The Screening Of Vitamin A Antioxidant And Its Application In Piglets

Vitamin A,as an essential nutrient for animals,has many biological functions.The animal can not synthesize vitamin A,so vitamin A should be added from feed.However,the chemical property of vitamin A is not stable,and it is easy to be oxidized when exposed to heat,light,humidity and so on.Therefore,the antioxidants often be added in the process of syntheticing Vitamin A.Ethoxy quinoline(EQ)is the most commonly used vitamin A antioxidant at home and abroad,however,the EU has issued an announcement to suspend the addition of EQ in feed because of its safety issues.In this study,the Antioxidant Sodium Ascorbate(VC sodium),which has better antioxidant activity,was obtained by comparing the antioxidant effects of four kinds of feed additives in vitro.Besides,VC sodium and EQ is processed with vitamin A as the core of vitamin A capsules,which were named The VC sodium’s type of Vitamin A and the EQ’s type of Vitamin A.Next,the effect of VC sodium and EQ on the stability of vitamin A was investigated.Finally,the application of VC sodium type vitamin A in piglets was studied.The main findings are as follows:1.The comparison of antioxidant activities of different antioxidants in vitroThe objective of this study was to evaluate the antioxidant activities of 4 antioxidants in vitro:EQ,BHT,α-tocopherol and VC sodium.The method of 1,1-phenyl-2-pi cry lhydrazyl(DPPH)was used to determine the scavenging ability of free radicals and the ophenanthroline method was used to determine the scavenging ability of hydroxyl radicals.The results showed that:1)the order of DPPH radical scavenging ability of the four antioxidants was Eq>VC sodium>Vc-tocopherol>BHT.2)the order of hydroxyl radical scavenging ability of four antioxidants was-tocopherol>VC sodium>BHT>EQ.By comprehensive comparison,the antioxidant with better antioxidant activity is VC sodium.2.The protective effect of VC sodium and EQ on the stability of Vitamin AThe EQ and VC sodium were mixed with vitamin A,after that they were stored at 25℃,60%RH,and 40℃ and 75%RH respectively for 6 months.The rest rate of vitamin A was measured regularly.The results showed that:1)the long-term stability of vitamin A of VC type was better than that of Eq type at 25℃ and 60%humidity.2)under the conditions of 40℃ and 75%humidity,the stability of sodium EQ type vitamin A was similar to that of vitamin EQ type vitamin A.3.The application of VC sodium type vitamin A in piglet production A total of 288 weanling piglets with an initial mean body weight of 8.34±0.02 kg at 30-day-old were randomly divided into 3 groups with 4 replicates and 24 piglets per replicates.The control group was fed basal diet without exogenous vitamin A,and the experimental group was Fed Basal Diet with 12000IU/kg EQ vitamin A and VC sodium vitamin A respectively.The effects of VC sodium type vitamin A on growth performance,immune function and antioxidant function of piglets were investigated.3.1 The effects of VC sodium type vitamin A on growth performance of piglets The addition of 12000IU/kg of Eq type and VC type of vitamin A to the Diet of piglets significantly increased the average end weight and average daily gain(P<0.05),the feed intake and feed-to-weight ratio of piglets were increased by adding EQ vitamin A and VC sodium vitamin A,but the difference was not significant(P<0.05).3.2 Effects of VC sodium type vitamin A on immune function of piglets On the 18th day of the experiment,the content of IgA,IgG and IgM in the group of EQ VA and the group of VC sodium type of VA was significantly higher than that in the control group(P<0.05).The content of serum lysozyme in the two groups was not significantly different(P>0.05).The content of IgG and lysozyme in test group was significantly higher than that in control group(P<0.05),IgA in VC sodium type of VA group was significantly higher than that in control group and EQ VA group(P<0.05),the content of IgM in test group was higher than that in control group,but the difference was not significant(P>0.05).3.3 The effect of VC sodium type vitamin A on antioxidant function of piglets Compared with the control group,the activity of GSH-Px was significantly increased(P<0.05)and the activity of MDA was significantly decreased(P<0.05)in the group of EQ VA and VC sodium VA on the 18th day of experiment.At the 36th day of experiment,the activity of GSH-Px in serum of piglets in the group of EQ VA and the group of VC Sodium VA was significantly higher than that in the control group(P<0.05),and the content of MDA was significantly lower than that in the control group(P<0.05).The total antioxidant capacity(T-AOC)of VC Sodium VA group was significantly higher than that of EQ VA group and Control Group(P<0.05),and the Superoxide dismutase activity of test group was higher than that of Control group,but the difference was not significant(P>0.05).To sum up,the protective effects on vitamin A of VC Sodium and EQ is similar.In addition,the new dosage form(VC sodium type)of vitamin A can significantly improve the average daily gain of piglets,improve the immune function of piglets,improve the antioxidant capacity of piglets compared with the control group,and the effect is slightly better than EQ type vitamin A.This study provides a theoretical basis for the application of new dosage form of vitamin A in piglets.