Influence of inbreeding on fertility in Holsteins

HOFMANNOVÁ, Michala, PŘIBYL, Josef, KRUPA, Emil and PEŠEK, Petr. Influence of inbreeding on fertility in Holsteins. Náš chov, 2017, vol. 77(9), p. 18-20. ISSN 0027-8068.
CathegoryPublication in specialized journals
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In this work, the breeding value of fertility was estimated simultaneously for cows and heifers with the inclusion of inbreeding effect. Average inbreeding increased from 1 % in 1996 to almost 5 % in 2013. Negative impact of inbreeding on heifers and cows fertility was found. The fertility of heifers and cows are not the same trait but are dependent. Correlation between heifers and cows was intermediate with value r = 0.56. Heritability for cows fertility was h2 = 0.020 with 6 % of repeatability. For heifer’s fertility, heritability was h2 = 0.013 and repeatability was 7 %. In a contrast of routine procedure in Czech Republic our evaluation included the random effect of permanent environment of females which is more important than animal genetic effect. Variability explained by the genetic effect of 1.30 % for heifers and 1.99 % for cows and by permanent environment of 5.67 % for heifers and of 4.09 % for cows. Correlation between inbred and non-inbred breeding values is 0.99. Therefore the consideration of inbreeding does not affect the breeding value, but fertility itself is affected by inbreeding.