Large-scale dairy farm working with renewables

Sustainable dairy farming was the main theme at Tuesday’s autumn meeting of the Ulster Grassland Society, hosted by Blakiston Houston Estates, Co Down.

The 800ac dairy unit supports a milk herd of 310 Holstein cows yielding 8,649l/cow/year from a total of 2.53t of concentrate per head, and also supplies feedstock for the estate’s anaerobic digestion (AD) plant.

In the dairy herd, milk from forage is a key focus, with calving running from early September to February in order to make use of grazed grass from spring through to autumn.

The herd is currently yielding 3,315l from a combination of grazed grass and conserved forage, approximately double the average dairy farm in NI.

Milk solids are 4.26% butterfat, 3.39% protein with SCC at 123 and Bactoscan of 31. Average milk price over the last 12 months was 28.57p/l with margin over purchased feed and forage of £1,713/cow.

Herd nutrition

Cows are managed in two groups based on yield. High-yielding cows are fed first-cut silage (11.3 ME, 70% D-Value, 15.2% protein) and a TMR of home grown wholecrop wheat, soya hulls, a protein balancer, minerals and yeast.

High-yielding cows are fed to maintenance plus 30l. Heifers are fed to maintenance plus 26l.

The low-yielding group is fed second-cut silage, wholecrop and the protein balancer with feed levels set at maintenance plus 22l.

Grazing

Cows go to grass by day from 1 April and resume full-time grazing once first-cut silage has been harvested in mid-May.

The grazing platform consists of 21 paddocks grazed in 24-hour allocations until October. Slurry produced on the farm passes through a separator.

The liquid part is applied to grazing paddocks after each grazing using a trailing shoe, and effectively replaces the need to spread chemical nitrogen.

Three bags/acre of CAN are applied to first-cut silage with 450 acres harvested. Second cut receives 22-0-14.

Parlour

Milking is done through a 24/48 swing-over parlour with feed to yield. Cows are EID-tagged and farm software records milk quality, yield, cell counts in the parlour. Animals pass through an auto-drafting race after each milking, and a footbath once per week.

Breeding

Breeding starts at the end of November with cows bred to AI. Heifers are served to a mix of sexed and conventional semen.

Angus, Hereford and Belgian Blue sires are used on late-calving animals. Heat detection is carried out using neck collars, with the herd calving interval at 391 days.

Calving

Calving starts at the beginning of September, with 164 cows calved to date. The target is to have 250 cows calved by Christmas every year.

There are 83 cows in the low-yielding group, with most to be dried off in the next few weeks. The target is to have just 24 animals to dry off post-Christmas.

All cows get an eight-week dry period, with antibiotics used to manage cow health at the end of each lactation. Select dry cow therapy is being considered for next year.

Fresh calved cows are currently averaging 35.2l/day with heifers averaging 31.4l daily.

Renewable energy

Renewable energy plays a huge role within the farm system. Three 75KW wind turbines, along with solar panels, supply 60% of energy used on the farm. Solar panels alone contribute £2,500 worth of power annually.

Boreholes and harvested rainwater supplies 90% of all water used, meaning just 10% of water use comes from mains supply.

Since the installation of the slurry separator, 600t of solid manure is now fed into the estate’s AD plant, replacing 450t of first-cut grass silage. Second and third cut silage is now used for the AD plant.