title: Genetic trend estimates of meat quality traits  in a male broiler line.
abstract: The present research was conducted to estimate the genetic trends for meat quality traits in a male broiler line. The traits analyzed were initial pH, pH at 6 h after slaughter, final pH, initial range of falling pH, final range of falling pH, lightness, redness, yellowness, weep loss, drip loss, shrink loss, and shear force. The number of observations varied between 618 and 2125 for each trait. Genetic values were obtained by restricted maximum likelihood, and the numerator relationship matrix had 107,154 animals. The genetic trends were estimated by regression of the broiler average genetic values with respect to unit of time (generations), and the average genetic trend was estimated by regression coefficients. Generally, for the traits analyzed, small genetic trends were obtained, except for drip loss and shear force, which were higher. The small magnitude of the trends found could be a consequence of the absence of selection for meat quality traits in the line analyzed. The estimates of genetic trends obtained were an indication of an improvement in the meat quality traits in the line analyzed, except for drip loss.
authors.affiliation: Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, Piracicaba, SP, Brasil.
authors.forename: G B
authors.initials: GB
authors.lastname: Mourão
authors.forename: L G
authors.initials: LG
authors.lastname: Gaya
authors.forename: J B S
authors.initials: JB
authors.lastname: Ferraz
authors.forename: E C
authors.initials: EC
authors.lastname: Mattos
authors.forename: A M M A
authors.initials: AM
authors.lastname: Costa
authors.forename: T
authors.initials: T
authors.lastname: Michelan Filho
authors.forename: O C
authors.initials: OC
authors.lastname: Cunha Neto
authors.forename: A M
authors.initials: AM
authors.lastname: Felício
authors.forename: J P
authors.initials: JP
authors.lastname: Eler