Characterization of Growth/Differentiation Factor 11 and The Role it Plays in Growth, Carcass, and Meat Quality Traits of Beef Cattle
Date
2025-05-15
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
0009-0001-6835-2235
Type
Thesis
Degree Level
Masters
Abstract
Growth differentiation factor 11 (GDF11) is a member of the Transforming Growth Factor β (TGFβ) superfamily and contributes to developmental functions in mammals including anterior/posterior patterning, formation of organs, and olfactory neurogenesis. The absence of GDF11 and mutations in this gene can cause severe developmental defects. A previously reported association between a non-coding variant in the 5’ region of GDF11 and changes in backfat and marbling, suggests a role in adipose tissue deposition (Spencer et al. 2023). This thesis reports a finishing trial conducted with 120 steers genotyped for the variant rs136619751 (GDF11-V1), a meat quality analysis performed on 75 striploins from the feedlot cohort, and an analysis of the variant effect on calf growth traits. Additionally, investigation of GDF11 variants and frequencies among other cattle breeds was performed and a quantitative Real-time PCR assay was executed to analyze relative gene expression of the GDF11-V1 variant. There were no differences observed in growth traits of feedlot steers or calves among genotypes (P>0.05), though there was a tendency (P=0.07) for an interaction between genotype and initial weight in relation to backfat thickness. CT cattle had greater marbling percentage and greater yield scores across weight classes (weight class × genotype, P≤0.03) while marbling of CC and TT did not differ across weight class. Lightness value (L*) of the striploin was less for steers with the CC genotype (36.48) than CT steers (37.96, P=0.04); while TT steers did not differ from either treatment (37.43). The proximate fat composition tended to be greater for TT striploins than CC striploins (P=0.08) with CT not differing. These data were interpreted to suggest that steer weight class and the GDF11 variant genotype interact to affect carcass fat characteristics. Relative gene expression did not change among genotypes (P>0.05). The GDF11-V1 variant was screened in 24 samples of 12 cattle breeds and identified in 5 individuals. Four additional variants were recorded in the GDF11 sequence. Wagyu cattle DNA was further genotyped for the GDF11-V1 variant and exhibited a higher frequency of the T allele than the crossbred steer population. The results of this study indicate the possibility of an interaction of GDF11 and weight in fat deposition however, further research should be performed with a larger sample size and blocking steers by weight.
Description
Keywords
Growth/differentiation 11, beef, marbling percentage, meat quality, SNP
Citation
Degree
Master of Science (M.Sc.)
Department
Animal and Poultry Science
Program
Animal Science