A free online tool has been launched to help calculate the ideal space needed for grazing and optimise performance of land and livestock.

The Grazing Calculator from farm management software provider AgriWebb can tell farmers how much area they will need for their herd or flock, based on the desired number of grazing days and the characteristics of their animals and sward. Created specifically for British farmers, it can be used to work out the total area needed on farm or per rotational grazing space.

The method of calculation has been developed through AgriWebb’s expertise in UK livestock farm management and in conjunction with grass management specialists. Results are provided by entering group size, average body weight, number of days rotation, food on offer and % bodyweight consumed.

For example, a herd of 200 with an average body weight of 500kg, grazing for five days with 1,200 kg/DM/ha on offer, and consuming 3% of their bodyweight, requires 12.5 ha.

The tool is intended to support farmers to improve rotational grazing and encourage regenerative agriculture practices. Using too much space for grazing can be wasteful, whilst too little space and overgrazing can threaten the balance of soil health and ecological systems, causing financial loss and environmental detriment. Getting it right, however, maximises feed quality, growth rates and resulting profitability.

The Agriculture and Horticulture Development Board (AHDB) estimates there is a potential £1.25 per day saving on cattle being at grass rather than being housed.

Clive Brown, AHDB’s head of knowledge exchange for beef and lamb said: “Rotational grazing works on the basic principle of ‘graze and rest’. The period of rejuvenation leads to higher yield, with research suggesting around 20% more grass is grown in a rotational grazing system. This, combined with the correct allocation of grass to stock class, results in more grass being utilised, which means more grass to convert into meat.

“Tools that make it easier to understand what action needs to be taken on farm to maintain good rotational grazing patterns are beneficial. For example, regularly sub-dividing paddocks can be a great way to control and maintain ideal grazing levels as your herd or flock matures.”

More efficient grassland management is also vital to addressing the carbon capture challenge. The ‘Climate Friendly Farming’ paper published earlier this year is aligned to the NFU’s goal of reaching net zero greenhouse gas emissions across the whole of agriculture in England and Wales by 2040. It highlighted that around 65% of farmland in the UK is best suited to growing grass rather than other crops and if we do not graze livestock on it, we cannot use it to produce food. Grazing livestock on this land allows us to turn inedible grass into high quality, nutrient-rich beef and lamb, boost CO2 absorption through increased grass growth, and provide a valuable habitat for many native wildlife species.