The benefits of grass measuring were highlighted at recent GrassCheck dairy farm walks held on the farms of Joe Cush and Harold Johnston organised by AFBI, AgriSearch and CAFRE.

The two farms are part of a group of 20 dairy farms in the GrassCheck project measuring grass across the province. Both farmers place a strong emphasis on grassland management within their respective dairy systems and highlighted to farmers in attendance the many benefits they see from grass measuring.

Joe Cush farms a herd of 70 Holstein-Friesian cows in Pomeroy, County Tyrone. The herd has an average milk yield of 7,000 litres per cow, with 3,429 litres/cow/year coming from forage. The 150ac farm focuses strongly on grassland management. Joe commented at the event “I have been measuring grass for the past four years and find it an essential tool when making grazing decisions.”

Joe Cush speaking at the GrassCheck Dairy Farm Walk on his farm at Pomeroy. Photograph: Columba O'Hare/

In 2018, Joe grew 11.7t dry matter per hectare (DM/ha). Joe commented “ I take a flexible approach to grazing on my heavy ground. In first rotation, I don’t focus heavily on achieving low post grazing residuals as ground conditions are often soft, however I make sure on the second rotation to clean out swards to 1500-1600 kg DM/ha in order to maintain grass quality.”

Typically, Joe aims for a pre-grazing cover of 2,800 kg DM/Ha and rotates cows around the platform, targeting drier paddocks when ground conditions are wet. At the event farmers heard about reseeding activity on the farm with Joe commenting  “I select the poorest performing paddocks each year for reseeding and tend to select diploids grass varieties with good yields and ground cover.”

Harold Johnston who farms with his sons Jack and Mark in Ahoghill, County Antrim hosted the second GrassCheck farm walk and grew 12.6t DM/ha in 2018. The farm runs 270 autumn-winter calving Holstein-Friesian cows averaging 9,000 litres/cow/year, with 2,600 litres/cow/year coming from forage.

Harold Johnston with his sons Jack and Steven speaking at the GrassCheck Dairy Farm Walk on his farm.

Focus on soil fertility has been central to achieving good grass production on the Johnston’s farm, with 89.5% of the farm’s soils at or above a pH 6 and a similar proportion at Index 2 or above for P and K. The family find grass measuring essential to capturing valuable data on each field, improving grass utilisation and reducing feed costs. Harold also commented ‘‘Measuring weekly gives us more confidence in our decisions and we use the data to plan our grazing and earmark underperforming grazing fields for reseeding”.

 For part of the grazing season, the high yielding herd is turned into pre-mowed paddocks which helps maintain grass quality and intakes while maintenance-plus values are reviewed daily and altered as necessary to balance cow nutrition for optimising cow performance and grazing efficiency on the farm.

At both events farmers heard about the practical day to day grazing decisions made on both farms including target pre and post grazing covers, grass allocation, grass variety selection and fertiliser applications. A copy of the farm walk handout for each event can be downloaded from the AFBI and AgriSearch websites and videos of the talks given on the day can be viewed via the GrassCheck Facebook page.

Joe Cush, centre, pictured at the GrassCheck Dairy Farm Walk on his farm at Pomeroy. Also included are from left: Jessica Pollock, AFBI PhD student; Jason Rankin, AgriSearch; Debbie McConnell, AFBI; Francis Lively, AFBI; Elizabeth Earle, AgriSearch and Kathryn Huson, Dairy Scientist, AFBI. Photograph: Columba O'Hare/