Estimation of genetic parameters for growth traits and scrotal circumference in Braunvieh cattle

Author(s)

Diego de Córdova Cucco

• Document type: Master's Dissertation
• Press: Pirassununga.
• Institution: Universidade de São Paulo (USP). Faculdade de Zootecnica e Engenharia de Alimentos (FZE/BT)
• Defense date: 2008-01-28

Examining board members

José Bento Sterman Ferraz; Gerson Barreto Mourão; Alexander George Razook

• Advisor: José Bento Sterman Ferraz

Abstract

The aim of this study was to investigate a database of the Braunvieh cattle in Brazil, to estimate genetic parameters for growth traits, preweaning and postweaning weight gains and scrotal circumference, as well as carcass traits in purebreed and crossbreed Braunvieh cattle. The growth traits analyzed were birth weight (PN), weight at 120 days (P120), 205 days (P205), 365 days (P365), 450 days (P450) and weight at 550 days (P550), Weight gains traits analyzed were, weight gain between birth and 205 days (GPN205), birth and 120 days (GPN120), 120 and 205 days (GP120205), 205 and 365 days (GP205365), 205 and 450 days (GP205450), 205 and 550 days (GP205550), 365 and 550 days (GP365550), 365 and 450 days (GP365450), 450 and 550 days (GP450550). The scrotal circumference was analyzed at 205 days (PE205), at 365 days (PE365), and at 550 days of age (PE550). The (co)variance components were estimated by full animal model, using MTDFREML program. The relationship matrix contained 35.188 animals, and 18.688 with production records. For the preweaning weights the coefficients of direct and maternal additive heritability increased your magnitude from the birth to weaning. In the postweaning weights were observed great maternal influence until the 550 days of age. Interesting response to selection can be expected to the selection for scrotal circumference realized at 205 and 365 days of age, due to high genetic correlation between these traits. The preweaning gain demonstrated great maternal influence until the 120 days, and environmental effect after this age. For postweaning gain great environmental effect was observed. Genetic correlation between the weights was larger for weights taken in shorter interval. Important relationship was not observed between weights and scrotal circumference, indicating independence between these characteristics. The genetic correlations between weights and weight gains were larger between the gain and the weight of the superior limit of the relative weight gain. Due to small amount of records for carcass traits, further studies are necessary to evaluate them. This study can contribute for the better delineated programs for genetic improvement of Braunvieh cattle in Brazil. (AU)