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Matt Ryan

Management Hints

June 2023


  • Set your June targets and take steps to achieve them.
  • Take great care not to miss cows on heat in late season.
  • Adhere to ‘normal’ grassland-management needs.
  • Make adequate quantities of quality silage.
  • Prepare now to sell your male calves next spring with a commercial beef value (CBV) tag.
  • Kale should be sown now!


    • You are under performing if you are not achieving the following standards in June:
    • A milk decrease of less than 2.5% from week to week.
    • The aim should be to maintain the peak, starting in April, for 40-50 days at over 2kg milk solids (MS) per cow per day.
    • A post-grazing height of 4-4.25cm (use plate metre to confirm).
    • Grazing quality grass (80+% DMD) by grazing covers of 1,400-1,600kg DM/ha.
    • Have 76% of your annual nitrogen allowance used by second week of June.
    • Less than 20% tall grass (dung-pads) in each paddock.
    • 80% of your silage made by mid-June.
    • All slurry tanks empty.
    • Somatic cell count (SCC) less than 120,000.
    • Total bacterial count (TBC) less than 15,000.
    • 75% of your cows in-calf after 42 days’ breeding.
    • All heifers must be in-calf.
    • Are you on target to have less than 5% of cows calving in April next year?
    • Now using high dairy beef index (DBI) beef bulls – a must!
    • Cows and calves on no meals.
    • In-calf heifers (R2s) weighing 350-380kg and heifer calves (R1s) weighing 125-140kg.


  • The minimum cost of a missed heat is €250.
    • It could be much greater (€800-€1,000) if it results in the cow not being in-calf at the end of the season.
  • National figures are extremely worrying (2023). Calving interval = 388 days; six-week calving rate = 66% (target of 90%); cows culled per year = 21% (target = 15-18%); and the average age at culling = 4.7 lactations (target = 5.5).
    • Serious financial losses!
  • This period of reproductive management is all about using the records to guide heat expectations and subsequent actions.
    • I hope you are not too busy to compile and use the records that you need.
    • Collars are great but you must make use of the information.
  • Minimise this problem by answering a few questions.
  • What percentage of my cows/heifers are repeating?
    • The target conception rate to first service is 60%+ or a non-return-rate (NRR) of 65%+.
    • Use the ICBF website to answer this question for you or examine your breeding chart.
    • If more than 35% of cows are repeating then you have a problem.
    • A NRR of over 65% for cows served more than 28 days is the target – may seem very high but some of them will ‘break’ later in the time.
      • Cows experiencing foetal death beyond day 34 of pregnancy will take up to eight weeks to return to a natural heat.
    • Rank yourself against targets in Table 1 and act.

Table1: Herd fertility targets for June


  • The possible causes of the problem may be some or all the following:
    • Cows are underfed due to tight grazing, shortage of grass, stemmy grass, letting cows out directly after milking onto 12-hour grazing block – allows the first cows out to eat all the best and easily accessed grass – or very wet conditions.
    • Cows are too thin or losing weight.
    • Bad semen (infertile bull – check with your discussion group if any particular bull is causing more repeats).
    • Cows under stress due to lameness, mastitis, lack of water, stray electricity (don’t underestimate), health issues (IBR, BVD, neospora, leptospirosis, fluke, etc.), mineral deficiency (phosphorous has become an issue). Get your vet to address these issues.
    • Cows are under stress on service day or when the heat was due.
    • Service procedure was poor (never presume you or your technician are perfect AI technicians). Over 65% of repeat service must be between day 18-24.
    • Associated with this is the AI person having to use an unsuitable service crate – very common?
  • Genetically, herd is infertile – this is probably the main reason! The following Table 2 highlights the issues associated with infertile cows compared with having a fertile cow. 

Table 2: Physiological mechanisms responsible for greater fertility in fertile cows compared with infertile cows (Source: S Butler, Moorepark)


Early post-calving At breeding

    • Minerals may be a problem (could be iodine, copper, selenium, cobalt or phosphorous) – this is probably fourth or fifth on the list of the issues to investigate. Consult your vet.
  • Cows being served in June will calve from March 11 to April 10 next year.
  • Do everything within your power to have all cows in-calf by the end of June:
    • You must use short gestation Friesian AI bulls because their gestation length is minus 11-13 days (worth over €70/cow profit next year).
    • The following breeding protocols should be your target: 
      • Four to six weeks, dairy AI, then three to four weeks high DBI beef AI bulls, finishing up with short gestation dairy AI.
  • Continue serious heat detection. Harder now as one cow/day/100-cow herd will be only on heat and she will only be mounted 11 times (compared with 50+ during first three weeks).
      • Top up paint daily if needed.
      • The optimum time to AI is 12-24 hours after the onset of standing heat.
      • When a cow has been served, mark the cow’s shoulder, so as not to re-serve her again the day after, as this can cause the loss of pregnancy as well as costing an extra €15-20.
      • Repaint or put on the scratch card the day after service.
  • Scan all cows 30 days after mating.
      • Why? You will identify non-pregnant cows and weak pregnancies; therefore, with good records you can resynchronise/PG them and they will be mated in the next few days, picking up at least 10 days in calving next year.
      • This scanning takes place once per week for three weeks, as follows, for a mating start date (MSD) of May 1:
      • June 6 (37 days post MSD) all cows served week one of AI.
      • June 13 (44 days post MSD) all cows served week two of AI.
      • June 20 (51 days post MSD) all cows served week three of AI.
      • Records will help you with this beneficial task but you need a highly competent scanner.
      • Shoulder ‘raddle’ (marking powder) all cows served week one with green marker, week two with blue, etc. so that they can easily be drafted out each week for scanning. Computerised identification overcomes that problem.
      • Note, if you plan to scan do not have a stock bull ‘running with’ either the cows or heifers between first service and the scan date.
      • It is worth noting that embryo loss beyond day 34 of pregnancy is primarily associated with either cows carrying twins or infectious diseases such as neospora or BVD. Issues that cause stress such as lack of water, lack of grass, etc. compromise the cows’ immune system and allows these diseases attack the foetus.


