Production of twin calves by transfer of embryos produced in vitro
Takada, N.; Ohisa, N.; Numabe, T.; Ishikawa, Y.
Veterinary Record 128(13): 307
1991
ISSN/ISBN: 0042-4900 PMID: 2035230 Document Number: 380657
Japanese Black cattle embryos produced in vitro and developed to the blastocyst stage were transferred by the transcervical method to Holstein dairy cows on day 7 of the oestrous cycle (oestrus=day 0). One embryo was transferred to each uterine horn of 44 cows and one embryo to the ipsilateral horn of the corpus luteum in 15 cows. Pregnancy was diagnosed by rectal palpation 40 to 60 days after oestrus. The mean proportion of embryos that developed to the blastocyst stage was 19.8%. The conception rate from bilateral transfer was 54.5% (24/44). Six of the 24 (25.0%) cows aborted and 7 (29.2%) delivered twins. Six of the calves were stillborn or died at birth. The production rate in these 24 cows was 79.2%. Of the 15 cows receiving a single embryo, 7 (46.7%) became pregnant and these cows all delivered live calves. A total of 13 male and 13 female calves were born alive. The mean gestation period of twin and single calves were 279.4+or-6.1 and 285.7+or-4.0 days, respectively. No reason was found for the high abortion rate. Although productivity was low in this study the possibility of increasing beef production by transfer of embryos produced in vitro was confirmed.