There was heavy rainfall in most parts of the country over the weekend, though it has not affected grazing conditions and will hopefully improve grass growth on farms.
Grass growth has been slow on most farms this spring but has picked up in recent weeks, with grass growing at a rate of 45-55kg dry matter (DM)/ha/day last week, according to PastureBase Ireland.
The majority of farmers will have silage completely out of the cows diet and should be looking to reduce the amount of meal being fed if they are in a comfortable position with grass supplies.
Milk supplies have been drastically improving around the country, with growth rates continuously improving, heat and moisture in the ground, and the majority of herds purely on grass and meal diets.
For the rest of April, the average farm cover (AFC) needs to be maintained above 600kg DM/ha on all farms and 180-200kg DM/livestock unit (LU) .
Farmers under this target should try and increase the grazing area or go in with extra supplementation.
Allocations
Grass allocation for farmers with sufficient farm covers should be now at 24-36 hours so cows can achieve their full intakes at grass.
By having proper allocations, it ensures that first lactation and less dominant cows are fully fed.
Farmers need to ensure paddocks sizes are optimal before strip fences are completely gone from the system. Milk production can be compromised when cows have to be moved midday as paddocks fall between one and two grazings or between two and three grazings.
In order to work out what your paddock size should be, farmers should use the following calculation: cow numbers X 19kg of grass (may vary between herds) X 1.5 days = cow requirement for three grazings ÷ 1,400 (pre-grazing yield) = the size of paddock in hectares to accommodate three grazings.
Example: 120 cows X 19kg DM grass X 1.5 days = 3,420 ÷ 1,400kg DM/ha = 2.44ha paddock required.
A 36-hour paddock is the ideal target but is sometimes impossible due to farm layout, etc., but farmers need to ensure the paddock is either 24 hours or 36 hours and not in-between to allow for full herd nutrition.
Grazing targets
Heading towards the end of April and into May, grass growth can really begin to take off and supply can change rapidly, which means that walking the farm twice a week is crucial to make timely decisions.
Heading into May, when cows are in a 20-day grazing rotation, 1,300-1,400 kg/ha of grass will be grown, and it can be hard to keep ahead if not managed right.
Drop off in peak milk production can occur in these months, and can often fall quite rapidly in the summer months, largely down to poor quality grass in the cow’s diet.
According to Teagasc, every 1% reduction in grass digestibility will reduce milk solids yield by 1-2% and grazing heavy covers will reduce milk solids by 15-20kg/cow in mid-season.
It is crucial to be grazing at cover of about 1,400kg DM/ha when the sward is green from top to bottom to ensure grass quality and regrowth.
At a pre-grazing cover of 1,400kg DM/ha, the grass plant should still be at the two to three leaf stage. If the grass starts growing the fourth leaf, the rotation is getting too long.
Going into May, AFC should be at 160-180kg DM/cow, which is the equivalent of 600-700kg DM/ha.
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AVERAGE FARM COVERS DAIRY DMI GRAZING 2025 GRAZING TARGETS SPRING GRAZING TEAGASC
