Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/12/2012
Publication Date: 6/1/2012
Citation: Tako, E.N., Glahn, R.P. 2012. Intra amniotic administration and dietary inulin affect the iron status and intestinal functionality of iron deficient broiler chickens. Poultry Science. 91(6):1361-1370.
Interpretive Summary: Inulin is a non-digestible starch and is present in a variety of plants at relatively high levels of up to 20%, for example, in chicory root. Previously, inulin was found to promote the growth of certain beneficial bacterial populations in the pig gut and was shown to improve the iron status of iron deficient pigs. Our objective was to assess the effect on the iron status of hatchling chicks of inulin solution injection into a fertile broiler egg at the day of hatch and to continue to monitor the chick’s Fe-status with/without dietary inulin for 42 days. Upon hatch and from each group, 10 chicks were sampled and their intestines were removed for gene expression analysis of intestinal iron-related transporters and bacterial analysis of intestinal content (test the prebiotic effect of inulin). The remaining chicks of each group were grown for additional 6 weeks. Results showed that hemoglobin concentrations and body-hemoglobin-Fe values (indicators of iron status) were higher in the inulin-treated group vs. controls (P<0.05). On day 42, we directly measured intestinal iron absorption. At the end of the procedure, tissue samples were taken for further analysis. Results showed that the iron-absorption rates were at times higher in the inulin-treated group vs. the other groups. Also, the expression of intestinal iron transporters were higher (P<0.05) in the inulin group vs. controls. This suggests that the dietary inulin increases the iron solubility in the diet and as previously shown directly affects the expression of these proteins. We conclude that dietary inulin improved the iron-status of iron-deficient broilers, which indicates that inulin may promote dietary iron absorption. The data presented in the current study is crucial for a better understanding of the effect that inulin has on mineral nutrition in general and Fe absorption in particular.
Technical Abstract: Inulin, a linear beta-fructan, is present in a variety of plants, with relatively high levels of up to 20% in chicory root. It exhibits prebiotic properties and was shown to enhance mineral absorption. Our objectives were to assess the effect of intra-amniotic administration of inulin at 17d of incubation on the Fe-status of broiler chicks (at hatch, 21d); and to continue to monitor Fe-status with/without dietary inulin on these hatchlings for 42d. The study included three pre-hatch treatment groups (n=30):1."Inulin": inulin solution (4%-inulin/0.85%-saline);2."Control 1": untreated eggs; 3."Control 2": saline solution (0.85% saline). Solutions were injected into the naturally consumed amniotic fluid of 17d old chicken embryos (groups 1,3). Upon hatch (93% hatchability) and from each group, 10 chicks were sampled and their small-intestine, liver and cecum were removed for mRNA abundance of intestinal Fe-related transporters, liver ferritin amounts and bacterial analysis of cecal content, respectively. From the remaining chicks of each group, chicks were allocated to a standard corn based-diet (+/- 4% inulin, n=10). During the trial, hemoglobin concentrations and body-hemoglobin-Fe values were higher in the inulin group vs. controls (P<0.05). On d-42, birds were anesthetized and their duodenal loops were exposed. A non-occlusive catheter was inserted into the duodenal vein for blood sampling. A solution containing Fe (0.1mg Fe/10mM ascorbic-acid) added to the digested diet sample was injected into the loop. Blood samples were collected every 5min and for 90min post injection and analyzed by ICP-MS for Fe-concentrations. At the end of the procedure, cecum contents and sections of the duodenum and liver were removed. Results showed that Fe-absorption rates were at times higher in the inulin group vs. the other groups. Also, mRNA abundance of DMT1 and ferroportin in addition to liver ferritin amounts were higher (P<0.05) in the inulin group vs. controls. Results indicate that intra-amniotic administration and dietary inulin improved the Fe-status of Fe-deficient broilers.