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Matt Ryan

Management Hints

April 2024


  • This is a seriously difficult spring to graze grass – apply fertiliser and slurry! It has left us with a number of grassland issues:
  1. Some farmers are far short of the target milking platform (MP) area to be grazed.
  2. On other farms the cover on the first few paddocks on March 15 is far short of the target 700-750kg DM required for an early April start to the second rotation.
  3. Some paddocks are badly poached.
  4. A lot of paddocks were poorly grazed in the wet weather.
  5. A lot of farms have received very low levels of nitrogen and slurry.   
  • The consequences:
    • We will be short of expensive winterfeed next winter and more, really expensive meal, will have to be purchased.
  • Issue number one: 
    • This is likely to lead to farmers not being able to complete the first rotation until April 15-22, if no action is taken.
    • A diet change of going from high levels of meal in April to moderate levels could have an adverse effect on cow fertility.
    • Solution: farmers will have to graze first rotation paddocks when the cover is 1,300-1,400kg. It would be best to overlap grazing some of these covers while also grazing some of the high covers from the end of the first rotation.
    • In many situations farmers will have to cut some of the ungrazed paddocks for silage, possibly bale, between April 16-25. 
  • Issue number two:
    • The likely solution here is to postpone the start of the second rotation until April 6-12 when 1,200-1,300kg DM are on the first three to four paddocks.
  • However, growth rates will determine the date.
    • While no two years are the same, one can predict this expected growth based on the average for the last two years for your farm on PastureBase.
    • For instance, if on April 1 your best paddock on the first rotation has a cover of 1,000, and the average growth rate on your farm for early April was 30kg DM/day, then you will have to delay the start of the second rotation by 10 days.
    • No matter how tight grass is, cows must be allowed out for at least three hours per day with the remainder of the diet made up of 4-5kg meal and good quality silage.
  • Issue number three:
    • It is best sorted by the cows’ feet grazing these paddocks on the second rotation on a very dry day, even if you have to graze at lower covers to match the weather.
    • If severely damaged, maybe reseeding should be considered.
    • But, under no circumstances is rolling part of the solution.
  • Issue number four:
    • Poorly grazed out paddocks must, on the second rotation, at a cover of 1,000-1,200, be grazed out very well; otherwise, they will be poor for the year due to lack of tillering.
  • Issue number five:
    • By April 1, all areas of the farm should have 65 units N/acre. If short, apply N.


  • This grassland plan is an essential exercise.
    • It helps not to be overstocked for the year – too many farmers are overstocked on milking platform.
    • It helps to have enough winter feed for the stock you intend to feed next winter and have enough grazing ground for your present stock in April and May.
    • It will also cajole you into having a large first cut of silage – this is a major way of reducing N input because you may not need a second cut or at worst very little.
  • This is one major way to save on contractor and silage feed costs per cow.
    • First cuts yield 10-12 tonnes (t) per acre compared with 5-7t for second cuts.
    • Quality is 6-8% units better.
    • If little or no second cut is taken, more land is available for summer grazing, a saving on N.
    • Pit second-cut silage is 25-40% more expensive than first cut.
  • The way to maximise first cut is to graze cows, cattle and calves at high stocking rates, as follows on the grazing area during April/May:

                                                      100 cows on                                 30 (330kg) yearlings on 

High stocking                        22ha (4.5 cows/ha)                  4.5ha (2,200kg/ha)

Medium stocking               25ha (4 cows/ha)                       5.5ha (1,800kg/ha)

  • Calves can be stocked at 22 per hectare during April/May.
  • With this information you should subtract the grazing area required (for cows, calves and replacements), as calculated above, from the total farm hectares to give you the area that can comfortably close up for first cut.
    • This exercise will alert you to the fact that you may be overstocked to provide enough winter feed and may need to rent silage ground, buy pit silage, or sell off stock.
  • To achieve these stocking rates, use the N levels recommended.
    • To carry these stocking rates, farmers, because they have applied little or no N to date, should apply 46-60 units/acre of N on the whole grazing area NOW.
    • If no P or K has been applied, spread three bags of 18:6:12 per acre.
    • If you do not get very high growth rates to sustain the very high stocking rates projected, you will need to feed some meal (2kg).

Table 1: Surplus bales generated per hectare (ha) for different growth and grazing stocking rates (cows/ha). Source: Teagasc. 




Rate on the grazing 


 Annual growth DM/ha





*4.5 for 1st cut then 3.5 for 2nd 

























*In this scenario, the farm is closed to 4.5 grazing stocking rate from April until early June for first cut, with a grazing stocking rate of 3.5 on grazing platform for second cut. Stocking rate period runs from confirmed silage closing (April 15 approx.) until mid-August start of building average farm covers. 

