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.
Cymbaluk NF, Schryver HF, Hintz HF.The effects of copper intake on stable copper and 64Cu metabolism and on the excretory pathways of absorbed copper were examined in ponies. Bile and feces collected from two bile duct-cannulated ponies following an intravenous dose of 64Cu showed that bile was the main route of endogenous copper excretion. Stable copper and 64Cu metabolism were examined in three intact ponies fed dietary copper to provide 5.6, 16.6 and 25.7 mg Cu/100 kg body weight/day. The amount of copper excreted in urine was not influenced by dietary treatment. Stable copper absorption and 64Cu retention significantly incr...
Luther DG, Cox HU, Dimopoullos GT.Fatty acid composition of plasma lipids of normal horses was determined. Four fatty acids (C16:0, C18:0, C18:1, and C18:2) comprised 86.73% of the total, with C18:2 comprising 44.04% of the total. Eight other fatty acids were found in small amounts. Unsaturated fatty acids constituted 66% of the total. Marked variation was demonstrated in fatty acid occurrence and distribution in the sterol ester, triglyceride, phospholipid, and free fatty acid fractions.
Doreau M, Martin-Rosset W, Barlet JP.In an experiment comparing pregnant then lactating mares with dry non-pregnant mares, the changes in plasma components were studied as indicators of the metabolic utilization of energy (glucose, non-esterified fatty acids, beta-hydroxybutyrate), nitrogen (urea, proteins) or minerals (calcium, phosphorus, magnesium). The mares were fed daily 2 kg concentrate and hay ad libitum. Beta-hydroxybutyrate, magnesium and to a lesser extent glucose were the only constituents whose levels were affected within the period starting one month before and ending one month after foaling. The increase in food in...
Cymbaluk NF, Schryver HF, Hintz HF, Smith DF, Lowe JE.The effects of molybdenum ingestion on copper metabolism were investigated in bile duct-cannulated ponies fed diets containing 1.01, 27.4 and 107.3 ppm molybdenum. Copper metabolism was assessed by examination of 64Cu and stable copper excretion in feces, bile and urine. The addition of molybdenum to the diet decreased copper absorption and retention as a consequence of increased excretion of dietary copper in feces and increased excretion of absorbed copper in bile. Only 5% or less of the absorbed copper was excreted in urine regardless of dietary treatment. Biliary molybdenum excretion was o...
Rose RJ.In this article a physiological approach to fluid therapy is discussed, commencing with examination of fluid distribution in the normal horse. The functions of individual plasma electrolyte concentrations are considered and practical causes of acid-base disturbances discussed. When fluid administration is necessary, selection of the route for fluid administration as well as the type of fluid are important considerations and these must be adjusted to the needs of the individual case. Balanced polyionic solutions appear to be most suitable for general use because normal saline can produce hypoka...
Hambleton PL, Slade LM, Hamar DW, Kienholz EW, Lewis LD.Four isocaloric diets containing 4, 8, 12 and 16% dietary fat (as soybean oil) were fed to four horses at four intervals according to a Latin square design. After 3 weeks of conditioning at each interval, diet effects were evaluated by trotting all horses at 3.2 m/sec for 6 hours. Pre- and posttrotting responses were measured in muscle and liver glycogen, serum long-chain fatty acids, serum electrolytes, serum enzymes, serum cholesterol, plasma glucose, packed cell volume and hemoglobin. Dietary fat was highly correlated with exercise-induced plasma glucose changes and with cholesterol concent...
Bryans JT.The immunogenic potency and safety of a chemically inactivated equine herpesvirus 1 vaccine with added adjuvant was evaluated by testing serum-neutralizing and complement-fixation antibody responses of pregnant Thoroughbred mares. The vaccinated population comprised 321 pregnant mares on 7 farms; 3 in Normandy, France; 1 in Kildare, Ireland; and 3 in central Kentucky. The pattern of antibody response to vaccination was found qualitatively and quantitatively similar to that of pregnant mares previously vaccinated and determined by challenge exposure to be immune to abortigenic infection under e...
