Interpretive Summary: Research shows genetic selection alters cellular development in muscle
By Anne Zinn
A recent study published in the August 2019 edition of the Journal of Animal Science has demonstrated that cellular development in muscle differs between Angus steers from low and high muscle score selection lines. The study assessed the cellular characteristics of longissimus lumborum and semitendinosus muscles in steers genetically selected for low or high muscling using live muscle scoring, and high steers with 1 copy of the loss-of-function 821 del11 MSTN allele (HighHet). The research team hypothesized that High and HighHet muscling achieved through genetic selection would alter cellular characteristics and mechanisms that increase muscling compared with low steers. Additionally, the team hypothesized that the presence of 1 copy of the 821 del11 MSTN mutation would affect muscle cellular characteristics in high muscle score cattle.
They reported that high Angus steers had muscles with more protein and tended to have more glycolytic fibers than the low steers and HighHet steers had muscles that had more glycolytic fibers than high Angus as a result of quantitative genetic selection. This ultimately means high steers had more protein in the muscle, but more glycolytic fibers may have reduced quality. The team concluded that while using muscle scoring for genetic selection can be positive, it is also important to include some type of quality evaluation/estimate system to avoid producing more protein, but with less quality. Continued research into genetic selection for increased retail yield is important and necessary for profitable beef production.
To view the full paper, visit the Journal of Animal Science.