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

ABSTRACT : 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 "LandracexYorkshire" 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 [micro]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 [micro]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 [micro]g/ml Con A was significantly higher following 0.5% green tea probiotics treatment (p<0.05), while TNF-[alpha] production after 10.0 [micro]g/ml LPS (lipopolysaccharide) was significantly higher in the 0.5% antibiotic treatment group (p<0.05). (Key Words : Green Tea By-product, Green Tea Probiotics, Growth Performance, Meat Quality, Immune Response, Pig)

INTRODUCTION

There has been extensive use of antibiotics to prevent diseases and improve growth performance in the animal industry. However, due to the occurrence of antibiotic-resistant bacteria and antibiotic residue in livestock products, the use of probiotics has been strongly recommended instead of antibiotics (Snyder and Champness, 1997). Probiotics are viable microorganisms that improve gut microflora by enzymes, organic acids, vitamins and nontoxic anti-bacterial substances that the microbes secrete once ingested (Jun et al., 2002). Probiotic supplementation seeks to repair these deficiencies and provides the type of microflora that exists in feral animals uninfluenced by modern farm-rearing methods. Sedo (1986) compared the post-weaning performance of pigs fed starter feeds containing a microbial culture to that of pigs provided with a feed grade antibiotic. It was observed that the pigs receiving probiotics in their feed were equal to or superior in daily gain, intake and feed efficiency when compared to pigs fed antibiotics. There was an improvement of the growth performance not only of weaning pigs but also of growing finishing pigs by adding probiotics to feed (Baird, 1977). In addition, various kinds of fermented products using lactic acid bacteria are reported to have anticancer activities and enhance immunity (Kroger and Krumann, 1989; Itoh, 1999).

Another method that is developing together with probiotics is the recently developed non-antibiotic use of functional medicinal plants (Berg, 1998; Harris et al., 1990; Martin and Nisbet, 1992; Lyons and Jacques, 2000; Kwon et al., 2005). Some examples of medicinal plants are green tea, artemisia, acanthopanax and others (Yang et al., 2003; Kwon et al., 2005). Green tea (Camellia sinensis) h as been used for centuries by Korean, Japanese and Chinese people as an anti-aging herb. In addition to human consumption, low grade green tea has been used as an ingredient in animal feed for fish (Kono et al., 2000), broilers (Kaneko et al., 2001; Cao, 2005), calves (Ishihara et al., 2001) and pigs (Suzuki, 2002) and the positive effects of green tea on animal performance have already been described. The inclusion of green tea in broiler diets had positive effects on growth performance and lean meat production (Kaneko et al., 2001) and showed positive effects on the increase of lactic acid bacteria and aerobic bacteria counts in ruminants (Bureenok et al., 2007). However, utilizing green tea in the livestock industry has a negative effect in that it has a high cost. That is why the use of green tea by-product to substitute for green tea has been studied (Jung, 2001; Yang et al., 2003). Kondo et al. (2006, 2007) reported that 10% FM of green tea waste added in silages for ruminant and goat diets with 5% of green tea by-product showed high nutritive values. In addition, the green tea by-product is obtained through the production of green tea beverages and is recognized as cheap and effective for its utility, so it has been used as a feed supplement. Yang et al. (2003) reported that the TBA value of broiler meat decreased significantly when broilers were fed diets containing 0.5 to 2.0% green tea by-product supplementation compared to those fed a diet containing antibiotics. Nishida et al. (2006) reported that green tea waste silage to Holstein steers increased the concentrations of high density lipoprotein cholesterol. Currently, a method to develop a probiotic containing both beneficial bacterial strains and medicinal plants has not been studied.