The Efficacy of a Novel Microbial 6-Phytase Expressed in Aspergillus oryzae on the Performance and Phosphorus Utilization in Broiler Chickens

Abstract

The efficacy and safety of a novel microbial 6-phytase expressed via the use of synthetic genes in Aspergillus oryzae was investigated from d 8 to 22 of age using 480 Ross PM3 broiler chickens. Five treatments were tested. A diet containing 5.6 g/kg of Phosphorus (P) was fed to the control treatment. Another diet containing 4.1 g/kg P was fed to another treatment as negative control. This diet was fed in 3 other treatments with the addition of phytase (500, 1000, or 2000 U/kg). Feed intake, body weight, tibia ash (%) and strength (N) and P and Ca utilization (% of intake) and excretion (g/kg DM) were measured. Enzyme safety was determined by genotoxicity and sub-chronic oral toxicity studies. Lower feed intake and higher weight gain was obtained with the treatment containing 2000 U/kg phytase compared to the two control treatments and the treatment containing 500 U/kg phytase, leading to a significant improvement in FCR with the 2000 U/kg phytase. Tibia strength and ash were improved with the latter and were dose-dependent described by an exponential function. Safety test using a concentrated preparation of the novel 6-phytase enzyme did not reveal any toxicological significant findings. The enzyme did not induce mutagenic activity in the Ames test and did not increase the frequency of micronucleated binucleated cells in the micronucleus assay. In conclusion, this novel microbial 6-phytase improved broiler performance and reduces the need for phosphate fortification of feed. In addition, it can be Generally Recognized as Safe (GRAS) feed ingredient according to the safety test carried out.

Performance of an Escherichia coli phytase expressed in Lactococcus lactis on nutrient retention, bone traits and intestinal morphology in broiler chickens

“…The results indicated that the use of phosphorus‐deficient diet reduced BWG as reflected on FCR and other performance parameters in broiler chickens. The findings are consistent with those in the previous studies (Aureli et al, 2011; Ravindran, Cowieson, & Selle, 2008; Rutherfurd, Chung, Thomas, Zou, & Moughan, 2012). Phosphorus is an essential mineral in chickens and plays the main role in bone strength and cellular metabolism, as a part of the energy currency of the cell.…”

“…It seems that the application of L. salivarius , together with RLL in the deficient diet, can enhance BWG, similar to those of PC and commercial phytase. In addition, a reduction in the amount of available phosphorus in the diet decreases feed intake and the addition of phytase can compensate for the negative impact on feed intake (Aureli et al, 2011; Ravindran et al, 2008). However, no reduction of feed intake occurred in the present study, which may be related to the fact that the deficient diet is fed to the chickens at seven days of age, and the birds are fed with a standard diet during this time, which may increase phosphorus reserves in the body.…”

“…Bone ash content and tibia breaking strength decreased by reducing dietary non‐phytate phosphorus (available phosphorus) levels, which may be related to the lack of available P for mineralization in developing the body and bone. Supplementing low available P diets with different levels of HiPhos ® (500–2,000 FYT/kg diet) increased the tibia ash percentage by 6%–14% (Aureli et al, 2011; Shaw et al, 2011). Ash percentage and bone‐breaking strength are known to improve as the phytase level increased in the diet (Shaw et al, 2011).…”

Soybean Meal and The Potential for Upgrading Its Feeding Value by Enzyme Supplementation

“…Supporting this there are a huge amount of in vivo studies demonstrating that phytases effectively releases phosphate in animals fed diets containing SBM e.g. Aureli et al [70] showing phytase efficacy in broilers.…”

Exploratory transcriptomic analysis in muscle tissue of broilers fed a phytase‐supplemented diet

“…The respective negative control diet was formulated with moderate deficiency of phosphorus and Ca and fed as such (negative control, NC) or supplemented with 2.0 g/kg non‐phytate‐P from dicalcium phosphate dihydrate (DCP) as a positive control (PC). NC was supplemented with bacterial 6‐phytase from Citrobacter braakii (DSM Nutritional Products Ltd, Kaiseraugst, Switzerland) at 1000 U/kg (Phy1000) (one unit (U) of phytase is defined as the activity that releases 1 μ mol inorganic phosphate from 5.0 m m phytate per minute at pH 5.5 and 37 °C) (Aureli et al., ). Activity of phytase in the diet was determined using the ISO 30024:2009 methodology entitled: Animal feeding stuffs – Determination of phytase activity.…”