Analyze Diet

Topic:Physiology

The physiology of horses encompasses the study of the biological functions and processes that occur within the equine body. This includes the examination of various systems such as the cardiovascular, respiratory, musculoskeletal, digestive, and nervous systems. Understanding equine physiology is essential for comprehending how horses adapt to different environmental conditions, perform physical activities, and respond to health challenges. Research in this field often focuses on the mechanisms of energy metabolism, thermoregulation, and muscle function during exercise, as well as the physiological responses to stress and disease. This page compiles peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine physiology, providing insights into the biological processes that support the health and performance of horses.
Arterial vs. rectal temperature in ponies: rest, exercise, CO2 inhalation, and thermal stresses.
Journal of applied physiology (Bethesda, Md. : 1985)    October 1, 1986   Volume 61, Issue 4 1577-1581 doi: 10.1152/jappl.1986.61.4.1577
Pan LG, Forster HV, Kaminski RP.We assessed in ponies the adequacy of using rectal (Tre) rather than arterial temperature (Tar) under conditions common to ventilatory control experiments, i.e., CO2 breathing, thermal stress, and particularly exercise. We were interested in whether, and to what extent, Tar-Tre differences could lead to errors in arterial blood gas corrections. At control environmental temperatures (Ta) of 5 degrees C in the winter and 21 degrees C in the summer, Tar and Tre (37.1 degrees C) did not differ (P greater than 0.05). Elevating winter or summer Ta by 10-18 degrees C for 2-days or lowering summer Ta ...
Metabolism of some essential minerals in ponies fed high levels of aluminum.
The Cornell veterinarian    October 1, 1986   Volume 76, Issue 4 354-360 
Schryver HF, Millis DL, Soderholm LV, Williams J, Hintz HF.The effect of dietary aluminum on the absorption, retention and pathways of excretion of calcium, phosphorus, magnesium, zinc, iron and copper was studied in balance trials in mature ponies in a three by three latin square experiment. A basal diet consisting of one third each of oats, beet pulp and a commercial pelleted, complete horse ration and containing 336 ppm aluminum was supplemented with AlC1(3) . 6H2O. The middle and high level aluminum diets contained 1370 and 4500 ppm aluminum respectively. There was little difference in effect between the middle level aluminum and basal diets. The ...
Recovery and evaluation of embryos from normal and infertile mares.
The Cornell veterinarian    October 1, 1986   Volume 76, Issue 4 386-394 
Woods GL, Hillman RB, Schlafer DH.To evaluate embryo transfer as a possible method to circumvent infertility in mares, embryos from 14 normal and 14 infertile mares were collected three times and examined. Fewer flushes (p less than 0.05) from normal than infertile mares (1/42 vs 9/42) contained only abnormal embryos whereas more flushes (p less than 0.05) from normal than infertile mares contained one or more normal embryos (28/42 vs 8/42). More flushes (p less than 0.05) from normal than infertile mares contained embryos (29/42 vs 17/42). The embryo diameters (mm) at either day-7 or day-8 post ovulation were greater (p less ...
Loosely coupled skeletal muscle mitochondria in exertional rhabdomyolysis.
Equine veterinary journal    September 1, 1986   Volume 18, Issue 5 418-421 doi: 10.1111/j.2042-3306.1986.tb03673.x
Van den Hoven R, Breukink HJ, Wensing T, Meijer AE, Tigges AJ.No abstract available
A comparison of the efficiency of water and ethanol at removing formaldehyde from immersion fixed muscle tissues.
Anatomia, histologia, embryologia    September 1, 1986   Volume 15, Issue 3 269-276 doi: 10.1111/j.1439-0264.1986.tb00718.x
Rumph PF, Williams JC.No abstract available
Changes in serum muscle enzyme levels associated with training schedules and stage of the oestrous cycle in Thoroughbred racehorses.
