Nutrition in horses encompasses the study of dietary requirements and feeding practices that support equine health, growth, and performance. It involves the analysis of nutrients such as carbohydrates, proteins, fats, vitamins, and minerals, and their roles in equine physiology. Proper nutrition is essential for maintaining optimal body condition, supporting metabolic processes, and preventing dietary-related disorders. Research in this field examines the nutritional needs of horses at different life stages and activity levels, as well as the effects of various feed types and supplements. This page compiles peer-reviewed research studies and scholarly articles that explore the composition, digestion, and impact of different dietary components on equine health and performance.
Rose RJ, Kohnke JR, Baggot JD.Plasma phenylbutazone concentrations were determined for up to 12 h in 6 horses following intravenous and oral phenylbutazone administration. To evaluate the bioavailability of different oral preparations, phenylbutazone was administered in a paste as well as the traditional powder form. The effect of the state of stomach contents on the absorption of phenylbutazone was investigated by administering the paste before and after feeding; the powder was given in a small bran mash and a full feed of lucerne chaff, wheaten chaff and bran. Despite great variability among individual horses both the pa...
Ford EJ, Evans J.1. Total entry, irreversible loss and recycling rates of glucose were measured in four non-pregnant female Shetland ponies before and after a 24 h fast by the continuous intravenous infusion of a mixture of [U-14C]glucose and [2-3H]glucose. 2. The post-fasting fall in the concentration of glucose and the rise in the concentration of ketones in plasma were not significant. 3. After fasting the total entry rate fell from 1.44 +/- 0.11 (n4) to 1.19 +/- 0.12 mg/min per kg body-weight (P less than 0.01) and irreversible loss fell from 1.36 +/- 0.10 (n4) to 1.05 +/- 0.10 mg/min per kg body-weight (P...
Luther DG, Cox HU, Dimopoullos GT.Fatty acid composition of erythrocytes of healthy horses was determined. Three fatty acids (C16:0, C18:0, and C18:1) were found in approximately equal quantities and comprised 72.17% of the total. Nine other fatty acids were found in small amounts. Saturated fatty acids constituted 67.2% of the total. Marked variation was demonstrated in the occurrence and distribution of fatty acids in the sterol ester, triglyceride, phospholipid, and free fatty acid fractions.
Ralston SL, Baile CA.The hypothesis that changes in blood glucose concentrations and(or) utilization rate affect feeding behavior in ponies was tested. Ponies (n = 4) were fasted for 4 h, then given iv injections of 50% glucose [.2 g glucose/BW.75 kg (low dose, LD) or 1.0 g glucose/BW.75 kg (high dose, HD)] or an equal volume of normal saline (HDS; LDS) 5 min before being allowed access to pelleted feed. Blood samples were drawn at regular intervals pre- and post-treatment and analyzed for plasma glucose (PG), immunoreactive insulin (IRI) and glucagon concentrations. All glucose-treated animals immediately ate mea...
Parodi PW.Milk triglycerides from the echidna, koala, Tammar wallaby, guinea pig, dog, cat, Weddell seal, horse, pig and cow were subjected to fatty acid and stereospecific analysis to determine the positional distribution of the fatty acids in the triglycerides. The samples presented a wide range of fatty acids, most of which varied in content among species. The compositions of the acids at the 3 positions also varied among species, reflecting the content of these acids in the triglycerides. However, there was a general similarity in fatty acid positional distribution patterns for all the species with ...
Gronwall R, Engelking LR.The effects of several treatments and their routes of administration on the reduction of hyperbilirubinemia in 9 pony mares after a 3-day fast were studied. Treatments were as follows: glucose given at doses of 1.2, 2.4, and 3.7 mg/min/kg of body weight; refeeding the base-line diet; feeding straw; and IV administration of taurocholic acid at a dosage of 0.07 mumol/min/kg. The 3 glucose dosages were each given by 3 different routes: IV, intraduodenal, and intragastric. The smallest dosage of glucose given by IV route reduced the plasma bilirubin concentration only 7%, even though other measure...