Gulick BA, Liu IK, Qualls CW, Gribble DH, Rogers QR.Plasma amino acid patterns were studied in 6 clinically normal adult horses during the course of hepatic disease induced by feeding them plants containing pyrrolizidine alkaloids. At death, there were significant (P less than 0.01) increases in glutamine, proline, tyrosine, asparagine, lysine, histidine, alanine, phenylalanine, methionine, aspartic acid, and ornithine values. There were no significant changes in glycine, valine, isoleucine tryptophan, and arginine values. There were significant (P less than 0.01) decreases in citrulline. Ammonia increased 4-fold. Alpha-Aminoadipic acid and alp...
Schryver HF, Hintz HF, Lowe JE.Absorption excretion and tissue distribution of stable Zn and 65Zn in mature ponies were studied in three experiments. In the first experiment, the metabolism of stable, dietary Zn and intravenously administered 65Zn was studied in three ponies in a 3 X 3 Latin square design. The ponies were fed a corn and beet pulp diet containing 35 mg Zn/kg or the same diet with 250 or 520 mg of supplemental Zn as ZnO. The ponies absorbed and retained more stable Zn when fed 250 mg of supplemental Zn that when fed the basal diet alone or the basal diet plus 520 mg of supplemental Zn. The ponies retained mor...
Archer M.The pasture needs for horses as compared to those for farm livestock are reviewed. The differing preferences of various types of grasses and other plants, and the patterns of grazing seen on"horse-sick" pastures, are discussed. Suggestions for practical management include frequent collection and removal of droppings, the use of grazing by cattle, adequate rest from horses and the application of cattle manure. Methods for controlling weeds and renovating horse-sick paddocks are discussed and compared to ploughing up. Finally, the place of fertilisers is considered for use on pastures for horses...
Maylin GA, Rubin DS, Lein DH.A survey of selenium and vitamin E concentrations in horses was conducted at four breeding farms in New York. There were no significant changes in mean blood selenium concentrations in horses at the three sampling dates whereas vitamin E concentrations underwent seasonal fluctuations. The mean blood selenium concentration in this survey for horses fed local feed was 7.7 microgram/dl. Horses fed commercial feed had a mean blood selenium concentration of 15.6 microgram/dl. A 0.94 correlation coefficient was found between blood glutatione peroxidase activity and blood selenium concentrations in h...
Franken P, van Beukelen P, Blok G.Two horses became ill, and one died, after being fed onions, presumably over a long period. Their intake of grass was low at the time of illness because the pasture was covered with snow. Examination of blood and urine revealed signs of severe haemolytic anaemia.
Arnbjerg J.With reference to previous reports on hypocalcemia in horses special attention is given to the principal symptoms such as anxiety, increased muscular tension, esp. of the musculature of the extremities, in severe cases leading to ataxia, and to a pulse-synchronized respiration (Synchronous Diaphragmatic Flutter). The time of appearance of the symptoms are much more variable than it is the case for hypocalcemic agalactia in cows. Furthermore the condition has been reported in foals as well as in geldings. Thus the triggering factor seems to be somewhat different from that of agalactia. Hypocalc...
Aho R.Hairsamples of domestic and laboratory animals suspected of dermatophytosis were examined for the presence of dermatophytes. A nutritionally poor base-medium developed by the author was successfully used in the isolation and identification of dermatophytes. Casein-medium supplemented with vitamins and Sabouraud-liquid medium were used in special cases. Dermatophytes were isolated in 36 of 331 samples (10.9%). The dermatophytes recovered were Microsporum canis: 13 isolates from cat. 4 from dog. 1 from horse; Trichophyton mentagrophytes var. granulare: 3 isolates from dog, 3 from horse, 2 from g...
Bell K, McKenzie HA, Muller V, Shaw DC.As part of a study of the 'whey' proteins of various mammals, a comparison is made of the alpha-lactalbumins and lysozymes of the kangaroo and horse. In the milk of the red kangaroo (Megaleia rufa) there is only one alpha-lactalbumin and it occurs throughout lactation, but no lysozyme has been detected. There are two alpha-lactalbumins in the milk of the grey kangaroo (Macropus giganteus), one, designated alpha-lactalbumin Zone B, is present throughout lactation; the second, designated alpha-lactalbumin Zone A, is present only in late lactation. One lysozyme is also present. The milk of the ho...
