Interaction of Increasing Level of Methionine and Zinc In Broilers Diet On Iimmune System and Performance

To evaluate the effect of adding methionine and Zn element on performance and immunity system of broilers,the experiment with 6 treatments and 4 replicates, 20 birds (including male and female of Ross 308) in each replication in a 42 days of priod was carried out. Treatments include:1- treatment with (Met 0%,Zino 0%) 2- Treatment with (0.2% Zno)3- Treatment with (0.2% Met)4- Treatment with (0.2% Met, 0.1 Zno)5- Treatment with (0.3% Met)6- Treatment with (0.3% Met, 0.1% Zno)Average of feed intake, body gain, feed conversion ratio in starter, grower, finisher and total priod and average antibody titer against Newcastle at 13-day, SRBC at 42-day and weight of Bursa of fabricus at 42-day were calculated. Results showed that increasing of Met and Zinc separately and in combination have no significant effect on feed intake in total priod of study.(p>0. 5).In relation to body weight, increasing Met has significant effect on body weight of broilers (p<0.5). zinc had no significant effect on body weight, feed conversion ratio, anti Newcastle. Antibody titer in 13-day, anti SRBC antibody titer and Bursa of fabricus at 42-day (p>0.5). By increasing Met separately a meaningful effect on average body weight of broilers were noted (p<0.5). A meaning effect on body weight with use of Met and Zinc were observed (p<0.5) feed conversion ratio were improved with use of Met (p<0.5) Interaction of Met and Zinc on feed conversion ratio were also significant (p<0.5). Anti Newcastle antibody at 13-day and bursa of fabricus at 42-day following the increasing of met levels had no notable effects (p>0.5).Increasing Met had significant effect on anti SRBC antibody titer (p<0.5). But interaction of Met and Zinc had no significant effect on anti Newcastle and SRBC antibody titer and bursa of fabricus weight at 42 day (p>0.5). The final result show that: in comparison with control group, increasing Met will improving feed conversion ratio and anti SRBC titer. Increasing Zinc element alone and in combination with Met had no significant effect on performance and Immunity system of broilers.