沙子岭猪优化育种方案的研究

发布时间：2018-10-29 12:44

【摘要】：本文旨在对沙子岭猪育种方案进行优化,以获得目前条件下最优育种方案。首先,通过对沙子岭猪育种资料的整理,对沙子岭猪群体进行基础性研究,包括生长发育性状校正公式的制定、遗传参数的估算、边际效益的计算及简化综合育种值。再根据所获得的数据,对沙子岭猪育种方案进行优化,优化的指标分别为沙子岭猪群体公母猪数量、公猪使用年限和育种投资期,以获得最大育种效益为标准,选择最佳优化组合。研究结果表明,Saturation模型为拟合沙子岭猪早期生长动态的最优模型,所得校正公式适用性最为广泛；沙子岭猪遗传参数估算主要对繁殖性状和生长发育性状进行了研究,其中繁殖性状包括产活仔数,出生窝重,21日龄窝活仔数,21日龄窝重,35日龄窝重和35日龄活仔数,各性状遗传力范围为0.15-0.28,性状间遗传相关范围为0.31-0.51；生长发育性状包括达50kg体重日龄,达50kg体重活体背膘厚,6月龄体长、体高、胸围、胸深、胸宽各性状遗传力范围为0.33～0.44,性状间遗传相关除达50kg体重活体背膘厚与其他各性状相关为负相关(-0.30--0.10)外,其余均为正相关(0.19～0.83)；利用多元回归法得出沙子岭猪经济性状边际效益为产活仔数(18.03)、出生窝重(0.89)、21日龄活仔数(12.30)、21日龄窝重(1.10)、35日龄活仔数(11.07)、35日龄窝重(0.21)、达50kg体重日龄(-0.91)、达50kg体重活体背膘厚(-0.88),经过与贴现因子获得的相应经济加权值为1].30、0.56、7.54、0.67、6.73、0.13、-0.69和-0.67(元)；考虑育种工作的效率和成本及准确性,简化综合育种值以保留产活仔数、35日龄窝重、达50kg体重日龄和达50kg体重背膘厚最为理想。以上述研究结果为基础,对沙子岭猪育种方案进行优化发现：在沙子岭猪公猪数目不变的情况下,沙子岭母猪数目越多,则所获得的遗传进展越大；沙子岭母猪数目不变的情况下,每世代选留种公猪越多引起选择强度降低,其遗传进展有变小趋势；各性状遗传进展与综合遗传进展随着沙子岭公猪使用年限变小而有递增的趋势；育种投资期的延长会导致性状标准化贴现因子的不断增大,从而引起经济加权值的增大,沙子岭猪育种产出也会随着育种投资期的延长而增大,育种成本也不会发生变化；同时发现,对试验结果中的优化水平进行任一组合,其年近交增量都不会超过0.5%。通过观察单一因素的变化对沙子岭猪育种效益的影响,综合三种最优因素进行组合,得到沙子岭猪目前状态下的最优育种方案,其综合遗传进展为7.0505元,年育种效益为116.67元。
[Abstract]:The aim of this paper is to optimize the breeding scheme of Shaoling pig in order to obtain the best breeding scheme under present conditions. Firstly, through sorting out the breeding data of SHALING pig, the basic research on the population of SHALING pig is carried out, including the formulation of correction formula for growth and development traits, the estimation of genetic parameters, the calculation of marginal benefit and the simplification of comprehensive breeding value. According to the data obtained, the breeding scheme of Shaoling pig is optimized. The optimized indexes are the number of boars, the number of boars and the investment period of boar breeding, which is based on the maximum benefit of breeding. Select the optimal combination. The results show that the Saturation model is the best model to fit the early growth dynamics of SHALING pig, and the correction formula is the most widely used. The genetic parameters of SHALING pigs were mainly studied on reproductive traits and growth traits. Reproductive traits included litter size, birth litter weight, litter size at 21 days old, litter weight at 35 days old and live litter size at 35 days old. The heritability range of each trait is 0.15-0.28, and the genetic correlation range among characters is 0.31-0.51. The traits of growth and development include 50kg body weight, 50kg body weight, body length, body height, chest circumference, chest depth, and the heritability range of each trait is 0.33 ~ 0.44, and that of 50kg body weight is 0.33 ~ 0.44, and the traits of growth and development include body length, body height, chest circumference, chest depth and chest width. The genetic correlation among traits was positive except for the negative correlation between backfat thickness and other traits (-0.30-0.10), and the positive correlation for all other traits (0.19 ~ 0.83). By using multiple regression method, the marginal benefits of economic traits of SHALING pigs were as follows: litter size (18.03), litter weight at birth (0.89), litter size at 21 days (12.30), litter weight at 21 days (1.10), litter size at 35 days (11.07). The weight of nest at 35 days (0.21), the weight of 50kg (-0.91), the backfat thickness of 50kg in vivo (-0.88), and the corresponding economic weighted value obtained by discount factor are 1]. -0.69 and -0.67 (RMB); Considering the efficiency, cost and accuracy of breeding work, the best way to simplify the comprehensive breeding value was to preserve the number of live litter, the litter weight of 35 days old, the age of 50kg body weight and the backfat thickness of 50kg body weight. On the basis of the above research results, the breeding scheme of Shaoling pig was optimized. It was found that when the number of SHALING boars was constant, the greater the number of sows was, the greater the genetic progress would be. When the number of sows in Shaling was constant, the selection intensity decreased and the genetic progress decreased with more boars selected for each generation. The genetic progress and comprehensive genetic progress of each trait showed an increasing trend with the decrease of service life of SHALING boar. The prolongation of breeding investment period will lead to the constant increase of standardized discount factor of traits and the increase of economic weighting value. The breeding output of Shailing pig will also increase with the extension of breeding investment period, and the breeding cost will not change. At the same time, it is found that the annual inbreeding increment is not more than 0.5 for any combination of the optimal level in the test results. By observing the effect of single factor change on the breeding benefit of Shaoling pig, combining the three optimal factors, the optimal breeding scheme of SHALING pig under the present condition was obtained. The comprehensive genetic progress was 7.0505 yuan. The annual benefit of breeding is 116.67 yuan.
【学位授予单位】：湖南农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S828

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