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Michael & Niall Biggins May/June 2023 Update



  • Getting silage ground closed
  • Fertiliser Plan for silage
  • Sugar and Nitrogen test will be critical this year


  • Breeding Plan for 2023
  • Settling in the new CH bull
  • Plan to use AI on heifers


The Biggins’s start calving their 65 suckler cow herd at the beginning of February and the target is to have calving over in 10 weeks. The system is simple , selling the quality bulls in late Autumn and the weanlings heifers are kept for the first winter. The plan going forward is to keep the heifers until late spring or early summer where they will be sold off grass.

The weight of these heifers will have a major bearing on the price received . The overall target is have the heifers achieving at least 1/kg/day since birth . Weaning heifers  need high-quality 70%DMD +  silage to continue growing over the housed period; feeding  a poor-quality silage will result in additional concentrates being required to reach the target of 0.6kgs/day. For example, heifers receiving a 66% DMD will need an additional 2 kgs  plus of high-quality concentrate feed to maintain the growth levels required over the winter period. This adds to inputs costs which could be saved by making high quality silage.

With a spring calving herd , cows need to be in a “fit condition” calving at a body condition score of 2.5. Any score above that can lead to calving difficulties.  Feeding high quality silage to spring calving cows could lead to an increase in body condition so  they need to be  fed differently to the heifer weanlings on the farm. As a result, the plan is to make high quality silage for the weanlings by cutting 14 acres at the end of May. The remainder of the silage ground will be allowed to grow on until the first week of June. This will be lessor quality but will be ideal for the cows next winter. The second cut will also be kept for the cows.

Closing ground to cut at the end of May has been a real challenge this year. The wet March has meant delays in the application of fertiliser . The 14 acres acres earmarked for May silage has been grazed bare in February and 3000gals of slurry was applied in early April. To target cutting at the end of May, Michael & Niall have reduced the chemical nitrogen application to 54 units which was applied on the 15th of april. The slurry application will add another 27units of nitrogen/acre giving total N application of 81units per acre. As a rule of thumb , grass growth will use 2 units of N per day. So this crop should be safe to cut in 40 days from the date of application ie end of May.

Sugar and Nitrate Test

Before harvesting , the Biggins’s  check their sugar and nitrate levels each year. They feel that this test will be particularly important this year due to the later application of fertiliser.

Two important factors in getting a good preservation in silage are the sugar and nitrate levels in the grass at ensiling.

When ensiling silage the aim is to get the bacteria in the silage to convert the sugars available as quickly as possible to lactic acid to drop the pH of the silage to around 4, this is where the silage is stable. The higher the sugar content the more food for the bacteria the quicker the pH drops. The target sugar content to ensure good fermentation is 3% or higher. Before harvesting the crop Michael will bring a grass sample into his local  Teagasc office  and the grass will be  tested using a refractometer to determine the sugar levels.

 Another concern is possible high Nitrate levels in grass which can  increase the buffering capacity making it more difficult to get the pH level down.  The Nitrate will also be checked in the local office. If the nitrate test reading is high, the most likely cause is that not enough time has elapsed from the spreading date. In this case , cutting the crop may need to be delayed.

However, delaying harvesting the crop will have consequences as grass digestibility decreases by 2 to 3 % units per week from the second-half of May. This decline reflects the increasing proportion of stem in the grass plant as the crop matures, typically:

  • A leafy sward with little or no stem should typically give a 75-80 DMD silage
  • On the point of the seed head emerging i.e. some stem typically you should get 70-72 DMD
  • If the seed head is emerging/emerged silage quality will typically be less than 68 DMD

Teagasc work has shown if the  sugar levels is above 3% with some nitrate your preservation will be okay. To increase the sugar levels you can, cut in the afternoon/evening when the sugar levels have increased in the grass and wilt the silage to >28% DM to increase the sugar concentration, this will negate the effect of a high Nitrate reading. However if the sugar level is below 3% and the nitrate level is high it is  advised to wait until the sugar increases and the nitrate decreases.



The breeding season  started over the May bank holiday weekend . The cows and replacement heifers have been vaccinated for Lepto. Michael also gives them  all-trace bolus “Cosecure”  which will supplement the cows and heifers with copper, cobalt and selenium for over 6 months .

The herd will be split into 3 main groups

  • Mature cows with a CH stock bull
  • First calvers with easy calving CH bull
  • 15 replacement heifers – using AI

The mature cows run with a high value terminal bull out of Fiston . As the target market is selling high quality weanlings , the progeny need a very good shape and size. Therefore, this bull is not used on heifers as the calving difficulty is on the high side at 9%. Two important traits are caracase weight at 39.3kgs and carcase conformation at 2.34. The bull is 5 star for traits.

A new CH bull has been recently purchased for the second group . The bull is genotyped and is a 5 star terminal at €179 and has excellent  figures for carcase weight at 46.2kgs.  The calving difficulty is 7% which is more suitable for cows that will calve for a second time next year. After arriving, the bull has been settling in with 2 mature cows that have been identified for culling.

Replacements Heifers

There are 15 replacement heifers this year. They will all be calving at 24-26 months of age. This is a priority group of stock on the farm and will need to be averaging 400kgs at bulling time. Normally, Michael and Niall ran  an easy calving bull like a Saler but purchasing a bull for this number of heifers is not justified. The plan this year is to use AI using the following  simple synchronisation programme .

Using Ai will give the Biggins a choice of bulls that are genetically proven, with high reliability that  will further improve their replacements into the herd going forward.