Meijer P.Two cases of tetany in the horse are reported. The two patients were thoroughbreds. One was eight and the other thirteen years old. The mares were in heat and were brought to the service (stud) station to be mated. Both patients were nursing a foal. One was a four-week-old foal and the other was seven weeks old. The calcium level of the serum had dropped in the two patients, to 4.0 mg and 5.4 per ml. respectively. The magnesium level was 1.0 mg and 1.9 mg per 100 ml. respectively. The animals responded satisfactorily to intravenous infusion of calcium borogluconate and magnesium chloride. One ...
Jacobs KA, Bolton JR.The effect of altering the diet during the week preceding the administration of an oral glucose tolerance test was studied in 7 horses. The results indicated that substantially lower oral glucose tolerance test curves are observed in horses fed a stable diet comprised of oat hay, a commercially prepared complete feed, and oat and alfalfa chaff, when compared with the curves for horses grazing clover and kikuyu pasture. It was concluded that, in utilizing the oral glucose tolerance test to assess small intestinal function in the horse, it may be necessary to consider the dietary history.
Harrington DD.Acute accidental vitamin D2 (ergocalciferol) toxicosis was diagnosed in a 6-month-old foal with extensive lesions of soft tissue mineralization. In an experimental study, three 18-month-old horses were given ergocalciferol per os at a rate of 9,300, 22,200, or 47,200 IU/kg of body weight/day for 21 days. Clinical signs or lesions were not seen in horses given the low and intermediate doses, whereas the horse receiving the highest dose developed clinical signs and lesions similar to those noted in the foal. Signs included depression, loss of appetite, weakness, limb stiffness with impaired mobi...
Canning JF.Bile flow, during feeding and fasting, was studied in three ponies in which catheters, maintained in the bile duct over 1-2 months, drained all bile continuously. During experiments bile was returned to the small intestine, via a second catheter, by means of a small pump which also measured bile flow rates. The mean +/- S.E. of the mean rate of bile flow in fed ponies with an intact enterohepatic circulation of bile salts was 1.33 +/- 0.10 ml/kg . h, n = 13; mean +/- S.E. of the mean concentration of bilirubin in bile was 10.82 +/- 0.91 mg/dl, n = 13. The effect on bile flow and bilirubin excr...
Caple IW, Bourke JM, Ellis PG.The calcium and phosphorus nutrition of thoroughbred racehorses was assessed by analysis of serum and urine samples collected from 90 horses in 1975 and 139 horses in 1980-81 at racetracks in Melbourne. Horses that were excreting greater than 15 mumole Ca/mosmole and which had a calcium to creatinine clearance ratio greater tha 2.5% were considered to have adequate Ca intake. Horses that were excreting greater than 15 mumole P/mosmole and which had a phosphorus to creatinine clearance ratio greater than 4% were considered to have excessive phosphorus intake. Sixty-percent of the horses sampled...
Blackmore DJ, Campbell C, Dant C, Holden JE, Kent JE.The activity of glutathione peroxidase (GSH-Px) was measured in the erythrocytes of 600 Thoroughbred horses in training; the selenium concentrations in whole blood and serum was measured in over 80 of these Thoroughbreds. A quadratic relationship was demonstrated between erythrocyte GSH-Px and whole blood or serum selenium concentration. There was no significant difference in the activity of aspartate aminotransferase, creatine kinase, or gamma-glutamyl transferase in the serum of Thoroughbreds with high erythrocyte GSH-Px activity (more than 25 u/ml) when compared with those with low erythroc...
Caple IW, Doake PA, Ellis PG.Studied were made to determine if a practical assessment of the calcium and phosphorus nutrition of horses could be obtained from an analysis of urine samples. The concentrations of Ca and P in urine samples changed markedly when groups of 4 mares were fed diets containing from 1.0 to 3.9 g Ca/kg and from 1.5 to 6.1 g P/kg, but serum concentrations of Ca and P remained relatively constant. The concentrations in single urine samples were considered unreliable indicators of excretion of the minerals because of variations in water excretion, and two methods to overcome this problem were examined....
Orlov VK, Servetnik-Chalaia GK.Physicochemical properties of fat and fatty-acid composition of mare's milk and shubath (sour milk product obtained from camel's milk) depend on the season. During summer these products show a higher content of fat and increased level of polyunsaturated fatty acids, particularly in mare's milk lipids. It has been shown that in mare's milk lipids 90% is due to acids with a carbon chain of C14-18, while shubath lipids contain almost 96% of such acids.
