【摘要】 实验以杜洛克×米猪杂交母猪为研究对象,采用大约克公猪配种,经2年研究分析了282窝3001头新生仔猪样本。结果表明:仔猪初生重呈现明显的季节性变化。春、夏、秋、冬出生仔猪的平均初生体重分别为1.101kg、1.049kg、1.152kg、1.163kg,其中春季和夏季分别显著低于秋季和冬季(P<0.05)。仔猪初生重的均匀度以春、冬季最佳。但供试母猪的妊娠期、产活仔数和初生窝重没有类似变化,提示仔猪初生重的这种季节性变化不是由这些因素所致,而很可能与不同季节的环境温度、光照周期以及动物的内分泌特点有关。子宫内生长阻滞(IUGR)的新生仔猪的比例在夏季为10.12%,显著高于秋季的4.83%(P<0.05),证明母猪妊娠后期的热应激会严重阻碍胚胎发育。更多还原

【Abstract】 With crossbreeding sows from Duroc and pig with cycti ce rcosis as its research objects, the experiment uses Big Yorkshire boars to breed , after two years research, it analysed 3001 newborn piglets samples from 282 l itters. The result shows that there is an apparent seasonal change for piglet s’ bir th weight. The respective average birth weight in spring, summer, autumn and win ter is 1.101 kg, 1.049 kg, 1.152 kg and 1.163 kg. The birth weight in spring and summmer is obviously lower than that it autumn and winter ( P <0.05). The uni form birth weigh of piglets is at its best in spring and winter. But the gestation p eriod, living piglets number and birth brood weight of sows being tested do not h ave the similar change. This shows that the seasonal change of piglets’ birth we ight is not due to these factors. It is likely caused by different environmen t temperature; different light period and animals’ internal secretion characteri stics in d ifferent seasons. The rate of IUGR newborn piglets in summer is 10.12%, which is noticeably higher than that in autumn (4.83%) ( P <0.05). This shows that the ther mal stress in the later gestation period of a sow can seriously prevent its embr yonic development.\;更多还原