ORIGINAL RESEARCH Effect of inclusion of tossign (Thymus serrulatus) in concentrate mix supplementation on performance and sensory quality of meat of Menz sheep Tewodros Eshete & Solomon Gizaw & Eyassu Seifu Accepted: 15 May 2012 / Published online: 26 May 2012 # Springer Science+Business Media B.V. 2012 Abstract The experiment was conducted to determine feed intake, digestibility, body weight change, carcass character- istics, and sensory quality of meat of Menz sheep supple- mented with a concentrate mix and combinations of different proportions of tossign ( Thymus serrulatus). Twenty yearling intact male Menz sheep were divided according to their initial body weight into five blocks of four animals in a randomized block design, and treatments were assigned randomly to each sheep within each block. The treatments were a basal diet of hay alone (T1) and supplemented with 300 g concentrate mix (T2), 200 g con- centrate mix + 100 g tossign (T3), and 100 g concentrate mix +200 g tossign (T4) on a dry matter basis. The results indicated that supplementation of tossign together with con- centrate mix significantly increased (P <0.001) feed intake and improved DM and nutrient digestibility compared to the non-supplemented group. Supplementation of tossign with concentrate significantly improved (P <0.001) daily weight gain, feed conversion efficiency, and carcass characteristics of sheep compared to the non-supplemented group. Flavor and aroma scores of meat samples of sheep in T3 and T4 were significantly higher (P <0.001) than the corresponding values in T1 and T2. The scores for tenderness, juiciness, and degree of marbling of meat samples of sheep were significantly higher (P <0.001) in T3 and T4 compared to meat samples of sheep in T1. Inclusion of small amounts of tossign as additive in concentrate mix supplementation can improve the sensory quality of meat of Menz sheep. Keywords Carcass characteristics . Growth performance . Menz sheep . Sensory quality of Mutton . Tossign Introduction In Ethiopia, small ruminants provide important protein sources in the diets of the poor and help to generate extra income and support livelihoods of many farmers. Among small ruminants, sheep contribute substantial amount to the farm household income, mutton, and non-food products (manure, skin, and coarse wool) (FAO/ILRI 1999). They are important compo- nents of the livestock subsector and are source of cash income and play a vital role as sources of meat, milk, and wool for smallholder keepers in different farming systems and agro- ecological zones of the country (Legesse 2008, unpublished PhD dissertation, Hoheinheim, Hohenheim University). Sheep are also particularly important for their owner because they require smaller investment, have shorter production cycle, and have faster growth rates and better environmental adaptability than cattle (Kocho 2007, unpublished MSc thesis, Awassa, Hawassa University). However, the productivity of indigenous sheep breeds is low as compared to temperate breeds due to limited genetic capacity and environmental factors. According to Tibbo (2006, unpublished PhD thesis, Uppsala, Swedish University of Agricultural Sciences), among the environmental factors, the major factors for the poor animal (sheep) production in T. Eshete Department of Animal Sciences, Ambo University, P.O. Box 19, Ambo, Ethiopia S. Gizaw Department of Animal Sciences, Debre Berhan Agricultural Research Center, P.O. Box 112, Debre Berhan, Ethiopia E. Seifu (*) Department of Animal Sciences, Haramaya University, P.O. Box 287, Haramaya Campus, Haramaya, Ethiopia e-mail: eyassu_seifu@yahoo.com Trop Anim Health Prod (2013) 45:177–184 DOI 10.1007/s11250-012-0189-y