Equine Stomach Development in the Fetal Period: An Anatomical, Topographical, and Morphometric Study

Abstract

Studies of equine stomach prenatal development are very rare, and descriptions usually focus on the processes taking place in the embryonic period. Only general information about gastric organogenesis in the fetal period is available in embryology textbooks on domestic mammals. The material for our study included twenty half-breed horse fetuses divided into three age groups on the basis of known fetal age (verified using the CRL method). Our study consists of the topographical, morphological, and morphometrical description of stomach development between the 4th and 11th months of gestation. Even though the skeletotopy, syntopy, and holotopy of the stomach in the fetal period seems to be relatively unchanged, the organ shape and the proportions between its anatomical parts differed in fetuses from the three age groups. The achieved results were statistically elaborated to estimate the dynamics of the stomach shape. This can be described as changing from medium-wide to wide and from slightly bent to sharply bent. A nonlinear correlation of all metric values with CRL in all age groups was observed. A positive allometric growth rate of different intensity was seen in all metric parameters. All the values increased as the fetal period progressed. Only the parietal surface growth rate gradually changed from strongly positive allometric in the first age group to strongly negative allometric in the third age group. A difference between the non-glandular and glandular mucosa of the stomach was visible in the first group. Development of a well-distinguishable plicated edge margin began in the second age group together with gastric pits and gastric areas. The third age group showed a well-developed gastric groove and angular incisura.

Equine Stomach Development in the Foetal Period of Prenatal Life—A Histological and Histometric Study

“…Poradowski and Chrószcz [ 15 ] proved an isometric growth of CRL in the foetal period between the 4th and 11th months of gestation ( Figure 13 ).…”

“…This tendency includes equine stomach morphology in the foetal period [ 28 , 29 ]. Detailed morphology and development of equine stomach in the foetal period was described by Poradowski and Chrószcz [ 15 ]. A similarly large anatomical and topographical study in domestic pig foetuses was carried out by Chrószcz [ 13 ] and it proved the usefulness of such an analysis as well as offered a valuable presentation of processes observed in more advanced phases of gestation.…”

“…Foetus age was known (mare history of pregnancy, day of miscarriage) and verified using the crown-rump length (CRL) method [ 27 , 29 , 31 , 32 ]. Subsequently, the accessible material was divided using the population cross-sections method [ 12 , 13 , 14 , 15 , 33 ] into three age groups, five foetuses each (n = 5): the first age group—4th–5th month of gestation, the second age group—7th–8th month of gestation, the third age group—10th–11th month of gestation. …”

“…Studies on domestic animal embryology have been frequently undertaken [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ], but usually the scientific interest has focused on domesticated pig and ruminants, and papers devoted to horse embryology are rare [ 15 ]. Moreover, prenatal development of the alimentary tract of laboratory animals and its postnatal morphology have been studied for years [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ].…”

“…Chrószcz [ 13 ] studied the morphometry and topography of a swine stomach in the foetal period between 35th and 114th day of gestation. An earlier study by Poradowski and Chrószcz [ 15 ] described the dynamics of equine stomach development in foetal period and provided a solid background for further studies on histological structure of the gastric wall. A detailed development of the stomach wall and its structures in the prenatal life of a pig was described by Chrószcz [ 12 ].…”