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n. pl. ab·o·ma·sa (-sə)
The fourth division of the stomach in ruminant animals, such as cows, sheep, and deer, in which digestion takes place.

[New Latin abomāsum : Latin ab-, ab- + Latin omāsum, tripe; see omasum.]

ab′o·ma′sal (-səl) adj.


(ˌæbəˈmeɪsəm) or


n, pl -sa (-sə) or -si (-saɪ)
(Zoology) the fourth and last compartment of the stomach of ruminants, which receives and digests food from the psalterium and passes it on to the small intestine
[C18: New Latin, from ab-1 + omāsum bullock's tripe]


(ˌæb əˈmeɪ səm)

n., pl. -sa (-sə).
the fourth or true stomach of the cow and other ruminants, from which partially fermented and digested food is passed to the small intestine.
[1700–10; < New Latin; see ab-, omasum]


The fourth division of the stomach in ruminant animals, and the only one having glands that secrete acids and enzymes for digestion. It corresponds anatomically to the stomachs of other mammals. See more at ruminant.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.abomasum - the fourth compartment of the stomach of a ruminantabomasum - the fourth compartment of the stomach of a ruminant; the one where digestion takes place
ruminant - any of various cud-chewing hoofed mammals having a stomach divided into four (occasionally three) compartments
stomach, tum, tummy, breadbasket - an enlarged and muscular saclike organ of the alimentary canal; the principal organ of digestion
References in periodicals archive ?
Abomasum of newborn lambs or grass "dalama otu" (rennet grass) were used for fermentation.
Hypocalcemia at parturition as risk factor for left displacement abomasum in dairy cows.
The necropsy was performed immediately after death, and fragments of rumen, reticulum, abomasum, intestines, liver, spleen, kidneys, lungs, heart, brain, and skeletal muscle were collected, fixed in 10% formalin and sent to the Sector of Veterinary Pathology of the Universidade Federal de Lavras (UFLA).
While a calf is born with a rumen, when they drink milk, the suckling action actually causes the milk to bypass the rumen and go straight into the abomasum, or "true stomach.
Microbial OM and nitrogen leaving the abomasum were calculated using purines as a microbial marker [16].
The non-fiber carbohydrates become energy source for the growth and microbial proliferation, resulting in the production of propionic acid, which is substrate for the production of lactose and thus can increase the volume of milk, as well as, increase the availability of protein since it will favor the greater contribution of bacteria in the abomasum, and thus increasing the total solids production of the milk.
It has a four-chambered "stomach" consisting of the rumen, reticulum, omasum and abomasum.
Two species of Trichostrongylus occur in small ruminants: T axei, living in the abomasum, does not appear to be an important pathogen, but T colubriformis causes black scours and contributes to parasitic gastroenteritis, ill thrift and diarrhea in kids.
Abomasum parasitism lowers liver Cu status and influences the CuXMOXS antagonism in lambs.
Delayed detection can lead to fatty liver, displaced abomasum (twisted stomach), inflammation of the uterus, or a retained placenta.
The stem bark extract of Acacia oxyphylla against Ascaridia galli (Nematode), seeds of Carum capticum against gastrointestinal nematodes of sheep, aqueous and ethanolic leaf extract of Adhatoda vasica has been observed for ovicidal as well as larvicidal activity against nematodes, leaves of Artimesiabervifolia (wormwood) and Zanthxylumzanthoxyloides (Fagara a native tree from Africa) in the form of powder has been proved effective upto 65% against eggs of Haemonchuscontortus in abomasum, hay of Cassava forage has been proved effective against eggs and larva of abomasal and intestinal nematodes of sheep and goats,
Among various compartments, abomasum appears more common to become fistulated traumatically followed by rumen (Deviprasad et al.