JUNE 2018 www.irishfarmersmonthly.com Management Hints X X X If you don’t know that, you are now going to be left behind. If you are under these target covers you will run short of grass and if over these, grass will get too stemmy. Cows will underperform if either of these two situations arise. Minimise weekly milk drop to 2.5 per cent This grass is far too strong and stemmy (probably 65-68 per cent DMD); Animals have to do an enormous amount of walking to get their ‘bellyful’ of feed. This is all about good grazing management. Limit milkyield drop from one week to the next to 2.5 per cent or 10 per cent per month. X A cow’s yield decreases naturally from her May peak by 8-10 per cent per month; X If it decreases more than that, you, the manager, are to blame. Check the bulk tank weekly: A 100-cow farmer could have 4,000L in the bulk tank every second day; X Next week, there should be 3,960L or more in the bulk tank; X This is easily checked. Students and employees should be asked to report on this weekly to keep them interested, and it will pay off if you act. A decrease of greater than 2.5L per 100L per week indicates: X Stemmy or strong grass is being fed to cows; X Grazing too tight (below 4cm), resulting in underfeeding; X Grazing the headlands of cut silage fields for two to three days; X Many cows bulling, or ill health (possibly sub-clinical magnesium deficiency, leptospirosis or infectious bovine rhinotracheitis [IBR]). If grass has got strong and stemmy, skip on to the next most suitable quality, over 80 per cent DMD, grass paddock. X This is difficult to achieve because most grasses get stemmy and seed in June/July; X Use baled silage to deal with strong grass (excess grass); X Grazing to the correct pre-grazing height for your stocking rate is the secret to grass quality with less topping and baling. Grazing too tight: X This may result when grass is scarce but generally we are not grazing tight enough; X Generally, in such situations, for every extra 1kgDM grass that is allowed to the cow, her intake will increase by 0.40.5kgDM and should result in an extra 1.1L/day of milk yield; X But leftover grass rots, which is wasteful. If your stocking rate is not too high, then grazing to 4.55.0cm may be sensible, but topping will be necessary. Grazing the headlands after a silage cut is too prevalent: Topping must be seen as a last resort – what you must do is have the pre-grazing cover (PGC) correct for your stocking rate and round-bale surpluses. However, if the ‘dung-pad’ area is greater than 25-30 per cent and the postgrazing height is 5cm, you have two choices. Either leave for baling in the next rotation or top it now. X When the PGC is higher than your target, then that paddock must be cut for baled silage within two or three days of its due grazing date. X This material should be cut, very low at 3.5cm, tedded or left in small rows for wilting, then bagged; X Apply 1,000 gallons of slurry (undiluted) for every four bales of silage removed from a paddock to replace the P and K removed; X This silage will be very good quality; it will be 80+ per cent DM, nearly as good as meal and one-third the cost; X It can and must replace meal in August-October; X Or it should be kept for feeding to milking cows next February; X The aim is to have one to two bales of this material for every four cows in the herd so as to reduce your autumnspring meal bill. Nitrogen: apply 75 per cent of annual amount by mid-June The advice is, for all farmers, to apply 28 units/ac in June, with heavily stocked farmers applying it in early June and low-stocked farmers applying it in mid-June. But you must work within your nitrate limits. X These are monthly recommended amounts. On sulphur (S)-deficient farms you will get a response of 10-50 per cent more grass by spreading 20 units/ac between now and September. X Because S interferes with copper, don’t use it if you don’t need it. Fields, after a silage cut, should get 40+ units of N for grazing, and silage ground 80 units. There may be a case, where soil P and K is low, that one round of 27:2.5:5 is required to improve grass yield. If you don’t spread all your slurry onto bare silage ground now, you won’t have the chance to spread it all in ‘one go’ later in the year. Go about this very important chore in a planned way: X Agitate the tanks before cutting the silage; X Have warning signs in and around sheds during agitation; X Have the contractor booked to spread as the silage is being picked up; X Have warning signs when using public roads and be able to clean it if need arises. 47