【作者】 唐国庆；

【导师】 李学伟； 王金勇；

【作者基本信息】 四川农业大学 ， 动物遗传育种与繁殖， 2003， 硕士

【摘要】 论文从育种目标和现行育种方案优化两方面对中国荣昌猪(CRP)配套系进行了研究。在育种目标的研究中，综合差额法及系统分析原理模拟CRP配套系生产的生物经济学过程，分别计算三个纯系窝产活仔数、21日龄窝重、仔猪育成率、饲料效率、日增重、瘦肉率、达100kg日龄、肉质指数和背膘厚的边际效益。结果表明：在预期的市场和生产条件下，这些性状的边际效益，A系分别为2.51、1.14，0.10、0.15、-48.41、7.42、-1.02、0.99、-10.49元；C系分别为1.43、0.58、0.06、0.09、-24.73、5.46、-0.55、0.55、-5.62元；B系分别为2.35、0.64、0.05、0.11、-27.61、4.17、-0.52、0.55、-6.70元。通过遗传标准差校正得到的相对经济权重，A系分别为6.29、8.29、0.63、11.90、-12.10、11.13、-13.26、2.22和-5.33元；C系分别为3.58、4.19、0.35、6.81、-6.18、8.19、-7.10、1.24和-2.86元；B系分别为5.87，4.64、0.28、5.12、-6.90、6.25、-6.75、1.24和-3.40元。通过简化综合育种值分析认为达100kg日龄包括在综合育种值中最有意义。当综合育种值中包括21日龄窝重、日增重、达100kg日龄和背膘四个性状就具备了很高的精确度，它与完全综合育种值的相关达到0.9935以上。通过对综合选择指数的优化结果认为，当只包括日增重和背膘厚两个性状时的综合选择指数就具备很高的准确度，它与综合育种值的相关达0.7164，而包括全部8个性状时综合选择指数与综合育种值相关为0.7728。 论文应用育种规划专用程序ZPLAN对CRP配套系现行育种方案进行预期效果分析和优化，并在此基础上考察了不同群体规模、公母猪使用年限、公母比例、测验群规模、测验公母猪头数及近交对遗传进展和育种效应的影响。结果表明： (1)现行育种方案能够取得较好育种效益，但在群体比例，测定制度和群体公母比例方面还有较大的余地。优化结果表明：当三个纯系的公猪和母猪使用年限为一年，B系群体比例为1％，C系群体比例为0.5％，A系群体比例为1％，祖代群体比例为7.5％，父母代群体比例为90％，三个纯系进行测量的公母猪头数为3头和0头，三个纯系后备猪全部进行性能测定，三个纯系公母比例为10，祖代公母比例为30，父母代公母比例为40时，整个生产体系育种效益为最大，纯系取得的年综合遗传进展最大。 (2)在总群体规模不变的情况下，纯系群体比例增大，有利于提高遗传进展，育种效益则是先增大后减小。当A系群体比例为1％，C系为0.6％，B系为1.2％时，育种效益达到最大。 (3)纯系公母猪使用年限延长，使世代间隔延长，选择强度增加，年遗传进展降低，并最终导致育种效益降低.当公母猪使用年限为1年时，取得最大的育种效益. (4)三个纯系公母比例增大，使育种产出增大，育种成本降低，育种效益增大，其中B系公母比例对育种效益影响最大，其次是C系和A系. (5)三个纯系测脸群比例增大时，育种进展和育种效益都是逐渐增大，B系测验群比例对遗传进展和育种效益的影响最大，其次是C系和A系.每窝进行测量的母猪头数越少，遗传进展越大;公猪头数越多，遗传进展和育种效益越大. (6)纯系群体比例和公母猪使用年限增大，年近交增黄下降;纯系公母比例增大，年近交增量增大.更多还原

【Abstract】 This paper involves two studies: (1) Study on the breeding goals for multiple crossbreeding system of CRP; (2) Study on the optimization for breeding programs for multiple crossbreeding system of CRP.In this study of breeding goal, a model integrated with difference method and system analysis was used to calculate the marginal profits of the traits which included number born alive (NBA, pig), adjusted 21-days litter weight (LW21,kg), piglet survival rate(PLSR%,%), feed gain ratio (F/G, kg/kg), average daily gain (ADG, g), estimated lean meat percentage (LEAN%,%), day to 100 kg (D100, day), meat quality index (MQI,%) and backfat(BF, cm) in three breeding lines. The results showed that in the situation of predicted market and production condition, the marginal profits for A line were 2. 51, 1.14, 0.10, 0.15, -48.41, 7.42, -1.02, 0.99 and -10. 49 RMB respectively, for C line were 1.43, 0.58, 0.06, 0.09, -24.73, 5.46, -0.55, 0. 55 and - 5.62 RMB respectively, for B line were 2. 35, 0. 64, 0. 05, 0.11, -27. 61, 4.17, -0. 52, 0. 55 and - 6. 70 RMB respectively. By adjusted with the genetic standard deviation, the relative economic weights for A line were 6.29, 8.29, 0.63, 11.90, -12.10, 11.13, -13.26, 2.22, and - 5. 33 RMB respectively, for C line were 3. 58,4.19,0. 35,6. 81, -6.18, 8.19, -7.10, 1. 24 and - 2. 86 RMB respectively, and for B line were 5.87,4.64, 0. 28, 5.12, -6. 90,6. 25, -6. 75,1. 24and - 3. 40 RMB respectively, by the analysis for simplified total breeding value, D100 which was involved in the total breeding value was most meaningful. While total breeding value included LW21, D100, ADQ and BF, it had a high accuracy. The correlation between simplified breeding value and whole total breeding value was 0. 9935. By the optimization for selection index, while the selection index only included ADG and BF, it had a high correlation (0. 7164) with total breeding value. By involving all eight traits, the correlation was 0.7728.75For the Optimization of present breeding programs of multiple crossbreeding system of CRP, A special PC-program ZPLAN was modified and adapted to particular situation . The method to improve present breeding programs were proposed. The influence of some control factors on breeding gain and breeding profit was studied on the base of optimum breeding programs. These factors were different population size, production lifetime of boar and sow, ratio of female/male in the production system, the test plan of genetic evaluation on the breeding values, Results involved:(1) The present breeding program can gain better breeding profits, but not reach the optimum breeding efficiency in proportion of herd, ratio of female/male and test plan. The programs which production life time of boar and sow in three breeding lines was one year, Proportions of B line, C line, A line, GP and PS were 1%, 0.5%, 1%, 7.5% and 90%, Ratio of female/male in three breeding lines, GP and PS were 10,30 and 40,Pigs for replacement in three breeding lines were all tested, and three males was tested per litter, can reach highest genetic gain and breeding profits.(2) Under the condition of unchanging total population size, increasing the population proportion of breeding lines could improve genetic gain per year, but to breeding profits, increasing faster in earlier than later. While proportion of A, C and B line were 1%, 0. 6% and 1. 2%, breeding profits would reach the most.(3) Increasing production lifetime could prolong generation interval, which increased selection intensity but decreased genetic gain per year and breeding profits. When the lifetime of boar and sow was one year, the breeding profits attached the most.(4) Increasing ratio by female/male in three breeding lines could increase breeding return, decrease breeding cost and increase breeding profits. The influence of sex ratio to breeding profits was most in B line, the latter was in C line and A line.(5) Increasing the proportion of tested population in three breeding lines could improve genetic gain and increase breeding profits. T更多还原