Effects Of Diludin And Nano-diludin On Laying Hens Lipid Metabolism And Approach To The Mechanism

The study was conducted to investigate the effects of 1, 4-diludin (DHP) and nano-1, 4-diludin (DHP) on fat metabolism of laying hens and approach to the mechanism.Four hundreds and eighty healthy laying hens of 40 weeks old were randomly allotted to five groups, each of which including three replicates of 32 hens. The groups were fed a basal corn-soybean diet, supplemented 0(control);150mg/kg 1, 4-diludin, 300 mg/kg 1, 4-diludin, 75mg/kg nano-1,4-diludin and 150mg/kg nano-1, 4-diludin. The hens were kept in three-layer ladder cage. Feed and water were provided ad. Libitum and layers received 17h light/day. The immune was according to routine immune procedure. The experiment lasted for 9 weeks, including 1 week pre-experiental time. The mumber of laying eggs and death hens were recorded and total egg weight in every replicates were weighed daily .Feed intake were calculated every week . At the end of the experiment, 12 hens were selected from every group (4 hens from every replication ) randomly. The total 60 hens were numbered and weighed then slaughtered for samples after fasting with ad libitum to water for 12 hours .The related biochemical parameters in serum, abdominal fat and liver and mRNA abundance of lipoprotein lipase in abdominal fat was examined. The morphological changes in the small intestine, uterine tube and liver were observed by tissue slices.The results indicated that DHP and nano-DHP had significantly improved laying performance. The laying rate were improved by 4.81 %(P<0.05)and 7.21 %(P<0.01) respectively by supplementation 300mg/kg DHP and 75mg/kg nano-DHP. There were no significant difference between the control group and the other two trial groups There were no significant difference in average egg weight, feed egg weight ratio and daily feed intake in all trial groups .Howerver, there was a trend of improving daily feed intake in the groups of supplementation 300mg/kg DHP and 75mg /kg nano -DHP. Compared with 150mg/kg nano-DHP group, 75mg/kg nano-DHP decreased feed/egg ratio significantly.Slaughter experiment and hepatic fat content analysis indicated that 150mg/kg DHP and 300mg/kg DHP decreased hepatic fat content of laying hens by 23.62 %(P<0.05)and 30.68 % (P<0.01), abnormal fat content by 15.17 % (P>0.05)and 19.81 % (P>0.05)respectively. 75mg/kg nano-DHP and 150mg/kg nano-DHP decreased laying hens hepatic fat content by 27.29%(P<0.01)and 18.91 %(P<0.05), abnormal fat content by 35.29 %(P<0.05)and 16.41 %(P>0.05). DHP and nano-DHP had no signifiant effect on relative liver weight.Routine serum bio-chemical parameters and hepatic FFA analysis indicated that hepatic FFA content were decreased by 32.46 % (P>0.05)and 41.15 % (P<0.05) in 150mg/kg DHP group and 300mg/kg DHP group respectively.Hepatic FFA content in 75mg/kg nano-DHP and 150mg/kg nano-DHP group were decreased by 43.74% (P<0.05)and 30.27 %(P>0.05)respectively. DHP and nano-DHP had no significant effects on serum concentration of TP, Alb, TG, G, HDL-Tc and Tc in laying hens.Antioxidation parameters indicated that 150mg/kg DHP and 300mg/kg DHP increased serum SOD concentration by 47.83 % (P>0.05)and 27.79 % (P>0.05), meanwhile serum MDA concentration decreased by 34.47 % (P<0.05)and 27.22 % (P>0.05)respectively. Hepatic SOD content in 150mg/kg DHP and 300mg/kg DHP group were increased by 26.52 %(P>0.05)and 31.38%(P>0.05), while MDA content were decreased by 23.13 %(P<0.05)and 33.89 %(P<0.05)respectively. 75mg/kg nano-DHP and 150mg/kg nano-DHP increased serum SOD concentration by 104.18 %(P<0.05)and 10.83 % (P>0.05), meanwhile serum MDA concentration were decreased by 36.05%(P<0.05) and 7.07%(P>0.05)respectively. Hepatic SOD content were increased by 43.58 %(P<0.05)and 49.61 % (P<0.05), meanwhile hepatic MDA content were decreased by 14.60 % (P>0.05) and 13.05 % (P>0.05) in 75mg/kg nano-DHP and 150mg/kg nano-DHP respectively. 150mg/kg nano-DHP increased hepatic GSH-Px activety by 59.35 % (P<0.05), however there were no significant changes in other groups compared with the control.Lipid transport related parameters indicated that 150mg/kg DHP and 300mg/kg DHP increased serum ApoB concentration by 83.15 %(P>0.05)and 126.04%(P<0.05); 75mg/kg nano-DHP and 150mg/kg nano-DHP increased serum ApoB concentration by 122.10 % (P<0.05)and 32.82 % (P>0.05)respectively. DHP and nano-DHP had no significant difference on serum ApoA1 concentration. Enzymes which take part in fat metabolism indicated 150mg/kg DHP and 300mg/kg DHP decreased heparinized plasma LPL activity by 1.80 % (P>0.05)and 22.91% (P>0.05);meanwhile increased HSL activity in abdominal fat by 9.09%(P>0.05)and 60.86%(P>0.05)respectively. 75mg/kg nano-DHP and 150mg/kg nano-DHP decreased heparinized plasma LPL activity by 57.99 %(P<0.05)and 7.28%(P>0.05), meanwhile HSL activity in abdominal fat were increased by 69.33 % (P<0.05)and 5.75 % (P>0.05)respectively. DHP and nano-DHP had no significant effects on serum HL activity.The serum hormone level analysis indicated 150mg/kg DHP and 300mg/kg DHP Increased serum T₃ level by 11.84%(P>0.05)and 87.23 %(P<0.05), meanwhile serum Ins level were decreased by 43.64 %(P>0.05)and 73.49 %(P<0.05)respectively. 75mg/kg nano-DHP and 150mg/kg nano-DHP increased serum T₃ level by 107.79% (P<0.05)and 59.50 % (P>0.05) , meanwhile serum Ins level were decreased by 60.67%(P<0.05)and 22.71 % (P>0.05)respectively. DHP and nano-DHP had no significant effects on serum T₄ level.The analysis of abdominal fat LPL on transcriptional level indicated 300mg/kg DHP and 75mg/kg nano-DHP had the trend of decrease abundance of LPL mRNA, but no significant difference.The anlysis of liver, oviduct, duodenum and jejunum slices indicated that the number of lipid drops in laying hens' liver of experimental groups reduced obviously, especially in 300mg/kg DHP and 75mg/kg nano-DHP groups. 300mg/kg DHP and 75mg/kg nano-DHP increased the plica height formed by mucous surface in laying hens' ampullaofuterine tube.There were no siginifiant difference in other two experimental groups. Villus height and and thickness of intestinal muscle layer in duodenum and jejunum among all groups had no significant change.