Adipogenic gene expression and fatty acid composition in subcutaneous adipose tissue depots of Angus steers between 9 and 16 months of age1

Abstract

We have demonstrated that among carcass adipose tissue depots, brisket subcutaneous adipose tissue contains the greatest concentration of MUFA and lowest concentration of SFA. Therefore, we hypothesized that brisket subcutaneous adipose tissue depots would exhibit greater adipogenic gene expression over time than other major subcutaneous adipose tissue depots. Four Angus steers, each at 9, 12, 14, and 16 mo of age, were harvested and fresh subcutaneous adipose tissue samples were collected from over the brisket, chuck, rib, loin, sirloin, round, flank, and plate. Relative gene expression for C/EBPβ, PPARγ, carnitine palmitoyltransferase-1 beta (CPT-1β), stearoyl-coenzyme A desaturase (SCD), AMP-activated protein kinase alpha (AMPKα), and G-coupled protein receptor 43 (GPR43) was analyzed by quantitative real-time PCR. Expression of C/EBPβ, PPARγ, and CPT-1β was greatest at 12 to 14 mo of age (all P < 0.0001) and declined to very low abundance by 16 mo of age in all depots. Expression of PPARγ and CPT-1β was greater (P < 0.03) in flank, rib, and sirloin subcutaneous adipose tissues than in brisket and round adipose tissues. The expression of the SCD gene did not differ among the 4 age groups (P = 0.95). The palmitoleic:stearic acid ratio (an estimate of SCD activity) was greater (P < 0.001) in the subcutaneous adipose tissues from brisket, plate, and round than in the loin, rib, and sirloin. Conversely, subcutaneous adipose tissue from the loin, rib, and sirloin had greater (P < 0.001) SCD gene expression than the brisket, plate, and round. In general, subcutaneous adipose tissues with the highest concentration of MUFA and least SFA consistently exhibited the least SCD gene expression and adipogenic gene expression. We conclude that MUFA in the brisket and other depots with large SCD indices were deposited before 9 mo of age, during a time when the subcutaneous adipocytes were highly differentiated.

Ground beef patties prepared from brisket, flank and plate have unique fatty acid and sensory characteristics

“…We previously demonstrated that fat trim from the brisket contained a higher percentage of MUFA than fat trim from the flank and plate (Smith et al, 2012;Turk & Smith, 2009), and these results were confirmed in this study. Oleic acid is the most abundant fatty acid in ground beef produced from fat and lean trim of commercial beef cattle (reviewed in Adams et al, 2010;Turk & Smith, 2009).…”

“…John et al, 1987), although fatty acid composition varies considerably across carcass fat depots and changes with animal age (Smith et al, 2012;Turk & Smith, 2009). Adipose tissue overlying the brisket is unusually high in MUFAs, especially oleic acid, and low in palmitic (16:0) and stearic (18:0) acids (Smith et al, 2012;Turk & Smith, 2009). The plate, which is typically used as raw materials for ground beef production, is intermediate in SFA content, whereas the flank has the highest proportions of SFA (Turk & Smith, 2009).…”

“…The plate, which is typically used as raw materials for ground beef production, is intermediate in SFA content, whereas the flank has the highest proportions of SFA (Turk & Smith, 2009). Furthermore, the proportion of MUFAs in subcutaneous adipose tissue overlying the brisket is high even in young cattle (Smith et al, 2012). For this reason, brisket fat trim can be taken at virtually any production age to produce ground beef consistently high in oleic acid.…”

The effect of calcium propionate supplementation on performance, meat quality, and mRNA expression of finishing steers fed a high-concentrate diet

“…The primer sequences of the target genes, PPARG, CEBPA, and a house-keeping gene, GAPDH (glyceraldehyde-3-phosphate dehydrogenase), were designed using Primer Express 2.0 software (Aplied Biosystems, Stockholm, Sweden).The primer sequences were: PPARG, forward 5′-CGACCAACTGAACCCAGA-3′ and reverse 5′-AGCGGGAAGGACTTTATGT-3′; CEBPΑ, forward 5′-CCCGATAAAGCCAGCACT-3′ and reverse 5′-CCACCTTCACGCAGAACA-3′; GAPDH, forward 5′-GGTGATGCTGGTGCTGAGT-3′ and reverse 5′-ATGATGACCCTCTTGGCG-3′. Quantitative real-time PCR (qPCR) was used to analyse the expression of PPARG (accession number: BC116098.1), CEBPA (accession number: BC149006.1), and the housekeeping gene, GAPDH (accession number: NM_001034034.1), which was used as an endogenous control (Smith et al, 2012). The qPCR reaction system had the following parameters: 1 μl of the cDNA template, 10 μl of 2 × SYBR real-time PCR premixture PR7002, (BioTeke, Beijing, China), 0.4 μl of the forward primer, 0.4 μl of reverse primer, and 8.2 μl to 20 μl of ddH 2 O.…”

Regulation of lipid deposition in farm animals: Parallels between agriculture and human physiology

“…Unfortunately, knowledge of factors controlling these processes and how production practices influence such factors is limited in cattle, especially concerning mechanisms that control the timing and extent of depot development. 88 Consequently, it has proven difficult to devise strategies that enhance marbling and simultaneously limit adipose tissue accretion in undesirable depots that negatively impact feed efficiency and yield grade in livestock.…”