| Studies were conducted to evaluate maternal performance differences between females with different porcine stress syndrome (PSS) genotypes. Two data sets were used to conduct this evaluation. The first involved 870 records from 333 females from a synthetic line of pigs selected for their PSS susceptibility. The second data set involved 3100 records from 841 purebred Landrace females. Only records from normal (NN) and carrier (Nn) dams were included.;The first study revealed that Nn females farrowed 0.91 and 0.69 more (P ;Normal females had 0.57 more (P ;The results from the study involving NN and Nn purebred Landrace dams revealed no significant differences for number born alive, number at 21 d, 21-d litter weight, survival rate to 21 d, and farrowing interval. This data set was also used to estimate genetic parameters for these traits. Heritabilities ranged from 0.04 to 0.06 for number born alive, from 0.21 to 0.32 for number at 21 d, and from 0.14 to 0.21 for 21-d litter weight depending on the method of adjusting for environmental factors. Heritabilities of 0.21 and 0.02 were found for survival rate to 21 d and farrowing interval, respectively. |
