| This study was to conducted to investigate the influence of nano-selenium on performance, egg quality and serum immunity and antioxidation activity of laying hens. A total of 324 healthy Lohmann layers (29 weeks of age) were randomly divided into 6 groups with 6 replicates per groups and 9 hens per replicates. Hens in the control groups were fed the basal diet. In another five groups were received the same basal diet and supplemented with 0.1,0.2.0.3,0.4,0.5 mg/kg nano-selenium. The adjustment period lasted for 7 days, and the experimental period for 63days. The results showed as follows:(1) Compared with the control group, in the 21st days,dietary supplemented with 0.1 to 0.5 mg/kg nano-slenium could increased laying rate by 4.25%,7.15%,7.21%,7.57%,1.75% (P>0.05) respectively,reduce the feed to egg ratio by 6.64%,12.45%(P<0.05),5.39%, 10.78%,5.81% respectively, but there are no significantly effects on average egg weight (P>0.05, in the 42nd,63rd days, dietary supplemented with nano-slenium had no significantly effects on laying rate, feed to egg ratio and average egg weight (P>0.05),0.1 to 0.4 mg/kg nano-selenium had the trend of increasing the rate of egg production, and reducing the ratio of feed to egg from the numerical value (P>0.05). The results show that nano-slenium could improve production performance of laying hes.(2) Dietary supplemented with nano-selenium had no apparent effect on egg shape index and eggshell thickness (P>0.05).0.3,0.4.0.5 mg/kg nano-selenium increased the egg weight, egg yolk color (P<0.01), the HU and eggshell weight (P<0.05) in the 21st days significantly, the egg weight of 0.4,0.5 mg/kg nano-selenium in the 42nd,63rd days was significantly increased (P<0.01), and the eggshell strenth of 0.3 mg/kg nano-selenium group in 63rd days was significantly increased (P<0.05), dietary supplemented with nano-selenium had no significantly effects on other egg quality indicators in the 42nd,63rd days. The results showed that dietary supplemented with nano-selenium could improve the egg quality, and the effect was obvious when the add leavel was 0.3 to 0.5 mg/kg.(3) compared with the control group, in the 21st days, dietary supplemented with 0.3 to 0.5 mg/kg nano-selenium could significantly increased the glutathione peroxidase (GSH-PX) activity and the total antioxidant capacity (T-AOC) (P<0.01), and decreased the malonaldehyde (MDA) content of serum (P<0.01),0.5 mg/kg nano-selenium increased the total superoxide dismutase (T-SOD) activity by 10.78% (P<0.05). In the 42nd days, dietary supplemented with nano-selenium had no apparent effect on GSH-PX and T-SOD activity (P>0.05), T-AOC activity of 0.4,0.5 mg/kg nano-selenium group was significantly increased (P<0.01). and MDA content of 0.3 to 0.5 mg/kg nano-selenium was decreased significantly (P<0.01). In the 63rd days, T-SOD activity had no significant difference (P>0.05), the T-AOC activity and MDA content was significantly increased and decreased (P<0.01) respectively, GSH-Px of 0.1 to 0.3 mg/kg nano-selenium group was increased obvious (P<0.05), and the 0.4,0.5 mg/kg nano-selenium group was not (P>0.05). The results showed that nano-selenium could increase the antioxidant ability of laying hens.(4) Compared with the control group, the content of IgM and IgA in serum of 0.4 mg/kg nano-selenium group in the 42nd days was significantly increased (P<0.05), increased by 17.00%,20.30%(P<0.05)respectively; the content of IgM, IgA and IgG in serum of experimental groups in the 63rd days was no sinificant difference (P>0.05). The results showed that nano-selenium could improve the immune activity of the serum.(5) Compared with the control group, in the 42nd days, the content of ALB of 0.3 mg/kg nano-selenium groups and TP of 0.5 mg/kg nano-selenium groups were significantly increased (P<0.05), and the content of TG and Glu were significantly decreased of 0.2 to 0.5 mg/kg nano-selenium groups (P<0.01),0.4 mg/kg nano-selenium groups was lowest, decreased by 32.31%,15.20%(P< 0.01) respectively, and the content of UA of 0.4 and 0.5 mg/kg nano-selenium groups were decreased by 32.73%,36.93% (P<0.05), ALP, TC had no significant difference (P>0.05); In the 63rd days, dietary supplemented with nano-selenium could increased the content of TP and decreased the content of ALP,0.5 mg/kg nano-selenium group reached a significant level (P<0.05), but had no effect on the content of ALB, TC, TG, UA (P>0.05), the content of Glu of 0.4,0.5 mg/kg nano-selenium group decreased by 8.96%,8.27%(P<0.05) respectively. The results show that nano-selenium can significantly improve serum biochemical indexes.(6) Dietary supplemented with nano-selenium could significantly improve the selenium content of egg yolk (P<0.05), but had no effct on the content of Fe, Cu, Mn in egg yolk (P>0.05). Compared with the control group, in the 21st days,0.2 to 0.5 mg/kg nano-slenium could increased the content of Se by 23.26%(P<0.05),27.84%(P<0.01),63.29%(P<0.01) 65.32%(P<0.01) respectively, in the 42nd days, the selenium content of egg yolk was significantly increased (P<0.01),0.5 mg/kg nano-slenium group increased by 80.01% (P<0.01). The content of Zn was significantly increased (P<0.05),0.5 mg/kg nano-slenium group increased by 17.76%(P<0.05). In the 63rd days, the Se content of 0.2 to 0.5 mg/kg nano-slenium group was significantly increased (P<0.01), and 0.5 mg/kg nano-slenium group increased by 62.98%(P<0.01). The result showed that the selenium content of egg yolk increased with the increase of nano-slenium concentration, with the time extened to 42nd days, the selenium content of egg yolk was higher than that in 21 st,63rd days.It is concluded that the basal diet supplemented with nano-selenium could improve grouth performance, egg quality, serum biochemical indicators, immune activity and antioxidant capacity, can effectively improve layers'health, and improve the egg selenium content of and had no effect the content of Fe, Cu, Mn in egg yolk, beneficial to maintaining the nutrition content of eggs. In conclusion, the optimum level of nano-selenium is 0.4 mg/kg, and the experiment last for 42 days'effect is more obvious. |
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