EVALUATION OF PRODUCTION PERFORMANCE AND HUMORAL IMMUNE RESPONSE OF TWO SAUDI CHICKEN LINES AND THEIR CROSSES WITH FOREIGN BREEDS UNDER KINGDOM OF SAUDI ARABIA ENVIRONMENT

摘要

Layer performance intensively rely on their ge- netic pool and feeding strategies. Researchers could alter genetic makeup through genetic crossing tech- niques, which reflects on the birds' requirements and performance including productivity immunological response. Four hundred female pullets at 18 weeks of age were divided into four groups of one hundred pullets each; Hajar, (H), Hajarz (H2), H1, crossed with Hi-Sex (HHI), and H2 crossed with 8Hi- Sex (H2HI). Birds randomly assigned into 4 groupswith 20 replicates of 5 birds. Humoral immune re- sponse against Newcastle disease (ND) and egg pro- duction performance of recently characterized chicken lines in Saudi Arabia, HI, H2, HHI, H2HI lines were determined. The evaluation of the hybrid performance was reflected on the actual require- ments and potential of those lines in a very importantperiod in the chicken life. The laying hens were eval- uated for general performance including egg produc- tion, mortality rate, and egg characteristics, as well as Newcastle disease (ND) antibody titer. The results of current investigation showed that egg production, egg mass and feed efficiency were significantly bet- ter (P<0.05) in H2HI group, while egg weight was significantly greater (P<0.05) in H2HI group. In ad- dition, the data of humoral immune response against ND in the four lines showed that all breeds suffered from limited protection. In conclusion, the cross line breeds (HHI and H2HI) showed higher improve- ment in the productive performance compared to na- tive Saudi local breeds (H; and H2) without jeopard- izing their immunity response.