How to get to grips with slow growth

THE last few weeks have brought many difficulties for both grass management and herd nutrition on dairy farms.

Persistent cold wet weather has severely impacted on growth rates across the country with current growth rates 50 per cent behind 2017 levels.

Many farms are reporting very low covers – in the region of 300 to 400kg of dry matter per hectare (DM/ha) on first areas grazed, instead of the target 500-600kg DM/ha. On heavier land types, farms are reporting less than 10 per cent of available land area grazed at this stage.

Fertilizer N applications are falling well behind targets also. A further complication to the situation is an emerging scarcity of silage on some farms. Collectively, these factors are placing increased pressure on herd management at a busy time of year.

As regards dairy cow nutrition the main objectives to be met in the short term are to: feed milking cows well to maintain good milk production, body condition and rumen health. Young stock and remaining dry cows will need to be correctly fed. From a grassland management perspective the objective is to manage grazing to protect ground conditions while utilising available grass.

Adequate grass cover will need to be maintained on the farm by managing rotation length and promoting new grass growth by getting winter covers grazed and fertilizer applied. Average farm cover must not be allowed to drop below 500kg DM/ha in early April – dropping farm cover below 500kg DM/ha will reduce subsequent growth rates by 30 per cent. Where farms have large areas grazed and/or little to no grass, farmers will need to get daily grass DM demand below growth rate to prevent covers from falling too much. If covers are dropping rapidly, now is the time to cut demand by reducing daily area grazed through introducing supplementary feed. Cows must be adequately fed in this situation. Housing just a proportion of the herd can be a potential solution if cubicles and feed space are under pressure.

With lengthening daytime, ground conditions should slowly improve so farms with a low percentage of paddocks grazed and good grass covers should have an opportunity to get areas grazed. This must be a priority especially where silage stocks are running tight. Graze some lower covers to settle cows into grazing and then move to graze the heaviest covers if the weather conditions are dry.

The reason for this is that these paddocks will lie dormant until new growth is stimulated by grazing. Use the on-off grazing method if conditions are marginal, and aim for two grazing bouts per day. Bring evening milking time forward to 3.30pm or 4pm to reduce labour impact. Fertilizer nitrogen( N) needs to be applied as a priority now. The aim is to have 87kg N/ha (70 units per acre) out by the end of March.

If no nitrogen has been applied to date, the target should be to hit 70 units by April 10. A bag of Urea (46 units) should be applied as soon as possible. Soil temperatures across the country are in excess of 5.5 degrees Celsius in most parts.

Some farmers on heavier land have brought in contractors with low impact machinery, such as ATV spreaders, to guarantee application. Explore all options. Apply P fertilizer after grazing heavy covers to aid root recovery.