Bovine sire selection based on maintenance energy affects muscle fiber type and meat color of F1 progeny1

Abstract

A total of 42 F(1) Red Angus progeny from sires divergent in maintenance energy (ME(M)) EPD were analyzed to determine whether selecting for sire ME(M) would alter end-product meat quality. Data from animals were grouped based on the divergence of the ME(M) EPD of their sire from the Red Angus Association-reported breed average and defined as either high or low, the assumption being that high-ME(M) cattle are less efficient because their maintenance requirements represent a larger proportion of their dietary intake. Steer progeny (n = 7) from the high group produced bottom round steaks with a greater a* (redness) color value (P = 0.02) after 5 d in a simulated retail display when compared with bottom round steaks from the low group (n = 18). Bottom round steaks from the high group had a greater b* (yellowness) color value at d 1 (P = 0.03) and d 5 (P = 0.01) of retail display. Samples from the biceps femoris were taken at 12 mo (from both steers and heifers) and 15 mo (from steers only) of age for fiber type proportion analysis. At 12 mo of age, steers from the low group had more type I fibers (P = 0.02), whereas steers from the high group had more type IIb fibers (P = 0.01). Furthermore, samples from steers in the low group at 15 mo had more type I fibers (P = 0.02), and steers from the high group maintained more type IIb fibers (P = 0.02). No changes in fiber type proportions were observed between the high- and low-ME(M) EPD heifers (n = 17). Relative mRNA abundance of genes involved in the synthesis, storage, and breakdown of glycogen were analyzed as a variable important for meat quality, but no statistical differences were observed. At 12 mo age, glycogenin (glyc) was negatively correlated with the proportion of type IIa fibers (r = -0.32 and P = 0.12) as well as with the proportion of type IIb fibers (r = -0.42 and P = 0.03) in the biceps femoris of the steers. In samples taken from the biceps femoris at 15 mo age, glyc was negatively correlated with the proportion of type IIa fibers (r = -0.42 and P = 0.03) in the steers. This indicates that relative mRNA expression of glyc may serve as a marker of muscle glycogen storage capacity in steers. Thus, selection for efficient Red Angus beef cattle based on sire ME(M) EPD does not adversely affect meat quality in F(1) progeny, based on the variables assessed in this study. Furthermore, selection for progeny from low-ME(M) EPD sires may improve fresh meat quality within Red Angus beef cattle.

Relationships among performance, residual feed intake, and product quality of progeny from Red Angus sires divergent for maintenance energy EPD1

“…All steers were harvested at Washington Beef (Toppenish, WA), where carcass data were collected for cohorts 1, 2, and 3 via the VBG2000 Vision Camera (Vision For You LLC, Dakota Dunes, SD) and a trained carcass evaluator. In addition, the LM (i.e., strip loin) and biceps femoris (Thornton et al, 2012) were collected from the left side of each carcass (cohorts 1 and 2 only) during the fabrication process for various measurements of product quality.…”

“…Steaks were allowed to age for an additional 4 d at 4°C before testing procedures were conducted. Individual steaks were used for the following analyses: proximate analysis, pH and color measurement, percent cook loss, Warner-Bratzler shear force (WBSF), glycogen content (Thornton et al, 2012), and sensory panel evaluation.…”

Effects of dietary inclusion of high concentrations of crude glycerin on meat quality and fatty acid profile of feedlot fed Nellore bulls

“…Consumers are increasingly demanding for quality and variety of products [35]. This way, the appearance of meat, such as color, has a decisive impact on the choice and consumer acceptance [36 – 37]. …”

An examination of the association of serum IGF-I concentration, potential candidate genes, and fiber type composition with variation in residual feed intake in progeny of Red Angus sires divergent for maintenance energy EPD1

“…In addition, results of GH-IGF axis and lipogenic gene expression were opposite in direction and magnitude between cohorts, indicating that different sires across the cohorts may have imposed a genetic influence on energetic efficiency independently of sire ME M EPD. For a complete discussion regarding the influences of sire ME M EPD on fiber type composition and end-product quality, the reader is referred to Thornton et al (2012).…”

“…A minimum of 250 fibers were counted per image, and the number of fibers (type I, type IIa, and type IIb) was reported as a percentage of the total fiber count for analysis. Representative serial images of fiber type staining are reported in Thornton et al (2012).…”