title: Visceral oxygen consumption during chronic feed restriction and realimentation in sheep.
abstract: The objectives of this study were twofold: first, to estimate the time required to reach equilibrium in splanchnic tissue oxygen (O2) consumption rates after a feed restriction that maintained BW; and second, to estimate the time following a subsequent realimentation required to reach equilibrium. Catheters were placed in a cranial mesenteric vein, the portal vein, a branch of the hepatic vein, and the abdominal aorta of six wethers. Wethers were allowed to eat ad libitum 2 h/d. At 49.9 +/- 2.7 kg two wethers were assigned to the high group, which continued to receive the 2 h/d ad libitum meal. Four wethers were assigned to the low group for 80 d and were restricted to 70% of the average meal each consumed during the week before restriction. Hepatic and portal-drained viscera (PDV) O2 consumption rates were determined the day before restriction (day 0) and on d 10, 24, 38, 52, 66, and 80 of restriction. After d 80 of restriction, wethers assigned to the low group were fed the 2 h/d ad libitum meal, and hepatic and PDV O2 consumption rates were determined on d 7, 14, 28, and 42 of realimentation. At 80 d of restriction, PDV and hepatic O2 consumptions were 60 and 65%, respectively, of the d-0 rate. Hepatic tissue required 21 d and PDV required 29 d to be within 5% of the new steady-state O2 consumption rates after restriction.
authors.affiliation: U.S. Meat Animal Research Center, ARS, USDA, Clay Center, NE 68933, USA.
authors.forename: H C
authors.initials: HC
authors.lastname: Freetly
authors.forename: C L
authors.initials: CL
authors.lastname: Ferrell
authors.forename: T G
authors.initials: TG
authors.lastname: Jenkins
authors.forename: A L
authors.initials: AL
authors.lastname: Goetsch
mesh_terms: D000821:Animal Feed / Q000592:standards; D000818:Animals; D001835:Body Weight / Q000502:physiology; D004032:Diet / Q000592:standards; D004063:Digestion / Q000502:physiology; D004435:Eating / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology; D005508:Food Deprivation / Q000502:physiology*; D006503:Hepatic Veins / Q000502:physiology; D008297:Male; D000455:Medicago sativa / Q000592:standards; D008642:Mesenteric Veins / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology*; D011169:Portal Vein / Q000502:physiology; D012039:Regional Blood Flow; D012756:Sheep / Q000502:physiology*; D013223:Statistics as Topic; D014781:Viscera / Q000098:blood supply / Q000378:metabolism*; D003313:Zea mays / Q000592:standards