Supplementation of Tea Polyphenol Mixed with Sweetener in Diet Included with or without Flax Oil Increased Antioxidative Capacity of Blood Serum and Longissimus Dorsi Muscle of Fattening Pigs

A natural antioxidant - tea polyphenol (TP) extracted from green tea can be used as feed additives to improve body antioxidative capacity. It can be applied together with a sweetener to avoid possible negative influence by its bitter taste. As a major source of omega-3 fatty acids flax oil (FO) can be included in diet for increasing omega-3 fatty acids in meat. The current study was designed to investigate effect of supplementation of TP mixed with sweetener to diet included with or without FO on growth performance and body antioxidative capacity of fattening pigs. The study was a 2 by 2 factorial trial with two main factors of TP mixed with sweetener and FO inclusions. Total 40 Large White castrated growing pigs with an average body weight of 62 kg were assigned to 4 groups fed ad libtum with following diets for 5 weeks: 1) a control diet (CON); 2) CON diet + 400mg/kg TP and 200mg/kg Lucta sweetener; 3) a 2% FO diet; 4) FO diet + 400mg/kg TP and 200mg/kg Lucta sweetener. During the experimental period weekly body weight changes and daily feed intake data were collected. Fasting blood samples were taken for analyzing general health related parameters and antioxidative capacity. At the end of feeding trial 4-6 pigs from each group were slaughtered for carcass and meat quality measurements. From the study it was found that the animal growth performance and their general health related blood serum parameters were not affected (P>0.1) by the treatments. Inclusion of TP with sweetener increased (P<0.01) blood major antioxidative capacity parameters e.g. GSH-Px, CAT, T-SOD and T-AOC, whereas that of FO increased (P<0.05) GSH-Px. On major carcass and meat quality characters, inclusion of FO resulted in more favorable (P<0.05) meat colour whereas that of TP with sweetener resulted in a larger (P<0.05) drop loss%. Inclusion of FO in the control diet also increased (P<0.05) meat ribeye area. Inclusion of TP with sweetener increased (P<0.01) longissimus dorsi muscle T-SOD and tended to increase (P=0.06) GSH-Px whereas that of FO decreased (P<0.05) it. In conclusion, inclusion of TP mixed with Lucta sweetener in either CON or FO diet increased antioxidative capacity of blood serum and the muscle without affecting growth performance of fattening pigs. The results suggest that inclusion of TP in FO diet is beneficial to prevent the possible oxidations in the muscle.