At the end of 2014 a number of growers were motivated to graze failed and unharvested crops, attempting to recoup some of their investment into their cereal paddocks.
To ascertain the value of this practice, BCG took Hindmarsh barley samples from the main research site at Beulah and Scope CL wheat samples from the Birchip research site. The intention was to assess the nutritional value of unharvested areas of crop where moisture stress and frost limited straw and grain production.
Feed tests conducted on the samples showed that the Hindmarsh barley adequately met the energy needs of all classes of lambs, returning a metabolic energy (ME) result of 11.9 MJ/kg DM. However, Scope CL wheat fell short at 11 MJ/kg DM and did not meet the energy (ME) requirements for light and faster growing lambs (Table 1).
Crude protein was fairly low in both crops (10.3%). As protein is particularly important for growing lambs (particularly lighter lambs and lambs with higher growth rates), an additional source of protein would have been beneficial if these paddocks were grazed.
Remember that in reality, the sheep will initially scout around and nip all the heads and leaves from the crop, ensuring they get the nutrients needed. However, as the heads and fallen grain disappear, only straw remains and the nutritional value falls dramatically.
This exercise reinforced the importance of feed tests and grain counts on the ground to ascertain the nutritional value sheep are likely to derive from unharvested crops and to determine what extra feed is needed.
This season taught us you can’t assume a failed grain crop will meet the needs of grazing animals every time. It is always important to feed test, and consider the economic impact of any necessary supplements.
