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.Sheep Diseases: Diseases of domestic and mountain sheep of the genus Ovis.Sheep, Domestic: A species of sheep, Ovis aries, descended from Near Eastern wild forms, especially mouflon.Sheep, Bighorn: A species of sheep, Ovis canadensis, characterized by massive brown horns. There are at least four subspecies and they are all endangered or threatened.Jaagsiekte sheep retrovirus: A BETARETROVIRUS that causes pulmonary adenomatosis in sheep (PULMONARY ADENOMATOSIS, OVINE).Goats: Any of numerous agile, hollow-horned RUMINANTS of the genus Capra, in the family Bovidae, closely related to the SHEEP.Scrapie: A fatal disease of the nervous system in sheep and goats, characterized by pruritus, debility, and locomotor incoordination. It is caused by proteinaceous infectious particles called PRIONS.Goat Diseases: Diseases of the domestic or wild goat of the genus Capra.Pulmonary Adenomatosis, Ovine: A contagious, neoplastic, pulmonary disease of sheep characterized by hyperplasia and hypertrophy of pneumocytes and epithelial cells of the lung. It is caused by JAAGSIEKTE SHEEP RETROVIRUS.Wool: The hair of SHEEP or other animals that is used for weaving.Fetus: The unborn young of a viviparous mammal, in the postembryonic period, after the major structures have been outlined. In humans, the unborn young from the end of the eighth week after CONCEPTION until BIRTH, as distinguished from the earlier EMBRYO, MAMMALIAN.Rumen: The first stomach of ruminants. It lies on the left side of the body, occupying the whole of the left side of the abdomen and even stretching across the median plane of the body to the right side. It is capacious, divided into an upper and a lower sac, each of which has a blind sac at its posterior extremity. The rumen is lined by mucous membrane containing no digestive glands, but mucus-secreting glands are present in large numbers. Coarse, partially chewed food is stored and churned in the rumen until the animal finds circumstances convenient for rumination. When this occurs, little balls of food are regurgitated through the esophagus into the mouth, and are subjected to a second more thorough mastication, swallowed, and passed on into other parts of the compound stomach. (From Black's Veterinary Dictionary, 17th ed)Lymph: The interstitial fluid that is in the LYMPHATIC SYSTEM.Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.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.Plant Poisoning: Poisoning by the ingestion of plants or its leaves, berries, roots or stalks. The manifestations in both humans and animals vary in severity from mild to life threatening. In animals, especially domestic animals, it is usually the result of ingesting moldy or fermented forage.Omasum: The third stomach of ruminants, situated on the right side of the abdomen at a higher level than the fourth stomach and between this latter and the second stomach, with both of which it communicates. From its inner surface project large numbers of leaves or folia, each of which possesses roughened surfaces. In the center of each folium is a band of muscle fibers which produces a rasping movement of the leaf when it contracts. One leaf rubs against those on either side of it, and large particles of food material are ground down between the rough surfaces, preparatory to further digestion in the succeeding parts of the alimentary canal. (Black's Veterinary Dictionary, 17th ed)Erythrocytes: Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.Stomach, RuminantFoot Rot: A disease of the horny parts and of the adjacent soft structures of the feet of cattle, swine, and sheep. It is usually caused by Corynebacterium pyogenes or Bacteroides nodosus (see DICHELOBACTER NODOSUS). It is also known as interdigital necrobacillosis. (From Black's Veterinary Dictionary, 18th ed)PrPSc Proteins: Abnormal isoform of prion proteins (PRIONS) resulting from a posttranslational modification of the cellular prion protein (PRPC PROTEINS). PrPSc are disease-specific proteins seen in certain human and animal neurodegenerative diseases (PRION DISEASES).Prions: Small proteinaceous infectious particles which resist inactivation by procedures that modify NUCLEIC ACIDS and contain an abnormal isoform of a cellular protein which is a major and necessary component. The abnormal (scrapie) isoform is PrPSc (PRPSC PROTEINS) and the cellular isoform PrPC (PRPC PROTEINS). The primary amino acid sequence of the two isoforms is identical. Human diseases caused by prions include CREUTZFELDT-JAKOB SYNDROME; GERSTMANN-STRAUSSLER SYNDROME; and INSOMNIA, FATAL FAMILIAL.