DAIRY HERD COLLAPSE – WHY?

• A dramatic statement! Because, of a huge decrease in replacements:
  • Over 45,000 fewer dairy calves (R1s) registered this year.
  • The number of first-calved cows (R2s) recorded in 2025 is 29,000 fewer than in 2024.
• The consequences are:
  • National dairy herd is decreasing in size due to:
    • Lack of replacements.
    • TB issues which could take out 60,000 dairy animals.
    • Lower incomes for dairy farmers and less dairy product exported.
  • Fewer replacements being available in 2026 and 2027:
  • For sure, they will be a lot more expensive to purchase.
  • Lack of replacements for new entrants – have no doubt that new people will want to enter dairying.
• Is there a solution at this stage of the breeding season? Yes, there are a few options:
  • Bull all repeating cows with dairy AI.
  • Bull all repeating R2s with dairy AI.
    • AI small R2s because there will be demand for them next March and April.
    • Plan on very low cow culling this year by being very active on heat detection from now to breeding season end in mid-July. Get your vet to address any significant repeat issues, sooner rather than later.
  • Animals served up to June 18 will calve before the end of March next year.
  • Don’t use sexed semen because of lower conception rates and we don’t want the possibility of having later calving and/or more cull cows.
  • Scan all AI’d cows 30 days post-mating to make sure there are no false pregnancies – see below.

REPLACEMENT – TARGET WEIGHTS ARE CRITICAL!

• A reminder: pre-weaning weight gain is very important.
  • For every 100g increase in average daily gain (ADG) pre-weaning, first lactation milk yield increased by 155kg.
• 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 cow’s 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 weight per 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 both contract-reared heifers or home reared.

• Calf (R1s) stage – weaning to puberty:
  • Puberty in replacements arrives as follows:
    • 180kg for Jerseys.
    • 220kg for smaller Holstein-Friesian strains.
    • 280kg for larger Holstein-Friesian strains.
    • This will generally be two months before the first heat.
  • There is a strong body of research that suggests that an elevated level of ADG in this period has a negative impact on subsequent milk production. The reason for this negative impact on milk production is not totally clear but could be related to greater mammary fat pad development and/or more likely due to an advancement of puberty in heifers experiencing accelerated growth and as a result, heifers having a shorter phase of allometric growth and less total parenchymal yield.
  • Consequently, the period from weaning to puberty is NOT a desirable time to put in extra feeding that will elevate ADG above the following targets:
    • 0.63kg/day for a 500kg herd average weight.
    • 0.69kg/day for a 550kg herd average weight.
    • 0.74kg/day for a 600kg herd average weight.
  • Much of this period will include the indoor winter period, which provides an easy opportunity to put in extra feed to bring heifers that are below target back on track.
  • Exceeding the target ADGs for this period could have a negative effect on subsequent milk yield, so caution should be exercised on feeding strategy.
  • Calves must always be 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
  • Strong calves on good grass require no meals as the response is poor.
    • Response is 8:1 now versus 4:1 in autumn.
  • Stay on top of parasites such as hoose and stomach worms. Dose for hoose when the 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. But there will be a demand for late calving cows next spring.
  • Underweight heifers may need to be separated out and run with calves on best grass to ‘catch-up’.

AIM TO FINISH BREEDING IN JUNE!

• This year might be the exception to that advice.
• 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 for 2024 are worrying: calving interval = 385 days; six-week calving rate = 68% (very target of 90%); cows culled per year = 24% (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.
  • Collars are great but you must make use of the information.
• Minimise this problem by answering a few questions:
  • What % 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 web site 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. This 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.

Table 1: 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 at AI). Over 70% of repeat service must be between day 18 and 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! Table 2 highlights the issues associated with infertile cows compared with having a fertile cow:

Table 2: Physiological mechanisms responsible for greater fertility in fert+ cows compared with fert- cows. Source: Stephen Butler, Teagasc, Moorepark.

