Case study: Hans van Wees
When I last spoke with Hans six months back in mid-December 2018, he was focusing on continuing to make a conscious effort to maintain good growth rates of young stock.
The spill date on Glenmaggie of 15 December had passed and only a 35 per cent allocation had been given.
Water budgeting calculations had indicated he had enough water from the MID irrigation system to irrigate the whole farm until the end of March, even if there was no decent rain events before then.
Having 400 megalitres of ground water for additional irrigation would help them get through until the end of autumn. There was not a huge pressure to cull early at that time.
When I spoke with Hans this time around, in early June, he said:
“Our irrigation strategy for autumn didn’t quite work as the evaporation rates were a lot higher than we expected, on top of coming off the back of a very dry summer.
So, we dried-off about 10 per cent of our irrigation country in late February/early March. We bought-in some extra temporary water as well as transferring some water right from one of our out-block properties to water the remaining 90 per cent of the home block.
The water that we transferred from the out block we could only use on the part of the dairy farm closest to it. We also used 320 megalitres of the 400 megalitres of ground water at the end of autumn.
We had one good rain event in middle of March, 40 millimetres in thunderstorms over a few days which was great. It wasn’t a true autumn break for us but it was enough so that we could postpone our next scheduled watering from the MID system for 10 days.
We got fairly short of feed probably in the last half of April, so we culled some cows then after we had the dairy herd pregnancy tested.
Since early May, we had some reasonable rain events and things are not looking too bad. We just started drying cows off. Although we haven’t got much pasture cover currently, it’s all growing.
This is because we were able to water the whole of the dairy farm one last time by the time the MID irrigation season ceased on the 15 May; a couple of paddocks we irrigated with water out of the reuse dam for a few days after mid-May.
With our autumn being mostly dry, we found that we didn’t waste much supplementary feed because the cows were utilizing everything.
Although our milk production will be down five per cent compared to last year, it would have been more expensive for us to make up that five per cent drop by having to buy-in temporary water and purchase more fodder.
Our young stock are going well, with the strategy of continuing to make a conscious effort to maintain good growth rates over autumn by offering the young stock the better pasture rather than to the milking herd.
We only lost a little bit of cow milk production as a result, but it was a small price to pay and we’ll get back more than what little we lost in heifer milk.
Their growth rates are on target based on our weighing results. We are up to date with giving them all their essential drenches. Pregnancy test results have indicated good ‘in calf’ rates for the heifers that will be milking for the first time this August.
There is enough fodder on-hand (including what we’ve just ordered) from now on to get us comfortably through until 1 October based on our feed budgeting. We’ve essentially budgeted for 700–800 kilograms DM per cow for winter of fodder on-hand for a total of four months.
A wet winter will be a huge risk for us as we will have trouble utilising our supplementary feed due to pugging and mud accumulation.
We are a true seasonal herd and we rely heavily on feeding our whole herd for at least two months in sacrifice paddocks over winter to the tune of 7 to 8 kilograms DM per cow per day. Particularly this time around, we don’t have much pasture in the paddocks and we want the cows to utilise this minimal pasture as possible.
We are not concerned about next spring at this stage, as we can kick off spring pasture growth with irrigation easily enough”.