Effects of tryptophan supplementation on growth performance, antioxidative activity, and meat quality of ducks under high stocking density

Abstract

High stocking density (STD) could affect duck welfare and production. The objective of our study was to investigate whether dietary tryptophan (TRP) supplementation could alleviate the detrimental effects of high STD on ducks. White Pekin ducks at 4 to 6 wk of age were raised at 11 birds/m(2) and fed diets containing 0.18, 0.48, 0.78, or 1.08% TRP for 21 d. Growth performance, concentrations of TRP and metabolites in the blood and hypothalamus, antioxidative activities in serum and tissue, meat quality, serum uric acid, and urea nitrogen were measured. Weight gain and feed efficiency were significantly improved by TRP supplementation at ≥ 0.48 and ≥ 0.78% (P < 0.05 and P < 0.001, respectively). Serum TRP, hypothalamic TRP, 5-hydroxytryptamine (5-HT), 5-hydroxyindoleacitic acid (5-HIAA), and 5-HIAA/5-HT were also increased significantly (P < 0.01). These increases plateaued at 0.48% TRP, and no further improvement was obtained by adding more TRP to the diet. Dietary TRP supplementation significantly increased levels of total antioxidant capacity, glutathione peroxidase (GSH-Px), and catalase (CAT) in serum; GSH-Px in liver; and GSH-Px and CAT in breast muscle (P < 0.05). Malondialdehyde levels in breast muscle decreased (P < 0.001). Drip loss of breast muscle and pH decline at 45 min postmortem were reduced by TRP supplementation (P < 0.01 and P < 0.05, respectively). Meat color was similar among different treatments (P > 0.05). Breast muscle shear force was increased significantly when dietary TRP level increased to 1.08% (P < 0.01). For ducks raised at 11 birds/m², dietary TRP supplementation could alleviate stress and improve growth performance, antioxidative activity, and meat quality.

Effect of dietary tryptophan supplementation on growth performance, immune response and anti‐oxidant status of broiler chickens from 7 to 21 days

“…Improved anti‐oxidant status mimics the stress in broiler chicken and ultimately facilitate to optimum weight gain and FCR. The similar results were coded by other investigations in which Liu et al () reported that in White Pekin ducks the anti‐oxidant, in terms of glutathione peroxidase (GSH‐Px) and catalase (CAT), has been increased meaningfully not only in serum and liver but also in breast muscles by dietary Trp supplementation above the NRC (1994) recommendation. Patil et al () demonstrated that the L‐tryptophan is the precursor of serotonin and melatonin and inhibited the oxidative damage in broiler birds, improved enzymatic action of catalase and superoxide dismutase.…”

Excess dietary tryptophan mitigates aflatoxicosis in growing quails

“…Elevated plasma levels of hepatic enzymes such as AST and ALT in the poultry species are a sign of hepatic cell damage caused by a variety of stressors or harmful agents (Bagherzadeh‐Kasmani & Mehri, ; Miazzo et al, ; Valdivia et al, ; Yarru et al, ). On the other hand, protective action of excess dietary TRP in stressful conditions has been reported in pig (Mao et al, ; Sève, Meunier‐Salaün, Monnier, Colléaux, & Henry, ), duck (Liu et al, ), broiler chicks (Corzo, Kidd, Thaxton, & Kerr, ) and laying hens (Dong, Azzam, Rao, Yu, & Zou, ). A part of beneficial effects of excess dietary TRP may originate from de novo synthesis of its metabolites such as, for example kynurenine, 5‐hydroxytryptophan and melatonin (Le Floc’h, Otten, & Merlot, ).…”

Effect of dietary resveratrol supplementation on meat quality, muscle antioxidative capacity and mitochondrial biogenesis of broilers

“…It is well known that dietary supplementation with many nutrients possessing antioxidant activity is beneficial to meat quality. For example, arginine in pig diet, curcumin, creatine monohydrate, soybean isoflavone and tryptophan in birds' diet can improve meat quality through improving muscle antioxidative status. Reactive oxygen species (ROS) is produced as an inevitable by‐product of normal animal metabolism.…”

“…Muscle antioxidative capacity is related to meat quality, and dietary supplementation with some nutrients that have antioxidant function can enhance the quality of poultry and pork meat . Resveratrol is a natural polyphenol that can be found in various plants and has been proposed as a powerful antioxidant compound.…”