Characterization of the mechanisms involved in lipid accretion in bovine subcutaneous and intramuscular adipose tissue as influenced by breed type /
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| Other Authors: | , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1993.
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| Subjects: | |
| Online Access: | ProQuest, Abstract Link to OAKTrust copy |
| Abstract: | This research was conducted in two phases. In phase 1, two groups of Angus X Simmental crossbred steers (n = 12) which were bred to differ phenotypically (smaller framed, earlier maturing (1960 version) versus larger framed, later maturing (1980 version)) were used to compare adipose tissue lipogenesis within breed-type. In phase 2, Angus steers (n = 10) and Wagyu crossbred (n = 10) steers were used to evaluate the influence of breed on adipose tissue lipogenesis, fatty acid composition and to develop a procedure that can be used to compare adipose cell proliferation using adipose tissue explants. In both studies, intramuscular adipose tissue possessed lower 14C-acetate incorporation rates for acute (0h) and long term (36-40h) incubation as compared to subcutaneous adipose tissue. Further, intramuscular adipose tissue possessed smaller adipocytes and lower cell volumes than subcutaneous adipose tissue. These studies provided further evidence that intramuscular adipose tissue is a less unique, mature depot as compared to subcutaneous adipose tissue. Based upon 14C-acetate incorporation into neutral lipids and lipogenic enzyme activity, few differences in lipogenesis occurred between breed-types (1960 versus 1980 Angus steers) or across diverse breeds (Wagyu crossbred versus Angus steers). This lack of difference may be partially attributed to similarities in carcass traits associated with physiological maturity. While trained sensory evaluation of longissimus muscle did not differ between Angus and Wagyu crossbred steers, triangle test evaluation indicated consumers could detect differences between breeds. Wagyu crossbred steers did possess higher percentages of unsaturated fatty acids and a higher unsaturated to saturated fatty acid ration than the corresponding tissues from Angus steers. These differences appeared to be more genetically influenced than environmentally based. The procedure developed within this study suggests that a population of "lipid filling" cells that has the capacity to proliferate exists. While no significant difference occurred between adipose tissue depot, adipose tissue from Wagyu crossbred steers did possess a higher 3H-thymidine incorporation rate into DNA associated with "lipid filling" cells than tissue from Angus steers. Once verified, this procedure may provide additional information regarding adipose cell development. |
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| Item Description: | Vita. "Major subject: Animal Science." |
| Physical Description: | ix, 75 leaves : illustrations ; 28 cm |
| Bibliography: | Includes bibliographical references. |