Equine veterinary journal    September 1, 1986   Volume 18, Issue 5 371-374 doi: 10.1111/j.2042-3306.1986.tb03657.x
Frauenfelder HC, Rossdale PD, Ricketts SW, Allen WR.Blood samples were collected twice weekly over a nine month period from 24 Thoroughbred racehorses in training at Newmarket to study the effects of daily training schedules and stage of oestrous cycle on serum enzyme levels and clinical signs of equine exertional myopathy. The sampling period extended from November to July and was performed between 16:00 h and 18:00 h so as to be at least 6 h after exercise. Serum creatine kinase, aspartate aminotransferase and plasma progestogen concentrations were measured. All horses were subjected to a similar traditional training programme. The study demo...
Case of equine cryptorchidism resulting from persistence of the suspensory ligament of the gonad.
Equine veterinary journal    September 1, 1986   Volume 18, Issue 5 412-413 doi: 10.1111/j.2042-3306.1986.tb03670.x
Wilson DG, Nixon AJ.No abstract available
[The topography of the heart valves in horses, cattle and dogs].
Anatomia, histologia, embryologia    September 1, 1986   Volume 15, Issue 3 240-248 doi: 10.1111/j.1439-0264.1986.tb00715.x
Habermehl KH, Schmack KH.No abstract available
Laser Doppler flowmetry: muscular microcirculation in anaesthetized horses.
Equine veterinary journal    September 1, 1986   Volume 18, Issue 5 391-395 doi: 10.1111/j.2042-3306.1986.tb03663.x
Serteyn D, Mottart E, Michaux C, Micheels J, Philippart C, Lavergne L, Guillon C, Lamy M.Muscular microcirculation was studied in seven halothane anaesthetised horses in lateral recumbency using a laser Doppler flowmeter. A significant difference between the dependent and the uppermost triceps brachii was recorded. In the dependent muscles, microflow at first decreased and then increased up to the starting value. In the uppermost muscles, a significant rise of the microflow was measured.
Development of a homologous equine relaxin radioimmunoassay.
Endocrinology    September 1, 1986   Volume 119, Issue 3 1100-1104 doi: 10.1210/endo-119-3-1100
Stewart DR.Equine relaxin (eRlx) immunoactivity has previously been measured in the mare during pregnancy using the porcine relaxin (pRlx) RIA (pRlx-RIA). This was not the optimal system for measurement of eRlx because the dose-response curve obtained with equine plasma was not parallel to the pRlx standard curve. A homologous eRlx-RIA has been developed and used to measure relaxin immunoactivity during pregnancy and parturition in the mare. Highly purified eRlx was used for the generation of antiserum in rabbits, preparation of tracer, and as assay standards. A double antibody eRlx RIA (eRlx-RIA) was de...
Equine energetics. I. Relationship between body weight and energy requirements in horses.
Journal of animal science    September 1, 1986   Volume 63, Issue 3 815-821 doi: 10.2527/jas1986.633815x
Pagan JD, Hintz HF.Energy balance studies using indirect calorimetry were conducted with four mature equids ranging in weight from 125 to 856 kg. Each animal was fed three different levels of intake of the same diet. The amounts of digestible and metabolizable energy required for zero energy balance were determined by calculating regression equations for energy balance against energy intake. It was concluded that the maintenance requirements of equids vary linearly with body weight. No advantage was found for the use of weight for the comparison of equids within the range studied. The digestible energy (DE) requ...
Fracture toughness design in horse hoof keratin.
The Journal of experimental biology    September 1, 1986   Volume 125 29-47 doi: 10.1242/jeb.125.1.29
Bertram JE, Gosline JM.An engineering fracture mechanics approach was applied to the analysis of the fracture resistance of equine hoof-wall. The relationship between fracture toughness and the morphological organization of the keratin hoof tissue was investigated. Fracture toughness was evaluated using the J-integral analysis method which employs the compact tension test geometry. Tensile tests were also conducted to evaluate the effect of the morphological organization on the stress-strain behaviour. Hoof-wall has greatest fracture resistance for cracks running proximally, parallel to the tubular component of the ...
Equine energetics. II. Energy expenditure in horses during submaximal exercise.
Journal of animal science    September 1, 1986   Volume 63, Issue 3 822-830 doi: 10.2527/jas1986.633822x
Pagan JD, Hintz HF.Energy expenditure was measured in four geldings (433 to 520 kg) during submaximal exercise on a racetrack using a mobile open-circuit indirect respiration calorimeter. A total of 304 5-min measurements of O2 consumed and CO2 produced were taken. Measurements were made with and without riders. The amount of energy expended by the horses was exponentially related to speed and was proportional to the body weight of the riderless horse or the combined weight of the horse plus rider and tack. Total energy expended by the four horses walking, trotting, cantering was best described by the equation: ...
