Response of laying hens to diets supplemented with microbial phytase and differ in their protein and methionine content

Abstract EN

A total number of 480 Bovans White laying hens 21 weeks of age were used to study the effect of dietary crude protein (CP), methionine (M) and microbial photoset (Phy) levels on laying hen performance, egg shell thickness, nutrient digestibility coefficients and economic efficiency.

Hens were randomly divided into 8 equal groups with four replicates of 15 hens each.

Two levels each of crude protein, methionine and microbial phytase were used in a 2X2X2 factorial design.

The two levels of crude protein were the optimum level, 18% (CP1) and low level, 16% (CP2) ; methionine levels were the optimum level, 0.42% (M1) and low level, 0.31% (M2) and microbial phytase levels were 0.0 (Phy1) and 500 FTU / Kg of the diet (Phy2).

The diet contained CP1 and M1 without microbial phytase supplementation represents the control.

Hens were kept in cleaned and fumigated cages of wire floored batteries in an open system house under similar conditions of management up to 40 weeks of age.

Water and feed were offered ad-libitum under a total of 16 hours light / day regimen.

The overall results showed that laying hens fed diets containing the optimum level of crude protein (18%) recorded significantly (P < 0.05) higher egg production and egg weight and better feed conversion ratio compared to those fed low level of crude protein (16%).

While, the average values of feed intake significantly (P < 0.05) increased with feeding laying hens diets containing the lower level of crude protein.

Feeding laying hens diets containing the optimum level of methionine (0.42%) significantly (P < 0.05) increased egg production values comparing to those fed diets containing low level of methionine (0.31%).

While, the average values of egg weight, feed intake and feed conversion ratio were not affected by using different levels of dietary methionine.

At the same time, supplemental microbial photoset at 500 FTU / Kg of laying hen diets significantly (P < 0.05) improved the average values of egg production, egg weight and feed conversion ratio.

Laying hens fed diets either containing optimal levels of crude protein or supplemented with microbial photoset recorded significantly (P < 0.05) higher values of egg shell thickness.

Also, either the optimum level of dietary crude protein or microbial photoset addition to laying hens diets significantly (P<0.05) improved digestibility coefficient of organic matter, crude protein and ether extract.

Economic efficiency values improved by feeding laying hens diets containing lower levels of either crude protein or methionine with supplemental microbial photoset.

Accordingly, the results of this study indicated that adding microbial photoset can spare part of dietary crude protein or methionine in laying hen diets without adverse effects on laying hen performance, egg quality or economic efficiency.