Omneity® Pellets
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Topic:Biochemistry
The study of biochemistry in horses encompasses the chemical processes and substances that occur within equine organisms. This field investigates the molecular interactions and pathways that are fundamental to horse physiology, including metabolism, enzyme activity, and genetic expression. Key areas of interest include the examination of metabolic disorders, nutrient absorption, and the biochemical basis of muscle function and energy production. Researchers utilize biochemical analysis to understand health and disease mechanisms in horses, contributing to the development of diagnostic tools and therapeutic strategies. This page gathers peer-reviewed studies and scholarly articles that explore various biochemical processes and their implications for equine health and performance.
Serum alkaline phosphatase in pregnant mares. Serum alkaline phosphatase was measured in ten mares during various stages of gestation. No significant change in serum alkaline phosphatase activity was detected during pregnancy. These data suggest that interpretation of serum alkaline phosphatase in horses can be made independently of their pregnancy status.
Equine marker genes. Polymorphism for transferrin alleles, TfF1 and TfF2, in Thoroughbreds. The equine transferrin F variant is distinguishable into two types, F1 and F2, on alkaline polyacrylamide gel electrophoresis. Gene frequencies in 63 related Thoroughbreds are 0.39 and 0.19 for TfF1 and TfF2, respectively. In contrast the frequencies for these two alleles in 375 related Standardbreds is 0.00 and 0.59.
Protease inhibitor system in horses: classification and detection of a new allele. A method of horizontal thin layer polyacrylamide gel electrophoresis at acid pH has been developed for the separation of the prealbumins in equine plasma. Using this method, it has been possible to split the S allele into two, S1 and S2, bringing the total number of prealbumin alleles in Thoroughbred horses to eight. The gene frequencies of these eight alleles in Australian Thoroughbreds are presented. All eight prealbumin types exhibit antiprotease activity and therefore, it is suggested that the name prealbumin (Pr) should be abandoned in favour of protease inhibitor (Pi) although at this st...
Pharmacological and immunological aspects of histamine release from horse leucocytes. Pharmacological histamine releasing agents, such as compound 48/80, poly-L-lysine, adrenocorticotrophic hormone (ACTH; beta 1-24 available commercially as Synacthen), catecholamines, purine bases, etc., are well known to induce histamine release from rat peritoneal mast cells and mast cells of other species; and to a lesser extent from peripheral blood leucocytes. It is reported in this paper that several of these potent histamine-releasing agents induce little or no histamine release from horse leucocytes. In particular the calcium ionophore A 23187 induced no histamine release. On the other ...
A new haemolysin from Staphylococcus aureus which lyses horse erythrocytes. A new haemolysin from Staphylococcus aureus produced opaque zones of haemolysis on horse blood agar but did not lyse equine erythrocytes suspended in phosphate-buffered saline. The haemolysin was not neutralized by normal rabbit serum and was distinct from alpha-, beta- and delta-haemolysins as well as human leucocidin. Partially purified preparations produced erythema when injected intradermally into rabbit skin.
Direct measurement of biliary bilirubin excretion in ponies during fasting. Biliary excretion of bilirubin, including the conjugate composition, was studied during feeding and during a 2.5-day fast of three pony mares with chronic external biliary (T-tube) fistulas. Fasting bilirubin excretion (1.96 +/- 0.74 microgram/min/kg of body weight), after establishing a new steady state, was not different from excretion during feeding (1.99 +/- 0.45 microgram/min/kg). Hyperbilirubinemia of fasting resulted from a reduced removal of plasma bilirubin rather than from an increased input of bilirubin into the plasma. Relative plasma excretion of the individual conjugate fractions...
The origin of nuclear bodies: a study of the undifferentiated epithelial cells of the equine small intestine. During an electron and light microscopic study of the equine intestinal epithelium, it was observed that some secretory granules of the undifferentiated crypt epithelium were incorporated into the nucleus during mitosis. A study was made of the chemical nature of the granules, using standard histochemical techniques: PAS-Alcian blue, Deamination-PAS, and Ninhydrin-Schiff reactions. The granules contained a neutral protein-polysaccharide complex with many terminal amino groups, possibly an antibody (IgA). The intranuclear granules underwent coalescence and degeneration during differentiation. T...
Quantitative comparisons of acidic prealbumin (PR) phenotypes in horses. Comparisons of Pr protein amounts in horse sera have been performed using .’s (1965) immunodiffusion technique. Relative values against a chosen standard of 100 % were determined for a total of 435 horses. There was considerable variation between horses, the highest Pr value being 125 and the lowest 50 % of the standard. In animals of the same Pr phenotype the mean Pr values were significantly higher (P < 0.001) in foals than in mares. In Norwegian Trotter horses the Pr value of Pr NN animals was significantly higher than that of Pr SS phenotypes, whereas the mean Pr values of Pr SS was sig...
