番鸭种蛋数量性状对孵化效果的影响

Effects of the qantitative characters of hatching eggs of muscovy duck on hatching result

在相同孵化条件下，ＲＦ系番鸭种蛋的种蛋重、蛋形指数、蛋壳气孔数和相对失重率对孵化率有明显影响．蛋重７５～８４ｇ，孵化率高达８３．５％～８５．１％；蛋重低于７５ｇ或高于８５ｇ，孵化率明显下降，分别为７５．８％和７２．１０％～７８．７０％．蛋形指数１．３４～１．３７孵化率高达８１．００％～８６．８０％；小于１．３３或大于１．３８其孵化率下降至６１．５％～６６．７％和７１．４％～７５．８％．番鸭初生重随蛋重的增加而增大，二者呈强正相关（ｒ＝０．９８），平均初生重占种蛋重６２．０％～６５．０％；孵化过程中，在同一胚龄绝对失重与蛋重呈正相关（ｒ１０＝０．９０，ｒ２４＝０．９４，ｒ３３＝０．９２），而相对失重较为稳定；正常出雏的胚蛋在孵化第１０、２４和３３天时相对失重率分别为４．５７％、１０．５％和１４．２０％，相对失重过高或过低都可能使胚胎致死．经检剖测定一照和三照死胚蛋、毛蛋（啄壳后死胚蛋）和健胚蛋的蛋壳气孔数，健胚蛋气孔数平均为７７．３个ｃｍ－２，明显高于死胚蛋和毛蛋的气孔数４７～６１个ｃｍ－２．

In the same hatching condition, the weight, the index of egg shape, the numbers of pores, the relative weight loss rates of the muscovy ducks hatching eggs of RF strain could significantly affect the hatchability. The highest hatchability (83.1%～85.1%) was obtained when an egg weighed between 75 g and 84 g. When an egg weighed less than 75 g or more than 85 g, the hatchability decreased significantly, which were 75.8% and 72.1%～78.7%, respectiveiy. The highest hatchability reaching 81.00%～86.8% were found in the groups in which indexes of egg shape were between 1.34 and 1.37; when the indexes of egg shape were less than 1.33 or more than 1.38, the hatchability decreased to 61.5%～66.7% and 71. 4%￣75. 8%, respectively. The day old duckling weight increased because of the heavier egg, they were positive correlation ( r =0.98), the ratio between the day old duckling weight and egg weight was 62%～65% . During the incubation period on the same embryo age, the absolute weight loss and the egg weight were positive correlation ( r 10 =0.[KG-4]90, r 24 =0.94, r 33 =0.92), but the relative weight loss was constant. The relative weight loss rates of the eggs hatched normally were 4.57%, 10.50% and 14.20% during 10th,24th and 33th days of inculation and too much or little relative weight loss the embryos may be killed. The numbers of pores of the first and third candling addled eggs, the pipped eggs and the eggs hatched normally were determined. The average pores number of the normal hatching eggs was 77.3 per cm 2,significantly more than that of addled eggs and pipped eggs (47～61 per cm 2) .