Vajiheh Nikoofard; Akbar Yaghobfar; Shahab Ghazi Harsini; Ali Asghar Saki
Volume 20, Issue 3 , November 2018, , Pages 463-476
Abstract
The effect of diet with different protein quality andsupplemented with crystalline amino acids on performance, immune response, enzyme activity in the intestinal tissue and litter characteristics, using 576 Ross 308 (mixed sex) broiler chickens,in a 2 × 4 factorial experiment with two experimental ...
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The effect of diet with different protein quality andsupplemented with crystalline amino acids on performance, immune response, enzyme activity in the intestinal tissue and litter characteristics, using 576 Ross 308 (mixed sex) broiler chickens,in a 2 × 4 factorial experiment with two experimental diets (high and low protein quality) and four levels of crystalline amino acids (recommended levels, without supplemented crystalline amino acids, 10 and 15% higher than the recommended levels)in a completely randomized design with eight treatments, six replicates and 12 chicks per replicate was investigated.The results of this study showed that, adding crystalline amino acids at levels of 10 and 15% higher than the recommended level to diets containing canola meal and wheat (as low quality protein source) caused an increase in performance (P<0.0001), the number of heterophile and heterophile to lymphocyte ratio (P<0.001) and decreased the number of lymphocyte (P<0.01). The treatments with crystalline amino acids hadn’t significant effect on the enzyme activity aminopeptidase and specific activity of the enzyme in jejunum. Also, adding crystalline amino acids at levels of 10 and 15% higher than the recommended level ina low-quality diet were not significantly affected dry matter, nitrogen and ammonia nitrogen in the litter. According to these results, the use ofcrystalline amino acids higher than the recommended levels in the diets with high quality (as maize-soybean meal) has no effect on the performance of broiler chickens and is not recommended.