Step changes in meat production systems from  dual‐purpose crops in the feed‐base

Summary

​An opportunity to dramatically change the feed supply curve, and reduce the risk associated with variable feed supply and animal production, is available from grazing crops. This project involves a series of interlinked grazing experiments (NSW, ACT, WA) that explores how integration of dual-purpose cereal and Brassica crops with a pasture feedbase can be used to achieve significantly more meat production with manageable or less business risk.

Findings

• Timely sowing of crops is important to minimise establishment risk (if spring sowing) and maximise the grazing opportunity
• Sowing both dual-purpose cereal and brassica crops can increase the sheep grazing days on crops and also mitigate against poor establishment or slower autumn growth rates of one species.
• Replacing permanent pasture with dual-purpose crops can provide a large amount of nutritious feed during late autumn and winter, allowing pastures to be rested and higher livestock production, however this may create a feed gap during the late summer and autumn while the crops are being established.
• Dual-purpose crops can increase meat and wool production. Prioritising grazing for young growing livestock may be more beneficial as meat production is increased and the lower intakes of young livestock may allow other livestock classes also graze crops for at least part of the winter.
• Spring sown canola can be used as a summer/autumn forage for grazing ewe lambs prior to and during joining. This practice can be used as a direct replacement for the sowing of typical forage brassica (such as Winfred) for grazing and will give similar performance in terms dry matter production, nutritive value and live weight growth and reproduction.
• There appear to be no negative effects of grazing brassica forages on ewe reproductive performance prior to and during joining. Gains in live weight during this period will improve reproduction and forage brassicas are able to produce good live weight gains at a time of year when perennial grass pastures are usually dormant. The brassica forage treatments also produced similar or better levels of dry matter compared to other possible summer/autumn forage options such as chicory and plantain.
• Grazing of spring-sown canola during summer and autumn will not affect canola seed yield at harvest providing grazing is stopped before the plants start producing flower buds.
• Use of spring-sown canola within a farm system will require careful consideration of the sowing risks, costs, increased management complexity and additional animal health management requirements.
  Lucerne and chicory are viable alternatives for summer forage generally achieving similar live weight gain and reproductive performance to the brassica forages.
• Plantain should not be recommended as summer/autumn forage due to possible effects on feed intake and live weight gain through poor palatability in summer/autumn.
• Including dual-purpose crops in the livestock system can increase farm returns and reduce risk. However there is an added level of management complexity added to the system by adopting dual-purpose crops.

Key messages

• Dual-purpose crops alter the feed supply.
• Dual-purpose crops sown in late summer and autumn can supply a large amount of high-quality feed during late autumn and winter. For systems that use autumn-sown crops, however, the main deficit in feed is during late summer and autumn, the period when crops are being established, and additional supplementary feeding may be required during this period. Consequently, the deferment effect of crops may not be extra feed availability in winter, but rather that resting pastures over winter allows them to 'catch-up' in comparison to systems that do not have dual-purpose crops.
• Sow dual-purpose crops early – whether in late-summer/early autumn or in spring. Sowing early in late-summer or autumn, when soil moisture is sufficient, can allow early establishment of crops and increase the grazing opportunity during autumn and winter. In environments suitable to spring sowing of canola, crops should be sown as soon as tractors can get onto paddocks in early spring to mitigate against dry spring conditions, however producers also need to be mindful not to sow too early to avoid vernalisation of the crops.
• Local advice should be sought.
• Grazing brassica and cereal crops in sequence – an opportunity to increase the period grazing crops and hedge against poor initial establishment or slow growth rates in one species. Where growing conditions are good, canola will have higher growth rates than wheat and can be expected to be ready for grazing first. The added advantage of grazing canola first is that it provides more time post-grazing for canola to recover. In more marginal moisture conditions wheat may have better establishment and higher initial growth rates than canola, and therefore may be available to graze earlier if canola growth rates are initially slow. Grazing crops in sequence (e.g. canola then wheat) can increase the time that livestock are grazing crops and pastures are being rested.
• Greatest opportunities for utilising dual-purpose crops are likely to be through prioritising crop grazing for young livestock. The high nutritive value and availability (ease of consumption) of dual-purpose crops can increase winter growth rates of young livestock compared to those grazing pastures, increasing sale weights and producer returns. Further, the lower per-head consumption of young sheep compared to reproducing ewes means that other livestock classes may also be able to utilise the crops (e.g. reproducing ewes, agistment or trading livestock), even if for a reduced period, or a smaller area of land can be devoted to dual-purpose crops if targeted specifically at young livestock. Spring-sown canola also provides an opportunity to increase growth rates of ewe lambs to allow joining as one year olds, or potentially for other young livestock.
• Including grazing crops can increase wool production. On farms where wool production is an important component of income, inclusion of dual-purpose crops can increase wool production per ewe. (It is not clear whether this is just due to improved nutrition during winter, or may also be affected by other factors such as reducing the worm burden in ewes.) An additional benefit is that ewe live weights may be heavier in spring, increasing the sale weight of cull ewes.
• Cereal crops can be grazed at low initial biomass, but beware chemical withholding periods. Dual-purpose wheat can be grazed at a starting biomass as low as 330 kg DM/ha, but using moderate stocking rates that allow the crop to continue to get ahead. Exploiting this opportunity may allow crops to be grazed early in tight seasons. Producers need to be mindful that withholding periods on chemicals applied at sowing may prevent early grazing of crops.
• Dual-purpose crops increase farm returns – but input costs are higher. The increased livestock production, reduced supplementary feeding costs and income from grain can increase returns when dual-purpose crops are included in the system. Input costs associated with crop establishment and management are higher compared to pasture-only systems. There may also be additional costs compared to grain only systems, such as additional fertiliser applications.
• Dual-purpose crops reduce business and financial risk – but complexity of management is increased. Business and financial risk and the variability of returns are reduced by including dual-purpose crops in the system, however producers also need to be prepared to deal with the extra management complexity involved with sowing and managing crops to maximise livestock production while minimising the effects of grazing on grain yield.