Forage for Knowledge

Grass growth remains highly variable

Grazing farmers are all trying to bank as much grass as possible for autumn grazing and winter forage to make up for the shortfalls caused by this summer’s drought.

Data from FFK farmers shows that some farms are currently experiencing exceptionally high growth rates, with very spring-like conditions. Others have seen a short-lived burst of growth over the last month before growth rates started to decline again.

Farmers reporting falling growth rates suggest this is due to continued dry conditions rather than the typical autumn slowdown caused by shorter days and lower soil temperatures. While they've had some rain, it has not been enough to keep the grass growth going beyond a few weeks’ respite.

Why is grass protein so high?

One consistent trend from fresh grass analysis over the last fortnight is lower dry matter, at around 16%, combined with exceptionally high protein levels, often in the high twenties.

So, what's driving these high protein levels?

Nitrogen from chemical fertiliser, slurry and grazing deposits has built up in the soils during the extended dry period, when it remained largely immobile. Following autumn rainfall, this nitrogen has been reactivated in the soil, allowing plants to take up nutrients very quickly.

As farmers chase as much grass as possible this year to make up for the deficit from summer, I suspect additional applications of chemical nitrogen have also been applied. This, combined with residual nitrogen, is contributing to the very high protein levels we are seeing in grass.

Balancing diets and supporting fertility

Excess dietary protein is often expressed through high milk urea levels. After an expensive summer in terms of feed costs, this presents a great opportunity to reduce the protein content and cost of supplementary feeds so that diets are better balanced against grass protein levels.

While relevant to all, it’s particularly important to those who are, or will be, mating cows in the next couple of months. In some cow types and production systems, high milk urea levels have a negative impact on fertility performance.

Making the most of the final rotation

As many of you enter the last rotation around the farm, your usual plan may need to be adapted. While some farms have managed to reach their target average farm cover, many remain below target, which has significantly affected grass availability and the proportion of grazed grass in the diet.

Hopefully, by now, you will have come up with an alternative feed strategy that supports cows in the correct way given their stage of lactation. However, grass remains an extremely valuable feed at this time of year, and many farms are still benefitting from favourable ground and grazing conditions.

Take full advantage of this opportunity while you can. Consider feeding your forage supplements in the field, reducing part-time housing costs and recovering some of the additional feed costs incurred during the summer.

Benefits of feeding forage in the field

The main advantage is keeping the cows off concrete.

Another key benefit is that because the cows are still going back out to grass for majority of their food, except parlour concentrate, grazing behaviour is less affected and you have a greater chance of achieving good residuals, which is a priority on the last round.

Reducing forage wastage

With winter forage stocks tight, some farmers may feel the risk of wastage is too high. However, feeding forage along the break fence in a long, narrow row works best.

If your total allocation of silage and grass dry matter is accurate to the demand of the herd, then wastage will be surprisingly low. There will always be a few cows prepared to be the tidy-up crew.

Wastage can be reduced further by moving the break fence back five metres into the already grazed section and feeding along this strip. This reduces the trampling on otherwise grazable grass along the fence line.

Keep measuring and monitoring

Most importantly, keep measuring.

Making the most of the remainder of this year’s grazing season without negatively impacting on next year is crucial. This can only be done confidently through active management of grass supply and demand, supported by regular monitoring of average farm cover.