Udén P, Van Soest PJ.1. The abilities of cattle, sheep, goats, equines and rabbits to digest mature timothy (Phleum pratense) hay were compared. Apparent digestibilities were partitioned into true digestibility, metabolic faecal output (MFO) and fibre digestibility. The aid of the study was to determine the relative effects of fermentation site (among groups) and of body-weight (within groups) on the efficiency of digestion. 2. The ruminants were superior to equines, which were in turn superior to rabbits, in digesting fibre-components of the hay. A large individual variation in digestibility was noted only for th...
Rose RJ, Sampson D.Total and individual non-esterified fatty acids (NEFA), pyruvate, lactate, alpha ketoglutarate, acetoacetate, beta hydroxybutyrate, glucose and insulin were measured in horses during an 80 km endurance ride and during four days of food deprivation. In the latter group venous blood-gas and acid-base parameters, and plasma cortisol concentrations were also measured. During exercise and food deprivation the NEFA became considerably elevated, the predominant of which were oleic (35 per cent), palmitic (24 per cent), linoleic (19 per cent) and linolenic (10 per cent). By one hour after feeding tota...
Sklan D, Donoghue S.1. Serum and intracellular distribution of retinol was determined in equines maintained on four levels of vitamin A intake. 2. The form of retinol transported in serum was determined by gel filtration and chromatography to be a complex of retinol bound to a protein of molecular weight (MW) of approximately 20000, which was in turn complexed probably with prealbumin to yield a complex with a MW of 75000 to 80000. 3. Increasing dietary vitamin A levels enhanced the concentration of lipoprotein-bound retinyl esters in the plasma. 4. Vitamin A in the liver cytosol was found predominantly as retiny...
Gibbs PG, Potter GD, Blake RW, McMullan WC.Milk production was measured in fourteen Quarter Horse mares at seven stages of a 150-d lactation period. Mares were divided into two groups of seven and fed diets containing either soybean meal or soybean meal and urea as nitrogen supplements. Rations were isocaloric, contained approximately 12.5% crude protein and were fortified with vitamins and minerals. Daily milk yield was estimated by the weigh-suckle-weigh method and milk composition was determined from samples taken by hand milking. Average daily milk yield ranged from 11.8 kg in early lactation to 9.8 kg in late lactation. Difference...
Gunson DE, Kowalczyk DF, Shoop CR, Ramberg CF.Several suspect causes of chronic zinc/cadmium toxicosis in horses near a zinc smelter were investigated following observations of lameness, swollen joints, and unthriftiness, particularly in foals. Two foals born and raised near the smelter were lame and had joint swellings that were attributable to severe generalized osteochondrosis. Zinc and cadmium concentrations were markedly increased in the pancreas, liver, and kidney. The serum of 1 foal, zinc and potassium concentrations were high, whereas calcium and magnesium concentrations were low. Marked nephrocalcinosis and osteoporosis were obs...
Stowe HD.The effects of 0.2, 0.4, 0.6, 0.8, 1.0 and 1.2% potassium, as K2CO3, in a purified diet were studied in orphaned foals of mixed breeding ranging in age from 11 to 57 days. Observations regarding feed intake, rate of gain, packed cell volume (PCV), erythrocyte counts (RBC), hemoglobin (Hb), leukocyte counts (WBC), and serum Na, K and Fe were made. Consumption of the 0.2% K diet after 8 days was inadequate to support growth. The foals consumed the 1.0 and 1.2% K diet at significantly higher rates (28.8 and 27.5 g/kg foal per day, respectively) than the 0.4% K diet. Rates of gain of foals fed 0.4...
Hallebeek AJ, Sloet van Oldruitenborgh-Oosterbaan MM.Small bumps or swellings of about 0.5 mm in diameter in the skin of horses are called 'haverbultjes' in the Netherlands. Comparable skin diseases described in the literature are 'sweet feed-, protein- and heat bumps'. The differential diagnosis and the possible nutritional causes of 'haverbultjes' are presented.
St Lawrence AC, Lawrence LM, Coleman RJ.Many studies have examined the effect of pre-exercise feeding on glucose and insulin responses of horses. The objective of this study was to determine whether exercise performed one hour prior to a meal would attenuate the glucose and insulin responses to a meal. Data collected from 8 mature geldings in a 2 period crossover design experiment were used to determine the postprandial glucose and insulin responses to a meal of oats offered 1 h postexercise. During each period, 4 horses received a test meal following a 14 h fast (NoEx) or a 14 h fast and exercise bout (PostEx) that consisted of 48 ...
