Distribution and development of embryos in the pig.

The distribution and development of pig embryos were determined in relation to the number of embryos and their positions within the uterine horn between Days 14 and 34 after mating. The observed distribution of 1-11 embryos within a uterine horn was highly correlated (r = 0-96) with the theoretical expected distribution. Embryo spacing was uniform regardless of the number of embryos within the horn. Nitrogen content of the embryo in relation to its position within the uterine horn indicated that development was similar for embryos located at the utero-tubal end or cervical end and comparable to those located in the middle portion of the horm. Placental development, as indicated by nitrogen content, was similar regardless of location within the horn.