Grass growth rates are on a knife edge, of that there is no doubt. The biggest factor limiting growth is soil moisture. Farmers should approach a grass deficit at the start of a drought differently to how they manage a general grass deficit.
Grass growth rates are on a knife edge, of that there is no doubt. The biggest factor limiting growth is soil moisture.
Farmers should approach a grass deficit at the start of a drought differently to how they manage a general grass deficit.
Ordinarily, the advice would be to intervene early and hold average farm cover as this will enable you to get out of the deficit situation faster.
However, in a drought situation you tend to lose average farm cover because the grass withers away due to heat, sun and lack of moisture.
What is the point of trying to protect grass now that will most likely wither away anyway if the drought continues?
Continue to graze
My advice is to continue to graze what grass is available and let average farm cover drop. This is a difficult step for many farmers as it is against their better instincts but I think it’s the right thing to do.
It is only when average farm cover is down to 400kg/ha to 500kg/ha that extra feed should be considered. Then at that farmers should go on a 25- to 30-day rotation length and fill the deficit with feed. What that deficit is will depend on growth rates at the time and what the pre-grazing yield is.
At this stage, most farmers are probably a week or two away from an average farm cover of 400kg/ha to 500kg/ha.
It’s important to remember that no matter how bad things get, there will always be some level of grass growth. In July 2018, average grass growth was still around 30kg/day.
Those that are pushing extra feed now are not acting in the best interests of farmers, whether they know it or not
Also, there is no certainty that this summer will get anything like that. There is a change in the forecast from Tuesday of this week and while the quantity of rain forecast is not hectic, at least there will be less evapotranspiration.
So there are reasons to be optimistic that the situation could turn around, as has happened many times in the past when the country was on the brink of drought and the weather changed.
Vested interests
And if it doesn’t, then we can manage that too. The key thing for the moment is to resist the “advice” from those with vested interests in selling feeds to maintain average farm cover now.
In my opinion, those that are pushing extra feed now are not acting in the best interests of farmers, whether they know it or not.
All of this said, farmers should be putting a plan in place for what to do in the event of drought. How much good-quality silage is available and how long will this last?
Do up a fodder budget for milking cows. In a very worst case scenario there may be only 6kg of grass that could be fed per day, so 12kg of other feed may have to be found. This could be made up of silage and meal.
Read more
Action needed to address grass surplus
Dairy management: have we had enough rain?
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