The Effect Of Exogenous Nucleotide On The Growth Performance Of Weaned Piglets And Its Mechanism

A single factor random test was used in the studies.135 21-day-old weaned piglets were selected to randomly divide into 3 groups,3 repeats in each group,and 15 pigs included in each repeat.The group A was fed basal diet,and diets of groups B and C added 0.05% and 0.10% exogenous yeast nucleotides in the basal diet respectively.The experiment lasted for 41 days.Feeding management was carried out according to the management mode of Guangdong Kaiping Guangsanbao Animal Husbandry Co.,Ltd.During the feeding experiment,data about consumption and surplus of feed in repeat were recorded daily.The body weights of pigs at the end of the trial were measured,and then the average body weight,average daily gain,average daily feed intake and feed to weight ratio of the experimental pigs were calculated.The blood samples were collected two days after the end of the feeding experiment.Three healthy piglets with an average weight were randomly selected,and the blood samples were collected from the anterior vena cava to determine the biochemical indexes.The second day after the end of the feeding experiment,samples of fresh feces from three pigs in each repeat were collected and mixed evenly to measure the number of microbes.On the 3rd day before the end of the feeding experiment,fresh feces were collected from each repeat for lasting three days,and feed samples from each group were collected as well.Then those above were used to measure the apparent digestibility of nutrients in diets.The results of the studies were as follows:(1)The weight of weaned piglets was increased with adding nucleotides in diets to different degrees(P>0.05),and the weight of the testing pigs increased by 3.90%(P=0.109)by the addition of 0.05% nucleotides group compared with the Control.Compared with the Control,the average daily gain of treatments was increased by the addition of nucleotides,which of 0.05% treatment group raised by 6.76%(P=0.058)and 0.10% treatment group increased by 6.74%(P=0.094).Compared with the Control,adding nucleotides had no significant effect on the average daily feed intake for piglets(P>0.05),and the addition of nucleotides had no significant effect on the weight ratio(P>0.05),but the treatment group had a certain decrease in numerical value,which decreased by 10.34%(P>0.05)and 2.46%(P>0.05)respectively.(2)The nucleotides had no significant effect on the digestibility of dry matter,energy,crude protein and crude fat in diets for piglets(P>0.05).(3)The nucleotides did not significantly affect the concentration of total protein and albumin in the serum of piglets(P>0.05).The addition of nucleotides had no significant effect on the serum alkaline phosphatase(P>0.05)in piglets(P>0.05),but increased by 5.56%(P>0.05)and 2.14%(P>0.05),respectively.The addition of 0.05% or 0.10% nucleotides significantly reduced the serum IgA concentration(P<0.01)and significantly reduced the IgG concentration in piglet serum(P<0.05).(4)The nucleotides to different degrees increased the concentration of MDA in the serum of piglets,and the concentration of serum MDA increased by 20.39%(P<0.05)in the 0.10% addition dose group compared with the control group,and the nucleotides increased the concentration of NOS in the serum of piglets in different degrees,and the concentration of NOS in the 0.05% addition dose group was significantly increased by 32.78%(P<0.05);the concentration of serum SOD in the 0.10% dose group was significantly lower than that of the control group by 11.22%(P<0.05),and significantly lower than 12.52%(P<0.01)in the 0.05% dose group(P<0.01),and the addition of nucleotides did not significantly affect the concentration of GSH-PX in the serum of piglets(P>0.05).(5)The nucleotides did not significantly affect the number of lactic acid bacteria in piglet feces(P>0.05),but the number of Escherichia coli in piglet feces was reduced in different degrees,and 38.15%(P>0.05)and 15.58%(P>0.05)were reduced in the 0.05% and 0.10% dosage groups respectively.The results showed that the addition of exogenous nucleotides of 0.05% and 0.10% yeast sources in the diet had a tendency to increase the weight gain for weaned piglets,and had no effect on the apparent digestibility of feed nutrients,significantly reduced the concentration of IgA and IgG in the serum of piglets,and reduced the antioxidant capacity of piglets to a certain extent,but could reduce in varying degrees the number of Escherichia coli in the feces.Further studies are needed on the value of exogenous nucleotides in weaned piglets.Under the conditions of this experiment,the suitable dose of exogenous nucleotides for weaned piglets was 0.05%,based on the weight gain,the application of exogenous nucleotides in the diet for piglets should be studied at low dose.