猪的品种（Breeds of pigs）.doc

猪的品种（Breeds of pigs） Breeds of pigs The main pig breeds: introduced from abroad a large white (about summer pig), Landrace (Landrace), Duroc, Hampshire, Pietrain and Springer pigs; our own breeding with Hubei white pig, Sanjiang white and junmu No. 1 white. The common feature of these pig breeds is the high lean percentage of carcass (more than 57%). Economic crossbreeding by using these pig breeds as male parent or female parent can improve the production of lean pork in commercial pig. A large white (Yorkshire) (a) the origin and characteristics of large white pig bred in England in eighteenth Century, is a kind of lean type pig famous in the world. After introduction of our country, it has been well adapted for many years after cultivation and domestication. The utility model has the advantages of fast growth, high feed utilization rate, relatively large birth rate and high lean meat percentage of the carcass. Our country has introduced the British (UK), law (France), Canadian (Canada) and large white (USA) etc.. (two) shape, appearance, physique, symmetry. Ears erect, nose straight, limbs longer. The body coat is white, so large white. Adult boars weigh 250-300 kilograms and adult sows weigh 230-250 kilograms. (three) the performance of growth and fattening is fast and the feed is saved. 5-6 months after birth, body weight can be reached by agreement of about 100 kg. In our country, feed per kilogram contains 13 digestible energy. 4 MJ, fine protein 16%, free feeding conditions, from weaning to 90 kg stage, daily gain of about 700 grams, the per kilogram weight gain consumption of 3 kg feed. Weight 90 kg, slaughter, slaughter rate of 71%-73%, eye muscle area of 30-37 square centimeters, lean carcass rate of 60%-65%. According to the statistics show that more than a dozen domestic national or provincial pig, in recent years, introduced from abroad, large white, the finishing performance is greatly improved. The daily gain of fattening period can reach 800-1100 gr