Development on the omasum of fetuses and neonates in Korean native goats

한국재래산양의 태아 및 신생아의 제3위 발달에 관하여

The development of omasum in fetuses between 60, 90, 120 days of gestation and neonates of Korean native goats was investigated by fight; scanning electron microscopy. The results were summarized as follows : 1. In the 60-day-old fetuses, the stomach was developed and differentiated into four compartments of rumen, reticulum, omasum, and abomasum. The mucosa of the omasum was thrown into folds which appeared to be three or four different orders of large, medium, small, and smallest laminae. 2. In the 90-day-old fetuses, the omasal laminae had increased greatly in length and cores of omasal laminae were invaginated laterally. 3. In the 120-day-old fetuses, the wall of the omasal laminae had increased in length and the lamina epithelialisis had slightly increased in thickness. The lateral invaginations at the dark zone had increased in length and depth. The tunica muscularis increased only slightly in thickness particularly within its inner circular layer. 4. In the neonate, the muscularis and the omasal laminae had increased in thickness. The lateral invaginations of the dark zone were observed in the first, second and third order of omasal laminae. 5. Scanning electron microscopic studies : In the 90-day-old fetuses, numerous microvilli and microridges were observed on the luminar surface of the omasal mucosa. The omasal papillae were already formed at 120 days of gestation. In the I20-day-old fetuses omasal papillae liked nipple shape. In the neonate, the omasal papillae liked the thumb.