Genetic markers of body composition and carcass quality in grazing Brangus steers

Abstract

ABSTRACT. The somatotropic axis is a major regulatory pathway of energy metabolism during postnatal growth in mammals. Genes involved in this pathway influence many economically important traits. The association of selected SNPs in these genes with carcass traits was examined in grazing Brangus steers. These traits included final live weight, ultrasound backfat thickness (UBFT), rib-eye area, kidney fat weight, hot carcass weight, and intramuscular fat percentage (%IMF). Genomic DNA (N = 246) was genotyped for a panel of 15 tag SNPs located in the growth hormone receptor (GHR), insulin-like growth factor I, insulin-like growth factor-binding protein 6, pro-melanin- Genetic markers of carcass traits in grazing Brangus steers concentrating hormone, suppressor of cytokine signaling 2, and signal transducer and activator of transcription 6 (STAT6) genes. Allelic and haplotype frequencies were compared with those of a sample of European breeds (N = 177 steers). Two tag SNPs in the GHR affected %IMF; one of them (ss86273136) was also strongly associated with UBFT (P < 0.003). The frequency of the most favorable GHR haplotype for %IMF was lower in Brangus steers. Moreover, the haplotype carrying two unfavorable alleles was present at a frequency of 31% in this group. Four tag SNPs on STAT6 had a significant effect on UBFT. One of these, SNP ss115492467, was also associated with %IMF. The STAT6 haplotype, including all the alleles favoring UBFT, was the most abundant variant (34%) in the European cattle, while it had a frequency of 14% in the Brangus steers. The four less favorable variants (absent in the European cattle) were found at a frequency of 38% in the Brangus steers. These results support the association of GHR and STAT6 SNP with carcass traits in composite breeds, such as Brangus, under grazing conditions.

Human-Mediated Introgression of Haplotypes in a Modern Dairy Cattle Breed

“…We observed an enrichment of QTL in the BSW-like haplotypes in mRDC that was close to significance ( P = 0.056). These genes and QTL mainly affected milk composition including fat and protein percentage and yield ( ITPR2 , BCAT1 , LAP3 , and MED28 ) ( Cohen-Zinder et al 2005 ; Pimentel et al 2011 ; Zheng et al 2011 ; Fang et al 2014 ), growth and body conformation traits such as stature ( NCAPG , LCORL , PPP2R1A , IGFBP6 , and CREBBP ) ( Kolbehdari et al 2008 ; Baeza et al 2011 ; Lindholm-Perry et al 2011 ; Cole et al 2014 ; Sahana et al 2015 ), calving and fertility traits ( EIF4G3 , TGFA , and LAP3 ) ( Bongiorni et al 2012 ; Hering et al 2014 ; Höglund et al 2015 ), and feed efficiency-related traits ( CLMP and PPP2R1A ) ( Prakash et al 2011 ; Cole et al 2014 ). We observed a significant enrichment of QTL associated with milk, production, meat, and carcass traits in the introgressed regions from BSW in mRDC ( P = 0.045 for milk, P = 0.019 for production, and P = 0.017 for meat and carcass traits).…”

Identification of Genomic Regions for Carcass Quality Traits within the American Simmental Association Carcass Merit Program

“…Putative QTL regions were compared to known QTL using AnimalQTLdb (http://www.animalgenome.org (accessed on 16 July 2020)). Previously reported QTL for carcass traits that overlap regions identified in this study are included in Supplementary Tables S1-S9 [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. Although the sire family structure of the data limited the resolution of our association analyses, areas of the chromosomes with vertical clusters of markers were of interest as they suggested putative QTL in those regions.…”

“…Putative QTL regions were compared to known QTL using Ani-malQTLdb (http://www.animalgenome.org (accessed on 16 July 2020)). Previously reported QTL for carcass traits that overlap regions identified in this study are included in Supplementary Tables S1-S9 [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30].…”

Evaluación de panel SNP en genes candidatos de vías metabólicas para carne en Hereford

“…Este estudio coincide con los resultados obtenidos por Hale et al (2000) que utilizaron el microsatélite GT en el promotor del gen descrito por Lucy et al (1998) que contenía una versión corta del microsatélite en novillos Angus con menos peso al destete, peso de la canal y puntuación (ó escala) de marmoleado en relación a los novillos con el alelo más largo. Baeza et al (2011) encontraron un efecto significativo sobre grasa intramuscular, donde la distribución de las frecuencias de los marcadores GHR en novillos Brangus mostró que el genotipo más abundante del SNP del promotor de este gen no fue favorable para la disposición de veteado (o marmoleado) mientras que el genotipo más abundante del otro SNP del gen GHR favoreció el mayor contenido de grasa. Este SNP fue identificado previamente por Ge et al (1999) y analizado para las asociaciones con características de crecimiento con niveles séricos de IGF1 en sangre (Ge et al, 2003).…”