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(vertebrate zoology)
The final chamber of the complex stomach of ruminants; has a glandular wall and corresponds to a true stomach.



the fourth and last part of the multicompartmental stomach of ruminants, corresponding to the simple uncompartmental stomach of most mammals. The abomasum is connected to the omasum (third stomach) and the duodenum. The mucous membrane of the abomasum is covered by prismatic epithelium and contains fundic, pyloric, and cardiac glands. It forms 13 or 14 long folds, which enlarge its surface. In young animals the mucous membrane of the abomasum produces rennin. The muscular membrane of the abomasum consists of external longitudinal and internal circular layers. Food is digested in the abomasum by gastric juice.

References in periodicals archive ?
A: Left view of the Dorcas gazelle (Gazella dorcas) stomach; B: Right view of the dorcas gazelle stomach; 1: Reticulum; 2: Rumen, Saccus dorsalis; 3: Rumen, Saccus ventralis; 4: Abomasum; 5: Rumen, Saccus cecus caudodorsalis; 6: Rumen, Saccus cecus caudoventralis; 7: Omasum; 8: Spleen; 9: Sulcus longitudinalis sinister; 10: Sulcus longitudinalis dexter; 11: Sulcus accesorius dexter; 12: Duodenum.
Haemonchuscontortus, a voracious blood sucking parasite found in abomasum causes anaemia, diarrhoea, loss of weight, oedema, recumbency, severe debility and ultimately death [3].
It is a strong determinant of the health and performance of cows throughout lactation and causes economic losses due to reduced milk production [4] and is associated with the occurrence of diseases such as displaced abomasum [5] and with impaired fertility [6].
The OMA tissue was taken within the lesser curvature of the abomasum. All of the tissue samples were immediately frozen using liquid nitrogen and stored at -80[degrees] C until the analysis.
(At that moment I'd already drunk the milk, the peasant's wife had already paged through the Messenger and placed it in the bin for newspapers, the farmer slept, the cows were lying already in the shadows.) (The manure pile is the fifth of the cows' four stomachs: after the men, reticulum, omasum, and abomasum, after the long and narrow passage through the intestine, after the deposition around the stall comes the final, longest act which takes place once again in the open.
Comparison ofthe odds of isolation, genotypes, and in vivo production of major toxins by Clostridium perfringens obtained from the gastrointestinal tract of dairy cows with hemorrhagic bowel sindrome or left-displaced abomasum. JAVMA 227: 132-138.
Changes in abdominal dimensions during large gestation and early lactation in Holstein-Friesian heifers and cows and their relationship to left displaced abomasum. Vet Rec.
Low DMI and deficiency in nutrient supply, specially protein and amino acids, lead to immunosuppression [34] and incidence of metabolic disorders consisted of rapid loss of BCS, ketosis, fatty liver and displaced abomasum [14,13,12].
(1967) A new method for the cannulation of the abomasum in sheep.
Having just studied bovine anatomy in a veterinary technology program, I'd like to point out that the order of the four stomachs of the cow (from esophagus to small intestine) are: 1: Reticulum (the honeycombed texture); 2: Rumen (actually has a texture similar to short pile chenile and is called papillae); 3: Omasum (the folds); and 4: Abomasum (mucous-lined and most similar to what a human stomach would look like).