Abstract #T79
Section: Breeding and Genetics
Session: Breeding and Genetics: Application and methodology in animal breeding - Beef
Format: Poster
Day/Time: Tuesday 7:30 AM–9:30 AM
Location: Gatlin Ballroom
Session: Breeding and Genetics: Application and methodology in animal breeding - Beef
Format: Poster
Day/Time: Tuesday 7:30 AM–9:30 AM
Location: Gatlin Ballroom
# T79
Assessment of genetic variability of Brazilian Brahman cattle raised either on pasture or stabled by pedigree analysis.
Ligia Cavani*1, Rafael Medeiros de Oliveira Silva2, Michel Marques Farah3, Rafael Keith Ono2, Luis Orlando Duitama Carreño2, Henrique Torres Ventura4, Ricardo Fonseca1, 1São Paulo State University (Unesp), Dracena, São Paulo, Brazil, 2São Paulo State University (Unesp), Jaboticabal, São Paulo, Brazil, 3Brazilian Agricultural Research Corporation (Embrapa), Juiz de Fora, Minas Gerais, Brazil, 4Brazilian Association of Zebu Breeders (ABCZ), Uberaba, Minas Gerais, Brazil.
Key Words: ancestor, inbreeding
Assessment of genetic variability of Brazilian Brahman cattle raised either on pasture or stabled by pedigree analysis.
Ligia Cavani*1, Rafael Medeiros de Oliveira Silva2, Michel Marques Farah3, Rafael Keith Ono2, Luis Orlando Duitama Carreño2, Henrique Torres Ventura4, Ricardo Fonseca1, 1São Paulo State University (Unesp), Dracena, São Paulo, Brazil, 2São Paulo State University (Unesp), Jaboticabal, São Paulo, Brazil, 3Brazilian Agricultural Research Corporation (Embrapa), Juiz de Fora, Minas Gerais, Brazil, 4Brazilian Association of Zebu Breeders (ABCZ), Uberaba, Minas Gerais, Brazil.
The aim of this study was to assess the genetic variability of Brahman cattle in Brazil by analyzing information obtained by genealogical records. The pedigree data were obtained from the Brazilian Association of Zebu Breeders and was formed by 207,747 Brahman animals from different regions of Brazil. In this data set, cattle were born between 1994 and 2012 and they were analyzed in 3 ways: considering all the pedigree information (Pt), and dividing the pedigree data according to animals raised either on pasture (Ppt) or stabled (Pst). The software R was used for data consistency and to generate the file with the following information: animal, sire, dam, birth date, and sex. The software Pedig was used to determine the inbreeding, generation intervals and the results of the parameters based on the probability of gene origin: number of founders (Nf), effective number of founders (fe), effective number of ancestors (fa) and founder genome equivalents (fg). Average inbreeding coefficients (F) were 0.31%, 0.30% and 0.22% for Pt, Ppt and Pst, respectively. However, mean F values for inbred animals were 5.94%, 5.13% and 6.52% for Pt, Ppt and Pst, respectively. In addition, average generation intervals were 4.73, 4.65 and 4.81 years for Pt, Ppt and Pst, respectively. For Pt, the results based on probability of gene origin were 13,764, 101.4, 97.07, 75.02, 1.04, 0.74 for Nf, fe, fa, fg, fe/fa and fg/fe; respectively. For Ppt, the results based on probability of gene origin were 6,906, 94.4, 91.57, 72.93, 1.03, 0.80 for Nf, fe, fa, fg, fe/fa and fg/fe; respectively. For Pst, the results based on probability of gene origin were 2,407, 68.8, 66.36, 58.42, 1.04, 0.88 for Nf, fe, fa, fg, fe/fa and fg/fe; respectively. The number of ancestors to explain 50% of the genetic variability in Pt was 46, in Ppt was 41 and in Pst was 24. The results showed a reduction in genetic variability, because fe > fa > fg. Values close to 1 observed for fe/fa and fg/fe showed no genetic bottleneck and a small process of genetic drift. Thus, genetic variability has been reduced in Brahman cattle population, especially on those from Pst.
Key Words: ancestor, inbreeding
