Brassica crops can play an important role in sustainable, rotational farming. Towards the end of summer and the start of autumn, a brassica crop such as stubble turnips or kale sown into post-harvest stubble fields can prove to be a useful supplement fodder crop as the nutritional value of grass declines throughout this period. Livestock will spread manure onto these fields as they graze, adding valuable fertility to the following crop planted.
It is important that the use of brassica as a forage crop must be managed responsibly and that its value as a feed crop should be to complement feed from pasture, not replace it.
Forage crops grown on arable fields should be part of a rotation and their inclusion should not adversely affect the potential for growing crops for direct human consumption
Animals should be introduced onto a brassica crop slowly to allow the rumen micro-flora to adapt to the higher quality diet.
Note: This process may take 7 to 10 days and initially, access should be restricted to 1 or 2 hours per day.
In order to avoid taints in meat, animals destined for slaughter must be removed from grazing brassica crops at least 10 days prior to slaughter.
Feed from brassicas must not exceed 10% of the total annual dry matter intake and no more than 40% of the total daily dry matter intake
Note: 10% of the total annual dry matter intake to a maximum of 40% daily dry matter intake equates to approximately 90 days access to brassica crops per year
In order to avoid taints in milk sold for human consumption, the intake of forage from brassicas must not exceed 30% of the daily dry matter intake.
In order to avoid taints in milk sold for human consumption there must be a period of at least four hours between access to brassicas and milking.
Animals fed brassicas must be supplemented with additional forage to counter the low fibre content of brassica crops.