The carcass lean meat rate of the original local pig breeds in China generally does not exceed 45%, while the foreign lean meat pig breeds can achieve a carcass lean meat rate of more than 60%, and some varieties have a carcass lean meat rate of up to 80%. Lean meat is the main source of animal protein in people's food, so the development of lean meat pigs can obtain higher economic benefits, which is the main direction of current and future commercial pig production.

At present, the price of lean meat in large and medium-sized cities and developed countries has more than doubled that of fat meat. The original hybrid pigs produced by local pigs as the female parent have a thick and lean rate and have lost market competitiveness. China's pig production has gradually developed towards specialization and industrialization, production is oriented to the market, and the market determines production. In order to improve the efficiency of pig raising, the quality of pork must be improved. At present, the carcass lean rate is the most important indicator to measure the quality of pork. Therefore, the development of lean pig production is the common aspiration of producers and consumers at this stage in China.

Hybrid combination

Ternary cross, which is the parent of the hybrid commodity hog, has three varieties. These three varieties have undergone two crosses, and finally get the ternary hybrid offspring. Among the two varieties that participated in the first mating, the sows belonged to the female parent, and the breed to which the boar belongs was called the first male parent. Obviously, the offspring obtained from the first mating are a generation of hybrids (F1). Selecting the fine sows in F1 for breeding, and then all the offspring of the third breed of boar mating are fattening, which is the ternary hybrid sow. Participating in the second mating boar is called the second male parent. For the second father, the ternary hybrid sow is still a hybrid.

It can be seen from the process of production of ternary hybrid hogs that in the parents, the father is a pure breed, and the mother is a hybrid, and the two parents of the ancestors are purebred. Compared with binary hybridization, the degree of hybridization is high, has a richer genetic basis, exhibits higher heterosis, and generally increases by 2% to 5% on the basis of binary hybridization. In the parental generation, the female parent is a generation of hybrids, especially in terms of reproductive performance, such as litter size, lactation, etc., with obvious heterosis, which is not found in the female parent of binary hybridization. However, compared with binary hybridization, it is necessary to maintain three purebred parents, and to retain a generation of hybrid sows. The hybrid breeding system is more complicated.

Main link

1. Selection and purification of parents

Ternary hybrids are derived from purebreds. The purer the parents, the higher the performance, and the better the hybrid progeny.

According to the role of the parental variety in the cross, the selection requirements for the female parent and the male parent should be different. The choice of female parent should focus on reproductive performance and adaptability, while the choice of male parent should emphasize fast growth, high feed compensation, and good carcass quality.

2, should screen the best hybrid combination

It is also a lean meat type, and the difference in hybridization between different varieties (lines) is also large.

To choose the combination of the best hybridization promotion. Therefore, it is decided to carry out the determination of the combining ability before the promotion of the hybridization combination, that is, the hybrid combination test. For various reasons, it is not possible to do many cross-combination comparison tests at one time. According to relevant theories, reference to existing data, social surveys, and scientific projections. The hybrid combination test must take into account the actual local breeding level to enhance the practical application value.

3. Establish and improve a thorough breeding system

Establishing a sound breeding system is a reliable organizational guarantee for the development of ternary hybrid lean pig production. The breeding system for the production of ternary hybrid lean pigs consists of four different types of farms, namely, commodity generation, parental generation, ancestral generation and ancestral generation. Each field has different nature and different functions. The commercial field mainly provides high-quality lean-type ternary hybrid pigs to the society; the parent-generation farm is specialized in producing ternary hybrid piglets for fattening for commercial fields (households); Add a generation of hybrid gilts to the parents' farm. The Zengzudai pig farm is the tip of the breeding tower in this breeding system. Its role is to ensure the continuous supply of high-performance purebred parents to the ancestors and parents (parents). The breeding system is a strict seed production project. To complete this seed production project requires unified planning, coordination, coordination, and clear division of labor. Indiscriminate hybridization, the quality of the breeding pigs is not guaranteed, it is impossible to mention the best hybridization effect. Practice has proved that only by establishing and perfecting a four-level breeding system can we ensure the best benefits of ternary hybrid lean pig production.

4, strengthen feeding management, improve nutrition levels Pigs are omnivores, can use a variety of feed.

In terms of nutrients required, lean pigs are no different from other types of pigs, but in the practice of feeding, the lean pigs cannot be raised in the same way as ordinary pigs. First of all, lean meat pigs, especially ternary hybrid lean pigs, have a high daily gain and fast growth, so they need more nutrients. When any nutrient is not met, the high yield potential cannot be fully utilized. The protein that pigs need must be met from the feed. Therefore, the wide source of feed, especially the supplement of protein feed, is particularly important for ternary hybrid lean pigs. Protein is composed of amino acids, protein nutrition, and essence is amino acid nutrition. There are 10 kinds of amino acids called pig essential amino acids, and any lack of them will reduce the biological value of the whole protein. In addition, lean-type pigs have a flat belly line, a smaller stomach capacity than native pigs, and an appetite that is often worse than other pigs. Therefore, it is necessary to pay attention to the modulation of feed processing and improve the palatability, but the proportion of various types of loose and succulent slag feed and roughage should not be too large to ensure nutritional needs.

In short, the growth of carcass and the lean meat rate of commercial fattening pigs are determined by the combination of good performance, feeding management techniques and feed nutrient levels. Therefore, to promote the ternary hybrid lean pigs, we must actively adopt advanced science and technology, and combine local actual conditions to continuously improve the level of feeding management.