rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    title: Factors associated with protein turnover in skeletal muscle of bulls and steers during normal growth and postmortem storage
  name:
    name part: Morgan, James Bradley
    name part: 1963-
    role:
      role term: creator
  name:
    name part: Savell, Jeff W.
    role:
      role term: degree supervisor.
  name:
    name part: Cross, H. Russell
    role:
      role term: degree committee member.
  name:
    name part: Sams, Alan R.
    role:
      role term: degree committee member.
  name:
    name part: Smith, Stephen B.
    role:
      role term: degree committee member.
  name:
    name part: Texas A & M University
    role:
      role term: degree granting institution.
  type of resource: text
  genre: bibliography
  genre: Academic theses
  origin info:
    place:
      place term: xx
    date issued: 1991
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: print
    extent: x, 106 leaves : illustrations ; 29 cm
  abstract: Six each, MARC III composite (1/4 Red Poll, 1/4 Pinzgauer, 1/4 Hereford and 1/4 Angus) bulls and steers weighing approximately 180 kg, were given ad libitum access to a typical finishing diet. At sampling periods of 0, 45, 90, 135 and 180 d, muscle biopsy and urine samples were obtained. This sampling technique allowed for correlating the relationship between myofibrillar protein turnover and the calpain and catheptic proteinase systems. Bulls exceeded steers in average daily gain throughout the duration of the study. Bulls displayed lower fractional degradation rates of myofibrillar proteins than steers at the 180 d sampling period. The direct mechanism by which castration alters protein turnover in muscle was not clear. However, the improvements in protein accretion observed in bulls appeared to be related to decreased fractional degradation rates. During the later sampling periods, bulls degraded approximately 30% less myofibrillar proteins per day than steers. Activities of the endogenous proteinase system m-calpain, m-calpain and calpastatin (calpain inhibitor) were measured at 0 and 24 h postmortem. Differences in either m- or m-calpain activities between bulls and steers were not detected. However, muscle calpastatin activity was greater for bulls than steers. Warner-Bratzier shear values, the myofibriliar fragmentation index and sensory panel tenderness ratings indicated that meat from bulls was tougher and exhibited less postmortem proteolysis than meat from steers. If calpastatin is related to protein turnover in living muscle, then an increase in calpastatin activity could possibly decrease calpain-mediated degradation and, in turn, reduce fractional degradation rate. The significant negative correlation (r= -.72) between calpastatin activity and fractional degradation rate of myofibrillar proteins (at 180 d) indicated that animals with higher calpastatin activities had lower fractional degradation rates. The depressed fractional degradation rate observed…
  note: Typescript (photocopy).
  note: Vita.
  note: "Major subject: Animal Science."
  note: Ph. D. Texas A & M University 1991
  note: Includes bibliographical references.
  subject:
    topic: Cattle
    topic: Nutrition
  subject:
    topic: Proteins
    topic: Metabolism
  subject:
    topic: Meat
    topic: Quality
  subject:
    topic: Major animal science
  identifier: http://proxy.library.tamu.edu/login
  related item:
    location:
      url: http://proxy.library.tamu.edu/login
  record info:
    record content source: TXA
    record creation date: 930218
    record change date: 20200904152558.0
    record identifier: in00001122026
    language of cataloging:
      language term: eng