Active immunization of intact mares against gonadotropin-releasing hormone: differential effects on secretion of luteinizing hormone and follicle-stimulating hormone.
Biology of reproduction    September 1, 1986   Volume 35, Issue 2 347-352 doi: 10.1095/biolreprod35.2.347
Garza F, Thompson DL, French DD, Wiest JJ, St George RL, Ashley KB, Jones LS, Mitchell PS, McNeill DR.Five lighthorse mares were actively immunized against gonadotropin releasing hormone (GnRH) to determine the relative importance of this hypothalamic hormone in the secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Five mares immunized against the conjugation protein served as controls. Mares were initially immunized in November and received secondary immunizations 4 wk later, and then at 6-wk intervals until ovariectomy in June. All mares immunized against GnRH exhibited an increase (p less than 0.01) in the binding of tritiated GnRH by plasma, an indication that a...
Absorption of phenylbutazone from a paste formulation administered orally to the horse.
Research in veterinary science    September 1, 1986   Volume 41, Issue 2 200-206 
Lees P, Higgins AJ, Mawhinney IC, Reid DS.The absorption pattern of phenylbutazone was studied in five horses during administration of the drug in a paste formulation on days 1, 5, 8 and 12 of a 12-day dosing schedule. Since two or more plasma concentration peaks were usually obtained following each oral dose, it was concluded that phasic absorption was a particular feature of the oil:water formulation of the product. Possible causes of this unusual absorption pattern are discussed and the therapeutic implications of both phasic absorption and the recorded values of Cmax, tmax and AUC024 for phenylbutazone and its active metabolite ox...
Endocrinologic, hematologic, and heart rate changes in swimming horses.
American journal of veterinary research    September 1, 1986   Volume 47, Issue 9 2004-2006 
Garcia MC, Beech J.Two identical experiments, using Standardbred and Thoroughbred horses (experiment A, n = 31; experiment B, n = 17) on a swimming regimen, were performed 1 week apart to evaluate short-term heart rate, hematologic, and endocrinologic changes. Horses were placed in 4 categories based on duration of swimming (1 to 5, greater than 5 to 10, greater than 10 to 15, and greater than 15 minutes). Heart rate, PCV, and plasma concentrations of total protein, cortisol triiodothyronine, thyroxine, insulin, and glucose of each horse were evaluated before, immediately after, and 1 hour after swimming. For ex...
Purification and characterization of equine relaxin.
Endocrinology    September 1, 1986   Volume 119, Issue 3 1093-1099 doi: 10.1210/endo-119-3-1093
Stewart DR, Papkoff H.It has been previously determined that the equine placenta is the sole significant source of relaxin during pregnancy and that relaxin immunoactivity is also present in term placentas. Therefore, placentas obtained at the time of foaling were selected for starting material for purification of equine relaxin. Frozen whole placentas were ground and then extracted with 0.5 N HCl-85% acetone. Relaxin was precipitated by raising the acetone concentration to 97%. Equine relaxin was further purified by stepwise elution ion exchange, gel filtration, and gradient elution ion exchange chromatographies a...
A study of roles of evolutionarily invariant proline 30 and glycine 34 of cytochrome c.
The Journal of biological chemistry    August 25, 1986   Volume 261, Issue 24 10976-10989 
Poerio E, Parr GR, Taniuchi H.The previous studies (Juillerat, M. A., and Taniuchi, H. (1986) J. Biol. Chem. 261, 2697-2711), using a three-fragment complex (1-25)H X (28-38) X (39-104) of horse cytochrome c, have shown that invariant leucine 32 and partially invariant leucine 35, both buried in the interior, exhibit a striking difference in perturbation of binding fragment (28-38) by substitution with isoleucine. Then the idea has been proposed that the energy states of leucine 32, the Met-80-S-heme-Fe bond and other distant residues such as tryptophan 59 would be coupled to generate extra force while leucine 35 would be ...
