Medellín, jul. 03 de 2012 - Agencia de Noticias UN- UN-Medellín researchers have studied 750,000 mutations within the dairy cattle genome using molecular markers in hopes of improving production and reproduction factors.

Every living being has information stored within its DNA, which is a sequence of nucleotides called adenine, guanine, cytosine and thymine. In some of these genes, these nucleotide sequences can change. 

Researchers  extract samples from animals at every stage of their lives, including the embryonic stage. The DNA is extracted from the cells, and the genes of interest are assessed. 

“We are currently working with molecular markers on a panel of ten plus dairy cow genes, including the bovine leukocyte antigen, prolactin, the growth hormone, kappa casein and lactoferrine 18, amongst others”, says Albeiro López Herrera, Animal Production Professor of the Agriculture Faculty. 

From the samples taken from the dairy cattle (calves, cows and bulls) we then assess the differences in these genes by linking them to their respective productive and reproductive characteristics. For example, if a gene has a change in its sequence, and that’s associated with greater or lesser milk production, that would constitute a molecular marker. 

However, in the productive and reproductive characteristics of cattle, two features, genes and environment, are particularly influential. López says, “within their environment we look into the animal’s living conditions, such as humidity, rainfall, nutrition, sanitary management and other characteristics like number of births. Through genetic improvements we try to manage these features by means of a statistical program in order to isolate those environmental effects and maintain them on the same baseline”. 

At the University of Milan, they have studied 750,000 mutations within the diary cattle genome and found alterations in chromosomes 1, 2 and 29 (bovines have 30 pairs of chromosomes, 29 autosomal and 1 sexual). 

One they had obtained the results they then  identified the best animals with the best genes, From these examples a genetic “package” was presented to the cattle rancher in order for him to select the most effective individuals in terms of reproduction and production. In fact, group researchers have already evaluated 196 bulls and 2500 cows from dairy farms in the Province of Antioquia. 

This project is part of the Biodiversity, and Molecular Genetics Research group (BIOGEM, for its Spanish acronym) in the animal improvement and molecular genetics division. 

(Por:Fin/dg/clc)

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