Pigs with slender limbs are most susceptible to this disease, with fast growth rates, high lean meat rates, and more readily available varieties with thin backs. China's local varieties and their cross-breeding pigs with exotic species are rarely ill, and the growth rate is slow in foreign countries, and the incidence of thicker backs is very low. Therefore, during the period of breeding and breeding, large-scale pig farms should be as large as possible with large limbs and shovel.
2. Nutritional factors
The gilts have relatively high demand for calcium and phosphorus in the feed. If the ratio is not appropriate, it is easy to cause hoof cracking. When selenium deficiency, it can cause foot deformation, hair removal, arthritis, etc. When chronic fluorosis and manganese deficiency, it can lead to limbs. Abnormal deformation, and more than manganese when there is a transverse crack, zinc deficiency is hoofed or lateral fissure, lack of vitamin D, affecting bone growth, rickets, limb hoof and arthritis swelling, etc., so that the pig's limbs Uneven force, leading to cracked hooves, especially intensive closed breeding, lack of exercise and sun exposure is more likely to occur. If the reserve pigs have been feeding the fertilizer after one hundred pounds, the nutrient development of the body bones will be insufficient. When breeding, the boars may be overwhelmed. At the same time, the reserve pigs have higher demand for biotin. In the late stage of reserve breeding, special attention needs to be paid to add biotin to meet nutritional needs.
3. Climate factors
In winter, the main air is cold, wind, cold and dampness, invading the skin, and invading the meridians, it will cause pain in the limbs and hoof, leading to lameness, so the occurrence of leg and foot disease is more common in winter. The cold is attracted, the wet evil will also be included in the body. When the spring is warming up, the wet evil will break out of the sun, which is also the initial "foot-and-mouth disease" pathological process. At the same time, for the lack of yang, the phenomenon of Weiqi is not solid, Weiyang can not warm the limbs, it will also cause the pathological status of cold and dampness, this situation will directly cause the clinical manifestations of sputum.
4. Circle factors
In the cleft-hoofed pigs, there are more hind limbs than for the front limbs. This is related to the smoothness of the circle surface. The smoothness of the circle surface is moderate. It can be seen that there are dense small sand grains, the circle surface is too smooth, the sand is not visible, the circle surface is too rough, and the larger sand grains are easy to see. The sows raised in these three types of barns have significantly different incidences of limb and foot weakness syndromes, the former has a lower incidence rate, and the latter two types have a higher incidence. In terms of the circle structure, pigs with hoof injuries (38% or more) raised in the intensive limit bar were significantly more than those on the ground (7.14%), and the hoof bottom (35.75%) on the cement floor was significantly higher. Pigs reared on slatted floors (27.91%).
The new cement ring surface is alkaline or corrosive due to unwashed and disinfected, which causes the pig's limbs to be damaged and cracked. Not a few, so the new pig pen is best to use the epidemic disinfection, neutralize the alkaline floor, reduce its corrosive.