Harun M A, Veeneklaas R J, Visser G H, Van Kampen M
Department of Veterinary Anatomy and Physiology, Utrecht University, The Netherlands.
Poult Sci. 2001 Feb;80(2):219-24. doi: 10.1093/ps/80.2.219.
This study was designed to gain insight into the influence of spraying and cooling, during artificial incubation, on the embryo metabolic rate and hatching ability of Muscovy duck eggs. Three times a week 93 incubated eggs were sprayed and cooled for 0.5 h at room temperature. Daily embryo metabolic rate was measured in 30 eggs with a water vapor conductance ranging from 1.15 to 2.07 mg/day-kPa. Egg weight ranged from 63.73 to 84.52 g; length and breadth ranged from 59.6 to 66.4 mm and 43.2 to 48.2 mm, respectively. According to observed hatching ability, eggs were classified by three categories: eggs that hatched normally; eggs that were assisted during hatching, and nonhatched eggs. Five ducklings were assisted during hatching. Four ducklings died on Day 31, two on Day 32, and two on Day 34. Two functions were derived by discriminant analysis and accounted for 100% of the variation among the three categories of hatching ability. Collectively, these functions were able to classify 93.3% of the eggs in the correct hatching category. Egg length and metabolic rate at Days 21 and 28 of incubation were the most important predictor variables of the two functions. The results obtained in the present study indicate that an incubation temperature of 37.5 C with spraying and cooling seems to be beneficial for larger eggs.
本研究旨在深入了解人工孵化过程中的喷水和冷却对番鸭蛋胚胎代谢率和孵化能力的影响。每周三次，对93枚已孵化的蛋进行喷水并在室温下冷却0.5小时。在30枚蛋中测量每日胚胎代谢率，这些蛋的水汽传导率范围为1.15至2.07毫克/天-千帕。蛋重范围为63.73至84.52克；长度和宽度分别为59.6至66.4毫米和43.2至48.2毫米。根据观察到的孵化能力，将蛋分为三类：正常孵化的蛋；孵化过程中得到辅助的蛋，以及未孵化的蛋。孵化过程中有5只小鸭得到了辅助。4只小鸭在第31天死亡，2只在第32天死亡，2只在第34天死亡。通过判别分析得出了两个函数，它们解释了三类孵化能力之间100%的变异。总体而言，这些函数能够将93.3%的蛋正确分类到相应的孵化类别中。孵化第21天和第28天的蛋长和代谢率是这两个函数最重要的预测变量。本研究获得的结果表明，37.5摄氏度的孵化温度结合喷水和冷却似乎对较大的蛋有益。
