【作者】 刘泽辉；

【导师】 徐刚毅；

【作者基本信息】 四川农业大学 ， 动物遗传育种与繁殖， 2006， 硕士

【摘要】 本研究利用四川农业大学羊业科教中心培育天府肉羊核心群育种场1999～2006年的育种资料，对系谱及性状记录资料进行整理，采用MTDFREML估测了不同月龄体重、日增重及部分繁殖性状的遗传参数；采用SAS8.1的GLM程序的LSMEAN过程估计了不同性别和出生类型山羊体重及部分日增重的最小二乘均数并进行多重比较；分析了其生长规律，建立了相应的体重估测模型。 MTDFREML估测结果表明，初生重、一月龄、二月龄、周岁体重和十八月龄的遗传力分别为：0.53、0.54、0.45、0.49和0.72，属高遗传力性状；四月龄、六月龄和八月龄体重的遗传力分别是：0.35、0.36和0.38，属中等遗传力性状；而成年体重的遗传力为0.28，属中等遗传力性状；出生到断奶的平均日增重的遗传力为0.16，属低遗传力性状。各体重性状之间的遗传相关都较高，尤其是四月龄以前的体重性状间的遗传相关较高，同时表型相关也较高，这对培育天府肉羊早期选种是非常有利的。而十八月龄体重与其余各月龄体重之间的遗传相关很低，但表型相关值较高。 窝产羔数的遗传力为0.24，窝产羔数与初生重和一月龄体重的遗传相关分别为-0.74和-0.55，分别属强的负相关和中等强度的负相关；窝产羔数与断奶前平均日增重之间的遗传相关为-0.34，也属中等强度的负相关；羔羊的初生重与窝产羔数之间的表型相关为-0.4380，遗传相关为-0.74，分别属中等强度负相关和强的负相关。 LSM分析结果表明，培育天府肉羊的体重和平均日增重因窝产羔数和性别而存在很大差异，公羔和单羔具有先天的生长优势。从体重性状来看，同一性别不同窝产羔数的羔羊的初生重和一月龄体重均存在极显著差异（P＜0.01）；二月龄时，同一性别内的双羔和三羔的体重差异显著（P＜0.05）；六月龄以后，公羔的生长优势得到充分体现，公羔三羔的体重都极显著或显著高于单羔母羔（P＜0.01，P＜0.05）。对于平均日增重，单羔公羔断奶前的平均日增重（ADG,）极显著高于双羔公羔（P＜0.01），而双羔公羔及三羔公羔与单羔母羔的断奶前平均日增重无显著差异（P＞0.05），且同一性别内双羔和三羔间断奶前的平均日增重也无显著差异（P＞0.05）；单羔公羔断奶至六月龄的平均日增重（ADG₂）极显著高于单羔母羔（P＜0.01），单羔母羔又极显著高于双羔公／母羔和三羔公／母羔（P＜0.01），母羔中的双羔和三羔断奶至六月龄的平均日增重（ADG₃）差异不显著（P＞0.05）；单羔公羔六月龄至八月龄的平均日增重最高，并与其余各性别和更多还原

【Abstract】 The breeding data from 1999 to 2006 of nuclear breeding farm of Tianfu goat was used for this study. The effect of sex and birth type on birth weight, weaning weight, the weight of different months and the average daily gain （ADG） of different period before and after weaning were analyzed by using LSMEAN; the genetic parameters for these eleve traits were estimated by using MTDFREML. Simultaneously, the growth rules of Tianfu goat were studied using the program of SAS 8.1.The results of the MTDFREML showed that the estimate of heritability about the weight at the age of 18 months (W₁₈) for Tianfu goat was 0.72, which was the highest of all the traits, and the estimates of heritability about weight at birth （Wo）, 1 months （W₁）, 2 months （W₂）, 12 months (W₁₂) and adult goats （W_A） were 0.53, 0.54, 0.45 0.49 and 0.28 respectively, which were middle heritable characters, and the estimates of the average daily gain of weaning goats （ADG₁） was 0.16, which was low heritable character. The genetic correlations between the weight at different ages for Tianfu goat especially that between the weights before 4 months were high, and the phenotypic correlations were high too. This was beneficial to selection in the earlier period of Tianfu goat. However, the genetic correlations between W₁₈ and the weight at other months were low, but the phenotypic correlations were high.The heritability of the litter number was 0.24. The genetic correlations between the litter number and the birth weight and lmonth were -0.74 and -0.55 respectively. The genetic correlation between the number of sibs and the average daily gain before weaning was -0.34. The phenotypic correlation and the genetic correlation between the birth weight更多还原