Histomorphometric and immunohistochemical study of the goat abomasum during prenatal development.

This study sought to chart the morphological changes taking place in the goat abomasum during prenatal development, using histomorphometric and immunohistochemical techniques. A total of 140 goat embryos and fetuses, from the first stages of prenatal life until birth. Differentiation of the abomasum as a separate compartment of the primitive gastric tube was observed at 35 days of prenatal life (CRL 3 cm, 23% gestation). Primitive abomasal folds were first observed at 38 days (CRL 4.3 cm, 25% gestation). The muscularis mucosae was visible by 64 days (CRL 13.5 cm, 43% gestation). Transformation of pseudostratified epithelium to simple cylindrical epithelium was also observed at this stage. Differentiation of gastric pits and glands first became apparent at 75 days (CRL 17.5 cm, 50% gestation) and 84 days (CRL 20 cm, 55% gestation), respectively. Neuroendocrine cells were detected by synaptophysin (SYP) at 64 days (CRL 13.5 cm, 43% gestation), while glial cell markers (glial fibrillary acidic protein - GFAP, and vimentin-VIM) were observed at 64 days (CRL 13.5 cm, 43% gestation) and 38 days (CRL 4.3 cm, 25% gestation), respectively. Neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP) were detected at 75 days (CRL 17.5 cm, 50% gestation). Gastrin-immunoreactive cells first appeared in the abomasum at 76 days (CRL 18 cm, 50% gestation). In conclusion, prenatal development of the abomasum appears to take place somewhat earlier in goats than in sheep or cattle, but at a similar rate to that reported in wild ruminants such as deer.