Franken P, van Beukelen P, Blok G.Two horses became ill, and one died, after being fed onions, presumably over a long period. Their intake of grass was low at the time of illness because the pasture was covered with snow. Examination of blood and urine revealed signs of severe haemolytic anaemia.
Valberg SJ.Although horses most commonly develop exertional rhabdomyolysis, there are numerous causes for nonexertional rhabdomyolysis (nonER) that pose a serious health threat to horses. Their etiologies can be broadly categorized as toxic, genetic, inflammatory/infectious, nutritional, and traumatic and a variety of diagnostic tests are available to discern among them. This study discusses causes of nonER as well as diagnostics and treatments that are specific to each etiology. General treatment of acute rhabdomyolysis is covered in detail in the study in this issue on sporadic and recurrent exertional...
Pagan JD, Valberg SJ.Many myopathies in horses can be managed by exercise regimes and dietary modifications. This includes modifying the amount of nonstructural carbohydrate, fat, amino acids, vitamin E, and selenium based on the horse's specific myopathy, metabolic status, exercise program, and optimal body weight. Because dietary recommendations differ substantially between myopathies, it is imperative to establish a specific diagnosis. A nutritionist will help practitioners select from the myriad of offered products to ensure a balanced diet. This article provides detailed recommendations for a variety of myopa...
Laroche N, Grimm P, Julliand S, Sorci G.Sainfoin (Onobrychis viciifolia), a polyphenol-rich plant, has shown promising anti-parasitic properties in ruminants, but results in horses are fewer and inconsistent. The mechanisms of action involved are not fully understood and different factors may influence its anti-parasitic properties. Recently, it has been shown that the effect of sainfoin depends on the horse's diet. Indeed, the inclusion of dehydrated sainfoin pellets in a high starch diet limited the rate of increase in strongyle egg shedding over a short period of time (21 days). The objective of this study was to evaluate, in viv...
Kerley BS, Harris P, Jacquay E, Askins M, McClendon M, Adams AA.Feeding small meals (∼1 g/kg BW DM basis) providing >10% nonstructural carbohydrates (NSC; starch + water soluble carbohydrate; WSC) has resulted in an augmented insulin response (AIR) in insulin dysregulated (ID) horses, but it's unclear if AIR reflects NSC content or the g NSC/kg BW/meal. Objective: The insulinemic responses of ID (n = 7) and non-insulin dysregulated (NID; n = 8) horses fed four feeds (A = 6.8% NSC; B = 14.9% NSC; C = 35.5% NSC; D = 44.6% NSC) at three levels of NSC intake (0.06, 0.11-0.12 and 0.17-0.18 g/kg BW) were evaluated in a randomized Latin square design across two...
Sillence MN, Holt K, Li FI, Harris PA, Coyle M, Fitzgerald DM.Ecdysterone controls moulting and reproduction in insects, crustaceans, and helminths. It is also produced by many plants, probably as an insect deterrent. The steroid is not made by vertebrates but has anabolic effects in mammals and could be useful for treating sarcopenia in aged horses. However, ecdysterone is banned in horseracing and equestrian sports, and with no limit of reporting, the risk of unintended exposure to this naturally occurring prohibited substance is a concern. To explore this risk, pasture plants and hay samples were analysed for ecdysterone content, as well as samples of...
van 't Klooster AT, Hallebeek JM, Beynen AC.The diet of horses should cover the energy and nutrient requirements of these animals. The desired composition of the ration depends on its digestion in the equine gastrointestinal tract. Nutritional problems or diseases caused by incorrect composition of the ration or by incorrect feeding should be prevented. The digestion of carbohydrates, fats, and proteins in the different parts of the gastrointestinal tract is described. In addition, the recently introduced net energy and digestible protein evaluation systems for feeds, and the energy and protein requirements of horses are presented.
Zhang Q, Li Q, Wang X, Wu Y, Chen R, Sun Y, Pan Y, Li S, Wang Z.Featured milk generally refers to less common dairy products with unique sources or specific nutritional components and functional characteristics. We used omics methods to study the lipids, metabolites, and proteins in donkey milk, mare milk, and camel milk and compared them with human milk and pig milk. The phospholipid content in camel milk is relatively high. Donkey milk contains metabolites that have potential therapeutic effects on mental disorders and chronic inflammatory diseases. Camel milk exhibits potential neuroprotective effects. Compared with other species, human milk contains mo...
