Effect of service sire on litter size traits in Czech Large White and Landrace pigs

Abstract

Litter size traits generally are lowly heritable (Hanenberg et al., 2001;Wolf et al., 2002;Chen et al., 2003). Therefore, using additional information in genetic evaluations may be beneficial for increasing the precision of predicted breeding values. A potential source of information is the effect of service sire. According to van der Lende et al. (1999), service sire can influence both fertilization rate and prenatal survival rate. Such an effect could be due to genetically determined differences in fertilizing capacity (sperm quality) and the genetic contribution of the sire to the viability of the embryo. Although the proportion of variance for litter size traits in pigs attributable to service sire has ranged from 0.00 to 0.05 (Chen et al., 2003;Hamann et al., 2004;Köck et al., 2009), most authors recommend inclusion of the service sire effect in the animal models for genetic evaluation.Until recently, the service sire effect has not been included in the model equations for genetic evaluation of number of piglets born alive in Czech dam breeds (Wolf et al., 2005), and no information on this effect has been available for those breeds. Therefore, the objective of the present study was to quantify the service sire effect in terms of (co) variance components and to propose models for the potential inclusion of this effect in the linear equations for breeding value estimation. Two additional litter size traits (number of piglets born and number of piglets weaned) were also included in the investigation, because very little information is available on the service sire effect on these traits. MATERIAL AND METHODS DataLitter size data were available from Czech Large White and Czech Landrace sows farrowing be- The proportion of variance for service sire effect was estimated for three litter size traits (numbers of piglets born, born alive, and weaned) in Czech Large White (89 231 litters) and Czech Landrace (28 320 litters) pigs. Each trait in the first parity was considered as one trait and that trait in the second and subsequent parities was treated as a repeated trait. Consequently, three two-trait animal models were evaluated for each litter size trait: (i) the service sire effect was included and the complete relationship matrix for all the animals (service sires and sows) was taken into account; (ii) the service sire effect was included as a random effect without inclusion of the relationship matrix; (iii) the service sire effect was omitted from the model. Using the residual variance as a criterion, both models including the service sire effect were slightly better than the model without this effect. Estimates of genetic parameters were very similar for the two models including the service sire effect. The proportion of variance for service sire was in the range from 2 to 3% (standard error approx. 0.2%) in Czech Large White and 2% (standard error approx. 0.3%) in Czech Landrace for all three litter size traits and all models. Models without service sire effect or models including service sire as a simple rand...

Variance components estimation for farrowing traits of three purebred pigs in Korea

“…Moreover, Chen et al [ 2 ] estimated a higher variation due to service sire effects relative to the values of 3.0% to 4.0% reported in the present study for NBA in Duroc, Landrace, and Yorkshire breeds. Wolf and Wolfova [ 8 ] also reported that 2.0% to 3.0% of the variance was due to service sire effects in Czech Large White, while they were responsible for 2.0% of the variance in Czech Landrace for TNB and NBA.…”

“…However, small reductions in heritability in all breeds were observed when service sire effects were added to the model. Models with or without service sire effects are recommended for genetic evaluation of litter traits [ 8 ].…”

“…Estimates should be breed-specific because there are differences in estimates of variance components among breeds [ 2 ]. Some studies have also revealed the implication of adding maternal or service sire effects in the estimation model [ 6 – 8 ]. Therefore, this study was conducted to estimate the genetic parameters for total number born (TNB), NBA, and mortality (MORT) in Duroc, Landrace, and Yorkshire populations in Korea.…”

Recent developments in cattle, pig, sheep and horse breeding - a review

“…Wolf and Wolfova (2012a) examined the impact of including a service sire effect on litter size traits for Czech Large White and Czech Landrace sows. Three different animal models were evaluated for each litter size trait (total number of piglets born, born alive and weaned): (i) the service sire effect was included and the complete relationship matrix for all the animals (service sires and sows) was taken into account; (ii) the service sire effect was included as a random effect without inclusion of the relationship matrix; (iii) the service sire effect was omitted from the model.…”

Genetic parameters including the service sire effect for the sow traits stillbirth and piglet losses in Czech Large White and Landrace

“…A flexible allocation of records to herd-year-season classes was applied as first described in Wolf et al (2005) and adapted for litter size traits in Wolf and Wolfová (2012). Herd-year-season classes preferably were formed according to natural seasons (spring, summer, autumn, winter) on the basis of the farrowing date and normally had a length of three months.…”