Effect of Replacing Dicalcium Phosphate by Rock Phosphate with and without Aluminium on Production Performance of Layers

The present study was carried out to study the utilization of rock phosphate (RP) with and without aluminium sulphate as an alternate to dicalcium phosphate in mineral mixture of layers. A total number of 270 layers of 20 weeks age were randomly distributed into nine treatments with three replicates in each group and ten birds per replicate. Layers of control group T₁ were fed diet in which dicalcium phosphate (DCP), a traditional phosphorus supplement, was used as a sole source of phosphorus. While, in treatment groups T₂, T₄, T₆ and T₈, DCP of control was replaced @ 40, 60, 80 and 100% with rock phosphate and diets of treatment group T₃, T₅, and T₇ and T9 were same as T₂, T₄, T₆ and T₈ with the addition of aluminium having Al: F ratio of 0.8: 1. The overall performance of layers indicated that use of 40% RP in place of DCP in the mineral mixture produced better performance (weight gain, feed intake, percent hen day production and egg weight), better egg quality traits (shape index, albumen index, yolk index and HU), higher dry matter utilization and retention of nutrients (CP, EE, CF, Ca and P) as well as increase in shell thickness, however, increase in the level of RP above 60% adversely affected these parameters. Supplementation of aluminium sulphate with higher levels of RP (80 and 100%) in place of DCP increased layers performance (feed intake, FCR, HDP, body weight gain, egg weight, egg quality traits (shape index, albumen index, yolk index and HU) and egg shell thickness. Hence, it was concluded that 40 RP and 80% RP along with aluminium sulphate was beneficial to replace DCP in the mineral mixture of layers. However, supplementation of aluminium sulphate to RP was not economical.