Figure 1. Effects of embryo transfer between breeds on placental and fetal weight in equids.

The effects of transferring embryos between Thoroughbred (TB) and pony mares on body weight of the foals at birth (A) the relationship between foal birth weight and placental weight and gross surface area (B) and stereological measurements of the surface density of the microcotyledons and total microscopic area of feto-maternal contact in the placenta (C) of the four groups of foals (Thoroughbred in Thoroughbred, TB-in-TB, ▪; Pony in Thoroughbred, P-in-TB, □; Pony in Pony, P-in-P, ♦; Pony in Thoroughbred, P-in-TB, ⋄). Data from Allen et al. (2002).