Last week we took a closer look at just how much is to be gained by managing grazing throughout the season. By moving from a set stocked system to paddock grazing there is the potential to grow and utilise over 90% more grass, with an energy supply increase to animals of up to 110% (Table 1). This not only leads to an increased stock carrying capacity of every acre of ground, but also significantly boost daily liveweight gains of grazing animals.
The benefits, therefore, are quite clear and while the above figures are achievable through extensive use of paddocks, the fact is that moving from set stocking to any form of rotational grazing is going to improve grass growth and utilisation, and in turn stocking capacity and daily liveweight gains – driving output per hectare on your farm.
Grazed grass is the cheapest feed we can produce and while we may not be able to enjoy the 280+ day-grazing seasons achievable in other parts of the world, to me this means we need to make all the more use of grass during the shorter grazing period that we have.
It’s never too late to set up a rotation for animals. Grass growth across the country has been phenomenal over the last fortnight, with growth rates sitting comfortably in the mid 80s kgDM/ha/day. This is nearly double the typical daily demand on most livestock farms.
Boost silage reserves
Having endured a poor second half of last year and a difficult spring this year, everyone is feeling the pinch of the prolonged winter routine. Fodder stocks are at an all-time low and work needs to be done to replenish them for the coming winter.
Every blade of grass grown on-farm needs to be utilised this year, as we try not only to conserve enough fodder for a normal winter but also replenish our buffer stock in the yard. Already this year the use of rotational grazing has allowed two of the six focus farms to conserve excess grazing as baled silage. In a set stocked situation this grass would have been trampled back into the ground by grazing stock, while reducing performance of those animals that grazed it.
Each of the focus farms have adopted some form of rotational grazing that best suit their farms. Here is what they are doing.
Sub-dividing fields for cattle
Last year the Mackays at Greenvale, Thurso, simply split one 16-acre field in two with a single strand of mains electric fence. This field was adjacent to another nine-acre field. Across the 29 acres they ran a bulling group of 35 cows for the full summer. As well as this they managed to take out eight acres as surplus grass. Calves averaged 1.3kg/day from birth to weaning. With three paddocks they were moving every five to seven days.
This year the three paddocks will be sub-divided again to create six paddocks for the grazing group. This is to give Mark and Shona greater flexibility over grazing decisions. If a paddock becomes too strong it is much easier to manage without one sixth of the grazing rotation, compared with taking out one third of the rotation when it was only three divisions.
The Gammies at Drumforber, Laurencekirk, divided one 15-acre field into three and an adjoining 12-acre field into two. This was done with temporary posts and two strands of rope wire. Rope wire was used to be easier for animals to see and get used to.
Again, one bulling group rotated around these paddocks for the most of the grazing season, barring one week towards the end of June when grass growth was poor.
Matching stock to field sizes
The Duffuses at Mains of Auchriachan, Tomintoul, had three similar-sized fields beside each other that they rotated autumn calvers around all summer. The cows were removed at weaning time and the calves remained on the rotation. This is a simple system yet still achieves the ultimate goal of rotational grazing – increased grazing pressure followed by a period of rest and recovery.
Last year the Duguids, Mains of Cranna, Aberchirder, grazed 150 ewes with predominantly double lambs at foot on a 17-acre field divided into four. This was achieved with temporary posts and four strands of temporary electric wire on a battery fence.
They also managed to take out nearly 30 bales of silage as surplus grass during a period of high growth. This year they have decided to increase the number of paddocks per grazing group to six as well to give them more options.
This year the Biffens at Mains of Arnage, Ellon, are grazing all their ewes and lambs across seven paddocks using a combination of a permanent spine fence and Gallagher Smartfence off of these to create more paddocks. The Websters at Ardhuncart farm, Kildrummy, have gone with a more permanent option with Octoposts every 15m and four strands of electric wire. This has been done to split a 22-acre field into four paddocks.
Shoulders of the year
One other area where we have seen progress made on the focus farms is getting stock out to grass earlier in spring time. While last spring we managed to get stock out up to six weeks earlier than in previous years. This spring was a lot more challenging, yet we still managed to get stock out two to four weeks earlier than prior to the start of the project.
This was achieved by doing two things:Not grazing all swards completely out in the back end of the year. Retaining even a small cover of grass over winter allows the grass to start growing that bit earlier come spring, as it has leaves to capture sunlight and photosynthesise. If a grass plant has been completely grazed out over winter, when it starts to grow in spring all of the energy to do so must come from the roots of the plant. This can take longer to achieve due to lower soil temperatures.Getting fertiliser out at the first available opportunity in spring. Each of the six focus farm were monitoring soil temperatures in spring and once soil conditions allowed and soil temperatures were consistently above 5°C, fertiliser was applied at a low rate (30 -40 kgN/ha) to kickstart growth.
Benefits of rotational grazing Increased stock carrying capacity/ha.Increased daily liveweight gains.Potential to boost silage reserves in times of high growth.Animals are easier to herd as they are used to being moved regularly.Any sickness can be detected earlier through increased herding.