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This Article Full Text (PDF) All Versions of this Article: jas.2007-0633v1 86/11/3194    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Dafoe, J. M. Articles by Hatfield, P. G. Search for Related Content PubMed PubMed Citation Articles by Dafoe, J. M. Articles by Hatfield, P. G.

Effects of supplemental safflower and vitamin E during late gestation on lamb growth, serum metabolites, and thermogenesis

Department of Animal and Range Sciences, Montana State University, Bozeman, 59717

hatfield{at}montana.edu

Abstract

Twin bearing Targhee ewes (Exp. 1, 1 yr, n = 42) and 1,182 single and twin bearing white face range ewes (Exp. 2, n = 8 experimental units over 2 yr) were used in a 2 x 2 factorial arrangement of treatments to determine the effect of supplemental energy source and level of vitamin E supplement on lamb serum metabolites and thermogenesis (Exp. 1), and lamb growth (Exp. 2). During late gestation, ewes were individually (Exp. 1) or group (Exp. 2) fed a daily supplement. Supplements were 226 g/ewe daily safflower seeds (DM basis; SS) with either 350 IU/ewe daily (VE) or no added supplemental (VC) vitamin E; or 340 g/ewe daily of a barley-based grain supplement (DM basis; GC) and either VE or VC. One hour postpartum in Exp. 1, twin born lambs were placed in a 0^oC dry cold chamber for 30 min. Lamb rectal temperature was recorded every 60 s and blood samples were taken immediately before and after cold exposure. In Exp. 2 lambs were weighed at birth, turnout from confinement to spring range (32 d of age + 7; turnout) and at weaning (120 d of age + 7). Ewes were weighed at turnout and weaning. In Exp. 1, a level of vitamin E by energy source interaction was detected (P < 0.10) for body temperature and change in NEFA and glucose concentrations. Lambs from SSVC ewes had the lowest (P = 0.01) body temperature and decreased (P = 0.08) NEFA concentration. The SS lambs tended to have lower (P < 0.11) levels of blood urea nitrogen (BUN) and thyroxine (T₄) at 0 min than lambs born to GC ewes. After 30 min of cold exposure, SS lambs increased and GC lambs had decreased BUN, triiodothyronine (T₃), and T_3:T₄ concentrations (P < 0.10). In Exp. 2, kg of lamb/ewe at turnout and weaning and lamb survival at weaning were greater (P< 0.07) for GC than SS lambs. Based on lower body temperature in SSVC lambs at birth, the greater change in BUN during the cold exposure for SS than GC lambs, and the lower survival rate for SS than GC lambs, it appears that SSVC supplemented ewes gave birth to lambs with an apparent decreased energetic capacity. This may compromise the newborn lamb’s ability to adapt to extreme environmental conditions.

Key Words: gestation • lamb survival • safflower seeds • sheep • thermogenesis • vitamin E