Parameter estimates for reproductive and carcass traits in Nelore beef cattle
M E Buzanskas1, P S Pires1, T C S Chud1
1Departamento de Ciências Exatas, Faculdade de Ciências Agrárias e Veterinárias, UNESP-Univ Estadual Paulista, Jaboticabal, São Paulo, Brazil.
Theriogenology
|February 27, 2017
Summary
Scrotal circumference in Nelore cattle shows moderate heritability and favorable genetic correlations with age at first calving and carcass traits. Measuring scrotal circumference at 365 days could improve breeding selection indices.
Area of Science:
- Animal Genetics
- Quantitative Genetics
- Livestock Breeding
Background:
- Genetic parameter estimation is crucial for effective livestock breeding programs.
- Understanding genetic influences on traits like scrotal circumference, age at first calving, and carcass quality is vital for Nelore cattle improvement.
- Maternal genetic effects can play a significant role in the development of certain traits.
Purpose of the Study:
- To estimate genetic parameters for scrotal circumference (at 365 and 450 days), age at first calving, and carcass traits (ribeye area, backfat, rump fat) in Nelore cattle.
- To provide essential data for optimizing the Nelore cattle breeding program.
- To evaluate the significance of maternal genetic effects on scrotal circumference.
Main Methods:
- Employed the Average Information Restricted Maximum Likelihood (AIRML) method for genetic parameter estimation.
- Conducted both single-trait and multi-trait analyses using various animal models.
- Incorporated statistically significant maternal genetic effects for scrotal circumference measurements in multi-trait analyses.
Main Results:
- Direct heritability estimates were 0.31 for SC365, 0.38 for SC450, 0.24 for AFC, 0.32 for REA, 0.16 for BF, and 0.19 for RF.
- Maternal heritability for SC365 and SC450 was estimated at 0.06 and 0.08, respectively.
- Strongest genetic correlations were observed between scrotal circumference measurements; favorable correlations were noted with AFC and carcass traits.
Conclusions:
- Scrotal circumference at 365 days (SC365) is a promising trait for inclusion in Nelore selection indices.
- SC365 selection can potentially improve age at first calving and carcass traits simultaneously.
- Further evaluation of maternal effects in genetic parameter estimation for scrotal circumference is recommended for accurate breeding value ranking in Nelore cattle.
Related Concept Videos
01:01Production Efficiency
18.9K
Net production efficiency (NPE) is the efficiency at which organisms assimilate energy into biomass for the next trophic level. Due to low metabolic rates and less energy spent on thermoregulatory processes, the NPE of ectotherms (cold-blooded animals) is 10 times higher than endotherms (warm-blooded animals).
18.9K
01:38Limits to Natural Selection
35.7K
Organisms that are well-adapted to their environment are more likely to survive and reproduce. However, natural selection does not lead to perfectly adapted organisms. Several factors constrain natural selection.
35.7K
01:26Distributions to Estimate Population Parameter
5.3K
The accurate values of population parameters such as population proportion, population mean, and population standard deviation (or variance) are usually unknown. These are fixed values that can only be estimated from the data collected from the samples. The estimates of each of these parameters are sample proportion, the sample mean, and sample standard deviation (or variance). To obtain the values of these sample statistics, data are required that have particular distribution and central...
5.3K
01:35Pedigree Analysis
90.3K
Overview
90.3K