Full text
| |
| Author(s): |
Luís Gustavo Girardi Figueiredo
Total Authors: 1
|
| Document type: | Master's Dissertation |
| Press: | Pirassununga. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Zootecnica e Engenharia de Alimentos (FZE/BT) |
| Defense date: | 2001-05-24 |
| Examining board members: |
Joanir Pereira Eler;
Mario de Beni Arrigoni;
Jose Bento Sterman Ferraz
|
| Advisor: | Joanir Pereira Eler |
| Abstract | |
This research was conducted to estimate variance components and genetic parameters of carcass traits of Nelore cattle, measured through ultrasound equipment, and also the genetic relationship of those traits with growth traits and visual scores. Data came from three different herds. 1,696 animals were measured in two farms owned by Agro-Pecuaria CFM Ltda. (herd 1) and 951 animals were measured at Fazenda Mundo Novo, owned by Manah Agropastoril Ltda. (herd 2). The traits analyzed were: loin-eye are (AOL, cm2), subcutaneous fat thickness (EGS, mm), weaning weight (PESDES, kg), weight gain from weaning to yearling (GP345, kg), yearling weight (PESSOB, kg), and height (ALT, cm). Visual scores were muscle score (MUSC), body conformation (CONF) e precocity (PREC). (Co)variance components were estimated by REML methods, using the software MTDFREML, under single traits (to estimate components for AOL and EGS) and twotraits analysis to estimate genetic correlations among AOL and EGS and the other traits. Heritability estimates for AOL were 0.19 (herd 1) and 0.41 (herd 2). While for EGS the values estimated were 0.04 (herd 1) and 0.19 (herd 2). The heritability coefficients estimated suggest that the traits can be selected. Further studies are suggested as related to (co)variance components estimation for ultrasound measurements in Nelore cattle. (AU) | |