by overgrazing In other words, maintain the sustainability of the pasturage Protecting the health of the animals against acute threats, such as: Grass tetany and nitrate poisoning Trace element overdose, such as molybdenum and selenium poisoning Grass sickness and laminitis in horses Milk sickness in calves A proper land use and grazing management technique balances maintaining forage and livestock production, while still maintaining biodiversity and ecosystem services. It does this by allowing sufficient recovery periods for regrowth. Producers can keep a low density on a pasture, so as not to overgraze. Controlled burning of the land can help in the regrowth of plants. Although grazing can be problematic for the ecosystem, well-managed grazing techniques can reverse damage and improve the land. On commons in England and Wales, rights of pasture (grassland grazing) and pannage (forest grazing) for each commoner are tightly defined by number and type of animal, and by the time of year when certain rights could be exercised. For example, the occupier of a particular cottage might be allowed to graze fifteen cattle, four horses, ponies or donkeys, and fifty geese, while the numbers allowed for their neighbours would probably be different. On some commons (such as the New Forest and adjoining commons), the rights are not limited by numbers, and instead a 'marking fee' is paid each year for each animal 'turned out'. However, if excessive use was made of the common, for example, in overgrazing, a common would be 'stinted'; that is, a limit would be put on the number of animals each commoner was allowed to graze. These regulations were responsive to demographic and economic pressure. Thus, rather than let a common become degraded, access was restricted even further. Systems Ranchers and range science researchers have developed grazing systems to improve sustainable forage production for livestock. These can be contrasted with intensive animal farming on feedlots. Continuous With continuous grazing, livestock is allowed access to the same grazing area throughout the year. Seasonal Seasonal grazing incorporates "grazing animals on a particular area for only part of the year". This allows the land that is not being grazed to rest and allow for new forage to grow. Rotational Rotational grazing "involves dividing the range into several pastures and then grazing each in sequence throughout the grazing period". Utilizing rotational grazing can improve livestock distribution while incorporating rest period for new forage. Ley farming In ley farming,