| Genetic analyses had been carried out on reproduction and production traits both Zhenghong and Yiyang farm of Hunan. Multi-traits animal model BLUP and MTDFREML were used to estimate variance and covariance of estimate breeding value(EBV), additive effect, maternal effect, maternal permanent environmental effect, common litter effect, and residual effect on 4061 records of reproduction traits from 1998 to 2003, and 1171 records of production traits from 2000 to 2003 .The traits were analyzed including total number of piglets born(TNB), number of piglets born alive (NBA), litter weight of born(LBW), age of reach 100Kg(AGE100),weight of 120 day (W,2o),back fat thickness of 120 day(BF120),body length of 120 day(BL120), chest girth of 120 day(CG120), hip girth of 120 day(HG120), body height of 120 day(BH120), weight of 180 day(W180), body length of 180 day(BL180) chest girth of 180 day(CG180) hip girth of 180 day(HG180), body height of 180 day(WH180) and back fat thickness of 180 day(BF180).The results showed that EBV of AGE100 of Yorkshire and Duroc in Yiyang farm decreased 0.45 day and 0.44 day, And their EBV of BF decreased 0.21mm and 0.07mm, respectively. At the same time, patrilineal index increased 3.99 and 3.06, respectively. Furthermore, EBV of AGE100 and BF of Yorkshire, Landrace and Duroc in Zhenghong farm also reduced 1.21, 1.17, 0.87day and 0.25, 0.45, 0.36mm, patrilineal index has increased 7.86, 4.76 and 4.81, respectively.The estimated heritability of reproductive traits ranged 0.07-0.21. Heritability of TNB,NBA and LBW in Yorkshire, Landrace and Duroc were 0. 12, 0. 13, 0. 15, 0.10, 0.13, 0. 07, 0.15, 0. 21, 0. 12, respectively. However, the estimated heritability of production traits ranged 0.11-0.58. Heritability of W120, BF120,BL120, CG120, HG120, BH120 in Yorkshire were 0.41,0.55,0.34,0.30,0.39,0.28 and in Duroc were 0.35, 0.29, 0.32, 0.45, 0.34,0.18, respectively. Heritability of W180, BF180, BL180, CG180,HG180, BH180 in Yorkshire were 0.49,0.53,0.38,0.37,0.11,0.36, in Landrace were 0.52, 0.55, 0.36, 0.31,0.20 0.30 and in Duroc were 0.58, 0.46,0.43,0.43,0.27,0.34,respectively.Genetic correlation of NBA/TNB, NBA/LBW, TNB/LBW for Yorkshire, Landrace and Duroc was 0. 78, 0. 56, 0. 43, 0. 79, 0. 68, 0. 56, 0. 82, 0. 75, 0. 62, respectively. And genetic correlation of W120/BF120, W180/BF180 was negative, genetic correlation of the other traits were positive.The genetic trends of reproduction traits and production traits were favorable. The genetic trends of TNB, NBA, LBW for Yorkshire, Landrace and Duroc were 0.0038, 0.0583, 0.0677, 0.0024, 0.0359, 0.0235, 0.0032, 0.0421, 0.0187, respectively. And production traits, the genetic trends were coincide with the performance trends, they were all favorable.All the results showed that the developing tendency of all traits was favorable, and the herds quality of the two farms have been improved by breeding over the past years.
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