Comparison of the Effect of Green Tea By-product and Green Tea Probiotics on the Growth Performance, Meat Quality, and Immune Response of Finishing Pigs

The objective of this experiment was to compare the effects of green tea by-product and green tea probiotics on the growth performance, meat quality and immune response of finishing pigs. A total of 72 crossbred "Landrace$\times$Yorkshire" finishing pigs with an average of 76 kg body weight were assigned to 4 dietary treatments in a completely randomized design. Each treatment had 3 replications with 6 pigs per replication. The four dietary treatments were control, antibiotics (control diet with 0.003% chlortetracycline added), and diets containing 0.5% green tea by-product or 0.5% green tea probiotic supplementation. Weight gain was increased in 0.5% green tea probiotics treatment compared to others, but there was no significant difference (p>0.05). The incorporation of 0.5% green tea probiotics to diets reduced the feed conversion ratio in finishing pigs (p>0.05). The incorporation of 0.5% green tea by-product into the pig diet reduced the crude protein and fat contents of the meat (p>0.05). Pigs fed diets containing 0.5% green tea probiotic supplementation had lowered meat TBA values compared to those fed 0.5% green tea by-product (p<0.05). The proliferation of spleen cells stimulated with Con A (concanavalin: 0.1, 0.3, and $1.0{\mu}g/ml$) significantly increased with 0.5% green tea by-product treatment compared to antibiotic treatment (p<0.05), but was significantly decreased in 0.5% green tea probiotics treatment compared to the antibiotic treatment (p<0.05). When stimulated with $1.0{\mu}g/ml$ Con A, splenocyte production of IL-6 from pigs treated with 0.5% green tea by-product or green tea probiotics was significantly increased compared to the antibiotic treatment group (p<0.05). Splenocyte production of TNF-${\alpha}$ after treatment with $1.0{\mu}g/ml$ Con A was significantly higher following 0.5% green tea probiotics treatment (p<0.05), while TNF-${\alpha}$ production after $10.0{\mu}g/ml$ LPS (lipopolysaccharide) was significantly higher in the 0.5% antibiotic treatment group (p<0.05).