Effects of carvacrol and cinnamaldehyde on intake, rumen fermentation, growth performance, and carcass characteristics of growing lambs

Effects of essential oil compounds (EOC) on feed intake, ruminal fermentation, growth performance, and carcass characteristics were determined using 60 lambs (24.6± 0.77 kg initial live weight, LW) fed either a barleyor corn grain-based diet without supplementation (control), or supplemented with 0.2 g/kg (DM basis) of carvacrol (CAR) or cinnamaldehyde (CIN). The experimental diets were arranged as a 2× 3 factorial with 11-week periods and fed to lambs ad libitum. Ruminal pH tended (P=0.06) to be lower and total volatile fatty acid (VFA) concentration was higher (P<0.01) for barleyAbbreviations: AA, amino acid; ADG, average daily gain; CAR, carvacrol; CIN, cinnamaldehyde; DM, dry matter; EOC, essential oil compound; FC, feed conversion; ME, metabolizable energy; VFA, volatile fatty acid. This paper is part of a special issue entitled “Enzymes, Direct Fed Microbials and Plant Extracts in Ruminant Nutrition” guest edited by R. J. Wallace, D. Colombatto and P. H. Robinson. Dairy and Swine Research and Development Centre Contribution #891. ♦ Presented at the 57th Annual Meeting of the European Association for Animal Production on September 2006 in Antalya, Turkey. Title, “Effect of carvacrol and cinnamaldehyde on performance of growing lambs”. ∗ Corresponding author. Tel.: +1 819 565 9174x117; fax: +1 819 564 5507. E-mail address: [email protected] (C. Benchaar). 0377-8401/$ – see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.anifeedsci.2007.04.016 A.V. Chaves et al. / Animal Feed Science and Technology 145 (2008) 396–408 397 versus corn-based diets. Addition of EOC reduced (P=0.02) ruminal pH and increased (P=0.03) total VFA concentration versus the control. Acetate and propionate molar proportions and ammonia concentration did not differ among treatments. Inclusion of EOC in barleyor corn-based diets did not alter dry matter intake or average daily gain of lambs. Lambs fed the control diets tended (P=0.10) to have lighter livers than those fed diets containing EOC. Neither type of grain nor inclusion of EOC substantially affected sensory attributes of lamb sirloins. © 2007 Elsevier B.V. All rights reserved.