January 2021 Monthly Management

Spring Fertiliser; Colostrum Quality; Grass and Grazing Review 2020

22 January 2021

Spring Fertiliser

Spring Fertiliser

The timing and rate of fertiliser will depend on many factors such as location, soil conditions, temperature, and length of growing season.

  • Check forecast and ensure at least 48 hours reasonable weather after application (i.e. rainfall less than 10mm will help urea move into the soil and reduce nitrogen losses through volatilisation).
  • Aim to apply 23 units of nitrogen/acre in the first application when conditions allow.
  • Urea is safer than ammonium nitrate-based fertilisers (i.e. C.A.N.) for early applications because there will be less nitrate-N, which is prone to leaching, in the soil.
  • Wait at least 3 months after liming before applying Urea.
  • Wait 10 days after slurry application before applying Urea.
  • Target most productive swards/recently reseeded fields with early nitrogen to get the best response.

Cattle slurry is a valuable source of N, P & K and performs best when applied in optimum conditions in the spring.

  • Aim to spread on fields with the lowest grass covers or paddocks that you do not intend on grazing within the next six weeks.
  • 1,000 gallons of cattle slurry equates to approx. the same value of one bag of 5-7-30.
  • Focus on low P and K soils with slurry before or after the first grazing round to maximise the efficiency of slurry nutrients.
  • If ground conditions allow, target 30% of the farm with slurry and the remainder with at least 23 units of nitrogen.

Colostrum Quality

Colostrum Quality

With calving season soon approaching, it is worth reminding ourselves of the importance of colostrum. When born, the calf’s immune system is not fully developed, and the calf depends on the immunity provided by the antibodies in colostrum for protection against disease. The level of antibodies is highest in the first milking and drops significantly in the second and third milking.

Milking Number
1 2 3 11
Colostrum Transition milk Whole milk
Total Solids, % 23.9 17.9 14.1 12.5
Fat, % 6.7 5.4 3.9 3.9
Protein, % 14 8.4 5.1 3.1
Antibodies, % 6 4.2 2.4 0.09
Minerals, % 1.11 0.95 0.87 0.74
Vitamin, ug/dL 295 190 113 31

Antibodies are absorbed through the calf’s intestinal wall reduce dramatically over the first 24 hours of life. Therefore, it is vital that all newborn calves receive colostrum shortly after birth.

Time Ig Absorption in the Calf
Within 2 Hours Highest
After 6 hours Reduced by 50%
After 12 hours Reduced by 75%

The 1,2,3 rule should always apply – first milking, within 2 hours and 3 litres to be fed.

Grass and Grazing Review 2020

The potential to achieve high levels of productivity from grazed grass gives Irish farmers a major competitive advantage over many of their European and global counterparts. Research has proven this competitive advantage by showing the following:

  • Increasing the proportion of grazed grass in the diet of a dairy cow by 10% reduces costs of production by 2.5 cent/litre (Teagasc, 2011).
  • Increasing grazing season length by 30 days will reduce costs of production by 1 cent/litre (Teagasc, 2015).

By adopting correct grassland management techniques, milk producers can ensure that they are exploiting the full potential of grazed grass on their farm, irrespective of production system or land type.

Grassland Management Techniques

Some of the best tools applied on farm to ensure the optimum level of grazed grass in the diet is achieved include:

  • Regular grass walking
  • Spring and Autumn rotation planner
  • On/off grazing during periods of challenging weather
  • Soil testing
  • Appropriate use of fertilisers
  • Regular reseeding protocol

To emphasize the benefits of successful grassland management and utilization, Drinagh have been collaborating with Teagasc and local milk suppliers in the management notes of the monthly newsletter. These farms are spread across the Drinagh catchment area with many factors differing across each production system, i.e. land type, cow type, feed supplementation and herd size. One common trait between all farms is that grazed grass acts as the cornerstone of each enterprise. Each month, one farmer generously offered their take on the grassland management practices applied on their own farms.

Following the completion of the 2020 grazing year, some of the key performance indicators from the sample farms is illustrated on table 1. It is clear to see from the data supplied, that with correct grassland management applied to a dairy enterprise, rewarding results can be achieved. In particular, kgs of milk solids per cow produced. On average, these farms produced over 100 kgs of milk solids above the Drinagh average – 392kg/MS/cow (ICBF).

Contributor Farms 2020 Results

Tons of Grass Grown 11 tonnes DM/hectare
No. of Grass Walks 20 walks
No. of Grazings/Paddock 8 grazings
Kgs of Milk Solids per
cow (sold)
495kg per cow
Soil Sampling All farms between
2020 &2021
Reseeding 7.5% of the milking
Low Emission Slurry
Spreading (Less)
All using low emission
slurry spreading
First Round Fertiliser for
23 units of urea
Opening Grass Cover 1,000 kg/DM/Ha

Grass and Grazing Review 2020

We wish to express our gratitude to all the Drinagh milk suppliers that helped in the assembly of the Grass and Grazing articles throughout 2020: Lawrence Hallihane, William O’Donovan, John O’Mahony, Gearoid Murphy, Ivor Deane, Sam Kingston, Charles Hegarty and Kieran Keane. Also, to Teagasc West Cork Advisors – Pauline O’Driscoll, Aoife Healy, Don Crowley and Matthew Ryan who aided in gathering information from the monitor farms.

If anyone would wish to express interest in featuring in these articles for 2021, please feel free to contact any member of the Agricultural Advisory staff in Drinagh.