Morphological studies on rumen development in West African Dwarf goats (Capra hircus)

Abstract

We studied the gross and light microscopic structures of rumen in fetal, neonatal and adult West African Dwarf (WAD) goats obtained from Nsukka and Igboeze South Local Government Areas (L.G.A) of Enugu State. After euthanasia the rumen was ligated, dissected out and the volume determined by flotation and displacement method. For histological studies pieces of rumen were fixed in Bouin`s fluid for 24hrs, processed and routinely stained with H & E. The volume of rumen was 7.25 ± 1.62, 14.3 ± 2.1, 211.6 ± 36.0 and 1620.3 ± 46.5 ml for gestation day 87, full term fetuses, neonates and adult goats respectively. The rumen volume body mass indices were 18.03 ± 3.45, 10.75 ± 4.29, 87.08 ± 6.50 and 108.02 ± 10.65 for gestation day 87, full term fetuses, neonates and adults respectively. Grossly, the mucosal surface was smooth and beige in fetuses, velvety and greenish brown in neonates and adults. Microscopically, the mucosa was lined by stratified squamous epithelium which was divided into larger lighter luminal and darker basal zones in fetuses and early neonates. The dark basal zone had finger-like projections into the lighter zone- proprial papillae. The papillae were tiny and covered by thin keratin layer in 4- week-old neonates. They were very tall especially in the ventral ruminal sac and the epithelium covered by thick keratin in adult goats. These results provide baseline data on rumen development in WAD goats.