“喷水凉蛋法”对瘤头鸭孵化率的影响

对不同胚龄的瘤头鸭受精蛋进行“喷水凉蛋”处理,其孵化率显著高于对照组(P<0.01);其中以10胚龄开始“喷水凉蛋”组孵化效果最佳,平均孵化率达83.95%.孵化至第10天,瘤头鸭胚蛋内脂肪含量减少0.38%,蛋温升到38.2℃,胚龄增长至26—27天时(尿囊萎缩)胚胎主要吸收蛋黄营养,蛋温也随之升高到39.5℃.孵化过程采取“喷水凉蛋”可防止蛋温过.高,保持孵化温度的稳定.由于瘤头鸭蛋壳(0.44mm)和壳膜(0.107mm)都比鸡蛋厚,而气孔数(68个/m~2)又比鸡蛋少,故对番鸭蛋喷洒温水可洗去胶质膜,使蛋壳、壳膜不断进行收缩和扩张,加大蛋壳的通透性,促进水分代谢和气体交换,从而增强胚胎活力,起到提高孵化率的作用.

EFFECT OF COOLING EGG WITH SPRAYING WATER ON THE HATCHABILITY OF MUSCOVY DUCK EGGS

The fertilized eggs of muscovy ducks were treated by the methods of cooling eggs with spraying water at the different embryo-ages during hatching.As a result,the hatchability of the eggs treated by this method was significntly higher than that of the eggs treated by the method of cooling egg without spraying water(P<0.01),and the best result was found in the eggs which began to be sprayed with water at the embryo-age of ten days.The average hatchability reached to 83.95%.At the 10th day during batching,the egg's fat content decreased by 0.38%,while the egg's temperature increased to 38.2℃.As the embryo-age reached to 26-27 days,when the allantoic atrophy occurred,the embryo absorbed nutrients mainly from the yold and the egg's temperatture went up to 39.5℃.Using the method of spraying water could help eggs dissipate the overheat produced by the embryo so as to maintain the hatching temperature in a stable state.In fact,both egg shell and outer shell membrane of the muscovy duck are thicker than those of chicken,but the numbers of the shell proe of duck egg are comparatively less.It is believed that sprayiny water over the eggs can wash off the outer gelatinous membrane of the egg cuticle and cause egg shell and egg membrane to contract and distend continuously.Thus,the permeability of the egg shell is increased and the embryo vitality may be strenghtened by the improvement in water metabolism and gas exchange.All of these give play to increasing hatchability.