Calving traits, postpartum reproduction and growth of calves in 28 Japanese Black-Holstein crossbred cows pregnant with twins including 3 cows with triplets by embryo transfer were compared with the data of 60 crossbred cows pregnant with single calves. After calving, all the cow-calf pairs were fed mainly roughage, grazed on pasture during summer and fed with grass silage during the winter season. No concentrate supplement for calves was given. Gestation length of cows giving birth to twins and calf birth weight were shorter by 8 days and lighter by 6 kg compared with cows giving birth to single calves, respectively. Significantly (P