Galli Roberta, Preusse Grit, Schnabel Christian, Bartels Thomas, Cramer Kerstin, Krautwald-Junghanns Maria-Elisabeth, Koch Edmund, Steiner Gerald
Clinical Sensoring and Monitoring, Anesthesiology and Intensive Care Medicine, Faculty of Medicine, TU Dresden, Dresden, Germany.
Clinic for Birds and Reptiles, Faculty of Veterinary Medicine, University of Leipzig, Leipzig, Germany.
PLoS One. 2018 Feb 23;13(2):e0192554. doi: 10.1371/journal.pone.0192554. eCollection 2018.
In order to provide an alternative to day-old chick culling in the layer hatcheries, a noninvasive method for egg sexing is required at an early stage of incubation before onset of embryo sensitivity. Fluorescence and Raman spectroscopy of blood offers the potential for precise and contactless in ovo sex determination of the domestic chicken (Gallus gallus f. dom.) eggs already during the fourth incubation day. However, such kind of optical spectroscopy requires a window in the egg shell, is thus invasive to the embryo and leads to decreased hatching rates. Here, we show that near infrared Raman and fluorescence spectroscopy can be performed on perfused extraembryonic vessels while leaving the inner egg shell membrane intact. Sparing the shell membrane makes the measurement minimally invasive, so that the sexing procedure does not affect hatching rates. We analyze the effect of the membrane above the vessels on fluorescence signal intensity and on Raman spectrum of blood, and propose a correction method to compensate for it. After compensation, we attain a correct sexing rate above 90% by applying supervised classification of spectra. Therefore, this approach offers the best premises towards practical deployment in the hatcheries.
为了在蛋鸡孵化场提供一种替代一日龄雏鸡淘汰的方法，需要在胚胎敏感之前的孵化早期阶段采用一种非侵入性的蛋性别鉴定方法。血液的荧光和拉曼光谱为在家鸡（原鸡家鸡变种）蛋孵化的第四天就进行精确且非接触式的胚胎性别鉴定提供了可能。然而，这种光学光谱法需要在蛋壳上开一个窗口，因此对胚胎具有侵入性，并会导致孵化率降低。在此，我们表明可以在灌注的胚外血管上进行近红外拉曼和荧光光谱分析，同时保持内蛋壳膜完整。保留壳膜使测量具有最小的侵入性，从而性别鉴定过程不会影响孵化率。我们分析了血管上方膜对荧光信号强度和血液拉曼光谱的影响，并提出了一种校正方法来对此进行补偿。补偿后，通过应用光谱的监督分类，我们获得了高于90%的正确性别鉴定率。因此，这种方法为在孵化场实际应用提供了最佳前提条件。
