title: Artificial induction of twinning in cattle by means of supplemental embryo transfer.
abstract: The induction of twins by surgical and nonsurgical transfer was performed 6 - 8 days after Artificial Insemination (A.I.) in a total of 142 cows. Of the 47 heifers, which received surgically transferred embryos, 32 (68%) became pregnant. Of the 95 cows, which received nonsurgically transferred embryos, 58 (61,6%) became pregnant. A total of 90 (63.5%) of the recipient animals became pregnant. Up to date 64 recipients have calved; twins have resulted in 40 and 48,2% resp, from surgical and nonsurgical inductions. Out of a total of 64 calvings 29 (45,3%) were twins, and of these 38% were males, 27% were females, and 34% were mixed births. Female - calves resulted in freemartinism. There was no increase in the incidence of either retained placenta or dystocia. The induction of twinning by means of embryo transfer can be regarded as a useful method for the increase in the reproductive performance cattle.
authors.affiliation: Department of Animal Reproduction, Veterinary Faculty Brno. Czechoslovakia.
authors.forename: L
authors.initials: L
authors.lastname: Holý
authors.forename: A
authors.initials: A
authors.lastname: Jirícek
authors.forename: F
authors.initials: F
authors.lastname: Vanatka
authors.forename: M
authors.initials: M
authors.lastname: Vrtel
authors.forename: V
authors.initials: V
authors.lastname: Fernández