  • Yes, it will be advantageous when selling male calves next spring to know their commercial beef value (CBV).
    • Dairy farmers MUST use high-beef-merit AI bulls on their cows from now to the end of the breeding season.
    • The top 20 Dairy Beef Index (DBI) bulls are listed on the ICBF site.
    • By using one of these bulls your male calf will have a 4- or 5-star rating when selling.
    • DBI, just like EBI, is a financial ranking of the beef bulls as a result of their various financial traits.
  • As much care should now go into choosing your beef bull as it did for your dairy bulls so that you have a male calf to sell next year with good beef genetics – the target is to have a 4- or 5-star CBV calf.
    • This will almost certainly mean that beef calves from stock bulls will be less valuable. 
    • See Table 3.

Table 3: Minimum required DBI beef sub-index of beef bull to achieve a 4- or 5-star CBV dairy-beef calf.


  • The larger the minus on your dairy-beef sub-index for your dairy cows, the higher the DBI must be used to achieve a 4- or 5-star CBV calf.
  • When choosing a bull from the DBI list, consideration must be given to gestation length and calving difficulty.
    • Every day a cow is not milking is €2.50 lost profit.
    • A difficult calving will have many consequences both for the cow, the calf and farm profit.
  • The final link in convincing the dairycalf buyer is getting the calf genotyped next spring.
    • You have to prove parenthood.
    • That information can be displayed at the mart when selling.
  • All dairy cows should now be genotype because we are in an era where only the best will do.


  • For those of you in a ‘normal’ situation, I hope a drought doesn’t develop from the time I write these notes to the time you read them. The following management is suggested:
    • Depends on how well you have grazed out paddocks in May but graze covers now that are appropriate to your stocking rate.
    • If badly grazed out, paddocks must be topped low to 3.5cm so as to set-up quality grass for next rotation.
      • This, unfortunately, will slow down regrowths, and delay the next grazing for 23-25 days.
    • The pre-grazing grass cover must not be greater than 1,600kg DM per hectare.
      • The following table gives the target covers to aim at on the grazing area.



  • If pre-grazing covers (PGC) and average farm covers (AFC) are greater than specified above, then you must take out the strong paddock for baled silage within the next two to three days.
    • This material should be cut, very low at 3.5cm, tedded or left in small rows for wilting, then bagged.
    • This silage will be very good quality.
    • It will be 80%+ DMD and should be labelled and later fed to milking cows.
    • Aim to have two to three bales of this material for every four cows in herd so as to reduce your autumn-spring meal bill.
    • This material will be nearly as good as meal and will only cost half as much.
  • If PGCs are greater than specified but AFC is below target, be careful before you take out the strong paddock.
  • The big message is to measure grass weekly and graze covers appropriate to your stocking rate but never, ever above 1,700kg.
  • Measuring grass is the most important driver to ensure adequate quality grass is always available while minimising topping.
  • As topping is effectively wasting grass or utilising less of the grass grown, we must avoid topping as an option by grazing out all paddocks to 4cm. Topping or remedial management is only required when more than 25% of the paddock has tall grass, that is areas around dung-pads and urine patches. 
  • Many farmers are now using a disc-mower (instead of toppers) to manage their grazing to very high-quality levels by cutting out ‘strong paddocks’ for baled silage. Being under-stocked on the grazing area during summer will result in more baled silage – Table 3.

Table 3: Surplus bales per hectare for different annual grass yields and grazing stocking rates on the grazing areas (cows/ha). Source: Teagasc.




Rate on the grazing 


Annual growth – tonnes (t) DM/ha





4.5 for first cut then 3.5 for second (*)

























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

  • Table 3 shows:
    • If you are growing 15.5t DM/ha on MP you will have to make a lot of bales, even 3.6 bales when cows are stocked at 4.5 cows/ha.
    • If only growing 10t DM/ha you will never generate bales, except at 3.0 cows/ha – you will be seriously short of grazing grass for all other grazing stocking rates.
    • A case can be made to make two to three quality bales/cow for feeding in a dry summer, late autumn or early spring to milkers, as highlighted in green.
    • Cutting a whole lot of bales on the grazing platform due to under-stocking only complicates the whole system. Remember, for ever four bales cut/ha, 1,000gallons (=1 bag 0:7:30) of slurry needs to be applied as they reduce nitrogen, phosphorous and potash availability.
  • The message is clear, know how much grass you are growing and match the grazing stocking rate accordingly to minimise complicating the system with bales.

