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Eamon & Donnchadh McCarthy May Update

Breeding season

Breeding season

  • Target 90% of breeding heifers and cows served in first 3 weeks of breeding season
  • Heat detection is very important
  • Set scanning dates to identify cows/heifers not in calf and plan to offload them
Grass management

Grass management

  • Monitor grass growth to determine if extra chemical/organic fertiliser is required
  • Walk silage ground to help decide cutting dates
  • Dividing bigger fields into paddocks will help to reduce labour during the breeding season and improve grass utilisation
Monitoring animal performance

Monitoring animal performance

  • Continue to weigh under 16 month bulls regularly, watch fat cover and check birth dates to draft them for slaughter as they come fit
  • Weigh younger stock to see how they are performing at grass
  • If any cattle that were turned out early are below their target ADG, check them for signs of coughing or scouring in case they require dosing


40/40 cows and heifers are now bred since breeding started on 1st May. 3 cows have repeated to date and were served again. Breeding will continue for 6 weeks and will finish on 12th June.

The cows will be scanned 4 weeks after breeding finishes (~10th July). Any cows not in calf will be sent to the factory after weaning and any barren heifers will be finished. Three have been selected for culling due to mastitis, abortion and poor calf docility/poor feet.



Eamon measured grass on 26th May and had an average farm cover of 853 kg DM/ha. The growth rate had dropped to 36 kg DM/ha since 19th May and the demand was 56 kg DM/ha, with 15 days of grass ahead. Eamon was aware that the grass growth was reducing on the farm and spread 1 bag of 18-6-12 per acre. The forecasted heat will hopefully help growth rates to improve, but the grass on the farm is visibly stressed from the weather as the leaf blades are after turning purple.

The McCarthys plan to cut silage on the farm this weekend. The older grasses in the sward are just starting to head out so they are expecting that it will come in at over 70% DMD for winter feeding.

One 3ha paddock was divided into 3 x 1ha paddocks on the farm. One ha paddocks are the ideal size for 40 cows, 40 calves are 20 heifers to spend approximately 1.5 days grazing. The paddocks were fenced with permanent stakes and wire, and two new water troughs were purchased which were located in the centre of the paddocks so that they can be subdivided at a later stage if required. As water piping was laid along a new boundary, approximately 200 metres of piping was required just to reach the field from the farmyard which was an extra expense, and one inch piping was used. The water fittings purchased are fast flow systems. The total costs are outlined below which amount to approximately €174.63/acre. The remainder of the roll of wire will be used to subdivide more paddocks at a later date.

As Eamon has been measuring grass for the last number of years, he will be able to compare how much grass the paddock grew as a 3ha block, versus as 3 separate divisions. Traditionally, cattle would have spent 5 to 7 days grazing the entire block which would have affected re-growths. It will also give Eamon and Donnchadh extra options if paddocks need to be taken out for silage and allows it easier to manage cows during the breeding season as the paddocks are smaller to get them out of.

By protecting grass regrowth it is estimated that the divisions will allow an extra 5 days grass growth at approximately 32 kg DM/ha/day (average grass growth in 2021) which amounts to an extra 160 kg DM/ha. The field was grazed nine times in 2021 which would amount to an extra 1440 kg DM/ha grown. At a value of €105/ha for every extra tonne of grass grown on a drystock farm, this is worth €151.20/ha/year (€453.60 total/year) to Eamon and Donnchadh, excluding the labour saving when moving cattle.

ItemNo. of unitsUnit cost (€)Total
1" water piping 3 174.19 + 175.61 + 175 +174.89 €699.69
Water fittings   94 + 160.66 + 67.11 €321.77
Fencing items   21.15 €21.15
75 gallon concrete water trough 2 140.70 €281.40
5ft3" stakes 24 4.17 €100.08
6ft4" stakes 12 7.12 €85.44
Roll of wire 1 82.15 €82.15
Total     €1591.68
Minus VAT reclaim     €297.64
Net cost for 3ha / 7.41 acres    





Three U16 month bulls were slaughtered on 4th May. They averaged a carcass weight of 402kg at an average grade of U-3=, making €2069/head at 14.6 months of age.

The remaining finishing bulls (11) averaged 635kg on 21st May (range 535 – 710kg). They gained 1.55kg/day since 21st May, although 3 bulls that were moved from straw to slats only averaged 0.76 kg/day.

The 2020 autumn born heifers (3) were weighed on 22nd May. They gained 0.9 kg/day since the 23rd April and averaged 496kg.

Some of the 2021 spring heifers (4) were weighed on 22nd May. They gained 0.71 kg/day since 23rd April and averaged 426kg.

The 2021 autumn born heifers (12) weighed 312kg on 22nd May, with an ADG of 0.87kg/day since 23rd April