Fine mapping quantitative trait loci for feed intake and feed efficiency in beef cattle1

Abstract

Feed intake and feed efficiency are economically important traits in beef cattle because feed is the greatest variable cost in production. Feed efficiency can be measured as feed conversion ratio (FCR, intake per unit gain) or residual feed intake (RFI, measured as DMI corrected for BW and growth rate, and sometimes a measure of body composition, usually carcass fatness, RFI(bf)). The goal of this study was to fine map QTL for these traits in beef cattle using 2,194 markers on 24 autosomes. The animals used were from 20 half-sib families originating from Angus, Charolais, and University of Alberta Hybrid bulls. A mixed model with random sire and fixed QTL effect nested within sire was used to test each location (cM) along the chromosomes. Threshold levels were determined at the chromosome and genome levels using 20,000 permutations. In total, 4 QTL exceeded the genome-wise threshold of P < 0.001, 3 exceeded at P < 0.01, 17 at P < 0.05, and 30 achieved significance at the chromosome-wise threshold level (at least P < 0.05). No QTL were detected on BTA 8, 16, and 27 above the 5% chromosome-wise significance threshold for any of the traits. Nineteen chromosomes contained RFI QTL significant at the chromosome-wise level. The RFI(bf) QTL results were generally similar to those of RFI, the positions being similar, but occasionally differing in the level of significance. Compared with RFI, fewer QTL were detected for both FCR and DMI, 12 and 4 QTL, respectively, at the genome-wise thresholds. Some chromosomes contained FCR QTL, but not RFI QTL, but all DMI QTL were on chromosomes where RFI QTL were detected. The most significant QTL for RFI was located on BTA 3 at 82 cM (P = 7.60 x 10(-5)), for FCR on BTA 24 at 59 cM (P = 0.0002), and for DMI on BTA 7 at 54 cM (P = 1.38 x 10(-5)). The RFI QTL that showed the most consistent results with previous RFI QTL mapping studies were on BTA 1, 7, 18, and 19. The identification of these QTL provides a starting point to identify genes affecting feed intake and efficiency for use in marker-assisted selection and management.

Genome-wide association studies for feedlot and growth traits in cattle1

“…The putative positions of their RFI QTL on these 2 chromosomes were in approximately the same positions as 2 significant SNP in this study (P < 2.7 × 10 −3 at 6 Mbp on BTA 1 and P < 3.5 × 10 −4 at 82 Mbp on BTA 3; Table 9). Other significant SNP from the present GWAS found on BTA 8,11,17,18,21,22,24,25,and 26 were also near to those reported by Sherman et al (2009) andNkrumah et al (2007;Table 9). In the report by Sherman et al (2009), the most significant QTL for DFI (P = 1.38 × 10 −10 ) was found on BTA 7 at 54 cM.…”

“…Other significant SNP from the present GWAS found on BTA 8,11,17,18,21,22,24,25,and 26 were also near to those reported by Sherman et al (2009) andNkrumah et al (2007;Table 9). In the report by Sherman et al (2009), the most significant QTL for DFI (P = 1.38 × 10 −10 ) was found on BTA 7 at 54 cM. The closest significant SNP to this DFI QTL in the present study was observed at 55.4 Mbp, with a threshold of P = 0.004.…”

“…Other researchers have reported QTL for RFI in cattle (Barendse et al, 2007;Nkrumah et al, 2007;Sherman et al, 2009). Perhaps because of the lack of power and high FDR, there is not a close agreement between the studies, despite some overlap between the cattle used by Barendse et al (2007) and the 50K SNP database used in this report.…”

Identification of single nucleotide polymorphisms in the ACADS gene and their relationships with economic traits in Hanwoo

“…현재 쇠고기의 품질은 육색, 지방색, 연도 및 근내지방도 등에 의해서 좌 우되며 (Geay et al, 2001;Hoequette et al, 2005), 이 중 근내지방은 쇠고기의 풍미와 연도를 증가시켜 육질등급 결정에 있어 중요한 척도가 되고 있다 (Tatum et al, 1982). (Casas et al, 2001;Casas 2003;Kim et al, 2003;Morsci et al, 2006;Nkrumah et al, 2007;Sherman et al, 2009). 육질 형질과 연관된 주요 유전자들이 여러 연구를 통해 보고되 었으며 그 중 일부는 현재 상업적으로 이용되고 있다.…”

Diferenças no metabolismo de bovinos de corte com eficiência alimentar divergente

“…A variação fenotípica individual que vêm sido encontrada em diversas raças pode ser devido a diversos fatores metabólicos Arthur & Herd, 2008) cuja regulação fisiológica é controlada por muitas centenas de genes (Barendse et al, 2007;Moore et al, 2009;Sherman et al, 2009 No Canadá (Basarab et al, 2003) foram avaliados 176 novilhos Bos taurus para os parâmetros de eficiência e composição corporal, e os animais de menor CAR consumiram menos energia metabolizável (-10,2%), produziram menos calor (-9,3%), tiveram uma menor retenção de energia (-12%), apresentaram vísceras menores (-8,24%), carcaça com menos gordura subcutânea (-12,3%), menos gordura intermuscular (-8%) e menos gordura interna (-6%).…”