Effect of dietry iron and supplementation of phytase on growth and mineral availability in broiler chicken

Abstract

An investigation over a period of eight weeks was carried out to study the effect of dietary iron and supplementation of phytase on growth and mineral availability in broiler chicken. One hundred and ninety two day-old broiler chicks (Ven cob) were divided into four identical groups having four replicates in each group with 12 birds in each replicate and allotted randomly into four dietary treatments viz., T1, T2, T3 and T4. The treatments consisted of a standard broiler ration (T1) containing mineral mixture as per BIS (1992), ration containing mineral mixture without iron (T2), ration containing mineral mixture with iron and supplemental phytase at 750 U/kg diet (T3) and ration containing mineral mixture without iron and supplemental phytase at 750 U/kg diet (T4). Performance parameters such as body weight, weight gain, dry matter consumption, feed efficiency, protein efficiency, tibial weight and tibial ash did not differ significantly between the groups. Significant increase (P<0.05) in the availability of phosphorus with marginal increase in the availability of Fe, Cu and Ca were observed for the groups fed T2 and T3 diets, when compared to other groups. Increased retention of iron in liver of birds fed T2, T3 and T4 diets were observed showing significant difference (P<0.05) with birds fed control diet T1. But the iron retention in spleen did not differ between treatments at sixth and eighth weeks of age. Overall evaluation of the results of the present study reveals that supplementation of inorganic iron through mineral mixtures over and above ingredient iron leads to interaction between Fe and other minerals especially P and Cu. Inclusion of phytase, even though did marginally improve iron retention in storage organs, it did not create significant improvement when added to diets without supplementation of inorganic iron. So it is concluded that levels of 620 to 660 ppm Fe from the ingredients satisfies the requirement for growth, mineral availability and retention in broilers.