The undigested phytates excreted through the feces causes the environmental pollution. The phytase enzyme in feed for layers increases the bioavailability of phosphorus, reduces its excretion and is also reported to be a valuable source of pigment for meat or egg. The objective of this study was to assess the effect of supplementation of phytase expressed intransgenic Lemna minor on growth performance, egg quality and mineralization levels of tibia of layers. The experiment was designed with three phytase supplemented groups (B, C and D) and one control group (A) with each 20 replicates of individually caged layers in a completely randomized design. Higher percent increase (P<0.05) in body weights have been recorded in phytase supplemented groups. Results for FCR have shown significant difference (P<0.05) in the phytase supplemented and control group. Increased egg shell thickness has been reported due supplementation of transgenic phytase. An overall significant (P<0.05) increase in egg-production, -weight and the quality of egg-protein has been observed in the layers supplemented with the transgenic phytase. The supplementation of transgenic phytase has significantly (P<0.05) enhanced the deposition of phosphorus and calcium in the bones. An overall significant (P<0.05) decrease in the excretion of phosphorus through feces has been recorded in the treatment groups. The corresponding findings on growth performance, productivity, quality of eggs, bone mineralization and decreased excretion of phosphorus through feces propose phytase derived from A. nidulans and expressed in the transgenic L. minor as an efficacious and cost effective approach.

Key words: Egg quality, Food conversion ratio (FCR), Lemna minor, Phosphorus, Transgenic phytase