A move to rotational grazing a decade ago is paying dividends for Scottish milk producer, Jim Baird. It has permitted a 25 per cent rise in cow numbers on the same acreage, while yields have increased by 30 per cent over the period. Wendy Short reports.
It takes a degree of confidence to take a leap into the unknown and move to rotational grazing from a set-stocking system, says Mr Baird, who farms Nether Affleck, near Lanark, in partnership with his wife Joyce.
The holding has been in the family since the early 1960s, with the 230-cow crossbred autumn calving herd currently yielding 8,200kgs at 4.09 per cent butterfat and 3.34 per cent protein.
The new grazing system has brought forward turnout by about three weeks, as well as offering a degree of protection from the rising cost of bought-in concentrates.
It has maximised milk from forage, with a latest rolling average of 5,410 litres and a concentrate cost of 6.2ppl.
The figure for purchased concentrate per cow has increased only minimally and fertiliser usage has remained virtually unchanged. Silage requirement has also been reduced due to the extended grazing season, adds Mr Baird.
The move to rotational grazing was inspired by Mr Baird’s entrepreneurial Nuffield farming scholarship, which was not linked to grazing systems but which prompted him to rethink his management plan.
It was achieved over one season and supported by advice from dairy consultants, Tom Rawson and Oliver Hall. And an estimated total of £10,000 has been invested in cow tracks, troughs and fencing material.
Mr Baird says: “It is essential to have the correct infrastructure for rotational grazing. One important element is the second-hand Astroturf, which sits on top of the stone tracks.
“It is cheap, extremely hard-wearing and requires minimal maintenance, giving grazing access to about 80 per cent of the farm.
“Another bonus is that Astroturf is kind to the cows’ feet. The herd previously came in and out for milking through one gate and the area suffered heavy poaching. There are now multiple entry points, so the pressure on access tracks has been greatly reduced and lameness is kept to a minimum.”
The cows are run as one group and go out on to fields of roughly 6 hectares (15 acres), divided by electric fencing. Turnout for the herd, which has a calving index of 360 days, is usually about April 10 and the cows are housed after calving, which starts on October 1.
The cross-breeding system aims to produce a robust cow which ’wants to graze grass,’ he says, and fertility is bred in by limiting heifer replacement production to females in the first six weeks of the breeding cycle. The pattern is followed by service with Aberdeen-Angus semen and any animal which has not calved by the end of the year is removed from the herd.
The basic grazing principle uses a strip system, with the cows turned out on to grass at 3,000kg of dry matter/ha and removed when the figure is halved. In practice, this means moving the herd about every 12 hours in the larger areas. The grazing land receives 25kgs/ha of nitrogen after each grazing.
There is minimal need to supplement grazing cattle, as they always have high quality grass in front of them, says Mr Baird. The general routine is to bring the herd in at 2pm and allow the cows access to the summer total mixed ration (TMR) comprising concentrates, brewers’ grains and straw or hay in a bunker.
They spend an hour eating prior to the afternoon milking, as there is no facility for in-parlour feeding. Mr Baird has observed that excess silage consumption can affect grazed grass consumption, but brewers’ grains and straw do not appear to have the same effect.
He says: “The most challenging element of rotational grazing is making sure that the cows graze down before being moved to the next strip.
“The method maintains grass quality and prevents the growth of stemmy material that will be rejected and lead to wastage. Obviously the area is heavily stocked for a short while, but it then has three weeks to recover.
“It will almost get to the point where the cows are bellowing for more food, but if they are moved too early they become lazy and will not eat down to the desired level. Nevertheless, the results will be visible in the bulk tank, if they are left for too long,” he adds.
Correct grazing management is crucial, but the production of top quality silage also plays a vital role in making the system a success, he says.
The farm has a loose policy of alternating grazing and silage areas annually and this has helped to prevent the cutting fields from becoming ’tender’.
Historically, two to three cuts of silage were taken annually but over the past five years the number of cuts has increased to four.
The farm has its own silage-making kit, which enhances timeliness of operation, although a contractor will be brought in if necessary. An inoculant additive is only applied to the final cut if the weather is challenging.
Slurry from the cubicle housing system is applied via a dribble bar and umbilical system and the silage fields receive a percentage following each cut, with a tanker used on the grazing land during the turnout period.
Meanwhile, farmyard manure is stored under cover and turned three times over the summer.
The compost is enormously beneficial, especially for any under-performing fields, says Mr Baird.
The ground also receives 50kg nitrogen/ha after each cut; applications have been reduced over the years with no detrimental effect on grass quality or quantity.
Over-seeding was practised with mixed results in 2020.
Mr Baird says: “An area which had been grazed hard was over-seeded to coincide with a damp spell in June. Germination was good and the cows were turned in three weeks later, but the new growth suffered somewhat. It is a dilemma, because the system relies on grass being grazed on a tight turnaround regime and strips cannot be left untouched for long periods.
“The silage fields have also been over-seeded, but again this was only partially successful. I think the new seedlings struggled to compete with the existing sward, although it is not easy to evaluate the results. Re-seeding has been carried out on another block with a mix containing plantain and chicory – these species help to improve soil structure and are highly palatable for the cows.”
The winter feeding system uses a TMR based on grass silage, brewers’ grains and straw, with hay also fed in the winter and concentrates added to the mix. This policy produces a margin over concentrate per litre of 21.55p and a margin over purchased feed per litre of 19.18p.
The farm has always made ’decent silage’ but the grazing management did require some attention, says Mr Baird.
“I feel that great strides have been made, but the process is ongoing and there is definitely still room for improvement. It is difficult to precisely quantify the benefits that rotational grazing has brought, but there have been definite financial advantages. In fact, my father, Jim, practised it many years ago and like many aspects of farming, the policy has come full circle.
“Additional re-seeding will be carried out in the coming season, but the technique needs to be refined. However the cows are producing more milk than I would ever have believed possible a decade ago. The plan is to go up to 240-250 cows over the next couple of years and that will mean keeping up the pressure on high quality grass production,” says Mr Baird.
Nether Affleck was one of the farms intended to be featured in the British Grassland Society farm walks this spring however it has been cancelled due to Covid-19.