Genomic selection for longitudinal traits of Holstein cattle

• Grant number: 13/23530-5
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: April 01, 2014
• End date: March 31, 2015
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Genetics and Improvement of Domestic Animals
• Principal Investigator: Sandra Aidar de Queiroz
• Grantee: Daiane Cristina Becker Scalez
• Supervisor: Sven König
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil
• Institution abroad: Universität Kassel, Germany
• Associated to the scholarship: 13/01068-8 - Genomic selection for longitudinal traits of Holstein cattle, BP.DR

Abstract

Longitudinal traits are of great significance for animal production, however, when it comes to genomic selection several methods are being evaluated for specific traits, such as milk yield in age-specific or total production. Thus, applying these methods to complete trajectories of the phenotype of interest over time can be an important tool for helping to decide the best time to select the animals. In this study, milk, protein and lactose yield, and somatic cell score data of dairy cattle will be used, in a two-stage method, where the nonlinear Wood (1967), Cobby & Le Du (1978), Wilmink (1987) and Pollott (2000) will be adjusted. The best model will be chosen by different criteria such as mean square residual adjustment (MSE), number of iterations, prediction error, Akaike (AIC) and Schwarz Bayesian (BIC) information criterion. This model has the estimates of its parameters subsequently used as phenotypes. In the second stage, different methods for estimating the genomic values (GBV) will be tested, such as: RR-BLUP, Bayes A, B and Bayesian LASSO, which use as phenotypes the parameter estimates obtained previously. The matching of phenotypes and GBV will be verified by cross-validation, enabling the selection of the most appropriate method for assessing longitudinal traits in dairy cattle. (AU)