title: Non-additive genetic effects on weights and performance of a Brazilian Bos taurus x Bos indicus beef composite.
abstract: The aim of the present study was to evaluate the heterosis effects on weaning weight at 205 days (WW, n = 146,464), yearling weight at 390 days (YW, n = 69,315) and weight gain from weaning to yearling (WG, n = 59,307) in composite beef cattle. The fixed models were: RM, which included contemporary groups, class of age of dam, outcrossing percentages for direct and maternal effects, and additive direct and maternal (AM) breed effects; R, RM model, minus AM breed effects, and H, RM model, minus additive breed effects. The estimates for W205 were in general positive (P < 0.01). The R and H models resulted in similar estimates, but they were very different from the ones estimated by the RM model. For W390, the R and H models resulted in general positive estimates (P < 0.05). For WG, the RM model resulted in general significant heterosis effects (P < 0.05). It can be concluded that the RM model seems to supply estimates of better quality (P < 0.01).
authors.affiliation: Departamento de Ciências Exatas, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, Piracicaba, SP, Brasil. gbmourao@esalq.usp.br
authors.forename: G B
authors.initials: GB
authors.lastname: Mourão
authors.forename: J B S
authors.initials: JB
authors.lastname: Ferraz
authors.forename: J P
authors.initials: JP
authors.lastname: Eler
authors.forename: R S
authors.initials: RS
authors.lastname: Bueno
authors.forename: J C C
authors.initials: JC
authors.lastname: Balieiro
authors.forename: E C
authors.initials: EC
authors.lastname: Mattos
authors.forename: L G G
authors.initials: LG
authors.lastname: Figueiredo
mesh_terms: D000818:Animals; D001835:Body Weight / Q000235:genetics*; D002417:Cattle; D003433:Crosses, Genetic; D006823:Hybrid Vigor / Q000235:genetics; D006824:Hybridization, Genetic / Q000235:genetics*; D008460:Meat