| A study was carried out to evaluate the effects of three kinds of complex antistressors on laying performance , egg quality, blood physiological and biochemical index and immune function in heat stressed E.sia layers among three kinds of complex antistressor in the high temperature of summer .756 healthy E.sia layers , 42 weeks of age , with similar laying rate , were randomly allotted into six groups with 6 replicates per group and 21 hens per replicate . The concrete experimental design: Group 1: Control group, the layers were fed on basic diet; Group 2:The basic diet was added with 500g/T complex antistressor of type I ; Group 3:The basic diet was added with 1000g/T complex antistressor of type I ; Group4: The basic diet was added with 1500g/T complex antistressor of type I ; Group 5: The basic diet was added complex antistressor of type II; Group 6: The basic diet was added with complex antistressor of type III. Pick and drink freely . Experimental period lasted for 30 days .The temperature of layers house was 28-32C.During the experiment , production performance of layers was evaluated,and in the end of the experiment, eggs were sampled to analyze and blood was collected at wing vein at 8:00 in the morning ,and serum was separated to determine GPT, GOT, AKP, LDH, TP, GLOB, ALB, G/A, GLU , IgA, IgG , IgM , T3 , T4 , K, Na+ , Cl-, Ca2 + , pH , T lymphocyte conversion ratio and plasma cortex .The results of the test indicated : (1)Diet supplemented with antistessor decreased the Feed/Egg efficiently , the difference between group 2,3,4 and the control was significantly (p <0.05),but the difference between group 5, 6 and the control was not significantly (p> 0.05). Laying rate of the experiments were improved (p> 0.05). The rate of soft and broken shell eggs was decreased significantly (p <0.05), comprehensive results of complex antistrcss additives of type I was superior to that of complex antistress additives of type II and III.(2)The albumin height of egg was improved extremely (p<0.01), the thickness of egg shell and Haugh unit was improved significantly (p<0.05), the egg shape index was not influenced obviously.(3)As to the blood biochemical parameters, compared with the control, complex antistressor of type I (1000g/T) reduced GPT and GOT activities , GLU , pH value , AB value significantly (p<0.05), improved AKP and LDH activities , and the content of TP, GLOB, ALB, K+, Cl- significantly (p<0.05), total result show 1000g/T of type I was superior to 500g/T , 1500g/T of type I and complex antistressor of type I was superior to complex antistressor of type II and III ; complex antistressor of type II and III improved the Na+ , Ca2+ , Cl-, but the difference was not significant (p>0.05 ), but increased activity of LDH and serum TP , GLOB, ALB contents significantly (p <0.05) , reduced the content of GLU and activity of GPT and GOT , but the difference was not significantly (p> 0.05), complex antistressor of type II increased activity of AKP extremely , complex antistressor of type III decreased activity of AKP extremely. (4)Function on the internal secretion system: complex antistressor of type I , II and III all reduced the content of T3 , T4 and plasma cortex , but complex antistressor of type I was superior to II and III. (5)Impact on immune system: complex antistressor of type I influenced the content of serum IgG , IgA, IgM significantly (p <0.05), result of complex antistressor of type I was superior to II and III; as to T cell conversion , complex antistress additives of type IIIwas the best , it increasd conversion ratio of T cell extremely (p <0.01).Therefore , diet added with complex antistress additives was benefit to enhance produce performance , improve egg quality , raise nutrient utilization and alleviate the metabolism disorderly because of heat stress. The antistress provent mechanism of complex of complex antistressor of type I was that it can regulate the stress system , endocrine function , protein and candy metabolism , electrolyte , base and acid balance of laying hens . Ove... |
