Ruminant Stomach Anatomy & Physiology
This large compartment of the ruminant stomach is lined with carpet-like papillae that maximize surface area for VFA absorption
What is the rumen?
This primary VFA is produced in the highest proportions on high-fiber forage diets and is essential for milk fat synthesis in dairy cows
What is acetate (acetic acid)?
Horses are anatomically classified as this type of herbivore because microbial fiber fermentation takes place in their cecum and colon
What is a hindgut fermenter?
Overconsumption of rapidly fermentable grains causes a drastic drop in ruminal pH below 5.0, a microbial shift to Lactobacilli, and severe dehydration
What is acute ruminal acidosis?
Characterized by signs of visceral abdominal pain such as rolling and pawing, this general condition can be triggered by sudden feed changes or coarse fiber intake
What is colic?
Characterized by its distinct honeycomb-like lining, this cranial stomach compartment functions to trap foreign material and heavy debris
What is the reticulum?
High-starch concentrate diets shift the ruminal microbiome to produce a higher proportion of this VFA, which serves as the primary source of glucose in ruminants
What is propionate (propionic acid)?
The typical adult horse requires this baseline percentage of its body weight in dry matter (forage) per day for health and maintenance
What is 1.5% to 2% of body weight?
Occurring near calving due to sudden calcium demand for lactation, this disease is managed preventatively using DCAD (Dietary Cation-Anion Difference) diets
What is hypocalcemia (or milk fever)?
Easily recognized by regional adiposity and high cresty neck scores, Equine Metabolic Syndrome (EMS) strongly predisposes horses to this painful foot condition
What is laminitis (or founder)?
Known as the "true glandular stomach" of ruminants, this organ secretes digestive enzymes and acid, functioning similarly to a monogastric stomach
What is the abomasum?
This specific VFA is converted into ketones, such as beta-hydroxybutyrate, within the ruminant epithelial wall
What is butyrate (butyric acid)?
This distinct serrated line inside the equine stomach forms the anatomical border separating the upper non-glandular squamous region from the lower glandular region
What is the margo plicatus?
Cattle grazing lush spring pastures low in magnesium can suffer from this disease, marked by muscle spasms, hyperexcitability, and convulsions
What is hypomagnesemia (or grass tetany)?
Horses with Hyperkalemic Periodic Paralysis (HYPP) must be nutritionally managed with a diet specifically low in this mineral
What is potassium?
In young suckling calves, this muscular fold allows ingested milk to bypass the rumen and reticulum directly into the abomasum to avoid fermentation
What is the reticular (or esophageal) groove?
These antimicrobial feed additives shift ruminal microbes away from gram-positive species, increasing propionate production and feed efficiency while decreasing methane
What are ionophores?
To prevent excessive starch from overflowing into the hindgut and causing fermentation disorders, individual concentrate meals for horses should not exceed this starch limit per kg of body weight
What is 2 grams of starch per kg of body weight?
In frothy bloat, normal eructation is prevented because fermentation gases become trapped in a stable foam created by fine particles and this bacterial product
What is mucoprotein slime?
Severely emaciated horses (BCS < 2/9) re-fed too aggressively can develop this fatal syndrome characterized by severe drops in blood potassium, phosphorus, and magnesium
What is refeeding syndrome?
Adult cattle secrete 100 to 150 liters per day of this liquid, which supplies critical bicarbonate to buffer ruminal VFA production
What is saliva?
Excess ammonia from dietary protein digestion is converted by the liver into urea; evaluating this parameter in dairy cows indicates whether dietary protein is in excess
What is Milk Urea Nitrogen (MUN)?
High in protein and calcium, this legume forage is colloquially nicknamed "Horse Tums" for its natural buffering effect against gastric ulcers
What is alfalfa hay?
Polioencephalomalacia in cattle and sheep causes cortical blindness and brain necrosis resulting from either toxicity of this mineral or a deficiency in this B-vitamin
What is thiamine (Vitamin B1) deficiency or sulfur toxicity?
Chronic deficiency of Vitamin E in horses leads to muscular weakness and abnormal standing posture associated with this specific neurodegenerative disease
What is Equine Motor Neuron Disease (EMND)?