随机挑选大白、长白、杜洛克纯种母猪各5头作为研究对象，对未饲喂烯丙孕素前、饲喂烯丙孕素18 d、妊娠30 d、妊娠60 d等4个不同时期的背膘进行测定。结果显示，饲喂烯丙孕素后能够显著提高母猪的背膘厚度，对长白猪的效果最显著，其次为大白猪，最后是杜洛克猪。

In a randomized block design， five purebred sows of Great white， Landrace and Duroc were randomly selected as the research objects， and before not being raised ally progesterone， the backfat of four different periods which having fed allyl progesterone for 18 days，30 days and 60 days were measured.The results showed that backfat thickness of sows could be increased by feeding allyl progesterone， and the effect of allyl progesterone on Landrace was the most significant， followed by large white pig， and the last Duroc pigs.

S828

甘肃农业大学大学生SRTP项目。