@article{oai:soar-ir.repo.nii.ac.jp:00010594, author = {Yamamoto, S and Tsujii, H and Hashizume, K}, issue = {1-2}, journal = {信州大学農学部紀要}, month = {Dec}, note = {The present study was undertaken to evaluate the shortening of conception interval by artificially controlling the function of corpus luteum. A commercial solution of polyvinyl pyrolidone and iodine was infused into the uterine cavity on d 10 postpartum, subsequently using human chorionic gonadotropin, PGF2α, or GnRH to induce estrus 30 to 40 d postpartum. Cows in the control group, showing normal signs of estrus approximately 35 d postpartum were used for artificial insemination without any other artificial treatment. Only 5 of 124 cows showed signs of estrus at 35 d after parturition, but these cows failed to conceive after artificial insemination. The follicular development and subsequent estrus signs were found 1/3, 2/2, 5/5, 3/4 and 2/4 for the treatment of polyvinyl pyroidone and iodine only, hCG+PGF2α, PGF2α, GnRH and PGF2α+GnRH, respectively. Subsequently, 13 of 18 cows showed signs of estrus and ovulation. Pregnancy rates were 50 and 60% for the cows treated with hCG+PGF2α and PGF2α alone, respectively; and the total treated conception cows were 22% within d 33.8 (mean) postpartum. Cows not conceived by d 35 postpartum usually (12 of 14) conceived within d 60 postpartum. The remaining 2 cows had ovarian cysts. Treatment with PGF2α alone or with hCG followed by the injection of PVP+I artificially adjusted the function of corpus luteum, took place ovulation, and occurred conception within d 35 postpartum., Article, 信州大学農学部紀要. 33(1-2): 61-70 (1996)}, pages = {61--70}, title = {Control of Corpus Luteum Function for Shortening the Conception Interval of Dairy Cows}, volume = {33}, year = {1996} }