title: Genetic trends for live weight traits reflect breeding strategies in registered Charolais Farms in Mexico.
abstract: Genetic trends are commonly used to verify genetic improvement; however, there are few reports on beef cattle in Mexico. Data from 1998 to 2013 from four Charolais bull breeding farms were examined to verify the genetic responses to different breeding management and selection criteria. Analysis included the comparison of regression lines of breeding values for birth (BW), weaning (WW) and yearling weights (YW), and maternal weaning weight (MWW) on the year of birth of the animals. Results revealed differential genetic progress for BW and YW and indicated that the overall analysis may have diluted the perception of genetic progress from the farmer's point of view. The use of breeding values as a tool for selection is effective to achieve genetic progress, even in negatively correlated traits, such as birth weight and yearling weight.
authors.affiliation: Centro de Biotecnología Genómica (CBG), Instituto Politécnico Nacional (IPN), Boulevard del Maestro SN, Esq. Elías Piña, Col. Narciso Mendoza, Reynosa, 88710, Tamaulipas, Mexico. gparra@ipn.mx.
authors.forename: G M
authors.initials: GM
authors.lastname: Parra-Bracamonte
authors.affiliation: Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11-222, Palmerston North, New Zealand.|Centro Universitario UAEM Temascaltepec, Universidad Autónoma del Estado de México, Km. 67.5 Carr. Fed. Toluca-Tejupilco, Temascaltepec, Estado de México, Mexico, C.P. 51300.
authors.forename: N
authors.initials: N
authors.lastname: Lopez-Villalobos
authors.affiliation: Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11-222, Palmerston North, New Zealand.
authors.forename: S T
authors.initials: ST
authors.lastname: Morris
authors.affiliation: Centro de Biotecnología Genómica (CBG), Instituto Politécnico Nacional (IPN), Boulevard del Maestro SN, Esq. Elías Piña, Col. Narciso Mendoza, Reynosa, 88710, Tamaulipas, Mexico.
authors.forename: A M
authors.initials: AM
authors.lastname: Sifuentes-Rincón
authors.affiliation: Charolais Herd-Book of Mexico - RON B Charolais Ranch, Hermosillo, Sonora, Mexico.
authors.forename: L A
authors.initials: LA
authors.lastname: Lopez-Bustamante
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D001724:Birth Weight; D001835:Body Weight; D001947:Breeding; D002417:Cattle / Q000235:genetics / Q000502:physiology*; D000072480:Farms; D005260:Female; D008297:Male; D008800:Mexico; D012641:Selection, Genetic; D014329:Tropical Climate
keywords: Beef cattle; Breeding values; Genetic change; Growth; Selection