Estimated genetic associations among reproductive traits in Nellore cattle using Bayesian analysis
Edson V Costa1, Henrique T Ventura2, Renata Veroneze3
1Department of Animal Science, Universidade Federal de Viçosa, 36570-000, Viçosa, MG, Brazil; ABCZ, Associacão Brasileira dos Criadores de Zebu, Pq. Fernando Costa, 38022-330, Uberaba, MG, Brazil.
Animal Reproduction Science
|February 24, 2020
Summary
Selecting bulls based on scrotal circumference can improve female reproductive traits like age at first calving and stayability in Nellore cattle. Indirect selection using scrotal circumference is more efficient for improving age at first calving.
Area of Science:
- Animal Genetics
- Reproductive Biology
- Quantitative Genetics
Background:
- Reproductive traits in cattle are influenced by genetic factors common to both sexes.
- Understanding genetic correlations is crucial for effective selection programs.
- Scrotal circumference in bulls may indicate genetic potential for female reproductive efficiency.
Purpose of the Study:
- To estimate genetic parameters for scrotal circumference at 365 days (SC365), age at first calving (AFC), and stayability (STAY) in Nellore cattle.
- To evaluate the relative efficiency of indirect selection for AFC and STAY using SC365.
- To assess genetic correlations between these key reproductive traits.
Main Methods:
- Bivariate Bayesian analysis using a linear-animal model for SC365 and AFC.
- Threshold-linear model applied for SC365 and STAY, and AFC and STAY.
- Heritability and genetic correlations were estimated using posterior means.
Main Results:
- Heritability estimates were 0.29 for SC365, 0.08 for AFC, and 0.09 for STAY.
- A favorable genetic correlation (-0.45) was found between SC365 and AFC.
- Indirect selection for AFC using SC365 demonstrated higher efficiency (ERS = 1.87) compared to direct selection.
Conclusions:
- Scrotal circumference is a potentially useful trait for indirect genetic selection to improve female reproductive performance in Nellore cattle.
- Selection based on bull scrotal circumference can enhance early reproductive maturity and longevity in female offspring.
- Genetic parameters estimated support the use of SC365 as an indicator trait for improving female fertility traits.
More Related Videos
Related Concept Videos
01:06Heritability
527
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"...
527
01:35Pedigree Analysis
88.6K
Overview
88.6K
01:49Multiple Allele Traits
37.7K
The Concept of Multiple Allelism
37.7K
01:43Incomplete Dominance
29.5K
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.
29.5K
01:25Genetic Variation
1.1K
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,...
Genes exist in different versions called alleles,...
1.1K
01:19X-linked Traits
58.1K
In most mammalian species, females have two X sex chromosomes and males have an X and Y. As a result, mutations on the X chromosome in females may be masked by the presence of a normal allele on the second X. In contrast, a mutation on the X chromosome in males more often causes observable biological defects, as there is no normal X to compensate. Trait variations arising from mutations on the X chromosome are called “X-linked”.
58.1K