Histomorphometric and Immunohistochemical Study of the Goat Rumen During Prenatal Development

Abstract

This study sought to chart the ontogenesis of the goat rumen by histomorphometric examination, scanning electron microscopy and immunohistochemical analysis. A total of 140 goat embryos and fetuses were used, from the first stage of prenatal life until birth. The appearance of the rumen from the primitive gastric tube was observed at 35 days of prenatal life (CRL 3 cm, 23% gestation). By 38 days (CRL 4.3 cm CRL, 25% gestation) the ruminal wall comprised three layers: an internal epithelial layer, a middle layer of pluripotential blastemic tissue and an external layer or serosa. Ruminal pillars were visible at 46 days (CRL 6 cm, 30% gestation), and by 76 days (CRL 18 cm, 50% gestation) ruminal papillae were starting to appear. Under scanning electron microscopy, by 50 days (CRL 7.7 cm, 33% gestation) small ruminal papillae were observed protruding from the surface. Finally, neuroendocrine cells (synaptophysin, SYP) were detected at 53 days (CRL 9 cm CRL, 35% gestation), while glial cell markers (glial fibrillary acidic protein-GFAP, and vimentin-VIM) were found at 108 days (CRL 31 cm, 72% gestation) and 39 days (CRL 4.4 cm, 26% gestation), respectively. Neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP) were detected immunohistochemically at 113 days (CRL 33 cm, 75% gestation) and 120 days (CRL 35 cm, 80% gestation), respectively. In conclusion, histomorphogenesis of the rumen in goats was similar to that reported in deer, but rather slower than observed for sheep or cattle. Anat Rec, 295:776-785, 2012. V C 2012 Wiley Periodicals, Inc.Key words: Capra hircus; forestomach; histochemistry; histology; prenatal developmentThe goat is among the ruminant species best able to make use of marginal pasturelands (Boyazoglu et al., 2005;Rancourt et al., 2006), and is highly adapted to grazing over a wide range of vegetation (El-Gendy et al., 2010). Browse appears to be an important component of its diet, and it is widely regarded as the best user of poor roughage (Gihad et al., 1980). Morphological analysis of the goat digestive tract has led to its being classed as an intermediate feeder, situated between the concentrate selectors at one extreme and the grass-roughage eaters at the other (Hofmann 1973(Hofmann , 1989.This ability to make use of grazing land is linked to the particular morphology of the ruminant stomach, which comprises four compartments: rumen, reticulum, omasum, and abomasum. The rumen, reticulum and omasum form the forestomach (proventriculus), whose tunica mucosa is lined by a squamous, keratinized stratified epithelium (Ramkrishna and Tiwari, 1979;

Immunohistochemical evaluation of the goat forestomach during prenatal development

“…SPY-positive neuroendocrine cells were observed at 53 days of prenatal development (35% gestation). Similar findings have been previously noted in the goat rumen, omasum and reticulum [11,12,13]. Similar results have also been reported for other ruminant species.…”

“…However, little research examining the prenatal development of these cell types in the stomach of ruminants such as sheep [37], deer [6,7,9,10,28,29], and goats has been conducted [11,12,13]. For the present study, immunohistochemical techniques were used to detect the presence and distribution of the neuroendocrine cell markers synaptophysin (SPY) and non-neuronal enolase (NNE), glial cell markers GFAP and VIM, and peptidergic innervation markers NPY and VIP in the goat forestomach in order to study the nature, origin and evolution of these different cell types during prenatal development.…”

Histomorphometric study of the goat stomach during prenatal development

“…, ; Garcia et al . ). By contrast, the lamina propria and submucosa grew constantly from the start to the end of gestation.…”

“…A slow growth phase was observed in the epithelium of non‐glandular stomach compartments in the early embryonic stages, coinciding with the transition from embryonic epithelium (Warner ) to stratified epithelium formed by the first two strata: basal and granulosum, as reported elsewhere in goats (Garcia et al . , , b). From 13.5 cm (64 days, 43% gestation) onwards, an active growth phase was observed, coinciding with an increase in the number of cells to form the stratum spinosum and the stratum corneum.…”

“…, b) and in goat (Garcia et al . , ). However, after the period of involution, an active growth phase was observed in the rumen and reticulum, reflecting the involvement of these layers in the formation of ruminal papillae (Vivo et al .…”