The Application Effects Of Different Types And Levels Of Iron Additives On Sows And Piglets

Iron is one of the essential trace elements for animal growth and development,and plays an important role in animal life activities.In animal husbandry,Iron deficiency anemia(IDA)occurs easily in lactating piglets with high iron requirement.Iron accumulated during pregnancy in the fetal liver is the main source of this microelement for erythropoiesis and other iron-dependent processes in the neonatal period.The main iron intake of lactating piglets comes from sow milk.Therefore,the iron nutrition status of sows during pregnancy and lactation is closely related to the healthy growth of piglets.In production,the addition of exogenous iron to feed has been widely used in breeding industry,among which inorganic iron is more widely used.However,inorganic iron has some disadvantages,such as low bioavailability,easily polluting the environment,stimulating the digestive tract of animals,and easily destroying other nutrients in feed.Therefore,it is important to find a safe and efficient trace element iron additive for the current breeding industry.Organic iron represented by amino acid chelated iron has the advantages of high biological titer,stable structure,good oral effect and environmental protection.It is a hot spot in the research of iron additives.This study investigated iron deficiency anemia in suckling piglets of a pig farm in Jiangsu Province,and evaluated the effects of different types and levels of iron additives on reproductive performance,blood physiological and biochemical indexes,antioxidant performance and iron storage of sows in late pregnancy and lactation.And then this study evaluated the effects of different types and levels of iron additives on growth performance,immune performance,blood physiological and biochemical indexes of piglets.The purpose of this study was to find out the best iron additive by evaluating the effects of different iron additives on sows and piglets.The study is divided into three parts.1.Investigation of iron deficiency anemia in suckling piglets in a pig farm in Jiangsu ProvinceIn a pig farm in Jiangsu,100 piglets of 1,11 and 21 days old were randomly selected.Hemoglobin concentration(HGB),hematocrit(HCT),red blood cell count(RBC),serum iron(SI),ferritin(Fn),total iron binding capacity(TIBC)and transferrin saturation(TAST)were measured to evaluate the anemia and iron nutrition of piglets at different ages.All piglets in this farm were injected iron supplement with iron dextran injection into the neck muscle on the third day after birth.The results showed that:Compared with the 1-day-old piglets without iron supplementation(anemia rate was 23%),the anemia rate of piglets after iron supplementation gradually decreased,the anemia rate of 11-day-old piglets and 21-day-old piglets were 13%and 2%respectively.Compared with 1-day-old piglets,the RBC,SI,TSAT of 11-day-old piglets increased significantly(P<0.05),TIBC decreased significantly(P<0.05);Compared with 1-day-old piglets,the HBG,HCT,RBC,SI,Fn,TSAT of 21-day-old piglets increased significantly(P<0.05),TIBC decreased significantly(P<0.05).The above results indicated that intramuscular injection of iron dextran could effectively improve the HGB,RBC and HCT,reduce the anemia rate,and improve the iron storage of piglets.However,anemia still occured in piglets after iron supplementation.And the hemoglobin level of 21-day-old piglets did not meet the standard of adequate iron content of NRC(HGB>100 g/L).In conclusion,the iron nutrition level of piglets in this farm needed to be improved to meet the healthy growth needs.2.The effects of different types and levels of iron additives on reproductive performance,blood physiological indexes,blood biochemical indexes,antioxidant activity and iron storage of sows during late pregnancy and lactationIn experiment 2,the effects of iron additive on reproductive performance,blood physiological and biochemical indexes,antioxidant activity and iron storage of sows during late pregnancy and lactation were investigated.A total of 49 sows with 2 to 4 pregnancies were randomly divided into 7 groups with 7 replicates in each group and one sow in each replicate.Group 1 did not add iron as control group.Group 2 and group 3 added 75 mg/kg and 150 mg/kg of ferrous glycinate in basic diet respectively.Group 4 and group 5 added 75 mg/kg and 150 mg/kg of ferrous fumarate in basic diet respectively.Group 6 and group 7 added 75 mg/kg and 150 mg/kg of ferrous sulfate in basic diet respectively.The test period was 28 days before the expected delivery and 21 days after delivery,totally 49 days.The reproductive performance of sows was recorded on the day of delivery.Colostrum and placenta samples were collected to determine iron content.The whole blood and serum samples were collected on the day of delivery and 21 days after delivery to determine the physiological biochemical blood and antioxidant indexes.The results showed that compared with the control group and group 4,group 2,group 3 and group 6 significantly increased the birth weight of piglets(P<0.05).On the day of delivery,the hemoglobin