The economical hybridization of pigs
There are many ways of crossbreeding pigs, and the type of crossbreeding adopted depends on the local feeding conditions and market demand. In rural areas, due to the low level of rearing, the requirement for lean meat ratio is not high. A simple two-variety fixed or recursive hybridization can be adopted; in the suburbs or areas with good conditions, three varieties or four varieties can be used for hybridization. The two varieties were fixed and crossed. The male and female sows of the two breeds were crossed. Parents were fixed and the first generation of the hybrids, both male and female, were marketed as commercial pigs and were not used for breeding. This method of hybridization is very simple, convenient and feasible, especially when screening hybridization combinations only need to do a determination of combining ability, but also to obtain the highest hybrid superiority of offspring, but the heterosis is not used because the hybrid generation is used as a commodity. Pigs can only use the heterosis in growth and fattening. Two rounds of crossbreeding, ie, the sows used in the hybrids of the two varieties, were alternated with the two parental purebred boars one by one. For example, the currently popular Landrace and Yorkshire hybrids were cycled. In this way of hybridization, except for the first cross, the sows are all hybrids to maintain the heterosis of the breeding performance of the sows, but the boars are replaced from generation to generation, even if the boars with good hybridization performance cannot continue. After use, the quality of hybrids stagnated at about 67% after a certain number of generations (about the 8th generation). The fixed hybrids of the three varieties use the hybrids produced by the crossing of the specific two varieties as females, and the third breed of boars are mated, and the resulting offspring are all marketed as commercial pigs. Hybridization in this way not only yields the highest maternal and offspring heterosis (especially in terms of reproductive performance), but also makes full use of the advantages of the first and second parents in growth, feed utilization, and carcass quality, but The crossbreeding system is more complex. It is necessary to maintain three parental species in the same field and also to produce and maintain a large number of hybrid sows. Four-species crosses (two-hybrids) are first cross-bred with four breeds and then crossbred between two crossbreds, for example, first with Duroc and Hampshire, then Landrace and Yorkshire, and then with Dhow. Crossbreeding sows with mature sows to produce commercial pigs. Hybridization in this way can get the highest parental heterosis, but the hybridization method is more complex. It is difficult to implement four purebred and hybrid generation parents in the same field. Hybrid pig performance Widely adopted in the vast rural areas of our province is a simple two-species hybrid crossbreeding method. The father uses more exotic lean type pigs such as Yorkshire, Landrace and Duroc, while the female parent uses more local pig breeds such as Jiaxing. Black pigs, Jinhua pigs and Pixian flower pigs. In recent years, with the development of urban and rural economies, the demand for lean meat has been increasing. The fixed hybridization method of the three varieties has been adopted in large quantities and has become the dominant model for the production of commercial pigs. (Source: Zhejiang Animal Husbandry News)
Dehydrated Green Bell Pepper,Green Bell Pepper,Bell Pepper
Brother International Trading Co., Ltd. , http://www.jn-food.com