Genetic and Phenotypic Parameters for Reproduction Traits of Landrace Sows in Latvia

Sa？etak The aim of this study was to investigate reproduction performance in the 1st and 2nd parity of Latvian Landrace sows, to estimate genetic parameters for reproduction traits, and to determine their genetic correlations with age at the first farrowing (AFF) and weaning to insemination interval (WII) in the Latvian Landrace swine population. Data from 2054 of the 1st parity and 1416 of the 2nd parity sows were collected from 2005 till 2010 and were included in the analysis. Four reproduction traits in the study were analysed: number of piglets born alive (NBA), number of piglets dead (ND), number of piglets weaned per litter (NW) and 21-day litter weight (W21). Genetic parameters were estimated with multi traits animal model using REML procedure. The heritability estimates in the first parity were 0.07, 0.16, 0.36, 0.01 and 0.32 for NBA, NW, W21, AFF and WII, respectively. Between AFF and sows reproduction traits in the first and the second parity unfavourable genetic correlations were found in the present data set. Moderate negative genetic correlation between WII and sows reproduction traits was observed