Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Pedigree Analysis

Pedigree Analysis

Heritability

Heritability

Heritability is a statistical concept that measures the degree to which genetic differences among individuals contribute to trait variations within a population. It is a fundamental idea in genetics, often prone to misinterpretation. Heritability is expressed as a percentage, reflecting the proportion of variation in a specific trait across a population that can be linked to genetic differences. However, it's important to understand that heritability does not determine how "genetic"...

Incomplete Dominance

Incomplete Dominance

Gregor Mendel's work (1822 - 1884) was primarily focused on pea plants. Through his initial experiments, he determined that every gene in a diploid cell has two variants called alleles inherited from each parent. He suggested that amongst these two alleles, one allele is dominant in character and the other recessive. The combination of alleles determines the phenotype of a gene in an organism.

Monohybrid Crosses

Monohybrid Crosses

Hardy-Weinberg Principle

Hardy-Weinberg Principle

Diploid organisms have two alleles of each gene, one from each parent, in their somatic cells. Therefore, each individual contributes two alleles to the gene pool of the population. The gene pool of a population is the sum of every allele of all genes within that population and has some degree of variation. Genetic variation is typically expressed as a relative frequency, which is the percentage of the total population that has a given allele, genotype or phenotype.

Genetic Variation

Genetic Variation

Genetic variation is the diversity in DNA sequences found among individuals of the same species. This diversity is crucial for a species' survival because it helps organisms adapt to environmental changes. Genetic variation begins with fertilization, where an egg and sperm cell merge. Each of these cells carries 23 chromosomes, up to 46 in the fertilized egg. Chromosomes are long DNA strands that contain genes, the basic units of heredity.
Genes exist in different versions called alleles,...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Genetic Indicators of Performance Resilience in Barrel Racing Quarter Horses.

Animal genetics·2026

Same author

Thermal Thresholds and Genetic Sensitivity in Barrel Racing Performance of Quarter Horses Across Temperature-Humidity Indices.

Journal of animal breeding and genetics = Zeitschrift fur Tierzuchtung und Zuchtungsbiologie·2026

Same author

Genotype-By-Environment Interaction for Scrotal Circumference in Young Nellore Bulls Under Pasture and Feedlot Conditions and Its Correlation With Days to Calving.

Animal genetics·2026

Same author

Genomic Prediction and Genome-Wide Association Analysis of Heat Tolerance for Milk Yield in Buffaloes Using a Reaction Norm Model.

Journal of animal breeding and genetics = Zeitschrift fur Tierzuchtung und Zuchtungsbiologie·2025

Same author

Genetic Parameters of Resilience Indicators Across Growth in Beef Heifers and Their Associations With Weight, Reproduction, Calf Performance and Pre-Weaning Survival.

Journal of animal breeding and genetics = Zeitschrift fur Tierzuchtung und Zuchtungsbiologie·2025

Same author

Genotype-by-environment interaction for yearling weight of Nellore cattle in pasture and feedlot conditions using a "double" genomic reaction norm model.

Journal of animal science·2025

Search research articles

Related Experiment Video

Updated: May 24, 2025

The Use of Traditional Fear Tests to Evaluate Different Emotional Circuits in Cattle

The Use of Traditional Fear Tests to Evaluate Different Emotional Circuits in Cattle

Published on: April 22, 2020

Genetic Evaluation of Barrel Racing Performance in Quarter Horses.

Mário Luiz Santana¹, Thiago Garcia Botelho Franco^1,2, Annaiza Braga Bignardi¹

¹Grupo de Melhoramento Animal de Mato Grosso (GMAT), Instituto de Ciências Agrárias e Tecnológicas, Universidade Federal de Rondonópolis (UFR), Rondonópolis, Brazil.

Journal of Animal Breeding and Genetics = Zeitschrift Fur Tierzuchtung Und Zuchtungsbiologie

|March 1, 2025

Summary

Genetic parameters for barrel racing time (BRT) in Brazilian Quarter Horses were estimated. Selection at younger ages (36-54 months) can optimize performance, but a strategic breeding program is needed for genetic progress.

Keywords:

equestrian sport genetic parameters heritability random regression speed

More Related Videos

Author Spotlight: Exercise Test for Evaluation of the Functional Efficacy of the Pig Cardiovascular System

Author Spotlight: Exercise Test for Evaluation of the Functional Efficacy of the Pig Cardiovascular System

Published on: May 12, 2023

Analysis of Chromosome Segregation, Histone Acetylation, and Spindle Morphology in Horse Oocytes

Analysis of Chromosome Segregation, Histone Acetylation, and Spindle Morphology in Horse Oocytes

Published on: May 11, 2017

Related Experiment Videos

Last Updated: May 24, 2025

The Use of Traditional Fear Tests to Evaluate Different Emotional Circuits in Cattle

The Use of Traditional Fear Tests to Evaluate Different Emotional Circuits in Cattle

Published on: April 22, 2020

Author Spotlight: Exercise Test for Evaluation of the Functional Efficacy of the Pig Cardiovascular System

Author Spotlight: Exercise Test for Evaluation of the Functional Efficacy of the Pig Cardiovascular System

Published on: May 12, 2023

Analysis of Chromosome Segregation, Histone Acetylation, and Spindle Morphology in Horse Oocytes

Analysis of Chromosome Segregation, Histone Acetylation, and Spindle Morphology in Horse Oocytes

Published on: May 11, 2017

Area of Science:

Animal Genetics
Quantitative Genetics
Equine Science

Background:

Barrel racing is a popular rodeo event demanding speed and agility.
Understanding genetic parameters for barrel racing time (BRT) is crucial for effective breeding programs.
Brazilian Quarter Horses are prominent in this discipline, necessitating breed-specific genetic analysis.

Purpose of the Study:

To estimate genetic parameters for barrel racing time (BRT) in Brazilian Quarter Horses.
To identify the most suitable statistical model for analyzing longitudinal BRT data.
To provide insights for optimizing genetic selection strategies to improve barrel racing performance.

Main Methods:

Analysis of 356,877 BRT records from 14,108 Brazilian Quarter Horses (2010-2024).
Comparison of a repeatability model with three random regression models (RRMs).
Selection of the cubic RRM as the best-fit model for longitudinal data analysis.

Main Results:

Heritability estimates for BRT ranged from 0.15 to 0.24, peaking between 36 and 54 months of age.
Strong genetic correlations (> 0.8) were observed between BRT at different ages, with a notable decrease between 36 and 144 months (0.65 ± 0.09).
Phenotypic improvement in BRT was observed, but significant genetic progress was lacking, attributed to the absence of a formal breeding program and use of estimated breeding values.

Conclusions:

The cubic RRM is the most appropriate model for analyzing BRT in this population.
Selecting horses at younger ages (36-54 months) is recommended for effective genetic improvement in barrel racing.
Implementing a strategic breeding program utilizing estimated breeding values is essential to enhance genetic gains and optimize barrel racing performance in Brazilian Quarter Horses.