Extraction Of Alfalfa Polysaccharides And Its Effects On Antioxidative Capacity Of Laying Hens

This study was conducted to investigate the extration parameters of alfalfa polysaccharides, evaluate its radical scavenging activity and effects on antioxidative capacity of laying hens. Fristly, factory extration parameters of alfalfa polysaccharides was optimized combined with the lab study and factory extration conditions. The contents of alfalfa polysaccharides was analysised as well. Then, antioxidative capacity in vitro of alfalfa polysaccharides was evaluated by scavenging radical trial. Moreover, the effects of alfalfa polysaccharides on antioxidative capacity of laying hens was investigated using a fatty acids induced oxidative stress model. The results were as follow:1. Extraction parameters of alfalfa polysaccharidesThe effects of ratio of water to material, extration times, degreasing, alcohol deposition temperature and acetocaustin addition in the deproteinization on yield of alfalfa polysaccharides was investigated. The extraction parameters of alfalfa polysaccharides were optimized. Based on the research of alfalfa polysaccharide extraction of the lab study and factory extration condition, factory extraction process of alfalfa polysaccharide was established. The extraction yield of alfalfa polysaccharides was 9.35 %. Contents of alfalfa polysaccharides were: moisture 8.78 %, ash 23.17 %, CP 15.25 %, polysaccharides 22.71 %, flavonoid 3.32 %, saponin 3.67 %。2. Antioxidative capacity of alfalfa polysaccharides in vitroAntioxidative capacity of alfalfa polysaccharides in vitro was evaluated by scavenging radical trial. Results suggested that alfalfa polysaccharides had good antioxidative capacity in scavenging DPPH and hydroxyl radical, and it was enhanced with concentration rose. At the concentration of 1.6 mg/mL, DPPH radical scavenging rate of alfalfa polysaccharides was up to 90.83 %. At the concentration of 3.0 mg/mL, hydroxyl radical scavenging rate of alfalfa polysaccharides was up to 62.77 %. Moreover, at the concentration of 0.5 mg/mL and 1.0 mg/mL, hydroxyl radical scavenging rates of alfalfa polysaccharides were higher than those of the Vc.3. Oxidative stress models induced by fatty acids and the effects of alfalfa polysaccharides on antioxidative capacity of laying hensOxidative stress model of laying hens was built by adding 8 % fish oil, soybean oil or coconut oil in the diets. Results showed that: Addition of 8 % fish oil decreased egg production, feed intake, egg shell color, yolk color serum GSH-Px, SOD activity and T-AOC level, increased feed/egg, egg shape index, serum AST activity and MDA concentration. Addition of 8 % soybean oil decreased egg production, feed intake, egg yolk color, serum GSH-Px, SOD, GR activity and T-AOC level, increased feed/egg, egg shape index. Addition of 8 % coconut oil decreased feed intake, egg yolk color, serum GSH-Px, GR activity and T-AOC level, increased egg shape index, serum MDA concentration and AST activity.Effects of alfalfa polysaccharides on antioxidative capacity of laying hens were investigated by adding 4 000 mg/kg alfalfa polysaccharides in the diets. Results showed that:Extra addition of 4 000 mg/kg alfalfa polysaccharides relieved the increase of feed/egg, serum AST activity and MDA concentration induced by fish oil, as well as increasing egg shell strength, serum GR activity, GSH concentration and decreasing serun UA concentration.Extra addition of 4 000 mg/kg alfalfa polysaccharides relieved reduction of egg production, serum GSH-Px, GR activity, T-AOC level, and the increase of egg shape index induced by soybean oil as well as increasing GSH-Px activity, GSH concentration, T-AOC level and decreasing serun AST activity.Extra addition of 4 000 mg/kg alfalfa polysaccharides relieved the reduction of feed intake, yolk color, serum GSH-Px, GR activity and the increase of serum MDA concentration induced by coconut oil, as well as increasing serum GSH-Px, GR activity, GSH concentration, T-AOC level and decreasing serun UA concentration.Results indicated that addition of 8 % fish oil, soybean oil or coconut oil induced oxidative stress on laying hens. Extra addition of 4 000 mg/kg alfalfa polysaccharides relieves the oxidative stress of laying hens produced by fatty acid addition and improves performance and egg quality.