Date of this Version
Eighty crossbred gilts were assigned randomly to treatments: 1) removal of an ovary and ipsilateral uterine horn (UHO) at 130 d of age and removal of the remaining ovary and uterine horn 12 d post-puberty; 2) UHO at 130 d of age, mated and reproductive tracts recovered when slaughtered at 30 d of gestation; 3) UHO 12 d post-puberty, mated and slaughtered at 30 d of gestation and 4) unoperated controls that were mated and slaughtered at 30 d of gestation. Age of puberty was not affected by treatments. Gilts in treatment 1 had a mean ovulation rate at the pubertal estrus comparable to gilts in treatment 3. But, gilts in treatments 2 and 3 had 16% fewer (P<.01) corpora lutea at 30 d of gestation than control gilts. Length and weight of the remaining uterine horn at 12 d post-puberty for gilts treated at 130 d of age were similar to the averages of gilts left intact. Gilts with one uterine horn had 2.2 fewer live embryos at 30 d of gestation than control gilts (P<.01). But, the proportion of corpora lutea represented by live embryos did not differ significantly among treatments. Gilts with one uterine horn had 1.1 fewer live embryos (P<.15) after adjustment for number of corpora lutea, less uterine space occupied by each embryo (P<.O1) and less total placental membrane per embryo (P<.05) than control gilts. Mean length of the remaining uterine horn was less for treatment 2 than for treatment 3 (P<.01), but time of UHO did not affect measurements of placental membranes and embryos. Number of corpora lutea and measures of uterine size explained from 25 to 67% of the variation within treatments in number of live embryos.