Viscera: Any of the large interior organs in any one of the three great cavities of the body, especially in the abdomen.Portal System: A system of vessels in which blood, after passing through one capillary bed, is conveyed through a second set of capillaries before it returns to the systemic circulation. It pertains especially to the hepatic portal system.Pneumoperitoneum: A condition with trapped gas or air in the PERITONEAL CAVITY, usually secondary to perforation of the internal organs such as the LUNG and the GASTROINTESTINAL TRACT, or to recent surgery. Pneumoperitoneum may be purposely introduced to aid radiological examination.Splanchnic Circulation: The circulation of blood through the BLOOD VESSELS supplying the abdominal VISCERA.Abdominal Cavity: The region in the abdomen extending from the thoracic DIAPHRAGM to the plane of the superior pelvic aperture (pelvic inlet). The abdominal cavity contains the PERITONEUM and abdominal VISCERA, as well as the extraperitoneal space which includes the RETROPERITONEAL SPACE.Portal Vein: A short thick vein formed by union of the superior mesenteric vein and the splenic vein.Ammonia: A colorless alkaline gas. It is formed in the body during decomposition of organic materials during a large number of metabolically important reactions. Note that the aqueous form of ammonia is referred to as AMMONIUM HYDROXIDE.Intestinal Perforation: Opening or penetration through the wall of the INTESTINES.Abdominal Injuries: General or unspecified injuries involving organs in the abdominal cavity.Oncorhynchus: A genus of the family SALMONIDAE (salmons and trouts). They are named for their hooked (onco) nose (rhynchus). They are usually anadromous and occasionally inhabit freshwater. They can be found in North Pacific coastal areas from Japan to California and adjacent parts of the Arctic Ocean. Salmon and trout are popular game and food fish. Various species figure heavily in genetic, metabolism, and hormone research.Mesenteric Veins: Veins which return blood from the intestines; the inferior mesenteric vein empties into the splenic vein, the superior mesenteric vein joins the splenic vein to form the portal vein.Bivalvia: A class in the phylum MOLLUSCA comprised of mussels; clams; OYSTERS; COCKLES; and SCALLOPS. They are characterized by a bilaterally symmetrical hinged shell and a muscular foot used for burrowing and anchoring.Digestive System Physiological Phenomena: Properties and processes of the DIGESTIVE SYSTEM as a whole or of any of its parts.Abdominal Muscles: Muscles forming the ABDOMINAL WALL including RECTUS ABDOMINIS, external and internal oblique muscles, transversus abdominis, and quadratus abdominis. (from Stedman, 25th ed)Anisakis: A genus of nematodes of the superfamily ASCARIDOIDEA. Its organisms are found in the stomachs of marine animals and birds. Human infection occurs by ingestion of raw fish that contain larvae.Abomasum: The fourth stomach of ruminating animals. It is also called the "true" stomach. It is an elongated pear-shaped sac lying on the floor of the abdomen, on the right-hand side, and roughly between the seventh and twelfth ribs. It leads to the beginning of the small intestine. (From Black's Veterinary Dictionary, 17th ed)Urea: A compound formed in the liver from ammonia produced by the deamination of amino acids. It is the principal end product of protein catabolism and constitutes about one half of the total urinary solids.Hypogastric Plexus: A complex network of nerve fibers in the pelvic region. The hypogastric plexus distributes sympathetic fibers from the lumbar paravertebral ganglia and the aortic plexus, parasympathetic fibers from the pelvic nerve, and visceral afferents. The bilateral pelvic plexus is in its lateral extent.Liver Circulation: The circulation of BLOOD through the LIVER.Animal Feed: Foodstuff used especially for domestic and laboratory animals, or livestock.Abdomen: That portion of the body that lies between the THORAX and the PELVIS.Animal Nutritional Physiological Phenomena: Nutritional physiology of animals.Visceral Afferents: The sensory fibers innervating the viscera.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Digestive System: A group of organs stretching from the MOUTH to the ANUS, serving to breakdown foods, assimilate nutrients, and eliminate waste. In humans, the digestive system includes the GASTROINTESTINAL TRACT and the accessory glands (LIVER; BILIARY TRACT; PANCREAS).Situs Inversus: A congenital abnormality in which organs in the THORAX and the ABDOMEN are opposite to their normal positions (situs solitus) due to lateral transposition. Normally the STOMACH and SPLEEN are on the left, LIVER on the right, the three-lobed right lung is on the right, and the two-lobed left lung on the left. Situs inversus has a familial pattern and has been associated with a number of genes related to microtubule-associated proteins.Random Allocation: A process involving chance used in therapeutic trials or other research endeavor for allocating experimental subjects, human or animal, between treatment