The Influencing Factors And Genetic Parameters Of Stillbirth And Mummy Of The Saw

Most reports are limited by study of infectious factors impact in sow borning stillbirth and mummy, however, in morden farm, such as work on improving vaccination, offering sufficient nutrition, might studied further non-infectious factors and genetic factors impact of the stillbirth and mummy. In this study, using generalized linear mixed model estimate fixed value, breeding value and heritability, which will be a theoretical basis for selection. And the use of Logistic regression model analysis of the factors impact stillbirth and mummy. Find out mummy and stillbirth's molecular markers,and potentially genetic factors.Using logistic regression analyze parity, breeding month, birth month, number born alive, total number born, mummies rate, stillbirth rate. Using generalized linear mixed model DMUAI estimated stillbirth and mummy's breeding values, values of fixed effects, and further estimated stillbirth and mummy's heritability. Finding new stillbirth and mummy related markers, and analysis of genetic markers found genetic factors of potentially relevant to stillborn and mummies.The results show that estimates the value of the fixed effects of stillbirth and mummies were from larger than large is species, parity, birth month and month of breeding. Logistic regression analysis of stillbirth had found number of born aive, mummy rate, total number born selected into multi-factor regression model, the OR values were: 36.266, 0.030,0.002. Regression analysis of the mummy's result is birth month, the number of born aive, the stillbirth-rate and total number born elected into multi-factor logistic regression model, their OR values were as follows: 1.092,0.404,0.227,2.561. Through Heritability estimates of sow production mummy and stillbirth are 0.344, 0.006 respectively. Breeding value estimates, the highest breeding value for the mummy: 1.9323; minimum: -1.0261. Breeding value of a maximum of stillbirth: 0.1364; minimum: -0.0860. Found out a microsatellite marker that associated with stillbirth, the marker located on chromosome 6 ,80.2cM , related to 13 and 17 weeks of backfat thickness.Through estimated fixed-effects of mummy and stillbirth demonstrated that species had lowest impact, compared to other factors the environmental effects had larger effect. But only the birth month access to the mummy regression model, and the impact of environmental factors on the relevance of mummies have not reported yet, it remains to be further studied. Regression equation of the mummy and stillbirth contain the litter size, this shows that the increase in total number born will increase the incidence of stillbirth and mummy. Through the breeding value and heritability is estimated that the mummy was found suitable for direct selection.The heritability of stillbirth is too low, so difficult to direct selection, might use marker-assisted selection. Marker SW1129 associated with the number of stillbirth and backfat thickness, maybe the number of stillbirth relate genetically with backfat thickness of the saw, and in the surrounding 80.2cM chromosome 6 maybe have a number of stillbirth's QTL,or gene.