| The MD ( Marek's disease) is a kind of lymphoid tissue disease caused by herpes increases virus. Characteristics of disease cause of chicken nerve, gonad, iris, various kinds of internal organs, muscle, skin monocyte, It is tumour disease of a kind of lymthoma disease. This disease has longer incubation period from infecting to having illness coming on. Generally incubation period is 2-3 months. There is very great influence on the size in incubation period in the factors, such as poisonous of virus, dosage, age and variety, etc.As broiler chickens, it produces performance cycle and delivers for sale for 56~65d, So generally thinking, Broiler chicken deliver for sale incubation period in disease, can't take place MD. So needn't inject MD vaccine. However, there are more and more materials that indicated that the wMDV make incubation period shorten, the shortest one can present the symptom or death on more than 20 days. On the other hand, make organism damage already incubation period in disease, result produce performance drop. In abroad at present had injects MD vaccine to the broiler chicken, The manufacturer of our country has not done in this way. It is to proceed from this purpose, Compared difference such as immunity and production performance in broiler chicken when inject MD vaccine.Fetch the age of 180 one mattress health Ivy broiler chicken, divide into A, B, C 3 group at random, 60 in every groups. Three groups isolate and raise each other under the same environment separately. In one age, A groups vaccinated CVI988 + HVT cell vaccine inoculate in the liquid nitrogen store, B groups is the more artificial to infect virulent MD virus during one age. Each chicken drips 4-5 drops of noses. C groups does not inject MD vaccine, as a natural contrast group. Carry on the immunity according to the immune method of the routine. Drip nose with ND IV and hypodermic injection with 0.3 ml deactivation oil. Infected IBD vaccine two times on the 15th and the 23rd age.HI of ND tests: collect blood at random A, B, C three groups separately in 7,14, 28 ,42, and separate the serum, Carry on HI tests with (3 - the micro-method. The result of the test shows : The HI antibody result prices of A group are higher by 1-2.4 Iog2s than that of B group and C group, The results remarkable(P<0.05). B group is similar to HI antibodyresult price of C group, The results is remarkable(P>0.05). There are 20%~40.9%of the HI result are lower than 3 Iog2s in B group and C group.Phagocyte bacteria tests: Fetching pig's E.coli diluted to 4xl06/ml, every groups collects 5 chickens, intravenous injection 1ml at random. Collects blood respectively after the note 60min, 120min, ISOmin. Carry on bacteria to train, calculate that the bacterium counts in order to observe the speed of removing to the bacterium of organism. The result of the test shows: After 180 min, it is 2.53><104/ml and 2.30 xlO4 /ml that the bacteria in B and C groups' blood respectively, and A group is 1.13* 102 / ml, the results is remarkable(P<0.05),B groups and C groups difference unremarkable (P>0.05).Increase weight and fodder conversion ratio test: Weigh to 30 chickens on the 1st, 14th, 28th, 42nd, 49th and 56th age separately. At the same time, note down and dawdle by material every day. The result shows that the weight on the 60th age of A group is higher than B group and C group notably, it's remarkable(P<0.05), The weight of A group are higher 275g and 220g on average than B groups and C groups, three groups of A, B, C material meat are 2.25, 2.43 and 2.39 than respectively, the material meat of A group is more smaller than B groups and C groups obviously. During the process of raising, Death in A, B, C are 5, 8, 9differentiate. Deathly is 8.3%, 13.3% and 15.0% respectively. Examine the death chicken, there are 5 find tumour and tubercle in B group and C group in the heart.Draw the following conclusion through testing: Inoculate MD vaccine groups' ND HI antibody higher than no inoculate groups, epidemic groups' HI antibody is similar to contra...
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