Effects Of Dietary Creatine Monohydrate And Guanidinoacetic Acid Supplementation On Protein Metabolism And Protein Changes Postmortem In Finishing Pigs

Our previous study confirmed that dietary supplementation creatine monohydrate(CMH)and guanidineacetic acid(GAA)significantly increased the average daily weight gain and pH 45min,and decreased weight gain of pork.Therefore,the present study was to investigate the effect of CMH and GAA supplementation on protein metabolism and protein change postmortem finishing pigs.And it will provide the technological and theoretical basis for the application of CMH and GAA on livestock production.The research can be divided into two parts:The first part was aim to study the effects of CMH and GAA on the protein metabolism of finishing pigs.One hundred and eighty healthy barrows were randomly allocated to three treatment groups which were fed three different types of dietary.Experimental treatments were as follows:basal diet(Control groups);the basal diets with 0.8%CMH(CMH groups);the basal diets with 0.1%GAA(GAA groups).Each treatment had three replicates,each replicate had twenty pigs,the experiment period was 28 d.After the experiment period,from each group nine pigs were randomly selected and slaughtered.The results showed that:compared with the control group and CMH group,the serum albumin concentration of the GAA group increased significantly(P<0.05).The total protein,AST,ALT and BUN concentration of serum did not significantly affect among three groups.Compared with the control group,CMH group increased significantly the RNA concentration of longissimus dorsi muscle,CMH group and GAA group increased significantly the RNA/DNA of longissimus dorsi muscle(P<0.05).There were no significantly affect of dietary CMH or GAA supplementation on the DNA concentration of longissimus dorsi muscle.The RNA,DNA,RNA/DNA of semitendinosus muscle did not significantly affect among three groups.Compared with the control group,CMH group decreased significantly Val,Ile,Leu,Tyr,Phe,Arg and Pro concentration of longissimus dorsi muscle,and increased significantly His concentration of longissimus dorsi muscle(P<0.05).GAA group decreased significantly Asp,Thr,Gly,Val,Met,Ile,Leu,Lys,His,Arg,and Pro concentration of longissimus dorsi muscle,and increased significantly Glu and Cys concentration of longissimus dorsi muscle(P<0.05).Compared with the GAA groups,CMH group increased significantly Asp,Thr,Gly and His concentration,decreased significantly Glu,Cys and Phe concentration of longissimus dorsi muscle(P<0.05).Compared with the control group and GAA group,CMH group decreased significantly Val,Met,Ile,Leu,Met,Phe,Lys,His,Arg and Pro concentration of semitendinosus muscle(P<0.05).The Asp,Thr,Ser,Glu,Gly,Ala and Cys concentration of semitendinosus muscle did not significantly affect among three groups.Compared with the control group,CMH group and GAA group increased significantly the mRNA expression of IGF-1 of longissimus dorsi muscle(P<0.05).The mRNA expression of IGF-1 of semitendinosus muscle did not significantly affect among three groups.Compared with the control group,CMH group and GAA group increased significantly the mRNA expression of MEF2C of longissimus dorsi muscle(P<0.05).The mRNA expression of myogenin and Myf6 of longissimus dorsi muscle did not significantly affect among three groups.The mRNA expression of MEF2C,myogenin and Myf6 of semitendinosus muscle did not significantly affect among three groups.The mRNA expression of MSTN of longissimus dorsi muscle did not significantly affect among three groups.Compared with the control group,CMH group and GAA group decreased significantly the mRNA expression of MSTN of semitendinosus muscle(P<0.05).In the second part,the study was aim to investigate the effects of CMH and GAA on the protein change of muscle in postmortem finishing pigs.The results showed that:The total protein solubility,sarcoplasmic protein solubility and myofibrillar protein solubility of longissimus dorsi muscle did not significantly affect among three groups.Compared with the control group,CMH group increased significantly the myofibrillar protein solubility of semitendinosus muscle(P<0.05).There were no significantly affect of dietary CMH or GAA supplementation on the total protein solubility and sarcoplasmic protein solubility of semitendinosus muscle.Compared with the control and GAA group,CMH group increased significantly Tm2,?H2 and ?H3 of longissimus dorsi muscle(P<0.05).Compared with the control,GAA group increased significantly Tm2 of longissimus dorsi muscle(P<0.05).There was no significant difference in the Tm1,?H1 and Tm3 of longissimus dorsi muscle among three groups.Compared with the control group,CMH group and GAA group increased significantly Tm2 of semitendinosus muscle(P<0.05).There was no significant difference in the Tm1,Tm3,?H1,?H2 and ?H3 of semitendinosus muscle among three groups.The SDS-PAGE photograghs of sarcoplasmic protein and myofibrillar proteindid not significantly affect among three groups.Compared with the control group,CMH group and GAA group increased significantly the mRNA expression of Calpainl of longissimus dorsi muscle and semitendinosus muscle(P<0.05).There was no significant difference in the mRNA expression of Calpainl of longissimus dorsi muscle and semitendinosus muscle between CMH group and GAA groups.The mRNA expression of CAST of longissimus dorsi muscle did not significantly affect among three groups.There was no significant difference in the mRNA expression of PRKAG3 and DECR1 of longissimus dorsi muscle and semitendinosus muscle.As stated above,the conclusions are as follows:Dietary supplementation CMH and GAA increased the RNA content of muscle,promoted muscle hypertrophy and muscle protein deposition.Meanwhile,Dietary supplementation CMH and GAA increased the mRNA expressions of IGF-1 and MEF2C mRNA in the muscle of finishing pigs,played a positive role in the molecular regulation of muscle growth and development.And CMH and GAA decreased the mRNA expression of MSTN,inhibited muscle growth negative regulator.In postmostem pigs,the role of dietary supplementation CMH and GAA on muscle protein denaturation and protein degradation is limited,meanwhile did not effect the mRNA expression levels of PRKAG3 and DECR1.