title: Physiological adaptations in adipose tissue of Brahman vs Angus heifers.
abstract: Nonpregnant yearling Brahman (n = 12) and Angus (n = 12) heifers were equally allocated to two dietary treatments in a replicated study to examine responses in lipid metabolism to nutritional treatments consisting of a moderate energy diet (2.0 Mcal ME/kg) fed at maintenance and a 2.5 x maintenance high-energy diet (2.4 Mcal ME/kg) fed for 30 d. In vitro lipogenesis and the activities of lipoprotein lipase (LPL) and hormone-sensitive lipase (HSL) were determined in perianal subcutaneous adipose tissue biopsies at the start and end of the trial. At the start of the trial, breeds had similar (P > .10) rates of lipogenesis and LPL activity. Brahman had greater (P < .05) HSL activity than Angus at the start of the trial and tended (P < .07) to have greater HSL activity at the end. Diet did not influence (P > .10) HSL activity. Heifers on the high-energy, higher-intake diet had greater lipogenesis (P < .001) and LPL activity (P < .01) than those on the moderate-energy diet. Inclusion of body condition score (BCS) nested within breed as a covariate explained breed differences for lipogenesis (P < .05). Thus, by including the covariate, the two breeds had similar (P > .10) rates of lipogenesis at the end of the trial. When adjusted for BCS nested within breed, Brahman had greater (P < .05) LPL activity than Angus.
authors.affiliation: Texas Agricultural Experiment Station, Uvalde 78801, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Sprinkle
authors.forename: H S
authors.initials: HS
authors.lastname: Hansard
authors.forename: B G
authors.initials: BG
authors.lastname: Warrington
authors.forename: J W
authors.initials: JW
authors.lastname: Holloway
authors.forename: G
authors.initials: G
authors.lastname: Wu
authors.forename: S B
authors.initials: SB
authors.lastname: Smith
mesh_terms: D000222:Adaptation, Physiological; D000273:Adipose Tissue / Q000201:enzymology / Q000502:physiology*; D000821:Animal Feed; D000818:Animals; D001835:Body Weight; D002417:Cattle / Q000502:physiology*; D003600:Cytosol / Q000378:metabolism; D002149:Energy Intake; D004734:Energy Metabolism; D005260:Female; D008055:Lipids / Q000096:biosynthesis; D008071:Lipoprotein Lipase / Q000378:metabolism; D015203:Reproducibility of Results; D013045:Species Specificity; D002787:Sterol Esterase / Q000378:metabolism
chemical_list: D008055:Lipids; D002787:Sterol Esterase; D008071:Lipoprotein Lipase