Make sure cows are hungry when you let them out to grass
Spring is officially upon us with calving under way and grazing has started across the country.
It has been a relatively dry few weeks and ground conditions are good for the time of year. The first item on the spring agenda after ‘calf check’ should be a farm walk to gauge how much winter growth there has been and what opening cover we have on the farm.
An opening cover has a huge impact on profitability as an adequate to high opening cover will result in little bought in supplement needed, whereas a low opening cover will mean tight grass rationing and a high level of bought in supplements.
A farm walk is step one.
Step two is completing a spring rotation planner. A spring rotation planner is designed to have a target allocated area to graze by certain dates; e.g. 20-30% (dependent on your location and soil type) of grazing platform to be grazed by end of February, 50-60% grazed by mid-march and the remainder by April 5-15. Set up your rotation planner now to help you best utilise your grazing area this spring.
Step three is completing a spring budget (the majority will have this done from last autumn), enter in number of cows calving weekly and how much grass you want to allocate. The budget will then illustrate the effect this allocation of feed will have.
When setting up a new budget, I generally enter in all cow numbers and try to fully feed them on grass from day 1. This will usually result in average farm cover (AFC) being too low by magic day (April 5-15), so I then reduce the allocation in February (and early march if needs be) to stretch out the grass covers and add in meal/silage were necessary to prevent dropping AFC too fast.
Depending on your stocking rate and calving spread (and therefore ‘demand’), it may be possible to have them at grass fulltime from calving. Be careful with fresh calvers and cold nights, by-day grazing only for first few days is desirable for these girls.
Target AFC by magic day is nine-10 times demand as a guide. Growth rates nearer the time will help us decide exact target but as an example, a farm stocked at 3.0lu/ha and demand/ha of 48kg, an AFC of 400-450kg/ha would be a guide for magic day. Set this target in your budget and ensure AFC does not drop below it before then.
Now that we have set up both the rotation planner and spring budget, we must marry the two so that we reach our target area grazed by x dates, but also that we are not dropping our AFC too fast.
So how do we do this?
- Use historic growth rates from your farm or neighbouring farm(s)
- Start cows grazing low covers (500-800kg/ha) to get them trained into grazing again
- Ensure they are hitting target residual by day three to four and maintain it
- Allocation allocation allocation – to calculate how much area to allocate, here is an example:
30 cows, 6kg grass/head, cover in paddock 800kg/ha.
30 cows x 6kg = 180kg grass required
Divide 180kg into 800kg Pre Grazing Cover (PGC) = 0.225ha
0.225ha x 10,000 (metres squared in a hectare) = 2,250 sq.metres e.g. 100m x 23m break
Cows must go to grass hungry. For convenience, lock cows off silage face at bedtime when checking springers. If this is not possible owing to shed layout, use an electric fence in front of feed face.
Unless cows go out with an appetite, they will eat less per mouthful, walk more (resulting in soil damage) and they will not eat down to the target 3.5cm residual. To ensure cows are being fully fed daily, ensure they have ad lib silage after they come in from grazing until six to eight hours later, thereby allowing enough feeding time.
Graze low covers for 10 days or so then start into higher covers, always keeping a careful eye on both the rotation planner and spring budget through regular farm walks.
Grass is exceptional high quality feed in spring, high energy, high protein, low hassle. The Dry Matter (DM) will range slightly depending how long the paddock has been growing.
Fertiliser should be spread when ground conditions and soil temperature allow. Grass will grow from 6 degrees celcius, Urea is a safe option as the N is in Nitrite form and not Nitrate (such as CAN), therefore will not be lost through leaching if soil temperature is low.
Slurry low covers that you are not going to graze and try and slurry any grazed paddocks behind cows; this will supply much needed N, P and K to the young roots. Max slurry allocation 2,000 gallons/acre.
To be profitable, you must put the time in to ‘plan’ and ‘budget’ how much grass will be offered and how much forage/supplement is needed to fill the gap.
The current low milk price should focus us all on low cost, high profit. Medium-high input farms must think along the same lines to optimise production and reduce bought in feed by managing their farm to its fullest potential.
Johnstown Castle dairy unit is an excellent example of how to maximise grass intakes in high yielding animals, achieving high grass tonnage grown/ha and high profitability/ha.
Cathal McAleer is a grassland consultant working with individual farmers and facilitating discussion groups throughout Ireland.
087 160 2491 / 0044 7749 531679 [email protected]