  • Amazingly, the above planning exercise is done by very few farmers – a fundamental mistake!
    • To make 70-75% of your silage requirements from first cut, close 40-45% of your farm for first cut silage in April.
  • Table 1 highlights the need to be appropriately stocked on the grazing area for the yield of grass your farm is capable of growing:
    • If you have been growing 12t DM/ha and stocked at four cows/ha on the grazing area, you would produce four bales of silage surplus.
  • Silage fields should get 80-90 units of N plus three bags 0:7:30 per acre. This can be reduced by 7-10 units N and one bag 0:7:30 for every 1,000 gallons of slurry used. Discount N used earlier for grazing by 30%.
  • The grazing area should get 32 units N/acre in April in the form of protected urea.
  • Sulphur is absolutely essential for N efficiency – result more grass grows.


  • Feed no meals in April, because, if grass is plentiful, it will produce 27 litres/day:
    • For every 4.5L a herd is yielding above that, feed 2kg meal.
  • A few facts about meal:
    • Every €1 spent on meal equals an actual cost to the farmer of €1.60.
    • Every 1kg extra meal fed reduces grazing time by 15 minutes.
    • The return on money invested in meal feeding is only 3%.
  • You must get yourself feeding the meal level by mid-April that you intend feeding cows in May:
    • This enables you to achieve better cow conception rates/less embryo loss because they will not be exposed to diet energy change during breeding.
  • There are many ways to feed magnesium (Mg), which is a must, but one kilogramme of meal with adequate Mg would be easiest.
  • The new regulation whereby the kg N/cow produced calculation can be reduced from 92 to 87 if farmers use meal with less than 13% P (for farmers in the middle band milk yield).
    • Barley (10-12% P), maize grain (8% P), oats (13% P), citrus pulp (6-9% P), sugar beet pulp (8-10% P), molasses (4-6% P), soya hulls (9% P).
    • Consult your nutritionist or feed merchant before feeding them on their own.
    • The average % P required in a cow’s total diet is 15-16.5%. 
    • Spring grass will have 20-30% P, therefore, we should feed meal 6-11% P now. The following ingredients might be considered:
  • If you are having to feed 3-4kg meal in April you will end up feeding approximately 1t/cow/year.


  • This option must be very seriously considered this year because it will save on:
    • Meal feeding during April.
    • Feeding pit silage or maize silage during April.
  • With this advice, closing-up date will start on April 15 and finish on April 25 (April 22 closing, on average).
    • Fields/paddocks earmarked for silage, regardless of how much grass is on them, must be grazed from April 1-15 or later on some farms.
  • With good growth rates, the cutting date will be somewhere near June 10-14. Early enough for a good cut of quality silage.
    • One should strive for a split cutting date – this would be advantageous to facilitate the early availability of after-grass.
    • Quality will be very good because of the short growing period and no ‘rotten butt’.
  • Some farmers, for the second time, will start grazing the silage ground on April 5 and finish on April 15; this will facilitate cutting in late May/early-June.
    • When the silage area has been grazed apply:
    • 3,000 gallons of slurry (= 20-30 units of N) per acre onto bare ground, otherwise that slurry will contaminate the silage.
    • Most fields will have received 50-60 units of N per acre and about 20 units (25-30% of applied N) of this will be available for the silage crop.
    • Therefore, with the slurry you only need 30-50 units per acre of protected urea plus sulphur.


  • There should be no doubt about reseeding. It’s a must as the return on investment is 58% on the money spent. New grass varieties will grow more t/ha in the year.
  • The best time to reseed is April-May because:
    • Weather is usually better.
    • More importantly, perennial ryegrasses can compete better with weed grasses compared with autumn sown.
    • They can be grazed several times during the year to ‘thicken’ the pasture.
    • There will be no loss in yield from that field in the year of sowing because it will be available for grazing 42 days after sowing with better yields for the remainder of the year.
    • Teagasc Moorepark has shown that pastures with less than 60% perennial ryegrass should be reseeded.
  • Identify fields with low perennial content or that have been poached:
    • Either plough up or use the one/two pass system to prepare the seedbed.
    • Spray with Roundup fields that are to be cut for baled silage (7-10 days before cutting or grazing).
    • They must be limed (1-2t/acre), generally whether they need it or not (to break down the sod).
    • The target pH is 6.5+.
    • Make sure to roll before seeding, harrow in, and roll again.
    • Use three bags of 18:6:12 or 10:10:20 per acre.
  • Choose your grass varieties based on the PPI index.
    • All new reseeds should have white clover included (2kg/ha). 
  • White clover reseeding/stitching-in on milking platform is an absolute must this year. Why?
    • N use is restricted for environmental reasons.
    • N is going to be expensive from here on.
    • It is best to sow it in April by stitching-in into pasture (not old grasses) free of perennial weeds.
  • Red clover should be seriously considered for sowing on outside silage blocks:
    • Teagasc research over six years has shown that, with no N, it grew slightly more silage than swards getting 480 units of bag N/acre.
    • Silage will be high quality, lowish in percentage protein, but is hard to preserve (needs 48-hour wilting).
    • Because of its growth habit it should not be grazed – shortens its life.
    • It has a life span of four to five years with the need for a four-year break before next reseeding of a 10-year reseeding cycle. 
    • James Humphreys, Teagasc, suggests a mix of 9kg perennial ryegrass plus 4kg red clover plus 1kg white clover. Buy from a reputable source.
    • Potash is essential (300 units/year) and K (40 units/year) and soil pH must be 6.5+.
    • It is best to sow red clover in April by ploughing or preferably min-till. 
    • There is a grant of €300/ha for sowing red clover,


