Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA 24061, USA.
Poult Sci. 2012 Aug;91(8):1796-803. doi: 10.3382/ps.2012-02169.
White Leghorn chickens were selected for 36 generations for high (HAS) or low (LAS) antibody response to SRBC 5 d after an intravenous challenge. The aim of this study was to investigate possible changes in reproductive soundness resulting from that selection. Age and BW at onset of lay (first egg), along with weight of the first egg, were recorded on 45 hens from each line. Intensity of lay was measured as the number of ovulations within a 15-d period over 15 sequential intervals (total 225 d). Three cycles of fertility also were assessed, coinciding with early, middle, and late production stages. For fertility of males and females within a line to be independently evaluated, roosters and hens were mated by artificial insemination to an unrelated control line of White Plymouth Rocks. Twenty roosters from each antibody line were considered, as well as the 45 hens. Pooled semen from the control line was used for mating the hens from the antibody lines. Hens from the LAS line commenced lay at a younger age (11.67±3.53 d; P<0.001), lighter BW (-169.46±40.20 g; P<0.001), and with greater intensity (2.68±0.25%; P=0.001) than those from the HAS line. Any differences in intensity thereafter were trivial between lines (P=0.42), with intensity decreasing sharply toward the end of the 7-mo production period in both lines. Length of fertility differed between hens of the antibody lines during the first cycle (3.35±0.85 d; P=0.002) and between roosters during the first (3.58±1.06 d; P=0.02) and second (3.38±1.07 d; P=0.03) cycles, with chickens from the LAS line having the longer length of fertility in both sexes. A correlated response in reproductive soundness to divergent selection for antibody response was observed. This may in part be due to differences in resource allocations, with particular impact on duration of fertility.
怀特莱杭鸡经过 36 代的选择，分为高（HAS）和低（LAS）抗体对 SRBC 反应的品系。本研究旨在探讨选择对生殖性能的影响。对每条品系的 45 只母鸡记录开产日龄（第一枚蛋）、体重、第一枚蛋重。产蛋强度以 15 天内 15 个连续间隔内的排卵数表示（共 225 天）。对 3 个产蛋周期的受精率也进行了评估，与早期、中期和后期的产蛋阶段相对应。为了独立评估每个品系中公鸡和母鸡的受精率，将公鸡和母鸡用人工授精与一个无关的怀特普利茅斯岩鸡的对照系交配。对每个抗体系的 20 只公鸡和 45 只母鸡进行了考虑。用对照系的混合精液来给抗体系的母鸡配种。LAS 系的母鸡开产日龄更早（11.67±3.53 d；P<0.001），体重更轻（-169.46±40.20 g；P<0.001），产蛋强度更大（2.68±0.25%；P=0.001），而 HAS 系的母鸡则没有。此后，两系之间的产蛋强度差异微不足道（P=0.42），在 7 个月的产蛋期结束时，两系的产蛋强度都急剧下降。抗体系母鸡的受精率在第一周期不同（3.35±0.85 d；P=0.002），公鸡在第一（3.58±1.06 d；P=0.02）和第二（3.38±1.07 d；P=0.03）周期不同，LAS 系的母鸡和公鸡的受精率都较长。对抗体反应进行不同选择的生殖性能的相关性反应观察到。这可能部分是由于资源分配的差异造成的，特别是对受精率持续时间的影响。