Plasma and sweat electrolyte concentrations in the horse during long distance exercise. Blood samples were taken from 20 horses competing in a 100 km endurance ride and plasma concentrations of sodium, potassium, chloride, bicarbonate and protein measured. Measurements were performed on samples taken before the ride (pre-ride), at the mid point and end of the ride and after a 30 min recovery period (post-ride). Sweat samples were collected from 6 horses competing in the endurance ride and 14 horses competing in a 3-day event competition and sweat concentrations of sodium, potassium and chloride measured. There were substantial decreases in plasma electrolyte concentrations, which...
[Comparative study of the digestion of a complete food in the pony and the rabbit]. A complete pelleted diet (table 1) containing 11 p. 100 of crude protein and 17 p. 100 of cellulose (ADF-lignine according to the method of Van Soest) was distributed to ponies and rabbits. Total digestibilities, partial cumulative digestibilities in different compartments of the digestive tract (stomach, small intestine, caecum, proximal and distal colon) and changes in biochemical composition, measured by pH, VFA, lactic acid and ammonia concentrations, were compared. Total digestibilities (table 2). There was no significant difference in dry matter between the two species. Crude protein dig...
Hematology and biochemistry reference values for the light horse. Reference hematology and biochemistry intervals are presented for a number of variables of clinical interest determined for blood samples obtained from 60 thoroughbred mares, 12 thoroughbred foals and 50 standardbred horses in training. The observations for each variable were examined for outliers and Gaussian distribution. Parametric analysis was used where the observations were Gaussian initially or after any of four transformations, otherwise nonparametric analysis was required for estimation of the 2.5 and 97.5 percentiles. Description of the sample collection procedures, laboratory method...
Metabolism of progesterone by placentas from several mammalian species in vitro. 20-alpha-Hydroxysteroid oxidoreductase (20-alpha-HSDH) activity and 20-alpha-dihydroprogesterone concentration (20-alpha-DHP) reach peak values in the human placenta after vaginal delivery. To determine if these findings are unique to the human, we measured 20-alpha-HSDH activity as well as endogenous progesterone (P) and 20-alpha-DHP concentration in the soluble supernatant fraction of placental tissues obtained from rodents (rat, rabbit, guinea pig), ungulates (horse, zebra, giraffe, cow), and primates (squirrel monkey, orangutan, man). P concentration was very low in rodents (mean 0.60 ng/m...
Minimal changes in blood cell counts and biochemical values associated with prolonged isoflurane anesthesia of horses. The potential toxicity to horses of 7.33 +/- 0.87 SD minimal alveolar concentration hours of isoflurane anesthesia was evaluated by sequential determination of blood cell counts, electrolyte concentrations, and certain blood chemical values. Minimal or no serious toxicosis was observed for up to 7 days after anesthesia was terminated.
Isoenzymes of equine alkaline phosphatase. Alkaline phosphatase isoenzymes from small intestine, cecum, large colon, small colon, liver, kidney, leukocytes, and serum from ten clinically normal horses were defined by their sensitivities to L-phenylalanine, L-homoarginine, levamisole and heat, and by polyacrylamide gel disc electrophoresis. Readily identifiable isoenzymes occurred in small intestine, granulocytes, kidney, cecum, and large and small colon. By contrast, alkaline phosphatases from liver, lymphocytes, and serum could not be discriminated by this group of tests.
Plasma and synovial fluid lysozyme activity in horses with experimental cartilage defects. Cartilaginous defects were created in the radiocarpal joints of 12 horses. Synovial fluid cytologic features, lysozyme activity, and beta-glucuronidase activity were monitored for 16 days. A comparison was made of plasma lysozyme and beta-glucuronidase activity and of synovial fluid lysozyme, beta-glucuronidase, and leukocyte concentrations. Plasma lysozyme was found to be independent of synovial fluid lysozyme activity. Synovial fluid lysozyme was significantly increased (P less than 0.001) in all joints with surgically induced defects (group I) compared with controls (arthrocentesis done; gr...
Differences in the interactions of liver alcohol dehydrogenases with probes binding into the substrate pocket. The interactions of three groups of probes (berberine alkaloids, tricyclic psychopharmaca and acridine derivatives) with isoenzymes of horse liver alcohol dehydrogenase and with rat liver alcohol dehydrogenase have been examined. These compounds inhibit the activity of the EE isoenzyme of horse liver alcohol dehydrogenase but differ in their behaviour towards the steroid-active enzymes (i.e. the ES isoenzyme of horse liver alcohol dehydrognase and alcohol dehydrogenase from rat liver): psychopharmaca inhibit, acridines activate and berberines do not bind. The ligands differ also in their influ...
Tissue and plasma activity of lactic dehydrogenase and creatine kinase in the horse. Lactic dehydrogenase, although widely distributed in most tissues, was more highly concentrated in skeletal muscle, cardiac muscle, kidney and liver. Isoenzyme patterns showed a selective concentration of LDH5 in skeletal muscle while in the heart LDH 1 and 2 were predominant. In contrast, creatine kinase was only present in substantial concentration in skeletal and cardiac muscle. The serum concentrationof both enzymes showed a wide range of activity.