Francis JM, Perry EB.Horse treat packaging may be composed of materials including plastic and paper which protect the product from the environment to improve shelf life. Objectives of this research were to 1) assess the impact of packaging on shelf life of horse treats and 2) evaluate the impact of packaging on horse preferences. Three packaging treatments (control, poly, and paper) were examined at five time points over a 12 month period. Treatments were analyzed for moisture, water activity, mold, yeast, pH, and volatile organic acids. Horse preference testing evaluated first treatment sniffed, consumed, and fin...
Thompson AC, Mochal-King C.Hypoparathyroidism is an uncommon endocrine disorder in the horse characterized by a transient or permanent parathyroid hormone insufficiency. Hypoparathyroidism is associated with hypocalcemia and hyperphosphatemia, primarily presenting with clinical signs consistent with hypocalcemia. This case report describes clinical presentation and treatment of a horse with severe hypocalcemia due to primary hypoparathyroidism. A 17-year-old, 542 kg Quarter Horse gelding presented for shaking and tremors. Significant findings include generalized muscle fasciculations, synchronous diaphragmatic flutter, ...
Doreau M, Martin-Rosset W, Barlet JP.In an experiment comparing pregnant then lactating mares with dry non-pregnant mares, the changes in plasma components were studied as indicators of the metabolic utilization of energy (glucose, non-esterified fatty acids, beta-hydroxybutyrate), nitrogen (urea, proteins) or minerals (calcium, phosphorus, magnesium). The mares were fed daily 2 kg concentrate and hay ad libitum. Beta-hydroxybutyrate, magnesium and to a lesser extent glucose were the only constituents whose levels were affected within the period starting one month before and ending one month after foaling. The increase in food in...
Gomaa N, Elemiri M, Hegazy Y, Zeineldin M, Nassif M, Alcala-Canto Y, Barbabosa-Pliego A, Rivas-Caceres RR, Abdelmegeid M.A retrospective cohort study was conducted on two Egyptian horse farms with most of horses were suffered from abdominal pain to describe the associations between the occurrence of mycotoxicosis and equine colic. The farms owner complain was an unexpected increase in number of colic cases and deaths among horses. The association between colic and risk factors (sex, type of food either dry or mixed with roughages and hematobiochemical parameters) was compared using independent sample T-test. The associations between possible prognostic indicators for colic caused by mycotoxicosis was estimated u...
Cohen ND, Donahue JG, Carey VJ, Seahorn JL, Piercy D, Donahoe JK, Williams DM, Brown SE, Riddle TW.To identify factors associated with abortions during early gestation classified as mare reproductive loss syndrome (MRLS). Methods: Case-control study. Methods: 324 broodmares from 43 farms in central Kentucky, including 121 mares from 25 farms that had early-term abortions (ETAs) associated with MRLS (case horses), 120 mares from the same farms but that did not abort, and 83 mares from 18 farms that were not severely Impacted by MRLS. Methods: Farm managers were interviewed to obtain data on various management practices and environmental exposures for the mares. Data for case and control hors...
Bertone AL, van Soest PJ, Stashak TS.Nutritional alterations were evaluated in 9 horses before surgery and 3 weeks, 3 months, and 6 months (4 total trials) after sham operation (group 1; n = 3) or extensive large colon resection (group 2; n = 6). Feed and fecal analyses were performed to determine apparent digestion of dry matter, organic matter, crude protein, calcium, phosphorus, magnesium, potassium, manganese, zinc, copper, and iron, and true digestion of dry matter, organic matter, crude protein, total plant cell wall, hemicellulose, cellulose, and lignin. Additional fecal and metabolic variables included the percentage of f...
White-Springer SH, Bruemmer J, Coleman RJ.A core group of 27 equine nutritionists and physiologists joined together in the late 1960s to formally address and enhance the direction of equine research, creating the Equine Nutrition and Physiology Society. In 2003, that growing society transformed into the Equine Science Society, which now serves as the preeminent, internationally recognized scientific equine organization. In recent years, it has been appreciated that equine science encompasses a wide range of focus areas, including exercise science, nutrition, genetics, reproductive physiology, teaching and extension, production and man...
