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M. M. SCHWOPE1, W. J. Means, and A. W. Wolf. (1) Dept. of Animal Science, Univ. of Wyoming, Meat Science & Food Technology Group, 1000 E. University Av., Dept. 3684, Laramie, WY 82070 Realimentation of mature cows has been shown to increase lean mass and decrease shear force values. The objective was to determine if realimentation of ewes after a period of nutrient restriction (NR) would cause changes in muscle leading to mass and shear force differences. We modeled this scenario in ewes by feeding 100% of the National Research Council (NRC) recommended diet for gestating ewes (control, C), or 50% of NRC recommendations during days 28 to 78 of gestation then 100% of NRC recommendations from 78 to 135 days (NR). Ewes were euthanized (day 78 or day 135 gestation), eviscerated, and hung 24 to 34 hours at 4°C. Subsequently, Longissimus dorsi (Ld) and Semitendinosus (St) were removed. Whole body, hot carcass (HCW), Ld, and St weights were recorded. Warner-Bratzler shear force (WBSF) of Ld was measured after 7 days aging. The HCW of NR ewes tended (P=0.072) to be lighter than C ewes at 78 days but not 135 days (P=0.34). St weights in NR ewes at 78 days were lighter (P=0.0007), although by 135 days, the difference (P=0.07) was reduced. Interestingly, there was not a difference (P=0.11 and P=0.24) between Ld’s at 78 or 135 days, respectively. The WBSF values were not different (P=0.46 and P=0.36) between treatments of 78 or 135 days, but the WBSF was lower (P=0.006) at 78 days verses 135 days. The muscle weight data indicates that there is a conservation of the Ld during NR, but not the St. Increased WBSF values later in gestation may indicate an increase in cross-linked collagen.
Session 81, Muscle Foods: Muscle biochemistry and fresh meat
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