  • Sexed semen, as Stephen Butler from Teagasc Moorepark pointed out, is now a key technology for the dairy industry. It results in:
    • But order straws early, and remember these straws are a fragile product and require careful handling.
    • Fewer male dairy calves.
    • Better EBI replacement heifers.
    • Better DBI non-replacement calves.
    • Improved sustainability metrics.
  • Over 200,000 sexed-semen straws will be used this year, but we need, from a society point of view, to be using 800,000.
    • You need to use two straws for every replacement calf required.
  • Choose your sexed semen bulls carefully – their EBI is as good as conventional semen. You will need seven AI bulls per 100 cows and one extra for every 50 cows thereafter. 
  • Table 2 gives you some choices for sexed semen and beef bulls, as suggested by discussion group members.

Table 2: My suggested 2024 B&W AI bull list (incomplete). Source: various catalogues, active bull list, discussion group suggestions*.

Bull code

Bull code

Bull code

Bull code

Bull code

Sexed/easy calving for heifers

Sexed/for cows


Beef: satisfactory calving OK

Beef: satisfactory calving OK

Beef: satisfactory calving OK


































































*This list may have inadvertent inaccuracies – double check beef bulls for ease of calving.

  • Choose your sexed semen cows carefully.
    • Be on target weight – confirm by weighing.
    • Be in BCS over 3.25.
    • Be cycling regularly, preferably on third.
    • On lactation 1-4.
    • Greater than 50 days calved.
    • In BCS of 3 or greater.
    • Cycling regularly, and
    • Have had no postpartum disorders or uterine infections since calving.
    • Heifers must:
    • Cows must be:
  • Fixed-time AI (FTAI) is now very common when using sexed semen on heifers:
    • Day 0: Insert PRID/CIDR + GnRH (1).
    • Day 5: Inject PG (1).
    • Day 6: Inject PG (2) and remove the PRID/CIDR.
    • Day 8: GnRH (2) [=MSD].
    • Day 8: Eight hours after GnRh (2) AI all heifers.
    • Stephen Butler found a 9% better conception rates to an eight-day, eight-hour protocol compared with the usual 10-day protocol (recommended for cows) as follows:
    • You must have your vet on side from the beginning – so give them plenty of notice.
    • If you are going to FTAI cows it is a 10-day protocol.
  • If farmers, for whatever reason are not ready to adopt sexed semen, they should consider a ‘contract mating’ agreement with a very high EBI herd.


  • If your six-week calving rate is poor, consider the ‘why wait’ programme.
    • That means for an MSD of May 1, pre-mating heat recording must start on April 5-7 with all calved cows painted red.
    • Cows identified as being on heat in weeks one, two and three are painted yellow, blue and green respectively, leaving the red ones to be seen by the vet. 
    • They will come bulling 2-4 days later (cows rarely come on heat the day after PG).
    • With this programme you will have AI’d 60% of your cows within 7 days and 90% within 14 days of MSD.
    • It has worked successfully on many farms.
    • This involves moving cows being served in week two to week one and from week three to week two, but you need very good pre-mating records.
    • See Table 3 for the date/procedures which must be followed to the letter of the law.
    • You must accurately identify and record cows coming on heat during the last 21 days before mating start date (MSD) – mark them with a special colour or marking, as per Table 3 suggestions. Collars overcome this requirement:
    • To move week two expected heats to week one, all cows with blue paint should get 2cc PG on the MSD.
    • On May 7 (or seven days after MSD), cows with green paint should get 2cc PG.
    • As you will see from Table 3, I am recommending an early scan, 32-39 days post service. It is done only once per week as outlined, scanning cows that have being served a second time and supposed to be pregnant.
    • Whether you do ‘why wait’ or not, this early scanning option is very worthwhile, instead of waiting until 30 days after the end of breeding season, which only confirms pregnancy.
    • So, at 30+ days, a good scanner can confirm pregnancies, early identify cows with ‘phantom’ pregnancies, and ‘weak’ pregnancies.
    • From this you could PG non-pregnant cows and reserve again in a few days.


  • Use ICBF sire advice to choose your AI bulls from the active bull list.
    • Very simple-to-use programme that enables you to mate the best cows with the best AI bulls.
    • I am amazed how few farmers use it.
  • I recommended the following when choosing (average) a team of black and white AI bulls:
    • EBI €300, fertility €140, calving €45, maintenance €20+, health €10+, MS 26kg, % F 0.33 and % P 0.20.
  • Jersey crossing can still be recommended if your herds’ genetics and % F and P are low, but use sexed semen.
  • Use a stock dairy bull if you wish to lose €80-€100 per year for every cow in your herd.
  • This is the most valuable/vital two hours you will spend this April.