and control groups, or among treatment groups. It may also apply to experiments on inanimate objects.Swine: Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).Amino Acids: Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.Sheep: Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS.Nitrogen: An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.Gastrointestinal Tract: Generally refers to the digestive structures stretching from the MOUTH to ANUS, but does not include the accessory glandular organs (LIVER; BILIARY TRACT; PANCREAS).Food Preservation: Procedures or techniques used to keep food from spoiling.Fatty Acids, Volatile: Short-chain fatty acids of up to six carbon atoms in length. They are the major end products of microbial fermentation in the ruminant digestive tract and have also been implicated in the causation of neurological diseases in humans.Celiac Artery: The arterial trunk that arises from the abdominal aorta and after a short course divides into the left gastric, common hepatic and splenic arteries.Hernia, Diaphragmatic: Protrusion of abdominal structures into the THORAX as a result of congenital or traumatic defects in the respiratory DIAPHRAGM.Medicago sativa: A plant species of the family FABACEAE widely cultivated for ANIMAL FEED.Rupture, Spontaneous: Tear or break of an organ, vessel or other soft part of the body, occurring in the absence of external force.Hepatic Veins: Veins which drain the liver.Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.Intestines: The section of the alimentary canal from the STOMACH to the ANAL CANAL. It includes the LARGE INTESTINE and SMALL INTESTINE.Dietary Proteins: Proteins obtained from foods. They are the main source of the ESSENTIAL AMINO ACIDS.Propionates: Derivatives of propionic acid. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxyethane structure.Eating: The consumption of edible substances.Abdominal Wall: The outer margins of the ABDOMEN, extending from the osteocartilaginous thoracic cage to the PELVIS. Though its major part is muscular, the abdominal wall consists of at least seven layers: the SKIN, subcutaneous fat, deep FASCIA; ABDOMINAL MUSCLES, transversalis fascia, extraperitoneal fat, and the parietal PERITONEUM.Glutamine: A non-essential amino acid present abundantly throughout the body and is involved in many metabolic processes. It is synthesized from GLUTAMIC ACID and AMMONIA. It is the principal carrier of NITROGEN in the body and is an important energy source for many cells.Mechanoreceptors: Cells specialized to transduce mechanical stimuli and relay that information centrally in the nervous system. Mechanoreceptor cells include the INNER EAR hair cells, which mediate hearing and balance, and the various somatosensory receptors, often with non-neural accessory structures.3-Hydroxybutyric Acid: BUTYRIC ACID substituted in the beta or 3 position. It is one of the ketone bodies produced in the liver.Diet: Regular course of eating and drinking adopted by a person or animal.Amino Acids, Essential: Amino acids that are not synthesized by the human body in amounts sufficient to carry out physiological functions. They are obtained from dietary foodstuffs.Stomach: An organ of digestion situated in the left upper quadrant of the abdomen between the termination of the ESOPHAGUS and the beginning of the DUODENUM.Hernia, Ventral: A hernia caused by weakness of the anterior ABDOMINAL WALL due to midline defects, previous incisions, or increased intra-abdominal pressure. Ventral hernias include UMBILICAL HERNIA, incisional, epigastric, and spigelian hernias.Body Composition: The relative amounts of various components in the body, such as percentage of body fat.Lactates: Salts or esters of LACTIC ACID containing the general formula CH3CHOHCOOR.Regional Blood Flow: The flow of BLOOD through or around an organ or region of the body.Pelvis: The space or compartment surrounded by the pelvic girdle (bony pelvis). It is subdivided into the greater pelvis and LESSER PELVIS. The pelvic girdle is formed by the PELVIC BONES and SACRUM.Laparotomy: Incision into the side of the abdomen between the ribs and pelvis.Physical Stimulation: Act of eliciting a response from a person or organism through physical contact.Body Weight: The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.Afferent Pathways: Nerve structures through which impulses are conducted from a peripheral part toward a nerve center.Fish Diseases: Diseases of freshwater, marine, hatchery or aquarium fish. This term includes diseases of both teleosts (true fish) and elasmobranchs (sharks, rays and skates).Peritonitis: INFLAMMATION of the PERITONEUM lining the ABDOMINAL CAVITY as the result of infectious, autoimmune, or chemical processes. Primary peritonitis is due to infection of the PERITONEAL CAVITY via hematogenous or lymphatic spread and without intra-abdominal source. Secondary peritonitis arises from the ABDOMINAL CAVITY itself through RUPTURE or ABSCESS of intra-abdominal organs.Digestion: The process of breakdown of food for metabolism and use by the body.