Part-time grazing a spring-calving herd

In an ideal scenario, all farmers would have a large grazing block surrounding their yard.

But in practice, everyone has to work with what they have and in the case of Armagh dairy farmer Josh Morton, a busy road is an additional complicating factor.

Josh milks 120 mainly cross-bred cows in a spring-calving system. The farm extends to 150 acres, with 70 acres in the main grazing block, 60 of which are on the wrong side of the road. The yard and 90 acres are farmed under a five-year lease agreement with a neighbour.

Josh returned home to NI in 2020 after working on farms in New Zealand, where he learned the skills to make the best use of grass. However, while he did graze cows full-time up until 2023, the decision was taken this year to switch to part-time grazing.

Cows are kept inside during the day, which means they only have to cross the road when it is quieter after evening milking and early in the morning.

With cows partially housed, there is an argument for moving towards a higher input, higher output system, however, Josh is reluctant to make any radical changes, given he is working on a short-term lease.

But after a wet spring and slow growth during June, he acknowledges that part-time grazing has helped make the system easier to operate.

“Last year I was always chasing grass. Litres from forage are down this year and there is around 2kg more meal being fed, but I have added a few cows, so overall production is slightly up,” he told farmers attending a Fane Valley event on the farm last Thursday.

Demand

With 120 cows grazing 50% of the time, they require 10kg DM per day of grass. To meet that demand requires daily growth of around 45kg DM/ha. If cows were out full-time this figure would stand at 60kgDM. Daily growth on the farm last week stood at 49kg DM/ha.

Josh is currently taking 14l of milk from forage, which is ahead of the 10l that other part-time grazing herds might typically achieve, suggested Fane Valley ruminant nutritionist, Laura McConnell.

When housed, cows are being offered first-cut round bales. Analysis is reasonably good (10.9ME, 33% DM) and probably ahead of many first-cut silages harvested this year.

Concentrate feed

Cold weather, resulting in a poor response to fertiliser, has also hit grass crude protein (CP) figures (as seen in GrassCheck data on page 4), so an 18% nut is being offered, said Laura.

She advised farmers who are full-time grazing to be realistic about the amount of grass DM cows are able to eat during changeable conditions.

Assuming the target is to get 15kg DM into cows, at 17% DM, it equates to 58kg of fresh material. If it is wet, grass DM might be closer to 12-13%, which requires cows to eat 80kg to 90kg of fresh grass.

“They can’t do that. On a wet day I would put in an extra 1kg in the parlour, or bring them in a bit earlier and offer them some silage,” she said.

Laura also pointed out that a maintenance allowance of 75MJ/cow should probably be increased to 85MJ/cow to allow for the energy expended walking to and from the paddocks.

Josh Morton has had his farm assessed as part of a new Forage Improvement Programme offered by Fane Valley.

Explaining the concept, Gary Spence from Fane Valley said it involves assessing the soil and the sward, ahead of putting in place a plan for improvement. Fields are scored from one to a top score of five. A sward reseeded within the last five years automatically gets a score of five. Paddocks on the Morton farm have a high average score of 3.9, however, some of the silage swards are in need of reseeding, leaving overall farm score at 3.5.

The starting point in any plan to improve a field is to correct soil pH, helping to ensure all nutrients are available for grass growth.

“Anything below 6.3, you are losing money because you are losing nutrient. Six is not high enough – at todays’ prices for 27:5:5 you are losing £15/t,” said Gary.

His advice is to aim for a pH of 6.5 and to spread lime in small and regular amounts. Where a granular product is used, every 50kg/acre will lift pH by 0.1.

Compaction

On many farms, soil compaction is an issue, especially close to gates. A sub-soiler can be used, but the soil must be very dry. It is best done later in the season to minimise impact on plant growth, suggested Gary.

“Don’t go out and subsoil unless you dig a hole first – a non-compacted soil will break apart easily,” he said.

Reseed

His advice to farmers is to reseed 10% of the farm each year. Josh sowed out a 13-acre field this spring with Killyleagh, which is a mix containing AberWolf, AberGain and AberZeus perennial ryegrass varieties. He also has 10-acres sown out in kale, with the plan to graze 35 in-calf heifers across this field from autumn to Christmas. The heifers are currently with a contract rearer.