Use your grassland management experience to set the targets which suit your situation
IN MANY wet parts of the country, very little autumn grazing can take place, in most years.
The early October rain has already caused severe problems in some areas this year.
Grassland managers should use their experience to alter these targets to suit their own situations of soil type etc.
In general, there are two aspects to autumn grassland management. One is to optimise the value of whatever grass is available now by using long rotations, on-off grazing, back fencing, multiple entrances to paddocks and adequate supplementation. The second is to prepare the pastures properly for a good supply of grass next spring. This can be achieved by starting the last rotation around mid-October, cleaning out pastures well in the last rotation, avoiding serious poaching, and ensuring that the soil has adequate P, K and lime.
The main objectives are to maximise the amount of high quality grass in the cow's diet for as long as possible, and finish the grazing season with the desired farm cover, without damaging pastures. Grass budgeting, or a good knowledge of correct grass covers, is essential. Well-managed autumn grass can be of good quality, about 20% crude protein and 70% DMD.
Farmers should remember also that preparation for spring grazing begins in autumn. The target on reasonably good quality soils is to have 60% of the farm closed off by early November, and the remainder grazed off before housing. This should result in a target cover of 220kg of dry matter per livestock unit, or 550kg of dry matter per hectare (at stocking rate of 2.5 livestock units/ha) at closing. Contrary to what often happens, the driest paddocks near the milking parlour should be closed early to provide very valuable early spring grazing.
Usually in autumn, farm covers of about 1,100kg should be reached in late September, providing a bank of grass to meet requirements for the rest of the autumn.
Paddocks should be well grazed out, to a little under two inches (4.5cms). This may be difficult in poor weather. In order to avoid damage, facilities such as intersecting cow paths, back fencing and multiple paddock entries will be required, together with on-off grazing.
Moorepark research findings indicate that cows will adjust their feeding pattern to on-off grazing, and this is a recommended practice in poor weather.
Autumn pre-grazing covers should not be allowed to exceed 2,500 kg of dry matter per hectare, in order to ensure optimum utilisation and maintain quality.
At this level of pre-grazing cover, quality is still high, and can be maintained for four to six weeks. If covers are left to grow any further, quality and quantity will be reduced, because of rotting at the base. Carrying heavy covers over winter has a very bad effect on pastures. Trials in Moorepark show that heavy winter covers results in very thin pastures in the following years.
If some paddocks cannot be grazed out well in the normal grazing cycle, because of weather conditions, every effort should be made to get them grazed out later, with light cattle for example.
