It looks like most farms have “turned the corner”. The bloom is returning to paddocks and growth is now ranging from the high 20’s to the high 30’s in the past week. On these warms sunny days it is estimated that individual paddocks are growing 50+ kgDM/ha/day and even more in reseeded paddocks from 2009. So, not that high growth rates look like remaining for the short term at least, it is time to make some important decisions.

Increasing Demand
First of all what do we mean by the term Demand? This is the amount of grass being removed from the farm on a daily basis, expressed as kgDM/ha/day. It is calculated by the multiplication factor of the number of animals and the amount of grass they eat per day divided by the grazing platform available to them. For example: 100 cows eating 10 kgDM grass/day, as well as 20 bulling heifers eating 6kgDM grass/day on a 30ha grazing platform: (100*14) + (20*6) /30 = Demand of 51 kgDM/ha/day. This is on average the amount of grass eaten off the farm every day. This figure is important when related to the growth on the farm which is expressed in the same units. If the demand is higher than the growth then over time your grass supply on the farm will fall and visa versa.

So why is this relationship so important now? Over the next two of three weeks most farms will begin to close paddocks for silage. This will mean that there is less area available in the grazing platform and therefore the demand will increase. This makes absolute sense in the context of higher growth rates through the remainder of April, May and June. But how high should you bring your demand to? The answer lies with what the farms is able to grow through the same period. If you have a few years of grass measurement data that you should have a good estimate of growth through this period – which emphasises the importance of regular grass measurement. Active growing farms with a good reseeding history can carry a demand of approximately 70kgDM/ha/day through the May/June period, while poorer growing farms with poor grass species may only carry a demand of 55-60 kgDM/ha/day through the same period.
Using the stock numbers above, this means that the active growing farm can afford to close 8ha for silage or reseeding while the poorer growing farm can only afford to close 5ha for silage or reseeding.

There will be a concerted effort this Summer to conserve enough silage to re-fill the pits again. The critical point here is to try to understand the limits of your farm with regard to demand for this first cut period. If you set it too high (well above its ability to grow the same amount) then it is likely you will run out of grass for the grazing animals and will consequently have to reduce demand again by feeding expensive concentrates.

Closing paddocks for silage
Most farmers are now into the 2nd rotation and farm covers are slowly rising. Ideally farm cover should rise to >550 kgDM/ha (but is dependent on stocking rate) before paddocks are formally closed for silage and spread for silage. If these paddocks are grazed, spread as normal after grazing as if they are going to be grazed again. Once farm cover climbs further then the formal decision can be made to close them and top up as necessary.

Increasing intake and daily allowances
Most Spring calving dairy herds should now be allocating 15-16 kgDM/day. If farm cover is increasing and pre-grazing covers are >1000 kgDM/ha, you should be in a position to take away the strip fence and allow for 24-36 hour allocations, especially in these good grazing conditions. Those who have done it are reporting a considerable increase milk solids output, often coinciding with the removal of silage from the diet. However, I am not advocating a relaxation of grazing pressure and graze out of paddocks. It simply means that the cows are sure to fill themselves in 2 out of 3 grazings with the final grazing being asked to reach the residual of 3.5-4cm. This is also sure to benefit the cow in preparation for the imminent breeding season

Dry Matter % of Grass
There have been numerous queries this week regarding dry matter % of grass when clipping and weighing as part of the farm walk. Even though practically all farmers are now in the 2nd rotation, some of the paddocks have been growing since early-mid February, and with the recent dry conditions, this grass is recording a DM% of 20-21%. Grass growing since mid-March is likely to have a lower DM% of 16-18%. These figures are assuming that the grass is relatively dry to touch. Many farm walks are done early in the morning when there is a heavy dew on the grass – expect to further reduce the DM% by 2-3% if this is the case. This is especially evident around the dungpads with cows refusing to touch them. Not a lot can be done I am afraid – over time the grass will use up this nitrogen in the plant.

Overall a good week for dairy farmers, increases in growth, cow performance, and milk price. Lets hope the upwards trends continues into the breeding season. Dare I say it “maybe we could do with a little rain to”…thats enough of that…for another week at least.