The Effects Of Taurine On Production Performance, Immune Function And Lipid Metabolism In Quails

The aim of this study was to evaluate the effects of taurine on production performance, immune function, egg quality, lipid metabolism and reproductive performance in quails (Coturnix Coturnix).1. Effects of taurine on production performance, lipid metabolism and tissue taurine contents in growing quail.1-day-old both sex Japanese quails (300) were randomly allotted to 12 groups with 25 quails in each group (3 dietary treatments 4 replicates). They were fed with maize-soybean meal-based diets containing 0,0.01% or 0.05% taurine for 42 d. On day 21 and 42, the production performance was compared. On day 42, the serum lipid parameters were determined; the taurine content in serum, liver pectoral muscle and leg muscle of quails were analyzed by High Performance Liquid Chromatography. The results showed that:in the starter phase, dietary 0.05% taurine decreased food take significantly, dietary 0.05% taurine increased weight gain and improved feed efficiency (P<0.05). In the grower phase, dietary 0.05% taurine improved feed efficiency and decreased food intake (P<0.05). In the experiment, adding 0.05% taurine improved feed efficiency and decreased food intake significantly (P<0.05). High density lipoprotein cholesterol content was increased significantly with taurine supplementation at 0.05% in quail serum (P<0.05). Dietary 0.05% taurine significantly increased taurine content in leg muscle of quail compared with the control (P<0.05).2. Effects of taurine on immune responses and antioxidant activity in growing quail.Based on the experiment one, twelve quails which had similar body weight of each group were randomly selected, bloods were drawn from the heart to measure ND hemagglutination inhibition antibodies titers and immunoglobulin G Quails were slaughtered and the immune organs were separated, weighted and calculated the organ index. One quail was selected from each replicate of every treatment on the day 42 and bloods were drawn from the heart and the changes of T-lymphocyte and B-lymphocyte proliferation in peripheral blood were detected by MTT test. The results showed that:the relative weights of thymus were greater in the quails given 0.01% taurine in diet (P<0.05); the relative weights of the bursa of Fabricius and thymus were heavier in dietary 0.05% taurine compared with the control (P<0.05). The response to phytohaemagglutinin which was measured as the foot web index was significantly increased by 0.05% taurine supplementation (P<0.05). Dietary taurine increased serum IgG content significantly compared with the control (P<0.05). Dietary taurine increased the ability of stimulation B-lymphocyte proliferation significantly and dietary 0.05% taurine increased the ability of stimulation T-lymphocyte proliferation significantly (P<0.05). Dietary 0.01% taurine enhanced the activity of total antioxidant capacity in serum, decreased the malondialdehyde level in serum (P<0.05).3. Effects of taurine on production performance and egg quality in laying quailThe effects of taurine on production, egg quality, egg nutrition and egg yolk cholesterol and taurine content of laying quails were investigated. The results showed that:In the earlier stage(28 day), dietary 0.01% taurine decreased broken and soft eggs ratio significantly (P<0.05), dietary 0.05% taurine increased laying rate, decreased feed conversion rate and broken and soft eggs ratio significantly compared with the control (P<0.05). In the later stage (56 day), dietary 0.05% taurine increased laying rate, decreased feed conversion rate and daily feed intake significantly compared with the control (P<0.05). Dietary 0.05% taurine could enhance eggshell thickness significantly on the 15th,50th and 55th day in the experiment period (P<0.05). Dietary 0.05% taurine could enhance eggshell strength significantly on the 45th and 55th day of the experiment period (P<0.05). Dietary 0.05% taurine enhanced the egg shape index significantly only at the 20th day during the experiment. Dietary 0.05% taurine enhanced the egg yolk index significantly on the 30th day during the experiment. Dietary taurine decreased cholesterol content in egg yolk with the experiment time extension. Dietary taurine promoted the taurine transferred to the egg yolk and dietary 0.05% taurine increased taurine content in the egg yolk significantly (P<0.05)4. Effects of taurine on fat metabolism and the mechanism in laying quailBased on experiment three, eight quails which had similar body weights of each group were randomly selected on the day 28 and 56, bloods were drawn from the heart to measure lipid constituents. The contents of cholesterol, triglyceride, low density lipoprotein cholesterol, high density lipoprotein cholesterol, apolipoprotein A, apolipoprotein B and malondialdehyde were analyzed in serum of quails. The enzyme activities of lipoprotein lipase, hepatic lipase, total lipase, total antioxidant capacity and superoxide dismutase were detected in serum and liver. The study showed that:on the day 28 and 56, compared with the control, dietary 0.01% and 0.05% taurine decreased serum triglyceride and atherosclerosis index significantly, dietary 0.05% taurine also enhanced serum high density lipoprotein significantly; dietary 0.05% taurine could enhance apolipoprotein A content significantly (P<0.05). Dietary 0.05% taurine could enhance the activities of lipoprotein lipase and total lipase in serum and hepatic lipase in liver significantly (P<0.05). Dietary 0.05% taurine enhanced the activities of total antioxidant capacity in serum and liver significantly compared with the control (P<0.05).5. Effects of taurine on growth performance and immune response in quail offspringBoth sex Japanese quails (female:male=3:1) were randomly allotted to 12 groups with 12 quails in each group (3 dietary treatments 4 replicates). They were fed with maize-soybean meal-based diets containing 0%,0.01% or 0.05% taurine. When egg laying rate reached 80 percent, the eggs were collected and egg white lysozyme contents were tested by kit, eggs were hatched by incubator and the effects of dietary taurine on hatching performance of quail were tested. After hatching, the quails were reared under the same condition and fed with maize-soybean meal-based diets. The experimental period lasted 21 days. The effects of taurine on production performance, antioxidant activity and immune responses were detected in quail offspring. The results showed that:dietary 0.05% taurine significantly enhanced breeding quail's immune function, lysozyme content of egg white and reduced the malondialdehyde production in egg yolk significantly(P<0.05). Dietary 0.05% taurine increased serum IgG content and enhanced the activity of total antioxidant capacity significantly in quail offspring (P<0.05).From above results, it was concluded that taurine could enhance the production performance in growing quail, it enhanced the immune function, antioxidant capacity, reduced the lipid peroxidation product malondialdehyde production. Dietary taurine could enhance the egg production performance and egg quality in laying quails, taurine could reduce the quail egg mg cholesterol per g yolk content with time extension, taurine increased the sediment of taurine in meat and egg of taurine. Taurine could improve the fat metabolism of laying quails through increasing the fat metabolism enzymes activities. Taurine could enhance the immune function and antioxidant capacity in quail offspring. Supplementation with taurine has some benefits on quail offspring'health. Therefore, adding taurine to produce healthy, nutritional and harmless quail meat and eggs that rich in taurine is feasible.