[Determination of progesterone levels in the milk of mares: a useful aid in the diagnosis of early pregnancy].
Tijdschrift voor diergeneeskunde    August 15, 1986   Volume 111, Issue 15-16 739-740 
Borst GH, Berghuis GA, Counotte GH.The concentration of progesterone in milk was determined in 327 mares to establish pregnancy in an early stage (sixteen days or more). The 5 ng/ml-level of progesterone as a threshold in the EIA-system used resulted in a very useful aid in the diagnosis of early pregnancy in mares. The results of testing were not in accordance with the confirmed reality in fourteen out of 327 mares (4.3 percent). The result of the test was false non-pregnant in five mares (1.5 percent) and false pregnant in nine mares (2.8 percent).
How drugs act in the body.
The Veterinary record    August 9, 1986   Volume 119, Issue 6 132-135 doi: 10.1136/vr.119.6.132
Marriner SE.No abstract available
Evaluation of androgenized mares as an estrus detection aid.
Theriogenology    August 1, 1986   Volume 26, Issue 2 261-266 doi: 10.1016/0093-691x(86)90031-2
McDonnell SM, Garcia MC, Blanchard TL, Kenney RM.Ten pony mares that had developed stallion-like sexual behavior as the result of anabolic steroid treatment (boldenone undecylenate, 0.55 mg/kg intramuscularly (i.m.), once weekly for 12 injections) were evaluated for ability to aid in detecting estrus in cycling mares. In across-the-fence estrus detection trials, androgenized mares failed to elicit signs of estrus or diestrus. In 10-min pasture trials, in which each androgenized mare was placed in a group of 10 cycling mares (six of which were estrous), seven of the 10 androgenized mares elicited estrous behavior from one or two mares. Observ...
Behavior and viability of the premature neonatal foal after induced parturition.
American journal of veterinary research    August 1, 1986   Volume 47, Issue 8 1870-1873 
Leadon DP, Jeffcott LB, Rossdale PD.Parturition was induced in 2 groups of mares, less than 300 (n = 49) and 300 to 320 days gestation (n = 31), by the administration of prostaglandin F2 alpha or fluprostenol and oxytocin. Foals were categorized into 4 groups according to their ability to adapt in, and survive, the neonatal period. Group A had no demonstrable coordinating reflexes, were weak from birth, and all died within 90 minutes. Group B had some righting reflexes, but had poor coordination and a weak suck reflex. They showed some improvement for about 2 hours, but all died within 9 hours. Group C foals had a good suck refl...
The equine protease inhibitory system (Pi): abnormal expressions of PiF, PiL, and PiS1.
Biochemical genetics    August 1, 1986   Volume 24, Issue 7-8 529-543 doi: 10.1007/BF00504333
Patterson SD, Bell K.Three cases of abnormal expression of the equine protease inhibitory alleles, Pi F, L, and S1, were observed following the examination of 30,000 plasma samples by one-dimensional acid (pH 4.6) polyacrylamide gel electrophoresis. Characterization of the abnormal proteins in terms of isoelectric point, molecular mass, inhibitory spectra, and sialic acid content was performed using one- and two-dimensional electrophoretic techniques. The Pi F and S1 abnormalities were postulated to be the result of amino acid substitutions causing alterations in the processing of the carbohydrate side chains. No ...
Histochemical staining characteristics of normal horse skeletal muscle.
American journal of veterinary research    August 1, 1986   Volume 47, Issue 8 1843-1852 
Andrews FM, Spurgeon TL.The histologic and histochemical staining characteristics of the triceps brachii (long head), extensor carpi radialis, gluteus medius, vastus lateralis, biceps femoris, semimembranosus, semitendinosus, and extensor digitorum longus muscles of 8 Thoroughbreds, 2 Quarter Horses, 1 Arabian, 1 Paso Fino, and 1 Shetland Pony are described. Muscle fiber morphology, staining distribution and intensity, amount of IM connective tissue, number of IM blood vessels and IM nerves, calcium-activated adenosine triphosphatase activity (CaATPase), percentage of fibertype population, percentage of relative fibe...
Pharmacokinetic disposition of dimethyl sulfoxide administered intravenously to horses.
