06 May 2024

Summer stocking rate effects on cow performance & silage stocks

With Spring milk supply down on many farms due to poor weather conditions this Spring, focus must be on maintaining good cow performance over the next few months. Martina Gormley tells us that summer stocking rate can have a big effect on cow performance.

Option 1

40ha milking block /120 cows= 3lu/ha

At an allocation of 20kg/dm of grass per cow that’s a demand of 60kg/ha

For 60kg demand/ha most dairy farms would be comfortable and have opportunities to take out surplus bales as required.

Option 2

Short on silage and decide to close up a 8ha on milking block for silage and reseed 2 ha

30ha/120 cows= 4lu/ha

At an allocation of 20kg/dm of grass per cow = 80kg/ha of a demand

The big question is with good grassland management and genetics and calving pattern can you achieve the same performance for the two different stocking rates options?

The first question is what is the farms average growth rates over the summer months?

How many farms can grow 80kg+ for May/June/July?

Very few on average will achieve this.

So what is likely to happen, the farm will run into grass quality issues and or quantity issues. Cows will not preform due to more fibre in the sward and this will limit intake. In addition, the cow’s wont milk well if the growth rates aren’t consistently at 80kg/ha while you are waiting for silage/reseeded ground to come back in. This is because the cows will be getting a lower allocation of grass.

Reducing the area closed to say 5ha would be safer option or follow option 1 and do not close up any area. Take surpluses as required.

The main disadvantage most farmers will say about option 1 is having to call on the contractor a few times over the summer for a lower number of bales.

Some farmers are working around this challenge by mowing the paddocks themselves and making 30+ bales at a time. In addition, some farmers will say they pay extra and are giving the contractor other work on the farm so it is not an issue.

If this will not work for your farm than a comprise is to reduce the closed up area to 5ha which will leave stocking rate at 3.4 lu/ha and demand at 68kg. There still will be surplus bales but not as many.

The main priority on the milking block should be that the cow is fed well with good quality grass for as long as possible. A fodder budget should be completed to work out if there is a deficit when silage from out farms are taken into account and a plan should be put in place to reduce deficit.