The present study was conducted at a private Farm, Shebin EL - Kom, Minoufia Governorate, Egypt, in order to investigate the effect of polyzyme* (multi enzymes) in broiler diets with low protein levels on growth performance, carcass traits, some blood components and economic efficiency. A total of 180 Ross 308 unsexed one - day old broiler chicks, were distributed at random into 3 groups each in 3 replicates, 20 chicks each.
Treatments were: T1: positive control, without Polyzyme, T2: negative control, without Polyzyme and T3: negative control, with o.5 g Polyzyme*/ kg diet through the starter (1 - 21 d) and finisher (22 - 35 d) period.
The results indicated that:
1- Body weight, body weight gain and performance index were improved significantly ( P ≤ 0.05) with addition of polyzyme (0.5g/ kg diet).
2- Daily feed intake decreased significantly ( P ≤ 0.05) with addition of polyzyme.
3- Feed conversion ratio, performance index and European efficiency index were improved significantly ( P ≤ 0.05) with supplementation of polyzyme.
4- Polyzyme addition significantly (P ≤ 0.05) increased Dressing, liver and heart%, while Gizzard % was not affected.
5- Polyzyme supplementation to low protein diet led to decreased serum total cholesterol and increased aspartic transaminase (AST) enzyme compared to the positive control.
6- Total protein, creatinine, glucose and alanine transaminase (ALT) enzyme were not affected by polyzyme supplementation.
7- In general, The obtained results in the present investigation are encouraging and indicated that supplementation of 0.5g polyzyme/ kg diet can be used in broiler diets with low protein level to get heaviest weight, best feed conversion, performance index, European efficiency index and economic efficiency.