Farm systems scientist, Tom Fraser, says the two to three weeks after a drought has broken is a real danger period, as feed quality can crash, good pastures can be ruined and livestock performance go backwards.
He urges farmers to carry on with their supplementary feeding regime for at least a further two to three weeks following the rain to allow pastures to recover.
He says desiccated pastures can maintain feed quality – but as soon as it rains, the cell walls of the plants collapse, feed quality disappears and the plants rot. Hence the need to carry on feeding stock, especially ewes over mating to maintain ewe condition.
“So long as they have plenty of water, stock generally do quite well in a drought because feed quality is OK from drought pastures, it’s when the rain comes and quality crashes that stock will go backwards.”
Continuing supplementary feeding will also give pastures a chance to recover so they are able to generate feed for late autumn, winter and most importantly – spring.
Fraser says the best pastures will always be first to recover after a drought, and while it is tempting to graze them, it is important the plants are given time to build up the reserves they will need to draw on in the months ahead.
“Hold off, continue supplementary feeding and feed the poorest paddocks first.”
Key points post-drought
- Continue supplementary feeding for 2-3 weeks
- Allow time for the best pastures to recover and build reserves (start thinking about spring production now)
- Feed the poorest paddocks first
- Hold-off applying nitrogen- there will be some in the soil, if still warm then apply nitrogen in 3 or 4 weeks
- Watch out for internal parasite burdens and facial eczema
- Not too late to sow Italian and short-rotation ryegrasses and cereal green feed crops
Ensure adequate cover
Farmers should be thinking about how they manage their pastures now to ensure they have adequate covers going into late winter and spring.
Typically, after an extended dry period, nitrogen (N) will have built up in the ground which will help plant growth in the first few weeks after rain. If the mild weather continues to drive plant growth through until mid-April, farmers can then decide whether or not to apply N.
New pasture growth after drought can be laden with internal parasite larvae, so farmers need to watch out for worm burdens and take the appropriate management action.
Similarly, moisture and warm temperatures make facial eczema a real risk in many areas of the North Island.
Fraser is hopeful that farmers might see a good six weeks of pasture growth before the soil temperatures fall. While it is too late to sow permanent pastures, there is still time to drill Italian or short-rotation ryegrasses and cereal green feeds such as ryecorn and oats.