How to grow and utilise more grass on my farm?
Underpinning good grass production and utilisation is having adequate soil fertility, unimpeded drainage, targeted application of fertiliser and good grazing infrastructure, coupled with appropriate grazing management practices. Specialist Catherine Egan and researcher Mark McGee have some advice.
As every tonne of additional grass dry matter (DM) consumed by a grazing animal will add €105/ha extra profit to a beef farm, it is important that investment in grazing is prioritised to give the maximum return. The foundation underpinning good grass production and utilisation is having adequate soil fertility, unimpeded drainage, targeted application of fertiliser and good grazing infrastructure, coupled with appropriate grazing management practices. A target live weight gain of 1 kg/day throughout the second grazing season should be attainable without meal supplementation; however, this is often not the case.
Productive soils are the foundation of grass production. Soil testing to indicate the soil fertility level on the farm is a critical first step. On the basis of the soil test results a targeted nutrient management plan can be drawn up by your local Teagasc advisor to determine the amount of lime, phosporus (P) and potassium (K) that is required. Soil pH is the first thing to rectify. Lime application to correct soil pH (>6.2 on mineral soils) will release nutrients from the soil as well as increasing the response to applied fertilisers. It can result in an increase in grass growth of 1/tonne DM/Ha; indeed, every €100 spent on lime can give a return of €700 in grass. Regardless of stocking rate on your farm the silage ground should be the first area to focus to target a pH of >6.2 and P and K Index 3. Silage is an expensive crop to grow and having soil fertility correct will permit timely harvesting of high yields of quality grass. Soil P and K can be built up by targeting slurry on the silage ground. Targeting Index 3 for P and K on the grazing area then becomes important, and especially at high stocking rates where demand for grass is greater. Initially start with the driest paddocks that you will graze most during the grazing season.
Improving grassland management is an area where high weight gain can be achieved at low cost. Turning cattle out to grass as early as possible in spring and ensuring an adequate supply of good quality leafy grass is an important start.
Grazing tightly and finishing the first rotation ‘on time’ is critical for good utilisation and ensuring high quality grass during subsequent grazing rotations. High animal performance can be accomplished by targeting grazing covers of 8-10 cm (~1,200-1600 kg/DM/Ha), grazing out tight (4-5 cm), while allowing 18 to 21 days for grass regrowth ‘recovery’.
This is broadly captured in the phrase “Grown in 3 weeks, graze in 3 days” and forms the basis for a rotational grazing paddock system. Use of temporary reels confines the stock in the paddock and allows you control the quality of the grass and manage grass to utilise it better. A back reel ‘protects’ the grass regrowth and results in greater herbage production. If grass supply exceeds demand, surplus grass can be removed as round bale silage.
Water trough location can be an issue on many farms when it comes to setting up a paddock system as it is often positioned in the corner of the field. Relocating a water trough (or installing a temporary drinker system) to a more ‘central’ position means that it can service multiple temporary paddocks.
Building up grass covers is required if cattle are to remain at pasture in late autumn. A key focus of autumn grazing management is to finish the grazing season with the desired farm cover, ensuring there will be sufficient grass for early-turnout the following spring. Prevailing soil type and weather conditions have a large impact on the duration of the grazing season.
Catherine Egan and Mark McGee, Teagasc, AGRIC