Fiber-type proportions and diameters in the longissimus muscle of beef heifers undergoing catch-up (compensatory) growth

• Author(s) / Creator(s)

  • Yambayamba, E.
  • Price, M. A.

• Fifty-three Hereford crossbred heifers (211 ± 28(mean ± SD) kg, 197 ± 13 d of age at day 1) were used to study the effects of mild, chronic feed restriction followed by refeeding on some longissimus muscle fiber characteristics. Five animals were slaughtered on day 1 for analysis of initial muscle fiber characteristics. The remaining 48 animals were randomly penned in groups of 6 and assigned to treatments as follows: three pens to ad libitum feeding; three pens to 2 mo of feed restriction followed by refeeding, and two pens to 4 mo of feed restriction followed by refeeding. Animals in one ad libitum and one restricted pen were slaughtered after 2 mo and those in one pen from each treatment after 4 mo, and the remainder at the final slaughter weight of about 410 kg. Two months of feed restriction had no effect on the proportions of longissimus muscle fiber-types, \"red\" (βR), \"white\" (αW), and \"intermediate\" (αR), but fiber diameters were smaller (P < 0.05) in the restricted than in the ad-libitum-fed animals. Four months of feed restriction was associated with a relatively higher (P < 0.05) proportion of βR fibers and lower (P < 0.05) proportion of αW fibers than ad libitum feeding. Muscle fiber diameters were larger (P < 0.05) in the ad-libitum-fed than in the restricted heifers. No significant feeding treatment differences were found in fiber-type proportions or fiber diameters at the final slaughter weight.

• Date created

  1991

• Subjects / Keywords

  • Fiber type
  • Realimentation
  • Compensatory growth
  • Muscle fibers
  • Feed restriction
  • Heifers

• Type of Item

  Article (Published)

• DOI

  https://doi.org/10.7939/R3CZ19

• License

  @1991 Yambayamba, E., Price, M. A. This version of this article is open access and can be downloaded and shared. The original author(s) and source must be cited.