Genetic parameters for fertility related disorders in Norwegian Red

Abstract

Heritabilities and genetic correlations were estimated for the 4 most common fertility related disorders in Norwegian Red: retained placenta, cystic ovaries, silent heat and metritis. Each of the 4 disorders was analyzed separately with the first 5 lactations as correlated traits using multivariate threshold sire models. Heritability estimates ranged from 0.03 to 0.14, and were lowest for metritis and highest for cystic ovaries. The genetic correlations between lactations for cystic ovaries (0.74 – 0.95) was high and close to 1. So was also the correlations for retained placenta for lactations 2 through 5 (0.86 – 0.94), while the correlation between first and later lactations was lower (0.59 – 0.68). The genetic correlations between lactations were moderate for metritis (0.40-0.77) and silent heat (0.37-0.79). The results suggested that cystic ovaries can be considered to be the same trait genetically across lactations, while metritis and silent heat was different traits genetically across lactations and retained placenta in first lactation was genetically different from the subsequent lactations.