Genetic relationship between calf livability and calving difficulty of Holsteins.

Multitrait procedure was used to investigate the genetic relationship between calf livability and calving difficulty of Holsteins. The genetic correlation between calf livability and calving difficulty was .66. Heritabilities were .9% for calf livability and 4.1% for calving difficulty. The product-moment correlation (.4) between sires' transmitting abilities estimated separately for livability and dystocia, with properties of Best Linear Unbiased Predicator, underestimated the genetic correlation (.66). The correlated response of calf livability is expected to be 41% greater when selection is for dystocia than is expected from direct selection on calf livability.