MAPPING QTL LOCI AFFECTING GROWTH AND DISEASE RESISTANCE TO AVIAN COCCIDIOSIS

Authors: Zhu, James; Lillehoj, Hyun; VAN TASSEL, CURT - USDA, ARS; EMARA, M - U DELAWARE, NEWARK; ALLEN, P - 1265-40-00; CHENG, H - EAST LANSING, MI; POLLOCK, D - PERDUE FARMS, MD; SADJADI, M - PERDUE FARMS, MD; SONSTEGARD, TAD - USDA, ARS

Submitted to: Poultry Science Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/30/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Selection of commercial poultry stocks with improved disease resistance using classical genetic breeding techniques has been unsuccessful due to technical difficulties. In order to develop a DNA marker-assisted selection strategy to improve disease resistance against avian coccidiosis in commercial breeder chickens, we are identifying chicken genes controlling resistance to coccidiosis. Over three hundred F2 offspring were produced from 12 full-sib families raised at a local commercial breeder for mapping quantitative trait loci (QTL) affecting disease resistance. F2 offspring were inoculated with 104 sporulated oocysts of Eimeria maxima at 4 weeks of age. Body weight gain and fecal oocyst shedding were measured. One hundred and twenty chicken microsatellite markers with an average genome distribution of 20 cM were used for genotyping. Genotypic data were analyzed with CRIMAP version 2.4 to construct a marker linkage map. A minimum LOD score of 3.00 was used as the statistically significant. QTL analysis was conducted using SOLAR based on the genotypes of the F1 and F2 and the phenotypes the F2 chickens. A locus on chromosome 1 was identified that was significantly associated with reduced oocyst shedding and 3 potential loci affecting growth were identified on chromosomes 1 and 6. Ongoing studies are underway to identify additional markers influencing coccidiosis resistance in meat-type chickens (Supported by Fund for Rural America, Grant No 9704985 and partially by ARS CRIS).