ABSTRACT
The following description of sheep embryos is taken from the works of Bryden, 31 Bryden et al., 32 and Robinson. 33 In Bryden’s studies early embryos up to day 20 were obtained from Columbia-Lincoln cross ewes which had been mated with Suffolk rams. Copulation times were known from direct observation, and the age of each embryo was taken from the time of mating (pc age). The older embryos were from the Cornell University Embryological Collection of Domestic Animals and were of unknown age, breed, and history. The estimation of the age of these embryos is detailed by Bryden et al. 32
