Review of the CAFRE Dairy Herd Grazing Season 2021

Date published: 08 July 2021

Managing grass growth and the resulting covers for the CAFRE dairy herd has posed various challenges as it has for many dairy herds in Northern Ireland this year.

Robert Patterson, CAFRE Dairy Technologist, measures grass growth on the Greenmount grazing platform.

College of Agriculture, Food and Rural Enterprise (CAFRE) Dairying Technologist, Robert Patterson found that: “following a slow start, grass growth then quickly turned around over a short period, peaking with a daily growth of 124 Kg DM/ha in late May.”

The following article summarises a review the performance of the CAFRE dairy herd at grass with CAFRE Assistant Farm Manager, Jim Fulton, and describes how the various challenges were addressed.

Just over 40 cows were turned out for a few hours on-off grazing by day on the 26th February. This group of cows was doubled around St Patrick’s Day and increased weekly thereafter. Part time grazing by day of higher yielding cows started on the first week of April.  Full time grazing of the late lactation group of cows started on 12th May and all cows in the herd were full time grazing with no buffer feed inclusion by the end of May.

Grass growth on the grazing platform for the CAFRE dairy herd is measured on a weekly basis. The Agrinet grass budgeting programme is used to make accurate decisions on grass allocation, based on grass growth, grass demand and grazing area available.

As of 24th June, the herd had a grazing demand of 58 Kg DM/ha day, a grass growth for the week previous of 52 kg DM/ha and an average farm cover of 2,606 kg DM/ha. The grazing platform at this time was stocked at 3.62 livestock units/ ha and cows were being allocated 16 kg DM per day. This is the first time since late April when demand has been greater than grass growth.

Some rainfall was recorded on 17th and 24th June, which helped to replenish soil moisture levels and boosted grass growth. However Jim felt that if grass demand continued to exceed growth at this stage of the season, that he has three options available to address this; round bales made from surplus grazing grass earlier in the season could be buffer fed to the cows, an area of third cut silage could be brought into the grazing rotation and/or considerations made to dry some cows off early.

Grass quality has remained high throughout the season so far, which has been evidenced in milk protein levels, remaining consistently around 3.49%. Grass samples are taken weekly and analysed using a hand held NIRS machine. Results to date show that paddock grazed grass has had an average metabolisable energy (ME) content of 11.8 MJ/kg DM and an average crude protein (CP) content of 21.2 % DM.

To maintain grass quality in the early season, the second grazing round and part of the third was pre-mowed ahead of the cows. This was due to some unsatisfactorily high grazing residuals in the first rotation, due to poor grazing conditions. Pre mowing will be carried out in the next grazing rotation to manage manure patches, maintain grass quality and maximise intakes.

Surplus grass was removed from the grazing platform as round bales on two occasions so far, due to the high spike in grass growth in late May. Some land which was harvested for first cut silage and laterally for second cut silage has been added to the grazing platform, which has provided more flexibility for removing various paddocks as bales when a surplus arises. Fertiliser is sown weekly, with each grazing rotation receiving 70kg/ha of protected urea.

Currently, cows and heifers are fed to yield in the parlour, with the feed system set at maintenance + value of 20 and 18 litres respectively. Cows and heifers are fed at 0.45 kg feed rate for each litre above maintenance+. The maintenance+ value is assessed and adjusted on a weekly basis, based on grass quality, cow body condition scores and grazing conditions.

The breeding season was completed on 13th June, when the bull was removed. Most cows are now well settled into calf, with the first 15 cows due to be dried off on the 30th July. The cows are body conditioned scored monthly, to allow corrective action to be taken if required, to achieve the correct body condition at drying off. 

Work also continues to develop the grazing infrastructure on the farm.  Cow lanes are renovated on an annual basis to minimise hoof damage during grazing and new water troughs were installed to increase water access for cows. Additionally, a water bowser has also been used this season to improve water access and combat water pressure issues in warm weather.

Now is an excellent opportunity to review the grazing system on your own dairy farm. Discuss current grazing management with your local CAFRE Dairy Development Adviser and within the dairying Business Development Groups (BDG’s) this summer.

Notes to editors: 

  1. Follow DAERA on Twitter and Facebook.
  2. All media queries should be directed to the DAERA Press Office.

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