• Minerals may be a problem (could be iodine, copper, selenium, cobalt or phosphorous) – this is probably fourth of 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:
    • Bull all high EBI cows now with dairy AI and remainder with high DBI beef bulls.
  • Continue serious heat detection. This is 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 hrs after the onset of standing heat.
    • When a cow has been served, mark the cow’s shoulder, so as not to reserve her again the day after, as this can cause the loss of pregnancy as well as being an extra €15-20 in cost.
    • Repaint or put on the scratch card the day after service.
  • Scan all cows 30 days after mating:
    • This is very important this year and every year, for that matter!
    • Why? You will identify non-pregnant cows and weak pregnancies; therefore, with good records you can resynchronise/prostaglandin (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/week for three weeks, as follows, for a MSD (mating start date) of May 1:
      • June 6 (37days 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.
      • Computerised identification helps identify AI’d cows by week, but many farmers have them recorded in the breeding chart.
      • 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.

GRASS MANAGEMENT – A CRUCIAL PERIOD!

• Many farmers are coming out of near drought conditions with low farm covers:
  • Set a rotation length of 30 days by allocating one-thirtieth of the platform each day,
    • Opt out of this approach if and when grass growth has reached targets,
  • Supplement to bridge the gap by feeding 4-6kg in parlour and 3-4kg PKE in troughs in field, plus some silage,
  • If you have missed out on fertiliser N during the drought, make up the difference, if you haven’t done so since the rain arrived.
• For those of you in a ‘normal’ situation, the following management is suggested:
  • Depends on how well you have grazed out paddocks in May (most were grazed out well) but graze covers now that are appropriate to your stocking rate.
  • If badly grazed out, paddocks must be topped low to 4cm so as to set-up quality grass for next rotation.
    • This, unfortunately, will slow down regrowth and will delay the next grazing for 23-25 days.
  • The pre-grazing grass cover must not be greater than 1600kg 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 4cm, 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 one to two bales of this material for every cow 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 while AFC is below target, be careful before you take out the strong paddock.
  • Some farmers are pre-cutting strong paddocks to maximise utilisation.
• 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 availability 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 the 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, and pre-cutting, if PGC is too high but you need to graze because AFC is below target.
  • 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, 1,000 gallons (=1 bag 0:7:30) of slurry needs to be applied as they reduce nitrogen, phosphorous and potash availability.

• 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.

GRAZING TARGET FOR A SECOND CUT:

• A secind cut of silage is almost certainly required on all reasonably stocked farms.
  • Because first cut were light, 2nd-cuts will yield 7 -9 tons of pit silage per acre.
• By stocking cows at 3.4 to 3.6cows/ha, calves at 14/ha and replacements at 2000kgs weight per 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 10units S per acre; but make allowances for nutrients in slurry.
  • Each 1000 gallons has 5 units of N, 5 units P and 30 units K.
  • Apply the slurry immediately after cutting and the fertiliser a week later.
  • 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 3.5 cms 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 immediately after cutting for after-grass grazing.

CONSIDER SOWING KALE CROP NOW!

• If 2nd cut silages aren’t good, winterfeed could be tight:
  • 1st cuts were light, but quality will be super.
  • Consider a forage crop on ‘outside’ land to make up the deficit.
• An 8 ton/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 8-12 tons DM/ha from an early June sowing.
  • With a 10-ton average crop and allocating 4kg and 7.5 kg 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 0.25 kg respectively per day.
  • Sow where fields need to be reseeded or after 1st Cut silage.
• Requirements:
  • Sow in early June – thereafter, 1 ton/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 to 5 kg/ha
  • Sow kale once per 5 yrs in same field to avoid clubroot.
  • You need a soil pH of 6.5 7.0
  • Nitrogen: It needs 100kg/ha(80units/acre) split in two applications, the second one at the 2-3 leaf stage.
  • For a soil index 3, per hectare (kgs) apply 30 P (24 units/acr) and 170 K(140units/acr) 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 2000 milking’s;

Food for thought quotation:

“A good leader takes a little more than his share of the

blame, and a little less share of the credit”

Arnold H Glasow

IRISH FARMERS MONTHLY

IRISH FARMERS MONTHLY