Fetuses used for histological analysis.

<p>The fetal age was estimated based on the relation between crown-rump length and time of gestation described by Schnorr and Kressin [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0127691#pone.0127691.ref024" target="_blank">24</a>]. They were genotyped for the 212 bp insertion-deletion variant (<i>indel</i>) associated with polledness in beef and dual-purpose breeds and for the Holstein polled mutation [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0127691#pone.0127691.ref017" target="_blank">17</a>].</p><p>Fetuses used for histological analysis.