Knowledge Title: Grazing

Other Title: grazing

Knowledge Content:

    One of the ways in which livestock are raised. It is a breeding method that allows herbivores under artificial control to harvest herds in grasslands and convert them into animal products, and it is also a grassland utilization method that is most economical and adapted to the physiological and biological characteristics of livestock. Grazing during the grazing season provides access to a fully nutritious and abundant fresh pasture, while livestock are given adequate sunlight and exercise to promote health and productivity.

    Effects of grazing on grasslands Livestock in grasslands for feeding, trampling and excretion of dung and urine, will have a variety of effects on grasslands: (1) grass species. Livestock are selective in the harvesting of pastures, and when the amount of grazing for a particular pasture does not exceed 50% of the plant body, it has little effect on the pasture and can promote the branching, branching and growth of pasture. However, when grazing times are excessive or grazing periods are arranged irrationally, good-sounding pastures will first decrease or disappear in the grass layer, while poor lysate pastures and poisonous grasses increase accordingly. (2) Soil structure. Livestock move and run on the grasslands, damaging to grass and topsoil. Long-term excessive trampling will make the grassland ground bare, soil permeability decline, resulting in soil erosion. However, the proper trampling of reasonable grazing can break the mulch formed by the ground moss and algae, which is conducive to the naturally scattered grass seeds to obtain the environmental conditions for growth and development, and can also make the dead plants fall, break, accelerate decomposition, and improve the organic content of the soil. (3) Soil fertility. During grazing, the feces of livestock are nutrients for grass, a 500 kg adult cow that excretes about 7.5 kg of nitrogen a year, phosphorus about 3 kg and potassium about 4 kg. Therefore, grazing can make pasture and livestock provide nutrients to each other, and promote the material circulation of grassland ecosystems. However, if the density of grazing livestock is too large, too much manure and urine excretion will pollute the pasture, the use of grassland has a negative impact. In the grazing process, the grassland can withstand the ability of livestock to eat, trample and manure is called grassland resistance, it is composed of the living force of pasture, regeneration and the elasticity of grass. Under the condition that the soil contains many machine quality, good structure and strong permeability, the root system of the plant is dense, and the soil is combined to form a strong lym, the grassland's herdresistance is strong.

    The grazing system and the grazing system can be divided into two categories: non-systematic grazing (free grazing) and systematic grazing, including the following main grazing methods: (1) continuous grazing. During the period of total grazing, livestock are grazing unrestricted on a grassy area, which belongs to free grazing and is a more primitive grazing method. (2) Fixed grazing. At a longer stage during grazing, a certain number of livestock are unrestricted grazing on a certain area of grass. It is also free grazing, but it is more advanced than the former. (3) Take turns grazing. The grasslands are divided into sections, in a certain amount of time and order, in return for grazing and leisure (see grassland management). It is the main form of systematic grazing and the main method of rational use of grassland. (4) Mixed grazing. Two or more kinds of different feeding characteristics of livestock grazing on the same grassland, such as cattle, sheep mixed grazing or cattle first, then sheep. Planned mixed grazing is systematic grazing. (5) Fence grazing. The grazing methods that allow young animals to enter a grassland area through a barrier gap, while the mother animals cannot enter, are also systematic grazing. In some agricultural areas in northern and southwestern China, a mixed herd of one or several families uses small patches of grass, grazing or ropes, which are generally free grazing.

    In modern times, intensive meat production and seasonal animal husbandry, which are supplemented by grazing-based or feeding-based grazing, are a kind of efficient grazing system.