Reitnour CM.Utilisation of nitrogen was studied in 4 crossbred ponies. A latin square design was used to study the effects of corn gluten meal, casein or urea when added to a low protein basal diet. Apparent nitrogen digestion, nitrogen retention, total plasma protein, plasma urea and plasma-free amino acids were measured. The addition of corn gluten meal, casein or urea to the basal ration increased apparent digestion of nitrogen. Casein produced a significantly greater (P less than 0.05) nitrogen retention than corn gluten meal or urea. Plasma urea nitrogen increased significantly (P less than 0.01) in ...
McKenzie EC, Firshman AM.Chronic exertional rhabdomyolysis represents a syndrome of recurrent exercise-associated muscle damage in horses that arises from a variety of etiologies. Major advances have been made in the understanding of the pathophysiology of this disease, and causative genetic defects have been recently identified for two conditions-polysaccharide storage myopathy of quarter horses, paints, warm bloods, and draft breeds. Dietary management in combination with a regular exercise regimen comprises the most effective means for control of clinical signs.
Jollès J, Donda A, Amiguet P, Jollès P.Mare lactotransferrin has been purified and analyzed. Its molecular mass is 81 kDa. A 28 amino acid long N-terminal sequence was established and a first series of comparisons with other transferrins was performed.
McClure JM.This article provides an overview of general health care management procedures commonly dealt with by racetrack practitioners. Although some of the conditions discussed are similar to those observed in a non-racetrack practice, the manner in which they are approached usually varies because of the unique circumstances encountered in the racetrack setting.
Oikawa M, Kaneko M, Yoshikawa T.To elucidate the pathomorphogenesis of extremely shortened small-intestinal villi, occurring spontaneously in neonatal foals, the morphology of the small intestine with stunted villi was studied in eight cases. All intestinal wall elements and the villi were poorly developed. Most villi were found to be extremely short throughout the entire length of the small intestine. The villous core consisted of undifferentiated, fibroblast-like cells held loosely together by ground substance which was rich in glycosaminoglycan. Development of the villous lamina propria was poor with respect to capillarie...
Laan TT, Spoorenberg JF, van der Kolk JH.Intake of Rumex, a plant genus of the Polygonaceae family, probably led through the assimilation of oxalic acid, to hypocalcaemia in a four-week old foal. This foal was presented with muscle rigidity and a stiff gait. Both the total and ionized calcium concentrations were low, 1.38 mmol/l and 0.54 mmol/l respectively. The foal was treated with a total of 150 ml of a 20% calcium solution IV. The foals neuromuscular signs resolved within a few hours after receiving calcium solution.
Argenzio RA, Hintz HF.Factors affecting glucose tolerance and the effect of volatile fatty acids on plasma glucose were studied with five ponies in two 5×5 latin square trials. The treatments were equimolar infusions of glucose, acetate, propionate, butyrate and isontonic saline in fed or fasted ponies.
Animals fasted for 72 hr. exhibited a markedly lower glucose tolerance than those fed ad libitum. Propionate appeared to be the only VFA stimulating a significant glucose response in the fasted animals, but no response was noted in the fed animals. The data suggest that length of fast is an important variable in...
Drews B, Milojevic V, Robles M, Wimel L, Dubois C, Rudolf Vegas A, Giller K, Chavatte-Palmer P, Daniel H, Giesbertz P, Bruckmaier RM, Ulbrich SE.Female mammalian reproductive functions are closely linked to body condition and metabolic status. Energy homeostasis is regulated by endocrine hormones such as insulin, IGF-I, leptin, and adiponectin via the hypothalamic-pituitary-adrenal axis. These metabolic hormones and their receptors are also expressed in reproductive tissues and the embryo. We investigated the relationship between circulating leptin and the fatty acid (FA) and amino acid (AA) composition of the equine uterine fluid (UF) and peripheral blood plasma (BP) by using a mass spectrometry-based approach. UF and BP were collecte...
Clayton HM, Duncan JL, Dargie JD.The mechanisms involved in the pathophysiological disturbances associated with the presence of mature Parascaris equorum in the small intestine were investigated with radioisotopic techniques. The results suggested that, compared with worm-free controls, infected foals had a reduction in gut motility, an increase in the body solids ratio, a lowering of the body pool of albumin and a decreased ability to incorporate dietary methionine into plasma protein.