American journal of veterinary research    August 1, 1986   Volume 47, Issue 8 1739-1743 
Blythe LL, Craig AM, Christensen JM, Appell LH, Slizeski ML.Dimethyl sulfoxide (DMSO) was administered IV to 6 Thoroughbred horses at 2 dosages: 1.0 g/kg and 0.1 g/kg. The pharmacokinetics seemed linear, with biological half-lives of 8.6 +/- 0.3 hours and 9.8 +/- 2.2 hours for the 1.0 g/kg and 0.1 g/kg dosages, respectively. This was further substantiated by mean residence times of 9.8 +/- 0.44 hours and 13.8 +/- 4.25 hours, areas under the curve of 12.55 +/- 1.42 mg/ml/hr and 1.63 +/- 0.49 mg/ml/hr, and the clearances of 0.081 +/- 0.009 L/kg/hr and 0.066 +/- 0.022 L/kg/hr for the large and small dosages, respectively. At 12 hours after 1.0 g/kg was ad...
A quantitative study of Sertoli cell and germ cell populations as related to sexual development and aging in the stallion.
Biology of reproduction    August 1, 1986   Volume 35, Issue 1 138-148 doi: 10.1095/biolreprod35.1.138
Jones LS, Berndtson WE.Testes from 47 stallions, 1-20 yr of age, were used to examine the influence of age on Sertoli and germ cell populations as well as on functional activity of Sertoli cells. For these stallions, the number of Sertoli cells per paired testes declined linearly with age, and was only 41.7% as great at age 20 as at age 2. However, development of reproductive organs proceeded until age 12-13, as evident from increases in paired testes weight and quantitative rates of spermatozoal production. Although the absolute number of Sertoli cells declined during this period of development, individual Sertoli ...
Equine arteritis virus-induced polypeptide synthesis.
The Journal of general virology    August 1, 1986   Volume 67 ( Pt 8) 1543-1549 doi: 10.1099/0022-1317-67-8-1543
van Berlo MF, Rottier PJ, Spaan WJ, Horzinek MC.Intracellular virus-specific proteins induced by equine arteritis virus (EAV) have been compared with in vitro translation products of virion and intracellular EAV RNAs. In infected BHK-21 cells, the two major virion proteins (C and E1) and polypeptides with mol. wt. of 60,000 (p60), 42,000 (p42) and 30,000 (p30) were found. There were no indications that the viral proteins were processed from a larger precursor as shown by pulse-chase, amino acid analogue and protease inhibitor experiments. The six polyadenylated RNAs that occur in EAV-infected cells were isolated and translated in an mRNA-de...
Normal motility of the cecum and right ventral colon in ponies.
American journal of veterinary research    August 1, 1986   Volume 47, Issue 8 1756-1762 
Ross MW, Donawick WJ, Sellers AF, Lowe JE.To study the normal motility of the cecum and right ventral colon (RVC) in 3 mature Shetland ponies, a 6-part, indwelling, intraluminal catheter system was used to measure intraluminal pressure changes. Three catheters were placed in the cecum at 10, 25, and 40 cm from the cecocolic orifice, and 3 catheters were placed in the RVC at 10, 20, and 30 cm from the cecocolic orifice. Recordings were made during the interdigestive period beginning 2 weeks after surgical operation was done. Frequent, low-amplitude peaks (0.35 +/- 0.13 coordinated peaks/min) were seen involving the cecal body and cauda...
Gastroenterology.
Equine veterinary journal    July 1, 1986   Volume 18, Issue 4 243-343 
No abstract available
Pi granules and related intracytoplasmic inclusions in equine Schwann cells.
Veterinary pathology    July 1, 1986   Volume 23, Issue 4 514-518 doi: 10.1177/030098588602300425
Force L, Jortner BS, Scarrat K.Suchwann cells from a variety of nerves in two adult horses and one adult pony contained perinuclear intracytoplasmic inclusion complexes consisting of lipid droplets, variably electron-dense rounded to elongated bodies and rod-shaped multilamellar structures. The latter were characteristic of pi granules of Reich. There were no significant axonal or myelin alterations associated with these inclusions. It was concluded that the inclusions are a component of normal equine Schwann cells.