Genetic correlations between production and semen traits in pig

Abstract

Genetic correlations between production traits (average daily gain from birth till the end of the field test and ultrasonically predicted lean meat content at the end of the field test) and semen traits (semen volume, sperm concentration, motility, percentage of abnormal spermatozoa, total number of spermatozoa and number of functional spermatozoa) were estimated from a large dataset (44 500 observations for production traits and more than 150 000 ejaculates from 2077 boars). The boars belonged to the breeds Duroc, Pié train and Large White or were crossbreds between them. All estimated genetic correlations were low (maximal absolute value 0.13). Therefore, selection on production traits is expected to have only low effects on semen traits.

Breeding programmes to improve male reproductive performance and efficiency of insemination dose production in paternal lines: feasibility and limitations

“…The variation in the magnitude of this parameter is due to several factors, such as: i) different genetic composition of buck populations among experiments; ii) variation in defining the trait, which in some cases consist of means of observations of 2 consecutive ejaculates or means of several records per male, whereas in other cases it corresponds to individual ejaculates (Ducrocq and Humblot, 1995;Wolft, 2009); and iii) the possible effect of collection frequency on the individual variation of seminal traits.…”

Exploring the genetics of the efficiency of fertile AI dose production in rabbits

“…The PM [HPD95%] of r was 0.25 [0.22, 0.28]. Estimates reported by other authors in rabbits are in agreement with these results for IM or mass motility score ) and with the percentage of progressive motility in different breeds of boars (Wolft, 2009) and bulls (Karoui et al, 2011). This low heritability and repeatability could be due in part to the great variability…”

“…The variation in the magnitude of this parameter is due to several factors such as: i) different genetic composition of populations of bucks in experiments; ii) variation in defining the trait, which in some cases consist of means of observations of two consecutive ejaculates or means of several records per male, whereas in other cases corresponds to individual ejaculates Wolft, 2009); and iii) the possible effect of collection frequency on the individual variation of seminal traits.…”

“…Several studies in different livestock species have estimated the genetic correlation (rg) between ejaculate volume and sperm concentration indicating the existence of a genetic antagonism: in pigs (-0.60 on average; Smital et al, 2005;Wolft, 2009), bulls (-0.31 on average; Karoui et al, 2011;, sheep (-0.36 on average in adult males; Rege et al, 2000;David et al, 2007b) and goats (-0.33 on average; . In rabbits, the only reported estimate of the rg between sperm concentration and ejaculate volume was very imprecise and cannot be considered to be different from zero (0.38 ± 0.45; Low h 2 values have been obtained for sperm motility traits when they have been evaluated in a subjective manner.…”

“…Estimates reported in pigs suggested that genetic correlations between growth and seminal traits such as ejaculate volume, sperm concentration, number of sperm produced, sperm motility and percentage of abnormal spermatozoa were negative, null or positive, but always had low magnitude (Oh et al, 2006a;Wolft, 2009). …”