1. Introduction
Criollo Bos taurus cattle like the Colombian breeds are adapted
to severe tropical and subtropical environments and could be
useful in cow–calf production. A large research effort to evaluate
the Colombian breed Romosinuano as purebreds and crossbreds
with Brahman and Angus was begun in the early 2000s in Florida
(USA) for multiple traits of economic importance in beef production
(Riley et al., 2007). Romosinuano crossbreds (with Bos taurus
cattle) had similar reproductive rates to Hereford, Angus, and
Bonsmara crosses, lower reproductive rates than Beefmaster and
Brangus cross cows, and weaned lighter calves than cows of all
other groups on the U.S. Great Plains (Wheeler et al., 2006). Forage
(tall fescue) containing a toxin predominates in some temperate