Dietary supplementation of ferrous glycinate improves intestinal barrier function by modulating microbiota composition in Cherry Valley ducks

Ferrous glycinate(Fe-Gly)has been increasingly used as iron fortification in the diets of weaned piglets and broilers,but the effect of Fe-Gly on intestinal barrier function in meat ducks has not been well defined.This study therefore investigated the effect of Fe-Gly on apparent nutrient utilization,hematological indices,intestinal morphological parameters,intestinal barrier function and microbial composition in meat ducks.A total of 672 one-day-old Cherry Valley ducks were randomly divided into 6treatments(8 replicates for each treatment and 14 ducks for each replicate)and fed diets with 0(control),30,60,90 and 120 mg/kg Fe-Gly or 120 mg/kg Fe SO4for 35 d.The results showed that diets supplemented with Fe-Gly significantly increased average daily gain(ADG),average daily feed intake(ADFI),hematocrit(HCT),mean cell volume(MCV),the apparent utilization of dry matter(DM)and metabolizable energy(ME),villus height(VH)and villus height-to-crypt depth ratio(V:C)(P<0.05).FeGly also significantly up-regulated barrier-related genes including zonula occludens-1(ZO-1),zonula occludens-2(ZO-2),mucin 2(MUC2)and lysozyme(LYZ)(P<0.05),and down-regulated the m RNA expression of claudin-2(CLDN2)and occludin(OCLN)in the jejunum(P<0.05).The 16S r RNA sequence analysis indicated that the diet with Fe-Gly had a higher relative abundance of Intestinimonas and Romboutsia(P<0.05),which have an ability to produce short chain fatty acids(SCFAs),especially butyric acid.It also decreased the relative abundance of pathobiont,including Megamonas,Eubacterium_coprostanoligenes_group and Plebeius(P<0.05).Additionally,diets supplemented with 120 mg/kg Fe-Gly significantly increased the apparent utilization of DM and ME(P<0.05)and decreased the relative abundance of Megamonas_unclassified and Bacteroides_unclassified compared with those fed120 mg/kg Fe SO4(P<0.05).These results revealed that diets supplemented with Fe-Gly exerted a potent beneficial effect on physical,chemical,immune and microbial barriers,thereby improving the integrity of the intestinal structure,promoting the digestion and absorption of nutrients to a certain extent,and ultimately elevating the growth performance of ducks.

Effect of different sources and levels of iron in the diet of sows on iron status in neonatal pigs

This study was conducted to determine the effects of maternal dietary supplementation of ferrous glycine chelate(Fe-Gly) and ferrous sulfate monohydrate(FeSO_4·H_2O) on the relative organ weight, tissue iron contents, red blood cells(RBC), hemoglobin concentration(HGB) and hematocrit(HCT) in blood, as well as ferritin(Fn), serum iron(SI), and total iron binding capacity(TIBC) in serum of newborn piglets.Forty-five sows(Landrace × Large white, mean parity 3 to 4, no significant differences in BW) were randomly allotted to 9 treatments(n=5 sows/treatment): control(basal diet with no Fe supplementation), the basal diet supplemented with 50, 80, 110 or 140 mg Fe/kg as Fe-Gly, and the basal diet supplemented with 50, 80, 110 or 140 mg Fe/kg as FeSO_4·H_2O.The neonatal piglets(n=45) were used to determine the relative organ weight, tissue iron contents and blood biochemical indices.Compared with the control, the relative weight of spleen and kidney were significantly increased(P < 0.05) in the Fe-Gly groups.The iron contents in liver,spleen, kidney and femur were also found increased(P < 0.05) in the Fe-Gly groups.The RBC(d 1 and 21),HGB(d 1 and 21) and HCT(d 1 and 21) in blood and Fn(d 1) and SI(d 1 and 21) significantly increased(P < 0.05), but the TIBC(d 1 and 21) in serum decreased(P < 0.05) in the Fe-Gly groups.Moreover, the kidney relative weight, iron content in liver, spleen, kidney and femur, RBC(d 1) and HGB(d 21) in blood, and SI(d 1)in the Fe-Gly groups increased(P < 0.05) compared with the FeSO_4·H_2O treatment.Linear and quadratic responses of the kidney relative weight, the iron content in liver, spleen, kidney and femur, RBC(d 1 and 21),HGB(d 1 and 21) and HCT(d 1 and 21) in whole blood, SI(d 1) and TIBC(d 1 and 21) in the Fe-Gly groups were observed(P < 0.05).Linear responses of Fn(d 1 and 21) and SI(d 21) in the Fe-Gly groups, and spleen relative weight, HCT(d 1), Fn(d 1) and TIBC(d 1 and 21) in the FeSO_4·H_2O groups were observed(P < 0.05).These finding suggest that Fe-Gly supplemented at the level of 110 mg/kg in the diet of sows in this experiment is superior to other forms of supplementation, based on HGB concentration, the relative organ weight, tissue iron contents and blood biochemical indices of piglets.