Effects of dietary pomegranate byproduct silage supplementation on performance, carcass characteristics and meat quality of growing lambs

In an experiment with 24 male growing Florina (Pelagonia) lambs, effects of dietary pomegranate byproduct silage (PS) on performance, carcass characteristics and meat chemical and fatty acid composition were determined. In the 9 week experiment, lambs were allocated to one of three dietary treatments (PS0, PSI 20, and PS240) of 8 lambs each. Lambs had an initial body weight (BW) of 18.8 +/- 2.28 kg, and were fed one of three isonitrogenous (crude protein 171 g/kg, dry matter - DM basis) and isoenergetic (net energy for gain 5.62 MJ/kg, DM basis) total mixed rations (TMRs) ad libitum. The PS was added to the TMR at inclusion levels (as mixed basis) of 0, 120, and 240 g/kg DM for treatments PS0, PS120, and PS240, respectively. No differences (P>0.05) occurred among PS treatments in final BW (34.3 kg), BW gain (0.24 kg/day), DM intake (0.94 kg/day), and FCR (3.95 kg DM intake/kg BW gain). Moreover, carcass characteristics were not affected (P>0.05) with increased PS feeding, except for the fat color, fat firmness, wetness and overall acceptability of carcasses, which improved (P<0.05). Fat content of meat was linearly increased (P<0.001) with increasing PS in lambs TMRs. PS supplementation caused linear (P<0.05) and quadratic (P<0.01) effect on 11-Hexadecenoic concentration and a linear decrease (P<0.05) in 6-9-Hexadecenoic and cis-11, 14-eicosadienoic acids concentrations, in intramuscular fat. A linear increase (P<0.05) was observed in linoleic acid and trans-10, cis-12 conjugated linoleic acid (CIA) (P<0.05) concentration, with increasing PS inclusion levels and a quadratic (P<0.05) and linear (P<0.01) effect on a-linolenic acid concentration. Meat total phenolic content increased linearly (P<0.05) and antioxidant activity was linearly (P<0.05) and quadratic affected (P<0.05), with maximum levels observed in intermediated group (PS120). Pomegranate byproduct silage supplementation, at levels up to 240 g/kg DM of TMR, in isonitrogenous and iso (net energy) energetic diets for growing lambs did not affect their performance and carcass quantitative characteristics, but improved qualitative carcass characteristics. More significantly, dietary PS supplementation improved the nutritional and functional qualities, as well as the antioxidant potential of meat, as indicated by the increase in essential fatty acids, linoleic, or-linolenic acid and trans-10, cis-12 CLA, in intramuscular fat and the increase in total phenolic content and antioxidant activity. (C) 2014 Elsevier B.V. All rights reserved.