A new study shows that cattle with higher heat tolerance have sustainable breeding benefits and offer the potential for improved breeding programmes.
The joint study published on March 27, which includes researchers from University College Dublin (UCD), was based on the distinct characteristics of Criollo cattle.
The breed originated in southern Spain, before being introduced to the New World during the second voyage of Christopher Columbus.
Over centuries, Criollo cattle adapted to the environment of Latin America, showing trait changes.
For the study, 34 breeds were analysed from Colombia and Venezuela, using whole-genome sequencing and single-nucleotide polymorphism (which help scientists locate disease infected genes).
The analysis found genes linked to thermotolerance, reproduction, fertility, immunity and distinct coat and skin coloration traits.
Sustainable breeding
The study results showed that over time the breeds evolved distinct characteristics, such as resistance to diseases and “exceptional heat tolerance”.
It showed changes to the prolactin receptor (PRLR) gene in Criollo cattle populations, which the study states has “major effects” on the length and the structure of hair coats, providing improved thermotolerance.
The same gene also increases fertility and milk yields in cattle populations that inhabit dry and tropical conditions.
The mutations can also cause other physiological changes.
For example, another gene was found in some of the breeds, which regulates heart and blood vessel formation and integrity.
Several genes associated with fertility were also highlighted during the analysis.
Criollo cattle
The study stated that results underscored “the remarkable adaptability” of Criollo cattle.
It added that the results highlighted the “genetic richness” and potential of these breeds in the face of climate change, habitat flux and disease challenges.
The study stated that in modern production systems, Criollo cattle face gradual replacement by more productive commercial breeds.
Further research will develop on these findings for more effective and sustainable cattle breeding programmes in the future.