Foster CV, Harris RC, Pouret EJ.After an oral dose of 10 g of L-carnitine the plasma concentrations of free and total carnitine increased in five yearling thoroughbred horses, reaching a peak two to four hours after administration, but in two horses there was no increase. In the five which responded, the mean (+/- sd) peak increase in total carnitine concentration was 15.1 +/- 6.9 mumol/litre from a predose mean of 18.8 +/- 3.4 mumol/litre, and the mean peak increase in free carnitine concentration was 13.5 +/- 3.1 mumol/litre from a pre-dose mean concentration of 12.5 +/- 2.2 mumol/litre. These changes were similar to those...
Henneman K.Addressing poor performance issues in horses is a common yet challenging request to veterinarians. Often, there are limited field diagnostic or therapy choices. Growing lay popularity in integrative therapies, as well as increasing clinical incorporation, is creating more awareness of their clinical applications. Many modalities are showing increasing evidence of positive outcomes with minimal harm, but additional safety and efficacy evaluation is needed. Integrative modalities have unique ways of perceiving disease patterns that are different from more modern approaches, and these different p...
Bertone AL, Ralston SL, Stashak TS.Each of 3 digestion trials (3 forage diets) was performed on 2 groups of horses 6 to 12 months after sham operation (group 1; n = 3) or large-colon resection (group 2; n = 5). Diets were alfalfa pellets, alfalfa hay, and grass hay. Feed and fecal analyses were performed to determine apparent digestion of dry matter, organic matter, and crude protein and true digestion of dry matter, organic matter, crude protein, total plant cell wall, hemicellulose, cellulose, and lignin. Additional fecal and metabolic variables determined were percentage of fecal water, total fecal water, metabolic organic m...
Orsini JA.The multiple topics summarized in this article and discussed in detail in this issue of VCNA are comprehensive and in-depth, exploring concepts and clinical experiences for state-of-the-art care of the equine foot. The research on the equine foot will translate to the clinical setting and with this the compassionate care of the horse.
Respondek F, Lallemand A, Julliand V, Bonnaire Y.Presence of drugs is completely prohibited in post racing urine samples by most of racing and competition authorities, even if environmental contamination might occur. Objective: To assess the daily dose of several contaminants absorbed through the diet that would result in detectable concentrations in urine. Methods: Caffeine, theobromine, theophylline, atropine, scopolamine, bufotenine, DMT or morphine were administered orally to 6 horses, in different dosages, for 3 days before their urine was sampled for regular anti-doping tests. Results: Theobromine, theophylline, bufotenine and morphine...
Hansen TO, White NA, Kemp DT.Total parenteral nutrition was accomplished in 4 healthy adult horses. During the 10-day study, the horses were not permitted to ingest food or water. Body weight was maintained at 94% of initial values without clinical evidence of dehydration. Serum urea nitrogen and triacylglycerol concentrations decreased during the study, without other significant hematologic or biochemical changes. Horses adapted without problems to the routine of IV feeding and confinement. All horses were healthy at the conclusion of the study. It was concluded that intravenous feeding with a lipid-glucose-amino acid-el...
van den Boom R, Driessen F, Streumer SJ, Sloet van Oldruitenborgh-Oosterbaan MM.Insect bite hypersensitivity (IBH) is most often caused by Culicoides spp., although other insect species are also thought to play a role in causing this disease. The disease has been reported to occur in most countries, with a prevalence of up to 28% in some countries in some breeds. The only truly effective therapy currently available is to prevent horses from coming into contact with Culicoides midges, which can be achieved by stabling horses during certain times of the day or by covering them with insect blankets. The effect of a new dietary supplement containing vitamins, polypeptides, an...
van Dyk E, Neser S.The possible spread by horse faeces of plants that may become weeds in sensitive areas was investigated. It was found that the period 24-48 hours after ingestion of seeds included in rations was the retention time for seeds passing through the digestive system of the horse. The ability of seeds to germinate was not influenced by exposure to digestive fluids or sea-water. A feeding regime of compound feeds is suggested.