concentration of group 3 sows was significantly higher than that of control group(P<0.05),the hematocrit of group 3 and group 5 sows was significantly higher than that of control group(P<0.05),and the serum ferritin(Fn)of group 2 and group 3 sows was significantly higher than that of control group(P<0.05).On the 21st day after delivery,the TSAT value of group 3 sows was significantly higher than that of control group and group 7(P<0.05);The colostrum iron content of group 2,group 3 and group 5 sows was significantly higher than that of control group(P<0.05),and group 3 sows was significantly higher than that of group 6(P<0.05).There were no significant differences in serum urea nitrogen(BUN),total protein(TP),albumin(ALB),total antioxidant capacity(T-AOC),superoxide dismutase(SOD)activity and malondialdehyde(MDA)content among sows in all groups.The above results indicate that:Dietary supplemental 75 mg/kg of ferrous glycine could effectively raise iron storage level,iron content of colostrum and newborn weight of sows.Dietary supplemental 150 mg/kg ferrous glycinate could effectively increase the piglets birth weight,hemoglobin concentration,hematocrit,iron storage level and colostrum iron content of sows,and the effect is better than ferrous sulfate;Ferrous fumarate supplemented with 150 mg/kg could significantly increase the hematocrit and colostrum iron content of sows on the day of delivery;The addition of iron in the diet had no significant effect on the antioxidant performance of sows.In conclusion,150 mg/kg of ferrous glycinate in the diet had the best effect on sows.3.The effects of adding different types and levels of iron additives to sow feed on growth performance,blood physiological indexes,blood biochemical indexes and immune performance of pigletsThe research objects of experiment 3 were the piglets born from sows in experiment 2.This experiment investigated the effects of different types and levels of iron additive in sow diets on growth performance,immune performance,blood physiological and biochemical indexes of suckling piglets.The experimental period was the whole lactation period of piglets(21 days from birth to weaning).All piglets were injected iron supplement with iron dextran injection into the neck muscle on the third day after birth.On the first,seventh,fourteenth and twenty-first day after birth,the average weight of piglets at each age and ADG during the whole lactation period were calculated.The whole blood of piglets was collected on the day of birth and the twenty-first day after birth to determine the blood physiological indexes.The serum of piglets was collected on the twenty-first day after birth to determine the serum biochemical indexes and immune performance indexes.The results showed that:At the age of 1 day,the weight of piglets in group 2 and group 3 was significantly higher than that of control group and group 4(P<0.05),and the weight of piglets in group 3 was significantly higher than that of group 7(P<0.05);At the age of 7 days,the weight of piglets in group 2,3 and 5 was significantly higher than that in group 4(P<0.05);At the age of 14 days,the weight of piglets in group 2 was significantly higher than that of control group(P<0.05);at the age of 21 days,the weight of piglets in group 2 and group 3 was significantly higher than that of control group(P<0.05),and the weight of piglets in group 2 was significantly higher than that of group 7(P<0.05).At the age of 1 day,the hemoglobin concentration and hematocrit of piglets in group 3 were significantly higher than those in control group(P<0.05).At the age of 21 days,the hemoglobin concentration and hematocrit of piglets in group 2 were significantly higher than those in control group(P<0.05);The serum SI content of piglets in group 3 was significantly higher than that in control group(P<0.05);The serum Fn content of piglets in group 2 was significantly higher than that in control group(P<0.05);The serum Fn content of piglets in group 2 and group 3 was significantly higher than that in group 7(P<0.05);The serum TSAT level of piglets in group 3 was significantly higher than that in group 7 and control group(P<0.05);The serum IgG content of piglets in group 2 and group 3 was significantly higher than that of control group(P<0.05);The serum IgG content of piglets in group 2 was significantly higher than that of group 6 and group 7(P<0.05).There was no significant difference in the serum IgA content,IgM content,IL-2 content and TNF-α content of piglets in each group.The experiment results show that:Ferrous glycine supplemented with 75 mg/kg and 150 mg/kg in sow diet effectively improved growth performance,hemoglobin concentration and hematocrit of piglets;The iron storage level of piglets at 21-day-old was effectively increased;The serum IgG content of 21-day-old piglets was effectively increased,and the immune performance of piglets was improved,the effect of 75 mg/kg was better than that of ferrous sulfate group.In conclusion,the effect of adding ferrous glycinate in sow diet was the best among the three additives for piglets,but there was no significant difference among different levels.