الفهرس 
ACKNOWLEDGEMENTOnly 14 pages are availabe for public view
 |  | from | 206 |  |  |
| | | from | 206 | | |
Abstract
his work was conducted to study the effect of breed and growth promoters on the performance (growth performance, carcass traits and some blood pictures including total and differential leucocytic counts) of broiler chickens. A total number of 180 unsexed one day old chicks of Cobb breed and 180 unsexed one day old chicks of Hubbard breed were used in this experiment. The chicks of each breed were allocated randomly into three treatments (probiotic Primalac® at dose of 1 g/kg ration, enzyme Allzyme® SSF at dose of 200 g/ton ration and a combinations of both) with control group for each treatment. Each treatment has three replicates. The results showed that dietary supplementation with Allzyme® (200 g/ton diet) in Hubbard breed improved body weight (2100g) and body weight gain (2056.77g). Hubbard breed showed numerical higher final body weight (2022.05g) and final body weight gain (1979.17g) than that of Cobb breed (1983.78g and 1941.02, respectively) for final body weight and body weight gain, respectively. The different dietary treatments had no significant effect on total relative growth rate and total feed conversion ratio in both breed. There were significant effects (P<0.05) among all treatments of both breeds for total feed intake but breed had no significant effect for total feed intake. There were significant effects (P<0.05) among all treatments of both breed for breast % and drumsticks %. Cobb Primalac treated group showed the highest breast% (25.59%) compared with other treated or control group. Breed had significant effect (P<0.05) on drumsticks % while, it had no significant effect (P>0.05) on either breast or thighs%. There were significant increases (P<0.05) among all dietary treated groups comparing with the control groups for total leucocytic count, lymphocyte and neutrophile count. Also, the results showed that there were significant effects (P<0.05) among all treatment of both breeds for monocyte and esinophile count. Breed had significant effect (P<0.05) on total leucocytic count, lymphocyte and neutrophile count while, breed had no significant effect (P>0.05) on monocyte and esinophile count. The results could be concluded that Allzyme® play an important role as growth promoters in both breeds. Allzyme® and Primalac® improved the immune response of broilers.