|Van Tassell, Curtis - Curt|
Submitted to: Animal Genetics International Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 2/28/2006
Publication Date: 7/15/2006
Citation: Avelar, G.A., Neto, L.R., Teixeira, L.A., Sonstegard, T.S., Van Tassell, C.P., Garcia, J.F. 2006. Detection of quantitatiave trait loci affecting growth and reproductive traits in bos indicus beef cattle (nellore) [abstract]. Animal Genetics International Conference Proceedings. pp 180.
Technical Abstract: The objective of this study was to identify quantitative trait loci of economic importance in purebred Bos indicus beef cattle breed (Nellore). Two half-sib families constituted of 187 (family 1) and 189 (family 2) female sisters, daughters from two distinct bulls, where used. Each parent (F0) was individually genotyped with 59 microsatellites covering cattle chromosomes 4, 5, 14 and 20, in order to select informative markers. Thirty-one informative markers have been used for genotyping F1 individuals. Genotyping information, expected progeny differences (EPD) values for birth weight (kg), weaning weight (kg), maternal effect (kg), weight gain in 345 days (between weaning and 18 months old) (kg), eighteen months weight (kg), scrotal circumference (cm), muscularity (un), height (cm), carcass precocity (un), body conformation (un) and early sexual puberty (%), and position of markers from Meat Animal Research Center (MARC) were assembled using software QTL Express at 1-cM interval for each chromosome by the regression approach and 10.000 permutations. In total, one genome-wide significant (P<0,05), eight suggestive and five QTL chromosome-wide were detected. The significant and all suggestive QTL affecting growth traits identified in chromosome 4 were in 24-cM position on MARC map. The QTL identified in chromosomes 4, 5 and 14 affecting growth and reproductive traits were mapped on regions already described in other populations. Regions identified underlying QTL should be investigated in other related Bos indicus (Nellore) populations. These results are the first description of efforts to identify and characterize QTL that could affect growth and reproduction traits in Nellore breed.