Induction of Twinning in Beef Heifers by Bilateral Embryo Transfer

This is the authors' abstract. We don't add key points for this paper.

Induction of twinning was attempted in 48 virgin beef heifers by bilateral surgical embryo transfer. Thirty-six heifers (75%) were diagnosed pregnant by rectal palpation at 45 to 60 days of gestation; 26 heifers produced 16 sets of twins and 10 single calves. Of the remaining 10 pregnant heifers that did not calve five returned to estrus without an observed abortion and five aborted twin fetuses. Twin calves had a lower birth weight (P<.005), weaning weight (P<.005), and average daily gain to weaning (P<.005) than singles when weaned at approximately 60 days of age. The same trends were observed with calves weaned at approximately 160 days of age, but these differences were not statistically significantly. Dystocia was not observed in females producing twins. Three of the animals producing twins had retained placentas.