Lacombe VA, Hinchcliff KW, Kohn CW, Reed SM, Taylor LE.Exercise depletes muscle glycogen stores, which could subsequently impair performance. Muscle glycogen replenishment is determined by substrate availability. Objective: To study the effects of feeding meals of varying glycaemic responses on blood concentrations of substrates used for glycogenesis in horses with exercise-induced glycogen depletion. Methods: In a 3-way crossover study, 7 horses received each of 3 isocaloric diets for 72 h after undergoing glycogen-depleting exercise: 1) a high soluble-carbohydrate diet, which induced a high-glycaemic (HGI) response; 2 and 3) a low soluble-carboh...
Prado Silva RH, Carneiro de Rezende AS, Ferreira WM, Bastianetto E, Mello MM, Pereira de Abreu A, Farinelli F, Colares de Araújo Moreira D....Weanlings undergo rapid body development in the first year of life and, in this period, are more susceptible to helminth infection that can impair their growth. The objective of this study was to compare the apparent digestibility of nutrients, blood parameters, and body development of deworming and not deworming weanlings. Fourteen Mangalarga Marchador weanling colts, on a farm in Northern Minas Gerais, Brazil, were divided into two groups: dewormed (D) and not dewormed (ND) groups. The weanlings were kept separately for 3 months in two pastures of Cynodon nlemfuensis cv. African Star Grass....
Bampidis V, Azimonti G, de Lourdes Bastos M, Christensen H, Dusemund B, Kouba M, Kos Durjava M, López-Alonso M, López Puente S, Marcon F, Mayo B....Yea-Sacc is an additive based on a live preparation of a strain of intended for use as a zootechnical additive (digestibility enhancer). The current assessment is performed in the context of the renewal of the authorisation of the feed additive; however, the applicant proposed also to lower (6.5 × 10 colony forming unit (CFU)/kg of complete feedingstuff) the minimum dose of the additive when used in feed for horses. The additive is produced in a powder (Yea-Sacc) and in a prills (Yea-Sacc_TS) forms. The Panel considered that the additive currently on the market complies with the existing ...
Mastellar SL, Barnes T, Cybulak K, Urschel KL.This study determined splanchnic extraction of phenylalanine at two intakes of threonine. Six Thoroughbred mares were supplemented with isonitrogenous amounts of either threonine or glutamate. Dietary threonine intakes were 119 (+Thr) and 58 (Basal) mg/kg/day, respectively. Each horse received each diet twice and each was studied once with an oral and once with an intravenous (IV) infusion of [1-(13)C]phenylalanine. A 2-h primed, constant IV infusion of [(13)C]sodium bicarbonate and a 4-h primed, constant infusion of [1-(13)C]phenylalanine, either orally or IV, were used to measure isotopic en...
Bischoff K, Moiseff J.Feed as a cause of poisoning in horses can occur on small or large scales. It is challenging to work up cases of suspected feed contamination, but there are resources available to veterinarians and owners. Feed contamination can be chemical or biological. This article focuses on and provides examples of chemical feed contamination including misformulation, adulteration, and natural contaminants. Additionally, recommendations for feed sampling and diagnostic submission, including legal documentation, are included.
O'Connor CI, Nielsen BD, Schott HC, Clayton HM.Weight training is commonly used by human athletes to increase strength and fitness. This study was performed to examine the effect of weight-carrying and nutritional supplementation on muscle development and growth in young horses. This study examined the effect of weight-carrying and nutritional supplementation on muscle development and growth. Seventeen horses were divided into 3 groups: controls exercised in a free-flow exerciser, a weight group that performed the same exercise, carrying progressively increasing weight up to 45 kg, and a weight-supplement group, that also received a myo-an...
Silva CA, Merkt H, Bergamo PN, Barros SS, Barros CS, Santos MN, Hoppen HO, Heidemann P, Meyer H.Excessive iodine supply of at least 700 mg inorganic iodine in foals and of more than 350 mg iodine in pregnant and lactating mares cause a high incidence of goitres in the newborn and disorders in the long leg bones of foals. Elevated phosphorus and alkaline phosphatase content in the blood may indicate a severe disturbance in the bone metabolism. Of 39 pregnant mares 17 aborted and some of the mares also showed goitres. After withdrawal of the iodine supply normalization took place. Foals born more than 6 weeks later showed normal conditions. The goitres in the mares and the high blood level...