Study On Eggs Quality Traits Of Muscovy Duck And Its Application

In order to further increase the hatchability of hatching eggs in muscovy duck, white muscovy duck' s eggs were studied. The conventional index and biochemical index of the eggs were analyzed and the structural characteristics of eggshell were revealed though Scanning electron microscope. Meanwhile, by conducting hatching experiments, the correlation between various indexes of egg quality and hatching performance was determined and criteria for evaluating the quality of muscovy duck' s eggs was established and tested. The results indicate as follow:1. The hatchability of white shell eggs (89. 1%) is significantly higher than that of green shell eggs (67. 4%)(P<0.05) and grit shell eggs (48. 7%)(P<0. 01). therefore, white shell eggs can be adopted and green shell eggs and grit shell eggs can be dismissed.2. During the first laying cycle of muscovy duck, the hatching eggs whose weight ranges from 70. Ig to 85. Og, shape index from 1. 311 to 1. 430 and specific gravity from 1. 085 to 1. 100 are suggested as better to hatch.3. As has been tested by experiments, the hatchability of eggs selected by the criteria established in this study is considerably higher than that of eggs conventionally selected by naked eye. This shows that this criteria for evaluating egg quality has practical value.4. It is determined that in order to ensure the normal growth of embryo, the appropriate shell thickness of normally-hatched eggs should be 0. 363 + 0.029mm and the number of pores should be 21. 57?. 60/0. 25cnf.5. hatching eggs of muscovy duck are at their best on condition that the hatching temperature is 37. 8c, relative humidity is 65~70% and the percentage of weight loss of hatching eggs is 2.00 + 0.33%, 3.95 + 0.59%, 5.62+0.82%, 7. 45+1. 07%and 8.64 + 1.25% respectively at the age of 7,14,21,28,32.6. The observation of the ultrastructure of muscovy duck' s egg shell through scanning electron microscope shows that similar to other poultry eggs, the shell consists of five layers: shell membrane, mammillary cone layer, palisade layer, verticalouter layer of shell membrane in muscovy duck,s egg. And there exist differences in the ultrastruture of egg shells due to their different traits. Abnormal structure (loose structure and big holes) can be easily observed on the outer surface, transverse section and inner surface of pipped eggs, while in white shell eggs and green shell eggs this difference can be found on the inner surface of the shell and in the evenness of mammillary cone and individual mammillary cones. Furthermore, normally-hatched eggs and pipped eggs also demonstrate different ultrastructure. The palisade layer and mammillary cone layer of pipped eggs are significantly thicker those of normally-hatched eggs. However, there is no significant difference in the thickness of shell membrane among these five kinds, which indicates the relative stability of the thickness of shell membrane.