Schubert R, Zander R, Gruhn K, Hennig A.Two lactating pony mares were given oral offers of 20 g 15N urea [95 atom-% 15N-excess (15N')] on 6 subsequent days. About 80% of the consumed 15N' were excreted via urine and faeces, but only about 2% via milk. The 15N' secreted via milk-lysine only amounted to 0.04% of the 15N' intake. The recovery was about 90% in each case. Tissues with active metabolism had an unexpectedly high labelling (greater than 0.3 atom-% 15N'). The low extent of the conversion of oral urea N into milk-lysine speaks against an essential participation of the enteral synthesis in meeting the amino acid requirement of...
Loch WE, Swantner LD, Anderson RR.Mean weight of 20 Quarter Horse placentas on a wet basis was 3.27 +/- 0.17 kg. These placentas contained mean dry fat-free tissue, DNA, RNA and collagen weights of 411 +/- 24 g, 11.2 +/- 0.6 g, 12.4 +/- 0.7 g and 210 +/- 15 g, respectively. In Ponies and Quarter Horses, there was a trend towards a decrease in these 4 values as gestation length increased. Analysis of placentas of Ponies fed different amounts of endophyte fungus-infected fescue seed showed that weight of dry fat-free tissue increased with increasing percentages of fescue seed in the diet. Diets containing fescue seed resulted in...
Andruskevich SM, Perry P, Houpt K, Houpt TR.The objectives were to measure changes in fluid balance of mares at parturition and relate those changes to the foals' acquisition of passive immunity. Twelve Thoroughbred mares and their foals were observed for suckling behavior for the first 12h post-partum. The mare's water intake, packed cell volume, plasma protein concentration, and plasma osmolality were measured pre- and post-partum. The foals' immunoglobulin concentrations were measured at birth and 24h later. The median increase from pre- to post-foaling in mares' packed cell volume was 4.0% (interquartile range=0.3-6.8). The median i...
Dickson EC, Kayser WC, Latham CM, Leatherwood JL, Daigle CL, White SH.Equine research and management is limited to single-housing systems if individual animal intake is to be precisely recorded. Even then, dry forage intake is difficult to quantify accurately due to stomping or mixing hay with fecal matter and bedding. In cattle management, GrowSafe Systems (GrowSafe) is a commonly used tool to closely monitor individual animal feeding data using radio frequency identification (RFID) tag technology. Animals are equipped with a unique RFID tag that is read by the feed bunks each time the animal lowers its head into the bunk to consume feed. The objectives of this...
Sibthorpe PEM, Fitzgerald DM, Chen L, Sillence MN, de Laat MA.To determine the effect of a starch-rich treat, added to the daily diet of ponies for 10 days, on enteroinsular responses to meal consumption. 10 mixed-breed adult ponies owned by Queensland University of Technology were used in the study. Six ponies were metabolically healthy, and 4 were insulin dysregulated at the start of the study, according to the results of an in-feed oral glucose test. A bread-based treat was offered twice daily for 10 days, adding 0.36 ± 0.04 g/kg body weight (BW) carbohydrates to the daily diet. Before and after treatment, the intestinal capacity for simple carbohydr...
Knych HK, Arthur RM, Stanley SD, McKemie DS.In order to ensure the welfare of performance horses and riders as well as the integrity of the sport, the use of both therapeutic and illegal agents in horse racing is tightly regulated. While Dehydroepiandrosterone (DHEA) is not specifically banned from administration to racehorses in the United States and no screening limit or threshold concentration exists, the metabolic conversion of DHEA to testosterone make its presence in nutritional supplements a regulatory concern. The recommended regulatory threshold for total testosterone in urine is 55 and 20 ng/mL for mares and geldings, respec...
Witte ST, Will LA, Olsen CR, Kinker JA, Miller-Graber P.Chronic selenosis (alkali disease) was diagnosed in horses of western Iowa, a region associated with marginal to adequate soil selenium. Two locally produced alfalfa hays (Medicago sativa L) were identified as the primary source. Difficulty in selecting diagnostic specimens to evaluate potential chronic selenosis cases is complicated by the wide range of tissue concentrations reported in previous cases, conflicting correlation of sample selenium concentrations in the literature, and different recommendations on specimen selection and diagnostic value. These problems arise form the similarity i...
