Effects Of Dietary L-arginine Supplementation On The Development Of Porcine Cloned Embryos And Its Fetoplacental Unit

As a kind of multifunctional amino acids in animal,arginine plays key roles in the regulation of nutrient metabolism,the enhancement of vessel growth and the development of embryo.Therefore,our study based on the nutrition and physiology function of arginine,with feeding arginine to recipient sows to explore effect of the regulation of nutrient metabolism on cloned embryogenesis and implantation,expect enhance the survival rate of cloned embryos,and then improve the cloning efficiency.In this study,a total of 178 Yorkshire or Duroc as recipient sows was selected.C loned embryos were transferred every time,randomly assigned into 2 dietary treatments including the control diet with 0 L-Arg(control group)and 1.0%L-Arg diet(1.0%L-Arg group).The trial period was conducted from days 12 to 70 after transplantation.The concentrations of plasma free amino acids,NO,TNOS,iNOS,ammonia and urea nitrogen were measured on days 30 and 60 of gestation.Pregnancy rate,parturition rate,litter size,birth weight of piglets,litter weight and other indicators of recipient sows were recorded.The placental traits were analyzed and comparing the difference in the efficiency of the placenta,and then the relative expression level of placental growth related genes was detected by qPCR method.Survival rate of cloned piglets after 3d was recorded.The results were showed as follows:(1)On days 30 of gestation,concentrations of arginine and ornithine in plasma were extremely significantly higher(P<0.01)in 1.0%L-Arg group than in control group,but the levels of glycine and leucine appeared the trend of decreased(P=0.09).O n days 60 of gestation,concentrations of arginine were extremely significantly enhanced(P<0.01),and ornithine were increased by 22.43%(P>0.05).The level of other amino acid did not differ between two groups(P>0.05).(2)Concentrations of NO,TNOS,iNOS,ammonia and urea nitrogen in plasma did not differ(P>0.05)between the control group and 1.0%L-arginine group at 30 d or 60 d of gestation.(3)Compared with the control group,1.0% L-arginine supplementation increased significantly pregnancy rate by 14.45%(P=0.05)and enhanced parturition rate by 6.58%(P>0.05),but cloned piglets birth weight,litter weight,the numbers of total piglets and the survival rate of 3 days after birth and other indicators did not differ(P>0.05)between the two groups.(4)Compare with the control group,the efficiency of clone embryos developed total piglets born alive was significantly increased(P<0.05)in the 1.0%L-arginine group.Meanwhile the efficiency of clone embryos developed total piglets born and the efficiency of clone embryos developed total healthy piglets born were higher 35.25% and 43.38%(P>0.05)respectively.(5)Compared with the control group,placental weight,placental area and placental efficiency did not differ in 1.0%L-Arg group.Histomorphometric analysis show the number of CT cells have a tendency to increase.However,the expression level of Grb10?Igf2?H19?VEGFA?VEGFR2?eNOS in placenta did not differ(P>0.05)by qPC R.In conclusion,Dietary 1.0%L-Arginine Supplementation of recipient sows can improve blood metabolism,enhance the ability of embryo implantation,and to improve the cloning efficiency.