Skip to main content
ARS Home » Research » Publications at this Location » Publication #209393
Title: Estimates of (co) variance components using random regression models for gastrointestinal helminthoid data in Angus cattle.

Author
item Silva, Marcos
item Van Tassell, Curtis - Curt
item Sonstegard, Tad
item COBUCI, JAIME - EMBRAPA
item Gasbarre, Louis

Submitted to: Brazilian Animal Science Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/27/2008
Publication Date: 7/24/2008
Citation: Silva, M.V., Van Tassell, C.P., Sonstegard, T.S., Cobuci, J.A., Gasbarre, L.C. 2008. Estimates of (co) variance components using random regression models for gastrointestinal helminthoid data in Angus cattle. Brazilian Animal Science Society. CD-ROM MEL036. p. 105.

Interpretive Summary:

Technical Abstract: A total of 6,375 FEC measures were determined for 409 animals between 1992 and 2003 from Beltsville Agricultural Research Center Wye Angus herd. Original data were transformed using an extension of the Box-Cox transformation to approach normality and to estimate (co)variance components. The Random Regression Models (RRM) may be used as a new tool for genetic and non-genetic studies of FEC. Phenotypes were analyzed using RRM, by the Restricted Maximum Likelihood method. Within the different orders of Legendre polynomials used, those with more parameters (order 4) adjusted FEC data best. Results indicated that the Box-Cox transformation has direct influence on the (co)variances and genetic parameters and the lambda value, estimated by ML, is the more accurate.