Effects Of Different Iron Supplements On Growth Performance And Immunity Of Suckling Piglet

Iron can form various proteins in the form of organic or inorganic cofactors,which are essential for oxygen transport,energy production,DNA synthesis and repair,and cellular respiration.Due to the inability to obtain sufficient iron from the maternal placenta and milk,suckling piglets are susceptible to iron-deficiency anemia,which leads to growth retardation,reduced T-cell counts,impaired lymphocyte synthesis,and decreased immune function.Currently,the most commonly used and effective method for iron supplementation is to administer intramuscular injections of iron dextran solution within 3 days of birth,but its main disadvantages are that it can cause piglet stress and has a short duration of action.In this study,three kinds of Disease-resistant nutrient needle（DRN）,Tiewezhuang（TWZ）and ZDB were selected to compare,and normal saline injection was selected as Control（CON）.Each treatment was injected within 24 hours after birth and the trial lasted for 21 days.Phenotypic indexes such as pre-injection body weight,weaning weight,fur index,diarrhea,blood routine,serum biochemistry,serum antioxidant and serum immune performance index were determined and transcriptome sequencing was used to explore the effects on growth performance and immunity of Suckling piglets.The main research results are as follows:1.Iron supplement injection group showed a certain improvement in body weight and daily weight gain on the 21st day.The highest daily weight gain was 268.13 g/d in the DRN group,261.64 g/d in the ZDB group,and 236.69 g/d in the CON group.2.Iron supplement injection group significantly increased the red blood cell count,hematocrit,mean corpuscular hemoglobin concentration,and hemoglobin concentration of suckling piglets compared to the CON group（P<0.01）.The white blood cell count and platelet count were also increased in the DRN and ZDB groups compared to the CON group,but the difference was not significant（P>0.05）.3.On the 21st day of weaning,the Fe content in the serum of DRN and TWZ suckling piglets remained significantly higher than that of the CON group（P<0.01）,while there was no significant difference in Fe content between the ZDB group and the CON group in suckling piglet serum（P>0.05）.This indicates that injection of Disease-resistant nutrient needle can more effectively maintain the iron requirements in the body of suckling piglets over a longer period of time.4.Compared with the ZDB group,the DRN group had significantly reduced levels of the anti-inflammatory factors IFN-γand TNF-αin the serum of suckling piglets（P<0.05）,while the Ig A and Ig M levels were 2.51 times and 1.62 times higher,respectively.5.A library was constructed and RNA-Seq sequencing was performed on 60 samples from the liver,spleen,thymus,lymph nodes,and peripheral blood lymphocytes（n=4）of suckling piglets in the DRN,ZDB,and CON groups.The main results were as follows:（1）Sample principal component analysis showed that m RNA could be classified into three groups,namely peripheral blood lymphocytes,liver,and immune tissues（spleen,thymus,and lymph nodes）using PC1（explaining variance=0.46）and PC2（explaining variance=0.31）.This indicates that the selected samples were dispersed between different types of tissues,and the samples within the same type of tissue were clustered.The biological variability between sample replicates was small,indicating good experimental reproducibility.（2）Genes with P<0.05 and|log₂（fold change）|≥1 were considered as differentially expressed genes,and a total of 15427 m RNAs were identified in each tissue.（3）GO enrichment analysis of differentially expressed genes identified in each tissue revealed that immune-related genes such as IGSF21,IGSF3,MIF,LSP1,and VSTM1 were highly expressed in the DRN group.In summary,the novel iron supplement-the Disease-resistant Nutrient Needle can effectively improve the growth performance and immune function of suckling piglets.