Storage Time and Eggshell Colour of Pheasant Eggs vs. the Number ofBlastodermal Cells and Hatchability Results

摘要

The aim of this study was to investigate the number of the embryo blastodermal cells andhatchability of pheasant from eggs of different eggshell colours depending on the length ofthe storage period before hatching. On the day of collection, dark-brown and olive eggs werecharacterised by a similar and significantly higher (by about 48%) number of embryo BCs incomparison with light-brown and blue eggs. Dark-brown eggs stored longer than one day hadthe highest, while blue-shelled eggs the lowest, number of BCs. The number of BCs found ineggs with blue and light-brown coloured eggshells stored for 10 days was similar andsignificantly lower (by 27.7%) in comparison with dark-brown eggs. With the lengthening ofthe storage period, the number of blastodermal cells in eggs of all eggshell colours declined asa result of necrobiosis. In comparison with the dark-brown and olive-shelled eggs, eggs withblue eggshells had higher (by about 7.0%) weight loss during the 21 days until hatching. Thedark-brown and olive eggs were found to have a 10.3% higher proportion of eggs consideredas fertilised in comparison with the blue-shelled eggs. Eggs with dark-brown shells stored for2-4 days prior to hatching, in comparison with blue-shelled eggs, had a higher proportion offertilised eggs. The dark-brown and olive eggs stored for 7 and more days before hatchingpossessed a higher value of this trait in comparison with the eggs of light-brown and blueeggshells (x = 80.9 against 66.4%). The highest drop in the share of fertilised eggs, whichamounted on average to 3.25% for each day of storage, was observed in the blue-shelled eggs.The dark-brown eggs stored for 7 days before being placed in an incubator had higherhatchability from fertilised eggs (by 17.8%) in comparison with the eggs with blue eggshells.In the case of eggs stored for 8 to 10 days, values for this trait were higher for the dark-brownand olive-coloured eggs than for the blue-shelled eggs. The highest mean decrease of chickhatchability from fertilised eggs was observed in the case of the blue-shelled eggs (7.93% foreach day). The dark-brown eggs had significantly higher (by about 22.0%) chick hatchabilityfrom fertilised eggs than the blue-shelled eggs. Moreover, the dark-brown and olive eggs, incomparison with the blue-shelled eggs, were characterised by a significantly higherhatchability after each period of storage before incubation. The highest negative trend-cyclewas observed for eggs with blue shells, while the smallest- for olive-shelled eggs. Directlyafter laying, pheasant eggs differed with regard to the developmental advancement of theblastodermal embryo depending on eggshell colour. Longer storage time caused the numbersof blastodermal cells in eggs to decrease. The group with blue shells had a lower proportion offertilised eggs and lower hatching results than the dark-brown eggshell group. It was alsodemonstrated that the value of hatchability indices decreased significantly irrespective ofeggshell colour after seven days of storage prior to hatching.