Pushing for growth from the ground up at Shane’s Castle

Date published: 22 May 2023

Grass is still the key ingredient for the herd at Shanes Castle estate just outside Randalstown in Co Antrim. Its value, in terms of being extremely digestible and high in crude protein, is why it is regarded as the highest quality feed on the farm.

Richard Gibson, CAFRE dairying adviser.

The team at Shane’s Castle recognise this and have been making headway in the past few years improving growth and utilisation of grass on the farm. They have set clear objectives to improve grazing management and soil fertility. Measurement is central on the farm with grass measured weekly and soils sampled every year to build an accurate picture of the farm.

Shane’s Castle is home to a herd of 200 autumn calving Holstein cows managed by a two man team, Andrew Hamill and Chris Gamble. They have implemented a variety of practices in recent years to not only make better use of grazed grass on the farm but also increase production of grass with a ‘ground up’ approach starting with soil fertility.

At a recent CAFRE Business Development Group meeting held on the farm, CAFRE dairying adviser Richard Gibson highlighted the practises implemented on the farm along with the progress Andrew and Chris have made. The importance of sampling the whole farm regularly rather than a few paddocks was one of the starting points. Gradually over the past two years the information from the soil fertility testing has been used to improve soil fertility with 55% of the farm now optimal for growing grass, this is a significant improvement with still more room for improvement. Early grazing and the basic management of grazing techniques was also mentioned as relevant, with on/off grazing and good farm laneways used to get cows out early to grass another key part of the plan on the farm. Shane’s Castle improvement plan is based on the following points:

  1. Use the soil analysis

Soil sample reports with phosphorous (P), potassium (K), and pH will provide sufficient information to calculate what nutrients need to be added to gain sufficient grass growth. The target for soil P and K is index 2+. Replacing nutrients removed by grazing or harvesting grass to maintain an index of 2+ will ensure optimum growing conditions for the grass plant. Soils at index 1 and 2 for P and K have a lower nutrient supply and therefore require additional nutrients every year to reach soil index 2+. Research conducted by AFBI and other research centres has shown that soils at index 2+ for P and K can produce an extra 1.5t /ha of grass dry matter over soils with index 1 for these nutrients. This is equivalent to 15% more grass production on many farms across the country, which can represent a significant saving in concentrate costs on farms if this grass is utilised correctly.

  1. Reseeding policy

The staff on the farm emphasised the importance of regular reseeding for increasing grass yields on the farm. When questioned on the seed variety, they had a clear picture of the grazing variety and silage choice. Both seed mixtures had only four seed varieties which have been tried and tested to work well on the farm soil type. Much of the additional yield and quality from a reseed is driven by an improved response to applied nutrients. The varieties used all had a similar mid-late heading date.

  1. Limiting chemical nitrogen purchases

Clover was mentioned as an option, but the team would like to improve soil fertility before introducing any clover on the farm, especially soil pH. Tackling the weed burden across the farm in both silage and grazing swards is also a priority. While clover is not in the sward currently both Andrew and Chris would like to introduce clover to reduce purchased chemical nitrogen. The team have just introduced a break crop of wheat this year for whole-crop forage, the intention is to implement this rotation to control weeds and establish clover in the subsequent reseed.

  1. Manage calving profile to hit the grass early

Herd fertility has always been a challenge on this farm, calving was spread over most of the year. The team have compacted the calving into 16 weeks, ending in early January. Cows must be back in calve before turnout in early March. It is a heavy farm with a high rainfall in this area, and while additional laneways have been introduced, more could be done to help improve the grazing especially in early season. Being an autumn calving herd, there is a high grass demand when conditions allow cows out, and the herd milk well on the early grass. The team have culled hard over the past three years to help achieve the more compact profile, however the benefits well outweigh the cost of this approach.

  1. Going for forage quality at Shane’s Castle

With a herd average of around 9300l/cow, forage quality is also a vital aspect for the system at Shane’s Castle. Nutritional quality is principally governed by grass digestibility (D-value), which starts to fall with the onset of stem formation and heading. Do not be tempted to sacrifice quality for quantity by delaying harvest. Cutting date is critical to the quality of second and subsequent cuts. At the Castle, Andrew and Chris are moving towards a multi- cut system with 3 to 4 cuts taken each year with the potential of also getting a grazing of this area. Grass silage can only be as good as the sward from which it is made. In a similar way grazing management at Shanes Castle is focused on grass quality, the silage-making process is centred on producing and utilising sufficient, high-quality forage.

Shane’s Castle Dairy Herd 2023

Cow in herd


Annual Milk yield (l/cow)


Concentrate (kgs/cow)


Young stock replacements

0-1 yrs – 85 head & 1-2 yrs – 90 head

Calving start date

1st September

Calving end date

31st December

Turn out date

Mid-March – (on/off grazing)

Housed date

20th October

Breeding start date

1st January

Number weeks breeding

16 weeks

Calving interval

381 days

% farm optimal for grass growth (pH 6.2, P 2+, & K 2+)


Challenging start to grazing 2023 for the team at Shane’s Castle

Challenging conditions during March prevented cows going out to grass as normal, with any limited grazing resulting in paddock damage. April and the start of May have been more of the same. Nitrogen was sown early on and so grass growth has been good. With better weather this week, grass is being utilised well.

Measuring tools like Agrinet, used by the Shane’s Castle staff for the weekly grass walk allows for a grazing plan for the farm. This coupled with the improvements in soil fertility, grass growth and basic infrastructure have improved production on the farm and built resilience for the business. Andrew and Chris have been able to improve farm output through better herd fertility, while at the same time reduce concentrate feed purchased and replace this with grass.

Notes to editors: 

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  2. All media queries should be directed to the DAERA Press Office: pressoffice.group@daera-ni.gov.uk

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