Hematology and serum biochemistry of broilers at the initial and growth stages submitted to different levels of digestible sulfur amino acids

ABSTRACT: The objective of this study was to evaluate the effect of digestible methionine and cystine (Met + Cys) levels on the hematological and serum biochemical parameters of broiler chickens during the initial and growth stages. For this, 1,800 male chicks of the Coob 500 strain were used, with 900 chicks in the initial phase (1 to 21 days old) and 900 chicks in the growth phase (22 to 42 days old), distributed in a completely randomized design of five treatments with six replicates of 30 birds. The treatments consisted of 0.545, 0.616, 0.711, 0.782, and 0.853%; and 0.514, 0.571, 0.647, 0.704, and 0.761% digestible Met + Cys for “1 to 21” and “22 to 42” days of breeding, respectively. Results showed that digestible Met + Cys levels in broiler feed altered some hematological parameters (erythrocyte, hematocrit hemoglobin, total leukocytes, heterophile: lymphocyte) and serum biochemistry (uric acid, PST, total LDL, and TG). The digestible Met + Cys levels in the diet of broilers affected the hematological parameters and serum biochemistry, especially at higher levels. From the inclusion level 0.761 of Met + Cist in the broiler diet, red blood cells, hemoglobin and hematocrit changes begin to appear.

摘要：本研究旨在评估可消化蛋氨酸与胱氨酸（digestible methionine and cystine，Met + Cys）水平对育雏期与育成期肉鸡血液学指标及血清生化指标的影响。本试验选用1800羽科宝500（Coob 500）品系雄性肉鸡雏鸡，其中育雏期（1~21日龄）与育成期（22~42日龄）各900羽；试验采用完全随机设计，设置5个处理组，每组设6个重复，每个重复纳入30羽肉鸡。针对1~21日龄育雏期与22~42日龄育成期，各处理组的可消化Met + Cys水平分别为0.545%、0.616%、0.711%、0.782%、0.853%，以及0.514%、0.571%、0.647%、0.704%、0.761%。试验结果表明，肉鸡饲粮中可消化Met + Cys水平会改变部分血液学指标（红细胞、红细胞压积、血红蛋白、白细胞总数、异嗜性粒细胞/淋巴细胞比值）与血清生化指标（尿酸、PST、总低密度脂蛋白（low-density lipoprotein, LDL）、甘油三酯（triglyceride, TG））；肉鸡饲粮中可消化Met + Cys水平对血液学指标与血清生化指标存在影响，且该影响在较高添加水平下更为显著。当肉鸡饲粮中可消化Met + Cys添加水平达到0.761%时，红细胞、血红蛋白及红细胞压积开始出现变化。