Effects Of Resveratrol And L-theanine On Growth Performance And Meat Quality Of Broilers And Its Preliminary Mechanism

With the increasing demand for meat safety and quality and the gradual prohibition of antibiotics,the search for green natural extracts for animal production has becomed a hot spot in animal nutrition research.Resveratrol and L-theanine have received more and more attention as green natural extracts.Studies have found that resveratrol and L-theanine possess a number of beneficial biological functions such as antiinflammatory,antioxidant and antistress.At present,resveratrol and L-theanine have been reported as feed additives for livestock and poultry production and have showed good potential,but their effects on the meat quality of broiler and its possible mechanism are rarely reported.In this paper,the effects of resveratrol and L-theanine on growth performance and meat quality of broilers and its preliminary mechanisms were investigated through two experiments.Test 1:The aim of this study was to evaluate the influence of dietary resveratrol supplementation on meat quality,muscle antioxidative capacity and mitochondrial biogenesis of broilers.180 21-day-old male Cobb broilers were randomly assigned to two groups,each of which included 6 replicates with 15 birds per replicate.The control group was fed a basal diet,the experimental group was fed the basal diet supplemented with 400mg/kg resveratrol.All broilers were freely accessible to the diets and water.The trial lasted for 21 days.After the feeding trial,two broilers close to the average body weight were selected for slaughter.The results showed that resveratrol tended to increase(P<0.10)pH24h.Resveratrol not only significantly reduced(P<0.05)feed weight ratio,but also significantly decreased(P<0.05)L*24h,ApH,drip loss and lactate content.Moreover,total antioxidative capacity and catalase activity were significantly increased(P<0.05)by resveratrol,while malondialdehyde content was decreased(P<0.10).Compared with the control group,resveratrol significantly increased(P<0.05)peroxisome proliferator-activated receptor y coactivator 1? and nuclear respiratory factor 1 mRNA levels,along with increased(P<0.05)citrate synthase activity.The above results indicated that resveratrol can improve meat quality of broilers,which may be associated with improved muscle antioxidative status and mitochondrial biogenesis.Test 2:The aim of this study was to evaluate the influence of dietary L-theanine supplementation on meat quality,muscle antioxidative capacity and amino acid composition of broilers.300 21-day-old male Ross 308 broilers were randomly assigned to 5 groups,each of which included 6 replicates with 10 birds per replicate.The control group was fed a basal diet,the experimental groups were fed the basal diet supplemented with 300,600,900,1500mg/kg L-theanine.All broiler chickens were freely accessible to the diets and water.The trial lasted for 42 days.At the age of 21 and 42 days,two broilers close to the average body weight were selected for slaughter.The results showed that L-theanine quadratically reduced(P<0.05)feed/gain ratio of 1-21 days and 1-42 days,as well as the drip loss,cooking loss,shear force and L*24h at the age of 42 days,and the optimal dosage was 600mg/kg.L-theanine quadratically increased(P<0.05)spleen index(21d),bursal index(21 day)and thymus index(42 day).L-theanine quadratically reduced(P<0.05)muscle T-AOC?CAT?GSH-PX activity and the content of MDA and protein carbonyl,suggesting that the oxidative stress in broiler was reduced after L-theanine intake.L-theanine significantly quadratic increased(P<0.05)the content of essential amino acids,including isoleucine,leucine,lysine,threonine and proline in the breast muscle(42 days),as well as non-essential amino acids,including alanine,aspartic acid,cystine,glutamic acid,glycine and proline content.The above results show that the addition of L-theanine in diet can significantly improve the growth performance and meat quality of broilers,its possible mechanisms are related to the beneficial change of muscle antioxidant status and amino acid composition.In summary,resveratrol and L-theanine have the ability to improve the growth performance,meat quality and muscle antioxidant status of broilers,and therefore can be used as potential new feed additives in poultry production.