Estimation of genetic parameters and breeding values for litter size in the first three parity of landrace sows

Abstract

The aim of this study was to estimate the genetic parameters and breeding values for reproduction traits of Landrace sows in the first three parities by Animal model. Records of 2238 first parity; 2125 second parity and 1872 third parity Landrace sows farrowing between 2007 and 2012 were included in the analysis. The traits included in the analyses were total pigs born (TB), number of pigs born alive (NBA), number of pigs weaned (NW) and litter weaning weight (LW) in the parities. The genetic parameters were estimated using a multivariate analyses Animal model using REML procedure. Estimates of heritability for TB were 0.03, 0.05 and 0.18, for NBA were 0.04, 0.02 and 0.17, for NW were 0.08, 0.08 and 0.01 and for LW were 0.09, 0.11 and 0.03 for parities 1 to 3. Genetic and phenotypic variance were increased from the first to the third parity. Between the majorities of studied reproductive traits were the recorded positive genetic and phenotypic correlations, except between LW and other analyzed properties where they recorded a high correlation negative in third parity. Means of estimated breeding values of reproductive traits from first parity to third parity was indecreased.

Phenotypic correlations between reproductive characteristics related to litter and reproductive cycle length in sows

“…We found strong positive phenotypic correlations between the litter-related traits, the strongest of which being that between litter size and the number of piglets born alive (0.90), a result confirming observations by Zhang et al (2016a), Lukac et al (2016), Lee et al (2015), and Popovac et al (2012), in whose studies this correlation ranged from 0.90 to 0.92. Some others, however, reported slightly different estimates, but all were https://doi.org/10.17221/108/2020-CJAS in pigs are missing.…”

“…We observed high correlation coefficients between the number of weaned piglets and litter size (0.68) and the number of piglets born alive (0.78), higher than those reported by other researchers, namely 0.63 and 0.57 in Lukac et al (2016) and 0.48 and 0.59 in Oh et al (2006). So high values of these correlation coefficients we obtained in the study may indicate that the conditions in which the animals were kept and the piglets were raised were optimal.…”

“…Variation in phenotypic correlations between the litter-related traits (litter size and the numbers of piglets born alive and weaned) may result from the fact that different sows, and particularly sows of different breeds, differ in behaviour, milk production, and how careful they are as mothers (Schwarz et al 2009) -but also from environmental factors, including feeding and herd management. Lukac et al (2016) observed higher correlation coefficients between litter-related traits in multiparous sows than in primiparous ones, an observation likely indicating that the reproductive capacity increases with age. This interpretation led Lukac et al (2016) to conclude that another important factor affecting this variation in correlation coefficients may be the number of farrowings a sow has had.…”

“…Lukac et al (2016) observed higher correlation coefficients between litter-related traits in multiparous sows than in primiparous ones, an observation likely indicating that the reproductive capacity increases with age. This interpretation led Lukac et al (2016) to conclude that another important factor affecting this variation in correlation coefficients may be the number of farrowings a sow has had.…”

Genetic parameter and genetic trend estimates for reproductive traits in Wistar rats

“…Estimated genetic parameters for reproductive traits are primordial to guide the selection process in animal breeding programs. In addition, the estimation of (co)variance component is essential to predict accurate breeding values (Lukač et al, 2016). Therefore, through knowledge of the genetic architecture of economically important traits, it is possible to define the best dam selection strategy in order to increase Wistar rat production.…”