The Antioxidant Status of Serum and Egg Yolk in Layer Fed with Mushroom Stembase (Flammulina velutipes)

Experimental chickens (ISA Brown) were purchased from Changchun Octavia farms and F. velutipes stembase (FVS) was collected from the local domestic mushroom farm in Changchun city, Jilin, China.

A single factor completely randomized design was used to select 150 healthy, 210-day-old ISA brown laying hens and were randomly divided into 5 groups. Each group had 5 replicates and each had 6 hens. The control group was fed the basal diet, the antibiotic group was fed with the basal diet with the addition of antibiotic, (flavomycin, 0.05%) and the 2%FVS, 4%FVS and 6%FVS fed groups were added with 2%, 4%, and 6% of the ground mushroom stembase on the basal diet. The experimental period is 63 days. The basal dietary nutrition level of laying hens is based on the nutritional requirements of laying hens in the NRC (1994). Feeds and water were provided ad libitum in the whole trial period. The hen house temperature was 240C and a 17 h light with 7 h dark period was maintained throughout the whole experimental period.

The mushroom stembase sample was prepared (0.01mm) by laboratory high speed universal sample grinder (Huanghua xinxing electric Appliance Co, Hebei, China). Six representative samples in triplicate were obtained and analyzed for proximate components dry matter (DM), crude protein (CP), crude fiber (CF), ether extract (EE), total minerals (Ash) including calcium and phosphorus following the method of AOAC. Nitrogen was determined using an FP-528 nitrogen determinator (LECO Corporation, USA). Total phenolics content was measured according to the method of Giannenas et al. (2010). The value was expressed as mg of gallic acid equivalents (GAE) per gram of dry weight (mg GAE/g) on dry weight) basis. The analyzed nutritional composition of the experimental diets and FVS were presented in Table I and Table II, respectively.

At the end of the experiment at d 273 (39 wk), blood samples were obtained via wing vein from 5 hens per experimental group. Serum was obtained by centrifuged at 3000 × g for 20 min at 4oC (Legend Micro 17R centrifuge, Thermo Fisher, Germany) and were stored at -80oC until measuring serum antioxidant properties. Similarly, at the end of the experimental period at d 273(39 wk), fresh eggs were selected (5 eggs per treatment) and egg yolks were collected for the test. Malondialdehyde (MDA) content, total superoxide dismutase (T-SOD) activity, glutathione peroxidase (GSH-Px) activity, and total antioxidant capacity (T-AOC) in serum and egg yolk were measured using commercial kits provided by Nanjing Jiancheng Bioengineering Institute, Nanjing, China (MDA A003-1, T-SOD A001-1, GSH-Px A005,T-AOC A015-3).

a FVS= F. velutipes stembase at 2%, 4% and 6%. bProvided per kg of the complete diet: retinyl acetate, 4500 IU; cholecalciferol, 1200 IU; DL-α-tocopheryl acetate, 25000 IU; thiamin, 5000 mg; riboflavin, 20000 mg; phylloquinone,10000 mg; niacin, 45000 mg; pantothenic acid, 35000 mg; biotin, 1500 mg; folic acid, 3000 mg; cyanocobalamin, 40 mg; zinc, 45 mg; manganese 50 mg; iron, 30 mg; copper, 4 mg; cobalt, 120 μg; iodine, 1 mg; selenium, 120 μg. cDM, dry matter; CP, crude protein; Ca, calcium; P, phosphorus; EE, crude fat; CF, crude fiber; ME, metabolisable energy.

One-way analysis of variance (ANOVA) was performed using SPSS 15.0. The results were expressed as the mean plus SEM value (standard error), and each set of data was processed using Duncan’s multiple comparison method.

Serum antioxidant T-AOC was significantly higher (P<0.05) in 6%FVS than control; GSH-Px was significantly higher (P<0.05) in all levels of mushroom fed groups and control groups than antibiotic fed groups; MDA was significantly lower (P<0.05) in all levels of mushroom fed groups and antibiotic groups than control fed groups. However, there was no significant difference were observed for T-SOD among experimental groups (Table III).

1Values are expressed as the mean ± standard deviation (n=6).

For yolk antioxidant T-AOC, and T-SOD were significantly higher (P<0.05) in 4%FVS than the control group and antibiotic fed groups; MDA was significantly lower (P<0.05) in all levels of mushroom fed groups than antibiotic group and control fed groups (Table IV).

This study assumed that mushroom contains different bioactive components especially phenolic compound, the amino acids that may role on improving the antioxidant capacity. The phenolics compounds, has the antioxidants activities, was discovered from the mushroom F. velutipes (Rahman et al., 2015). The various proportion of F. velutipes mushroom has been reported as a potential source of antioxidants (Tang et al., 2016). Form some past studies it has been known that the polysaccharides and oligosaccharide present in F. velutipes mushroom shows the antioxidant function (Ma et al., 2015; Xia, 2015). Liu et al. (2016) reported that different polysaccharides originated from F. velutipes mushroom residue were purified and the antioxidant function has been considered in the study. Zeng et al. (2012) stated that F. velutipes mushroom holds the higher phenolic with the highest antioxidant activities. Besides, F. velutipes mushroom was found to exhibit vitamin-C that may play a role in antioxidant function (Tang et al., 2016). In a recent study by Han et al. (2017) found that dietary inclusion of yeast selenium and selenite could improve the activity of glutathione peroxidase in serum, and improve the activity of superoxide dismutase in the liver in chicken. Adding polyphenols in feed could increase the activity of glutathione peroxidase and superoxide dismutase in serum and improve the total antioxidant capacity of serum in weaned pigs (Chen et al., 2018). In addition, adding L- arginine in the diet of laying hens could improve the total antioxidant capacity and reduce the concentration of malondialdehyde in egg yolk and serum (Duan et al., 2015).

T-AOC, total antioxidant capacity; MDA, malondialdehyde; T-SOD, total superoxide dismutase; GSH-Px, glutathione peroxidase. 1data represent the mean value of 5 samples for each treatment (n=5). a, b,c means in the same row with different letters are significantly different at P<0.05. SEM, pooled standard error of the means.

T-AOC, total antioxidant capacity; MDA, malondialdehyde; T-SOD, total superoxide dismutase. 1data represent the mean value of 5 samples for each treatment (n=5). a, b,means in the same row with different letters are significantly different at P<0.05. SEM, pooled standard error of the means.

The present study explored that FVS could be a good source of natural feed supplement as well as antioxidant that can improve both serum and yolk antioxidant properties. Focus on quality eggs production and sound health status, F. velutipes mushroom stem base can be used as a natural supplement as well as a substitute for antibiotic on layer production.

This work was supported by “Innovation Platform for Economic Fungi in Jilin Province” [Grant No. 2014-2016] Changchun, P.R. China.

Authors have declared no conflict of interest.