Niraula Abhisek, Wolc Anna, Fulton Janet E, Taylor Robert L, Dalloul Rami A
Avian Immunobiology Laboratory, Department of Poultry Science, University of Georgia, Athens, GA 30602, USA.
Hy-Line International, Dallas Center, IA 50063, USA; Department of Animal Sciences, Iowa State University, Ames, IA 50010, USA.
Poult Sci. 2025 Apr 17;104(7):105151. doi: 10.1016/j.psj.2025.105151.
Coccidiosis, a major poultry protozoal disease caused by several Eimeria species, compromises gut health causing significant losses. This study assessed the association of haplotypes of the major histocompatibility complex (MHC) and other blood alloantigens found in commercial egg production chickens with resistance to coccidiosis. Pedigreed White Leghorn offspring segregating for the MHC-B region, plus four additional alloantigen systems A (C4BPM), D (CD99), E (FCAMR), and I (RHCE) were tested for differential resistance to coccidiosis in five 26-day (d) trials (n= 235 birds in total). On d 19, all birds were inoculated with a cocktail of E. acervulina, E. maxima, and E. tenella oocysts and allocated to individual cages. Phenotypes evaluated included body weight gain (BWG), feed intake (FI), feed conversion ratio (FCR), gross and microscopic lesion scores (GLS and MLS), and oocyst shedding (oocysts per gram, OPG). Haplotypes of the five blood systems were determined by SNP genotyping. A positive and negative association means an increase and decrease in a phenotypic trait, respectively, with each additional copy (0, 1 or 2) of a given haplotype. Results were considered statistically significant at P ≤ 0.05. The CD99-H01 haplotype association was positive with BWG but negative with FCR. Genotype B21B21 had the highest GLS in the jejunum establishing a positive association between MHC B21 and jejunal GLS. Further, the B12B15 genotype had a lower E. maxima OPG compared with the B12B21 genotype. The I system I-H01 haplotype had a negative association with jejunal and cecal GLS. Duodenal GLS was lower in E-H02/H02 compared to the E-H07/H07 genotype of the E system. Haplotypes B21, blood systems D-H01, E-H02, and I-H01 were associated with improved resistance to coccidiosis. The association of specific haplotypes of the MHC-B and other alloantigen systems D, E, and I with resistance and susceptibility traits during mixed Eimeria infection underscores the need for further investigations of these haplotypes' effects on coccidiosis resistance in commercial lines, validating the inclusion of different blood systems in selection programs.
球虫病是由几种艾美耳球虫引起的主要家禽原生动物疾病，会损害肠道健康，造成重大损失。本研究评估了商业蛋鸡中主要组织相容性复合体（MHC）单倍型及其他血液同种异体抗原与球虫病抗性之间的关联。对在MHC - B区域分离的纯种白来航后代，以及另外四个同种异体抗原系统A（C4BPM）、D（CD99）、E（FCAMR）和I（RHCE）进行了五次26日龄试验（共235只鸡），以检测其对球虫病的抗性差异。在第19日龄时，所有鸡均接种了堆型艾美耳球虫、巨型艾美耳球虫和柔嫩艾美耳球虫卵囊混合液，并分配到单独的笼子中。评估的表型包括体重增加（BWG）、采食量（FI）、饲料转化率（FCR）、大体和微观病变评分（GLS和MLS）以及卵囊排泄量（每克卵囊数，OPG）。通过单核苷酸多态性基因分型确定了五个血液系统的单倍型。正相关和负相关分别意味着给定单倍型每增加一个拷贝（0、1或2），表型性状增加和减少。当P≤0.05时，结果被认为具有统计学意义。CD99 - H01单倍型与BWG呈正相关，但与FCR呈负相关。B21B21基因型在空肠中的GLS最高，表明MHC B21与空肠GLS之间存在正相关。此外，与B12B21基因型相比，B12B15基因型的巨型艾美耳球虫OPG较低。I系统的I - H01单倍型与空肠和盲肠GLS呈负相关。与E系统的E - H07/H07基因型相比，E - H02/H02基因型的十二指肠GLS较低。B21单倍型、血液系统D - H01、E - H02和I - H01与球虫病抗性提高相关。MHC - B以及其他同种异体抗原系统D、E和I的特定单倍型与混合艾美耳球虫感染期间的抗性和易感性性状之间的关联，突出了进一步研究这些单倍型对商业品系球虫病抗性影响的必要性，证实了在选择计划中纳入不同血液系统的合理性。
