Effects of vitamin E supplementation on fattening performance, non-carcass components and retail cut percentages, and meat quality traits of Awassi lambs

Abstract

This experiment was carried out to evaluate the effects of vitamin E supplementation on growth, non-carcass components and retail cut percentages, and meat quality traits of Awassi male lambs at approximately 8 months of age. The lambs were divided into two groups as control (CG, n=12) and experimental (VG, n=12) at the beginning of the fattening period. The CG and VG lambs were fed with a concentrate and grass hay close to ad-libitum by biweekly adjustment of the amount offered. In addition, the VG received a supplement of 45 mg vitamin E per lamb per day during a 75-day fattening period. Inital weight, final weight, daily weight gain and feed conversion efficiency were 31.8±1.40 kg, 45.5±1.37 kg, 183±13 g and 7.6 for CG, 32.5±1.45 kg, 46.7±1.42 kg, 189±15 g and 7.0 for VG, respectively. Vitamin E supplementation did not have a statistically significant effect on animal performance traits, non-carcass components and retail cut percentages, but produced an 8.1% improvement in feed conversion efficiency. After slaughter, carcasses were chilled at 4 °C for 24 h. Then, the carcasses were dissected into wholesale cuts, and m. longissimus dorsi (LD) muscles excised. The samples of muscle were subjected to moisture, protein, ether extract and ash analyses. Samples were cooked for shear test and cooking yield measurements. There were no significant differences between CG and VG lamb groups in chemical composition of meat samples from the LD muscles. Though the influence of vitamin E supplementation on color parameters (L*, a*, b*) was not statistically significant, the mean a* (redness) values decreased on days 2 and 4 and increased on days 7 and 12 of the storage period. However, the a* values of muscles from the VG were higher than those grouping CG. L* and a* values in LD muscle from vitamin E-treated lamb groups were also preserved for a period of 12 days of maturation. In this study, drip loss was relatively preserved by vitamin E supplementation to the diet of animals. The results showed that vitamin E supplementation to the diet of Awassi male lambs at an inclusion rate over the amount of nutritional recommendations relatively reduced lipid oxidation, drip loss and tended to maintain meat redness.