Rain on Sunday evening and Monday morning was welcomed by farmers in the southern and eastern parts of the country, where soil moisture deficits have been affecting growth rates.

As is usually the case, the areas that needed the rain the most got the least amount of it, with the west getting most of the rain so far.

On some of the worst affected farms where grass is gone brown and yellow the farmers are filling almost two-thirds of the diet with meal and silage, with grass making up just one third of the diet.

It’s a huge additional expense at a time when input costs are still historically high. So the change in weather this week will be welcomed, but it will take a lot of rain and a good bit of time for the situation to revert to normal on the worst affected farms.

Some science can be deployed to assess the situation. If soil moisture deficit was 60mm and the farm receives 10mm of rain this week, then the benefit of that rain will be minimal enough, particularly as moisture will continue to be lost through evaporation and evapotranspiration.

The best case scenario would be that these farms get 40mm to 50mm of rain over the next week or two, which would bring the soil moisture deficit back to normal ranges of 30mm or so.

The point being, farmers in badly affected areas are going to have to continue feeding sharply for at least another 10 days before average farm cover recovers to target range and growth equals demand without supplement.

At this stage, it’s important to continue to measure the farm regularly and take swift action to either increase or decrease demand by adjusting the level of supplement.

Average farm cover should be in or around the 170kg to 190kg/cow mark and growth rates should be equal to demand.