Abstract
A total of 152 sows and gilts were clinically diagnosed as anestrus and their ovaries were observed by transrectal ultrasonography. Abnormal ovaries were depicted in 66 animals (43.4%)，and the remainder were normal. Feeding and management modification (adjustment of feed composition and volume with boar contact) was applied to 136 animals，except those with foot disease. In abnormal ovaries， eCG 1000IU was administered to ovarian quiescence (n=48) and GnRH-A 200μg to multiple ovarian cysts (n=2). Animals with normal ovarian findings (n=73) and oligo ovarian cysts with corpora lutea (n=13) were intact as control. As a result， the estrous return and conception ratio for the treated and control group were 96.0% vs. 98.8%， and 91.7% vs. 78.8%，respectively; (conception ratio : P<0.05). Both groups showed high estrous returns; however the conception ratio was low for the control. These results suggest that factors other than ovaries were considered in the conception ratio.
