.
The standing crop can be utilised any time, but care must be taken if introducing animals to the crop
once grain has set. Introducing lambs to the crop during head emergence, flowering and early grain
fill ensures they are grazing the crop as it matures, and grains develop, so the rumen microbes can
gradually adjust to the change in nutrition. Once grain has set, lambs must first be carefully
introduced to a full ration of grain before entering the crop to avoid animal health issues (except
when grazing oats).

The practice is low cost and low risk. The standing crop is sown and grown as a crop would be for
harvest, i.e. locally adapted varieties are sown on time with adequate fertiliser and weed
management to maximise dry matter production, as opposed to just ‘banging something in’ with
little or no management. The crop is then assessed in early spring for its best end-use opportunity;
responsive decisions are made to graze, cut for hay or harvest the crop based on lamb and grain
commodity prices, and seasonal conditions or events such as heat stress or frost that may cause a
grain crop to fail.

Risk is also managed by growing the standing crop on winter rainfall, compared with summer crops
which are opportunistic and have a greater risk of failure due to limited soil moisture and unreliable
summer rainfall.

It’s a solution that reduces grain handling and labour costs during spring and summer feedgaps, as
the frequency and duration of feeding needed to meet target sale weights can be reduced.
Grazing of senesced pastures and stubble residues during dry months will eventually expose soil to
the elements, increasing the chance of wind and water erosion from summer storm events. Because
a full standing crop offers greater biomass and can meet the higher nutritional demands needed for
lamb production, lambs will reach sale weights faster and can be removed from the property earlier.
This relieves the stocking rate pressure over summer months, preserving groundcover levels, and
ideally reduces the risk of overgrazing, erosion and soil nutrient loss.

COMMERCIAL PRACTICE
South Australian livestock consultant, San Jolly, has been advocating for growers to use a standing
crop for finishing lambs for over 15 years. San herself is a lamb producer and has worked with many
growers in South Australia and Victoria to use standing crops to fine tune their lamb finishing
systems. Along the way they have learnt which oat or barley varieties are better to graze and how
animals should be introduced to make best use of the feed. This includes taking into account the
biomass and height of the crop, the willingness of lambs to enter the crop, preference for certain
varieties, starch contents of grain and feed introduction implications.

Alan Bennett and daughter Ellen farm in the west Wimmera and have been using standing crops to
wean and finish lambs for the past five years. Using different combinations of barley, rye and oats
with vetch, lucerne, clover and medic, they’ve achieved growth rates between 300 – 435g/head/day
with crossbred lambs weaned onto the standing crops. Alan describes it as a great pasture system
because it makes management so much easier. Once he’s done the planning and has the crop in, he
knows that there will be abundant feed to wean lambs on to in August and October, and they can
stay there comfortably for eight to 10 weeks.
The advantage of grazing a standing crop to finish lambs is that it is a low risk, proven practice. There
is no need to learn new skills – you are already growing crops and have adapted varieties that
perform well in your environment – you are just using the crop for a different and highly profitable
purpose.

ACKNOWLEDGEMENTS
In 2019, with the support of the Australian Government’s National Landcare Program, grower
discussions, demonstrations and economic analysis will present how standing crops can benefit
lamb finishing systems and paddock health.

This project is funded by the Australian Government’s National Landcare Program and delivered by
BCG and Mackillop Farm Management Group.

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