The following are the nitrogen recommendations for June:


    • If you are following the Moorepark Grass Clover 150 system you will be applying 9kg N/ha (7-8 units/acre) after each grazing from May to August.
    • If you have substantial levels of clover in paddocks you will not be using any nitrogen for the remainder of the year. But apply one bag 0:7:30 after every second grazing.


  • A second cut of silage is almost certainly required on all reasonably stocked farms.
    • According to Teagasc, silage reserves on farms are at their lowest in years and we need to make silage for a 4.5 to seven-month winter.
  • By stocking cows at 3.6cows/ha, calves at 14/ha and replacements at 2,200kg/ha the remainder of the farm should be closed up for silage.
  • For second cut, use 70-80 units of N, 14 units P and 60 units K and 10 units S per acre but make allowances for nutrients in slurry.
    • Each 1,000 gallons has 5 units of N, 5 units P, and 30 units K.
  • Get the silage contractor to cut from the centre of the field out so as to allow wildlife and young pheasants to escape.
  • Silage preservation and quality has disimproved during the last few years.
    • If silage needs an additive that preserves it, use it.
    • You need a preservative when sugars are low due to excess moisture (rain) or very lush high-quality grass.
    • If you can cut in dry conditions, tedding and wilting also helps, and you definitely need no additive.
    • As the quality of our silage has slipped over the last few years, we must improve the quality by cutting earlier (a few days makes all the difference) and don’t wait for bulk. 
  • You must get your silage contractor to cut low, definitely no higher than 3.5cm off the ground.
    • Otherwise, you will have poor quality aftergrass from these fields later.
  • You must collect all silage effluent in your tank.
    • Don’t take for granted that this is happening but ensure that it is.
    • Fish kills are high risk and the consequences are very serious for the offending farmer.
  • Apply 40-50 units/acre of nitrogen for after-grass grazing.


  • You must know target weights so that you can make sure animals achieve the correct weight at calving down. The following are June 1 targets:


    • The cows’ mature weight is got by weighing third calvers and older cows in June – worth doing NOW. Or if the herd’s maintenance is €20, then the herd will average 541kg/cow. Every €10 difference from this changes the cow’s weight by 50kg. 
    • You must weigh replacements regularly to make sure you know what’s happening and, therefore, deal with underweight animals. This advice is imperative for contract heifer rearers/farmers with heifers on contract so that no disputes occur later in the year.
  • Calf (R1s) stage:
    • Calves must always on the best grass, with residuals eaten off by the R2s or cows. As well as best grass, there are fewer parasites high up on the grass plant. 
    • Small calves would benefit from milk and/or meals in June.
    • Big calves on good grass require no meals as the economics is poor.
    • Stay on top of parasites such as hoose and stomach worms. Dose for hoose when oldest calf starts to cough and dose for stomach worms, if not on the ivermectin programmes, with a white/yellow dose in late June and move onto aftergrass.
  • Heifer(R2s) stage: 
    • Heifers mated after June 12 will calve down after March 22 – it is getting very late to start calving heifers into a herd. If she hasn’t ‘held’ by now there is something wrong with her.
    • Underweight heifers may need to be separated out and run with calves on best grass or fed 1-2kg meal separately.


  • An 8t/ha crop of kale will be the cheapest source of feed next winter.
    • It is 80% DMD, as good as barley. 
    • It and fodder beet will cost less than €1/day to feed a cow next winter. 
    • The expected yield is 8-12t DM/ha with early June sowing.
    • With a 10t average crop and allocating 4kg and 7.5kg respectively to weanlings and cows per day (with another roughage), the crop will feed 40 weanlings or 20 cows for 60 days.
    • The weanlings and cows will gain 0.6kg and 0.25kg respectively per day.
    • Sow where fields need to be reseeded or after first cut silage.
  • Requirements:
    • Sow in early June – thereafter, 1t/ha/week DM is lost.
    • A fine, firm seed bed is essential.
    • Seed can be drilled or broadcast (need higher seeding rate) at 4.5-5kg/ha.
    • Sow kale once per five years in same field to avoid clubroot.
    • You need a soil pH of 6.5-7.0
    • Nitrogen: It needs 100kg/ha (80 units/acre) split in two applications, the second one at the two to three leaf stage.
    • For a soil index 3, per hectare (kg) apply 30 P (24 units/acre) and 170 K(140 units/acre) at sowing. Poorer soils require more.
    • Watch out for pests as the crop develops.
    • There should be a run-back area available to the animals during feeding.
    • Strategically place round bales of silage in the field, near headlands, when the crop is being sown.

Bits and pieces

The IBR annual vaccine may be due in June/July.
Test the milking machine now and change liners at 2,000 milkings.


“When your values are clear to you, making decisions comes easier.”