4. Conclusion and implications
The high performance of F1 and Romosinuano cows for calving
and weaning rate was an important result of this work. The direct
Romosinuano effect was favorable on these critically-important
reproductive rate traits. Heterosis for calving and weaning rate
was as large as earlier reports for Bos indicus–Bos taurus crosses.
Romosinuano direct effects on day of conception were unfavorable,
yet these results merit strong consideration of this Criollo
breed in such an environment. Although the effect of grazing endophyte-infected
tall fescue was detrimental on most of the
evaluated traits, the estimates of genetic effects were minimally
affected by adjusting for the type of forage grazed during the
breeding season. The detection of these genetic effects in temperate
(Arkansas) conditions but not subtropical conditions (Florida)
provides more evidence for the importance of genotype–environment
interactions in beef production systems