Chemical gasification: An alternative approach to in vitro maturation of bovine oocytes.

This study aimed to evaluate the effect of chemical gasification and HEPES as alternative systems to pH control during in vitro maturation on bovine oocytes competence. Groups of 20 bovine cumulus oocytes complexes (COCs) were randomly distributed and cultured for 24 h in one of the following experimental groups: (i) chemical reaction (ChRG) system: CO2 generated from sodium bicarbonate and citric acid reaction (ii) culture media TCM-HEPES (HEPES-G); and (iii) control group (CNTG) in conventional incubator. After in vitro maturation (IVM), the COCs were in vitro fertilized (IVF), and in vitro cultivated (IVC) in a conventional incubator.

Genome-wide association study for growth traits in Blanco Orejinegro and Romosinuano cattle.

Growth traits are economically important characteristics for the genetic improvement of local cattle breeds. Genome-wide association studies (GWAS) provide valuable information to enhance the understanding on the genetics of complex traits. The aim of this study was to perform a GWAS to identify genomic regions and genes associated to birth weight, weaning weight adjusted for 240 days, 16 months, and 24 months weight in Romosinuano (ROMO) and Blanco Orejinegro (BON) cattle.

Genomic variability and population structure of six Colombian cattle breeds.

Analyses of the genetic diversity of indigenous cattle are essential for implementing conservation programs, promoting their sustainable use and maintaining productive advantages offered by these breeds in local conditions. The aim of this study was to investigate the genetic diversity and population structure of six Colombian cattle breeds: Blanco Orejinegro (BON), Costeño con Cuernos (CCC), Romosinuano (ROM), Sanmartinero (SAM), Casanareño (CAS), and Hartón del Valle (HDV). Two additional breed groups were included for comparison: Zebu (CEB) and a crossbreed of Colombian cattle breeds × Zebu.

Prevalence and risk factors of bovine viral diarrhea in Colombian cattle.

Background And Aim: Bovine viral diarrhea virus (BVDV) is present in most cattle-raising countries around the world, and it has a negative economic impact in cattle herds. In Colombia, previous studies have estimated the prevalence of BVDV in specific locations. The aim of this study was to estimate the prevalence of BVDV in cattle herds located at several municipalities across the country and to identify the associated risk and protective factors.

Tick burden in Bos taurus cattle and its relationship with heat stress in three agroecological zones in the tropics of Colombia.

Background: Ticks have a negative effect on dairy and beef cattle production systems around the world, with the concomitant risk they represent for the transmission of some important infectious diseases. Colombian cattle breeds are distributed across different agroecological regions and are exposed to different environmental challenges. In humid and warmer climates such as those from the tropics, tick burden and heat stress are important factors that can compromise livestock performance.

Linkage disequilibrium levels and allele frequency distribution in Blanco Orejinegro and Romosinuano Creole cattle using medium density SNP chip data.

The linkage disequilibrium (LD) between molecular markers affects the accuracy of genome-wide association studies and genomic selection application. High-density genotyping platforms allow identifying the genotype of thousands of single nucleotide polymorphisms (SNPs) distributed throughout the animal genomes, which increases the resolution of LD evaluations. This study evaluated the distribution of minor allele frequencies (MAF) and the level of LD in the Colombian Creole cattle breeds Blanco Orejinegro (BON) and Romosinuano (ROMO) using a medium density SNP panel (BovineSNP50K_v2).