| This study aims at optimizing the various Shaziling Swine breeding program to obtain the best one. Firstly, the study builds the fundamental experiment by using the original production data. The fundamental experiment includes the correction formula of growth traits, genetic parameter calculation, the calculation of marginal benefit and the simplification of comprehensive breeding value. Then, according to the data obtained, researchers optimize the Shaziling Swine breeding program by various population of sows and boar, various boar use fixed number of year, and various investment term. The study chooses the best optimum combination based on breeding benefit maximization.Saturation model is fit for describing the early growth progress of Shaziling Swine, because it has the most extensive applicability. The majority traits of Shaziling Swine include reproductive traits, growth and development traits. The reproductive traits contain the number of alive born piglets(NBA), the litter weight of alive born piglets(LWB),the number of litter pig at 21 days(NL21), the litter weight at 21 days(LW21), the number of litter pig at 35 days(NL35).The growth and development traits contain the day of Shaziling Swine grown to 50Kg (AGE50), the backfat when grown to 50kg (BF50), and the body length at six month(BL), the body height at six month(BH), the chest measurement at six month(CM),the chest deep at six month(CD), the chest wide at six month(CW).The heritability of reproductive traits range from 0.15 to 0.28, but growth and development traits range between 0.33 and 0.44. Genetic correlation of reproductive traits range from 0.31 to 0.51. Though Genetic correlation among reproductive traits is positively correlated, BF50 is negatively correlated with other growth and development traits (-0.3?-0. 1).Except for BF50, The remained growth and development traits is positively correlated(0.19-0.83). The results of this study are consistent with domestic and foreign research. By using multiple regression method, it is concluded that the marginal benefit of each traits is 18.03(NBA? 0.89(LWB)? 12.30(NL21)?1.10(LW21)?11.07(NL35)?0.21(LW35)?-0.91(AGE50)?-0.88(BF50). After the discount, the economic weight value of each traits is 11.30?0.56?7.54?0.67?6.73? 0.13?-0.69 and -0.67. Consider breeding work efficiency and cost and accuracy, we choose to keep NBA?LW35?AGE50 and BF50.Based on the above research results as the background, The results showed that when keeping the number of sows fixed, the Genetic progress is along with the decrease of number increased and vice versa. Various characters genetic gain and comprehensive genetic gain are along with the decrease of Shaziling boars use time, but the breeding cost as the same as the original. The breeding investment period's elongation directly leads in the increase of standards close to the discount factor, which will cause the rising of economic weighted value. The output of pig breeding will increase along with the prolongation of breeding investment period while the cost of breeding will not change greatly. At the same time, if choose the optimized level breeding to make a combination at random, the output of inbreeding will be less than 0.5%. Through observing the single factor to the influence of pig breeding benefits in Shazi-ling Swine and gathering three types of the best Shaziling Swine under this perfect situation to make an excellent breeding scheme, the study shows that the development of comprehensive genetic gain is7.0505 and the benefit of breeding in one year is 116.67. |
PDF Full Text Request