How new lagoon will drive silage quality and milk from forage

A major slurry lagoon project is a Lanarkshire family farm’s next step in their organic journey.

Andrew Stewart, of Draffan Marshill, Kirkmuirhill, says the simplicity of organic farming, and the premium it attracts, have proved to be a significant advantage while he has been completing several renewables projects and a tourism diversification, alongside managing the farm.

Farmers Weekly asked Andrew, his parents, Hugh and Jeanie, and his wife, Jenni, what going organic has meant for their farming system. 

See also: How a farm vet team cut antibiotics use in calf castrations

Why go organic?

We always grazed for half the year, yielded 8,000 litres a cow like we do now and used lime and clover, so our system already suited organic farming.

After getting just 20p/litre in 2015 and 2016, we were keen to add value somehow.

The organic premium has been up to 12p/litre and as close as 5p/litre over conventional.

How did you manage the transition?

Importantly, Muller agreed to us producing organic milk. We transferred from conventional to their organic pool.

To ensure cows had enough forage, we sold month-old calves instead of 12-14-month-old stores.

We now have Wagyu-crosses going into Warrendale’s integrated scheme and sell other beef-crosses at Lanark, so it meant losing a 250-head store cattle cheque.

However, we had five years of conversion payments, which helped the business transition to organic.

Has it affected your output?

Our silage requirement is about 5,400t, which we have always managed to achieve.

We grow roughly 9.5t dry matter/ha now, which is 15% lower than before.

I only measure grass in the spring and autumn to budget covers and plan, so it’s an educated guess.

Did herd health plans change?

We use more vaccines, but I think we’d have done that anyway.

We use a Streptococcus uberis mastitis vaccine, which has brought good results, a colostrum booster for rotavirus, and a lungworm vaccine.

We have recently tried the new cryptosporidiosis vaccine for the calves, too.

Calves have faecal egg counts taken monthly from July to the end of the grazing season to monitor worm burdens. We worm less because of this.

Is it more work?

It just means one more inspection. We have Muller, Red Tractor and Soil Association inspections pretty much annually.

We’ve also gone from two to three silage cuts to three or four silage cuts to increase digestibility value, but we would have probably done that anyway.

How have your costs changed?

Savings are made on fertiliser costs and herbicide, but with organic parlour cake at £490/t, and blend at £540/t, driving milk from forage (MFF) is vital.

We fed 1.5t of cake a cow before and have continued since being organic.

Weed control is through silaging and rotational grazing on paddocks of 12-48 hours.

How do you plan to increase MFF?

We are building a 5m gallon lagoon in the middle of the farm, to which slurry from our 1.1m gallon slurry store will be pumped.

We aren’t in a nitrate vulnerable zone, we just feel it will help us target slurry when there is a crop need.

Alongside more frequents cuts of silage, this should mean slurry can be focused on spring cuts, hopefully lifting metabolisable energy (ME) and crude protein (CP) 1% each, to 12MJ ME/kg DM and 16% CP.

Currently, about 3,700 litres come from forage. Target yield is 9,000 litres with 4,000 litres from forage.