1 November 1996

Plan now to provide your herd with top quality spring grass

Improved grass management this autumn will lift profits by guaranteeing early spring grazing. NZ dairy consultant Paul Bird, currently working in Ireland, reports in the first of a regular series focusing on grass use

GRASS management required to achieve good cover for early spring grazing by dairy cows starts this autumn.

Producers who can use grass to provide most of the milkers ration in February and March will minimise concentrate and feed costs and maximise profit margins.

What is more, early spring grass is high in digestibility and its energy is 11MJ/kg ME compared with most concentrates at 10-10.5. But to ensure there is sufficient grass for early grazing, it is important to plan now.

Grazing the farm out bare just before all the animals are housed going into the winter is a poor management technique. It greatly reduces grass cover in February and March and increases reliance on silage and concentrates over the early spring period.

There should still be a reasonable grass cover on the farm when the animals are housed. Milkers should now be grazing about one 40th to one 50th of the farm every 24 hours (a 40-50 day rotation).

If the last grazing rotation started on Oct 10, then grazing should be stopped about 50 days later on Nov 30. At this point grass grazed on Oct 10 will be of reasonable length. This will be the first paddock to be grazed in February. This approach of grazing paddocks in early to mid-October and then not grazing them again will ensure grass is there for February grazing. And it applies to herds that have a proportion of cows calving in the autumn as well as the spring.

To encourage higher winter growth rates apply nitrogen at 37.5kg/ha (30 units/acre) through October and November after grazing. Urea is the most efficient form of nitrogen, as it is less prone to leaching. Even at low response rates, nitrogen-grown grass is significantly cheaper than concentrates or silage.

Farms with higher phosphorus also grow more grass in autumn, winter and early spring. In general slurry does not provide adequate P. A soil test will give an indication of the soils nutrient status. &#42

Ensure there is reasonable grass on the farm when animals are housed.


Ireland all-change

Dairy producers attending farm discussion groups throughout Ireland have changed their grass management over the past three to five years. They now focus on ensuring they have grass available for early grazing from February. Benefits are much higher profits – as measured by analysing farm accounts – due to similar milk production and fertility performance, but less reliance on costly silage and concentrates; less need for machinery and buildings; less slurry/ pollution; and less labour.