Effect of genetic strains (Ross 308, Cobb 500 and Hubbard F15) on immune response against Newcastle disease vaccine in broiler chickens
Background: Immune responses are crucial for optimal health and can be affected by several factors including host genetics.The increasing need for chicken meat has provoked producers to try to optimize breeding through genetic methods. We expect that new broiler lines have shorter breeding period and grow fast, be resistant to disease, be robust (characterized by a high level of utilization of nutrients and a good metabolism), have a high viability rate, powerful skeleton, have high flexible capacity and show consistent growth. Unluckily, genetic advancement has also led to several negative influences. So, in broiler chickens, changes are now found which not happened before or were relatively unusual. These changes involve: pulmonary hypertension syndrome, limb disease ,sudden death syndrome, abnormal bone growth, subclinical diseases such as Escherichia coli and Clostridium perfringens, immunosuppression and sensitivity of chickens to mycotoxin intoxication.
Objectives: The recent study was performed to examine the effects of genetic strain of broiler chickens on immune response against Newcastle disease vaccine. So three genetic strains of broiler chickens including Ross 308, Cobb 500, and Hubbard F15 were investigated in this study.
Materials and Methods: 36ooo one-day-old broiler chicks Hubbard F15, Cobb-500 and Ross308, were divided into 3 equal groups with 2 replicates and 6000 birds per replicate. The birds were reared under similar conditions from one-day-old to 49 days of age. All groups were vaccinated against Newcastle disease. Blood samples were collected before vaccination and on 7, 17, 27, 35, 42, 48 days and antibody titer against Newcastle disease vaccine was determined by HI test.
Results: The Cobb 500 and Hubbard stains respectively had the highest and the lowest immune response against Newcastle diseases vaccine. Ross 308 had second status among strains.
Conclusions: On the basis of present study Cobb 500 and Ross308 chickens had better immune response against Newcastle diseases vaccine and recommended for rearing respectively.