Rotational grazing was one of the main topics discussed at the recent Clyde monitor farm meeting at Carstairs Mains in South Lanarkshire.
Carstairs Mains is farmed by Andrew Baillie who runs the 650 acre (263 ha) unit which is one of the network of Quality Meat Scotland (QMS) monitor farms throughout Scotland.
Mr Baillie runs a herd of 75 spring calving suckler cows and a breeding ewe flock totalling 300, the majority of which are pedigree Beltex and Texel.
In mid-April, using a single strand electric fence, Mr Baillie had sectioned a 16 acre field into four, equal sized blocks, each with access to water. At the meeting, 25 cows and calves were grazing one of the four acre blocks.
Irish livestock farmers are becoming increasingly aware of the benefits of good grazing management and Aidan Murray and Adam Woods of Ireland’s “Better Farm” programme, outlined some of the main points for successful rotational grazing.
They reminded the community group that one of the crucial basics was to soil test to ensure pH is at the correct level to achieve optimum efficiency of N (Nitrogen), P (Phosphorus) and K (Potassium).
One of the fundamentals for good management of a rotational grazing venture is the confidence to accurately assess the amount of available kilos of dry matter per hectare of grazing.
Adam Woods outlined the basics regarding measurement of dry matter. “The rule of thumb is that for every centimetre of grass, there’s 250 kilos of dry matter per hectare.
“There are various measuring methods, including a plate meter which, when placed on the grass, assesses the kilos of dry matter. Some farmers use sward sticks, others have an ordinary walking stick with bands of tape round it at various measurements and the really confident paint lines on their wellingtons. Measurements should be taken in a variety of places within each grazing block.
“The ideal is to turn stock into a grazing block when grass is at 10 centimetres and to move them on when it’s down to four. That gives you six centimetres of grazing.”
With 250 kgs of dry matter per hectare for each centimetre to be grazed - six centimetres equates to 1,500 kgs of dry matter on each hectare for grazing.
“Grazing animals need two per cent of their body weight of dry matter per day,” explained Aidan Murray. “So the daily requirement for a 500 kg bullock is 10 kgs of dry matter.”
He added: “Preparation for spring and summer rotational grazing begins the previous autumn. We start to close up paddocks earmarked for rotational grazing four to six weeks before the soil temperature drops below six degrees centigrade and grass growth ceases. By early spring there should be 1,200 to 1,300 kilos of dry matter per hectare. But resist taking the tempting bite which becomes available between close up and the drop in soil temperature!”
“A grass plant is driven to grow three leaves,” explained Adam Woods. “And once leaves are grazed the grass plant will re-generate. The re-generating re-growth is sweet and nutritious and stock eagerly graze this, but if they do, the plant’s re-growth will be stunted. So stock should be moved on before they have the chance to eat the re-generating re-growth, which means moving them at least every three to four days.
“Grass grows grass and the more leaf area, the greater capture of sunlight. With May generally being the peak growing month, it’s really important that you get your stocking rate and grazing management right for this month. If you don’t you’ll struggle all season.”
Mr Woods added: “You need to keep the stem of the grass plant green as far down as possible, avoiding white stem at the base of the plant. White stem length increases when grass is not grazed for about three weeks.”
Aidan Murray emphasised the importance of walking all rotational grazing blocks at least once a week, to assess amount of grazing available and importantly, the amount of grazing ahead of the stock.
“If you have too much grass ahead, don’t waste it - you have the option to either close it off for buffer grazing or to cut and incorporate it into a silage crop.”
Monitor farmer Andrew Baillie had been concerned by the second week of May, that he did not have enough grass ahead of his rotationally grazed cows and calves, so held them back.
“Ten days later the grass had grown so quickly that I was considering shutting one of the four blocks off, cutting it and adding it to the silage crop to be taken off a neighbouring field.
“Although I’ve rotationally grazed sheep in larger numbers for several years, this is the first time I have made specific grazing blocks within one field, and I can already see the better grass utilisation. In previous years I would have turned the 25 cows and calves into the whole field, but now, if there’s more grass than the cattle need, I can cut the excess for silage, instead of it being wasted.”
Mr Baillie said that compared to this stage in previous years, the cows are looking healthier and calves are thriving better.
“As soon as the cows are moved onto a fresh block, their heads are down straight away, tucking into the fresh grass. So they’re eating more and milking better, with the improvement showing in the calves.
“An unanticipated benefit of the frequent moves between grazing blocks is that the cows have become more relaxed and their calves are learning good manners at an early age!”
Aidan Murray told the group: “When grazing cows and calves, include calves in the dry matter requirement calculation once they hit 200 kilos liveweight. Also a one strand electric fence enables calves to forward graze, which can be a benefit come weaning time – they’ve almost weaned themselves.”
The next Clyde monitor farm meeting will be on 6th August when calf health will be the main topic.
For more information on monitor farms, plus detailed reports of meetings, visit www.qmscotland.co.uk/monitor-farms