Assessment of Genetic Variability Using Pedigree Analysis of the Brahman Breed in Brazil

Abstract Text: The aim of this study was to assess the genetic variability of Brahman cattle in Brazil by analyzing information obtained by genealogical register. The pedigree data was formed by 207,747 Brahman, the animals were born from 1994 to 2012. The effective population size in the year 2012 was 108. 5.17% of animals had some level of inbreeding and the inbreeding coefficient average was 5.94. Average generation interval was 4.73 years and equivalent number of known generations was 2.36. Results of the parameters based on the probability of gene origin, effective number of founders (f_e), effective number of ancestors (f_a) and founder genome equivalents (f_g), show a reduction in the genetic diversity in which f_e > f_a > f_g. The f_e/f_a and f_g/ f_e ratios observed show that the decrease in genetic variability was not assigned by the bottleneck effect and genetic drift. 

Keywords: inbreeding, ancertors, probability of gene origin