Following a tough spring and summer in 2018, the mild autumn and winter allowed for ideal grazing conditions of brassicas across the country. Fodder crops such as kale, forage rape and hybrid brassicas provided a valuable feed supply this winter, with many farmers achieving high crop yields and improved livestock performance.
At this stage, most farms have finished grazing brassicas. However, there is still some small acreage to be grazed, as we move into February, it is now time to finish grazing these crops.
Forage brassicas contain SMCO (S–methyl cysteine sulphoxide) which is generally not an issue for animals once they are introduced to the crop slowly and have a fibre source such as silage or straw which contributes 30% of the total diet.
However, flowering brassicas crops will present a higher risk to animals as they have the greatest concentration of SMCOs. Brassicas generally flower in late February, however due to the mild winter, this may occur sooner this year. Excess levels of SMCO’s can lead to anaemia, appetite loss and animals are also likely to develop a condition known as “red water”.
Signs of Red Water
- Urine will be dark brown to red.
- Animal may appear weaker with a decreased appetite.
- Pale or yellow mucous membranes.
It is important to monitor your crops for flowering and aim to have them grazed before it occurs. Do not introduce stock to a brassica crop for the first time now; only graze the crop with stock that have been turned out on it for the last while.
If red water is observed, affected animals should be immediately removed and offered a silage or hay–based diet to reduce SMCO intake. Increase fibre supplementation to the remainder of the herd’s diet and consult with your vet.