Campo J L, Davila S G
Departamento de Mejora Genética, Instituto Nacional de Investigación y Tedcnología Agraria y Alimentaria, Madrid, Spain.
Poult Sci. 2002 Oct;81(10):1448-53. doi: 10.1093/ps/81.10.1448.
The objectives of the current study were to estimate the heritability of the heterophil to lymphocyte ratio and to evaluate the effects of age, sex, and crossing on that ratio. There were three different experiments. In Experiment 1, we used a total of 711 birds from two generations with complete pedigree of a Spanish breed of chickens (Quail Castellana) to estimate the heritability for the leukocyte ratio at 36 wk of age by restricted maximum likelihood. The estimated heritability (0.59 +/- 0.09) indicated that leukocyte ratio should easily respond to selection. Heritabilities for heterophil and lymphocyte numbers were also high (0.56 +/- 0.07 and 0.65 +/- 0.07). In Experiment 2, leukocyte ratio differences among ages and sexes were investigated at 8, 12, 16, 20, 24, 28, 32, and 36 wk, in 576 birds from the same breed. Males showed significantly greater heterophil to lymphocyte ratios than females at the onset of sexual maturity and as adults. Significant variations with age for leukocyte ratio were observed in both sexes, which were mainly related to onset of sexual maturity, from which the leukocyte ratio increased more or less continuously. In females, the effect of age was also significant on heterophil and lymphocyte numbers. Finally, in Experiment 3, crossing effects were evaluated in 96 birds from a cross between the Quail Castellana and a White Leghorn population at 8 wk of age. The negative heterosis percentages found in the F1 and F2 generations were significant (-26% and -36%, respectively).
本研究的目的是估计异嗜性粒细胞与淋巴细胞比例的遗传力，并评估年龄、性别和杂交对该比例的影响。共有三个不同的实验。在实验1中，我们使用了来自西班牙品种鸡（鹌鹑卡斯特拉纳）两个具有完整系谱的世代的711只鸡，通过限制最大似然法估计36周龄时白细胞比例的遗传力。估计的遗传力（0.59±0.09）表明白细胞比例应该很容易对选择作出反应。异嗜性粒细胞和淋巴细胞数量的遗传力也很高（分别为0.56±0.07和0.65±0.07）。在实验2中，对来自同一品种的576只鸡在8、12、16、20、24、28、32和36周龄时的年龄和性别间白细胞比例差异进行了研究。在性成熟开始时和成年期，雄性的异嗜性粒细胞与淋巴细胞比例显著高于雌性。在两性中均观察到白细胞比例随年龄有显著变化，这主要与性成熟开始有关，从性成熟开始白细胞比例或多或少持续增加。在雌性中，年龄对异嗜性粒细胞和淋巴细胞数量的影响也很显著。最后，在实验3中，对来自鹌鹑卡斯特拉纳和白来航群体杂交的96只鸡在8周龄时的杂交效应进行了评估。在F1和F2代中发现的负杂种优势百分比显著（分别为-26%和-36%）。
