Topic:Digestive Tract
The digestive tract in horses is a complex system responsible for the breakdown and absorption of nutrients essential for maintaining equine health. It includes several key components: the mouth, esophagus, stomach, small intestine, cecum, large colon, small colon, and rectum. Each segment of the digestive tract performs specific functions, from the mechanical breakdown of feed to the enzymatic digestion and absorption of nutrients. The horse's digestive system is uniquely adapted to process fibrous plant material, relying heavily on microbial fermentation, particularly in the hindgut. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, physiology, and function of the equine digestive tract, as well as common disorders and their management.
Effect of diet on cecal pH and feeding behavior of horses. Three cecal-fistulated horses were used in a 3 × 3 latin square experiment to determine the influence of diet and of cecal infusions of Na2C03 on cecal fermentation and feeding behavior. The three treatments were hay, concentrate and concentrate plus hourly infusions of Na2CO3. Cecal fluid samples and cecal pH readings were taken at zero through 11 hr following feeding at the end of each experimental period, and animal activity was measured by the use of a movie camera set to take 5 sec of film every 5 minutes. Cecal pH was significantly lower at 4, 5 and 6 hr following feeding for the horses...
[Cochliatoxum periachtum Gassovsky, 1919, entodinimorphic Ciliate of the horse digestive tract]. The topography of Cochliatoxum periachtum is studied. The cuticle is very thick. The digestive, nuclear and excretory systems are located in the ectoplasm, they are not surrounded by the mesoplasm. The endoplasm is very large, it contains vegetable inclusions. By the features of its topography, this species is similar to some species belonging to the Family Ophryoscolescidae and, especially, to Eudiplodinium giganteum.
Comparison of three techniques for intestinal anastomosis in Equidae. Thirteen horses and ponies were used to evaluate an anastomotic technique utilizing a modified Gambee suture pattern. The modified Gambee technique was compared with a single-row everting technique and a double-row inverting technique. The double-row inverting technique predisposed to intestinal obstruction and resulted in minimal adhesions. The everting technique predisposed to leakage of intestinal contents and subsequent peritonitis. Adhesions were formed at the site of the anastomosis to such an extent as to jeopardize the proper position of the bowel. The technique did not cause any lumin...
Measurement of volatile fatty acid production rates in the cecum of the pony. Three experiments, each utilizing three ponies, were conducted using a mixed VFA solution of [1−14C] acetate, [1−14C] propionate and [2–33H] butyrate to determine VFA production rates in the cecum of the pony. Diet A used in experiment 1, contained a forage to grain ratio of 1:2, while diet B, used in experiments 2 and 3, contained a forage to grain ratio of 3:1. Experiment 1, in which a constant infusion technique was used, resulted in net VFA production rates (mmoles/min) of 3.667 to 3.977 (x̄=3.836) for acetate, .410 to 1.664 (x̄=1.213) for propionate and .342 to 1.124 (x̄=.629) fo...
[Esential comparative, morphological and topographical differences and characteristics of the cecum in man and domestic animals]. The caecum in man as a part of the large colon (intestinum crassum) differs morphologically and topographically from the caecum of domestic mammals. The caecum in domestic mammals differs not only from the human caecum but also comparatively morphologically and topographically among the domestic mammals. The appendix vermiformis does not exist in domestic mammals, which represents the main difference between the human caecum and that of domestic mammals. There are certainly some differences in the physiological function of the caecum in man and the caecum in domestic mammals, which are carnivo...
Nitrogen utilization within equine large intestine. The distribution of nitrogen in ligated segments of the stomach and intestine of two groups of ponies has been examined at sacrifice 2, 4, 8, and 12 h following the final 12-h scheduled feeding of diets designed to provide either 1) ample protein, or 2) limited protein plus supplemental urea as the major nitrogen source. Concentrations and total quantities of total N, NH3, urea plus NH3, and alpha-amino N were determined, and protein N was calculated by difference. Liquid marker (PEG) distribution rate constants and N concentrations were used to calculate rates of entry and exit by digesta flo...
Malabsorption in the horse associated with alimentary lymphosarcoma. Three horses suffering from malabsorption were shown to have alimentary lymphosarcoma predominantly affecting the small intestine and the associated lymph nodes. The diffuse cellular infiltration in two of the case produced marked changes in the villous architecture reducing the available mucosal surface area, and, with lowered or barely detectable disaccharidase activities, contributed to the impairment of digestive-absorptive processes. One of the horses maintained a voracious appetite and was not diarrhoeic, but failed to gain weight, indicating differences in the production and utilisation...
Recent research into the nutrition of the horse. The majority of recent experiments in equine nutrition relates to the metabolism of protein, non-protein nitrogen, carbohydrate, calcium and phosphorus. An understanding of the significance of the nitrogen cycle is emerging in which there is a two-way movement of compounds across the wall of the G.I. tract. Some quantitative estimates of the role of microflora in this process have been made for comparison with similar processes in ruminants. However, the pathway by which the microflora contributes to the nitrogen economy and the extent to which this occurs is not established in the horse. It i...
Cyclic changes in ionic composition of digesta in the equine intestinal tract. Effects of diet and time after feeding on osmolality and inorganic ion content of gastrointestinal digesta were studied in 24 ponies. Animals, fed either a conventional or a low-protein, high-cellulose diet, were sacrificed 2, 4, 8, or 12 h after a meal. Animals fed the conventional diet showed cyclic variations in the ionic composition and osmolality of digesta with time after feeding. The most marked variations were seen in the contents of the stomach and small colon. However, results also indicated a cyclic appearance and disappearance of Na in large intestinal contents that correlated with...
Intestinal absorption of calcium and phosphorus by horses. Recent knowledge regarding the absorption of calcium and phosphorus from the intestine of the horse has been reviewed. Consideration has been given to sites, mechanisms and factors affecting absorption as well as to the availability of calcium and phosphorus from feedstuffs commonly used in Eastern North America. Although the anatomy of the digestive tract might appear to impose restrictions on the ability of the horse to assimilate minerals, studies of absorption show that the horse utilizes the calcium and phosphorus of many feeds very efficiently.
Digestive physiology of the horse. Recent studies on the digestive physiology of the horse are reviewed. It was suggested that the small intestine is the primary site of digestion and absorption of protein, soluble carbohydrates, most minerals, fats, fat soluble and water soluble vitamins. The large intestine is the primary site of fibre digestion and net water absorption. Significant amounts of phosphorus are also absorbed from the large intestine. Many factors such as rate of passage, processing of feeds, level of intake, work and maturity of plant may influence digestive ability.
Intestinal surgery in the foal. Intestinal surgery in the foal is seldom necessary but some conditions in which it is essential are well recognized. The foal is a good surgical subject but success depends mainly on operating promptly before irreversible degenerative changes take place. Exploratory laparatomy is recommended whenever mechanical obstruction is suspected. Indications fall broadly into two main categories: 1. Cases arising from congenital defects. These form a miscellaneous group and present considerable difficulties in diagnosis and effective treatment. 2. Cases related to acute onset of obstruction, mainly due ...
[Cecal motricity and ceco-iliac transit in the horse]. Electrical spiking activity of the caecum is increased eight-fold and the rate of passage of digesta is increased four-fold when the volume of caecal contents is doubled. The role of caecal motility in regulating the volume of caecal contents is discussed.