Hallebeek JM, Beynen AC.A fat-free liquid diet was formulated to be administered by nasogastric tube as therapy for hyperlipaemia in ponies. The liquid diet provided energy, protein, minerals, trace elements, and vitamins in accordance with the requirements of ponies. As sole source of nutrition, the liquid diet fully counteracted fasting-induced hyperlipaemia in two healthy ponies. The liquid diet was also used in hyperlipaemic patients, but only in combination with conventional therapy, consisting of intravenous administration of glucose, insulin, and heparin. Although no patients were treated with the liquid diet ...
Jensen RB, Kyrstein TD, Junghans P, Tauson AH.Energy expenditure (EE) can be estimated based on respiratory gas exchange measurements, traditionally done in respiration chambers by indirect calorimetry (IC). However, the (13)C-bicarbonate technique ((13)C-BT) might be an alternative minimal invasive method for estimation of CO(2) production and EE in the field. In this study, four Shetland ponies were used to explore the effect of feeding on CO(2) production and EE measured simultaneously by IC and (13)C-BT. The ponies were individually housed in respiration chambers and received either a single oral or intravenous (IV) bolus dose of (13)...
Murphy D, Reid SW, Love S.The aim of this study was to establish the normal patterns of breath hydrogen excretion in adult ponies following either voluntary consumption or administration per stomach tube of a test meal/carbohydrate substrate. After an overnight fast, the ponies (n = 7) received either no test meal (ie fasted), glucose, xylose, lactose, lactulose, wheat flour or oats. Exhaled breath samples were collected in duplicate at 0 minutes and at 30-minute intervals thereafter for eight hours. Analysis of duplicate breath hydrogen measurements (n = 714) indicated that the breath hydrogen collection/storage metho...
Barton C, Hassel DM.A successful outcome to management of the critical colic patient is highly dependent on how the patient is monitored and treated, particularly, in the perioperative period. In this article, we will provide an update on monitoring techniques, advances in fluid therapy, nutrition management and pharmacotherapeutic agents, inclusive of pain monitoring and management, prokinetics, and management of systemic inflammatory response syndrome and the hypercoagulable state.
McKenzie RA, Gartner RJ, Blaney BJ, Glanville RJ.A supplement system for the control of equine nutritional secondary hyperparathyroidism (NSH) was evaluated on 4 farms in the Arcadia Valley of the Queensland brigalow region. Thirty-three local stock horses (of which 13 had clinical NSH and 7 were recent introductions) were grazed on buffel grass (Cenchrus ciliaris) for the 6 months from September 1979 to February 1980. Each horse was fed 1.0 kg of a mixture of ground limestone plus dicalcium phosphate (1:2) in 1.5 kg molasses each week. The pasture was hazardous during this time (total oxalate content above 0.5% and calcium: oxalate ratio be...
Walker WT, Callan RJ, Hill AE, Tisher KB.This study evaluated the effects of administering oral powder electrolytes on packed cell volume (PCV), plasma chemistry parameters, and incidence of colic in horses participating on a 6-day 162-km trail ride in which water was not offered ad libitum. Twenty-three horses received grain with powder electrolytes daily while 19 control horses received grain only. Horses were ridden approximately 32 km a day at a walk or trot. Packed cell volume and plasma chemistry parameters were analyzed daily. Episodes of colic were diagnosed and treated by a veterinarian unaware of treatment group allocation....
Bampidis V, Azimonti G, Bastos ML, Christensen H, Durjava M, Kouba M, López-Alonso M, López Puente S, Marcon F, Mayo B, Pechová A, Petkova M....Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of an essential oil from the seeds of Houtt. (nutmeg oil), when used as a sensory additive in feed and water for drinking for all animal species. The additive contains myristicin (up to 12%), safrole (2.30%), elemicin (0.40%) and methyleugenol (0.33%). For long-living and reproductive animals, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) considered of low concern the use of the additive in complete feed at 0.2 mg/kg for laying hens and...
