• provision of substrates for maintenance of bodyweight and replenishment of energy reserves in working muscle and other tissues • promotion of tissue adaptation, growth and repair • promotion of general health and well-being • application of competition feeding strategies appropriate to the athletic task. As for all animals, athletic horses require an adequate and balanced intake of energy, protein, vitamins, minerals (macro and micro) and water in order to support health and activity. The background details to why and how these nutritional components are digested, utilized and stored can be found elsewhere;1,2 the focus of this chapter is to place this information into the context of feeding management for the athletic horse. A summary of the nutrients required and some specific comments with respect to the exercising horse are given in Table 36.1. Table 36.1 Guide to the nutrient requirements for a 500-kg athletic horse as well as typical nutrient concentrations in some common feedstuffs (‘As fed basis’ unless otherwise stated). Due to marked variations due to cultivar, processing, etc., these data only represent the average nutrient content of feedstuffs. Requirements need to be adapted to the individual circumstances Adapted from Harris PA (2013) Nutrition in Equine Veterinary Nursing Manual Coumbe K (ed) with kind permission from John Wiley & Sons Ltd.88 Globally, several different feeding systems (e.g. NRC, INRA, GEH) and units (e.g. digestible vs. net energy) are used for the description of energy and nutrient requirements.3,4 Requirements can be expressed as a function of actual bodyweight or on the basis of metabolic bodyweight (typically BW0.75) and also quantified on either an ‘as fed’ (actual feed weight that includes water content) or ‘dry matter’ (the weight of feed after removal of moisture) basis. Most concentrate feeds such as cereal grains, cubes, pellets, etc., contain around 10% moisture with a dry matter content therefore of ~88–92%, whilst the water content of preserved forage typically ranges between 10 and 50%. It is important to be aware of these differences – a single system should be chosen and consistently applied when evaluating or developing an equine ration. In the UK and USA energy requirements for athletic horses are most commonly expressed as megacalories (Mcal – USA) or megajoules (MJ – UK) of digestible energy (DE), where 1 Mcal = 4.184 MJ. Energy requirements are the sum of maintenance requirements plus an allowance for the work being undertaken and will depend not only on work duration and intensity but also the environmental conditions, terrain, weight of the rider and tack, ability of the rider, and fitness of the horse, etc.3 Two primary approaches can be used to estimate energy requirements:3,4 • Categorization of workload: The NRC Nutrient Requirements for Horses uses the work categories of light, moderate, heavy and very heavy exercise to estimate DE requirements (e.g. NRC 2007). For light work (e.g. horses at the start of a training program), the DE requirements in Mcal/day are stated as (0.0333 × BW) × 1.20, whereas for very heavy work (e.g. all racing animals and elite three-day event horses) the requirements are given as (0.0363 × BW) × 1.9. These estimates do not take into account different training and exercise workloads for different animals and disciplines.5 Nonetheless, surveys of racehorse trainers have indicated that these estimates compare favorably with feeding practices.6–8 • Individual estimate of workload: A second approach is to base requirements on some measure of the individual work load, usually running speed e.g. DE (kJ per kilogram of horse, rider and tack) = 4.184 × {[e(3.02 + 0.0065Y) – 13.92] × 0.06}/0.57 where Y is running speed (meters per minute) and 0.57 accounts for the efficiency of utilization of DE.9 This method also does not take into account fitness, jumping efforts, environmental conditions, etc. An alternative approach is to base DE requirements on the horse’s current diet, bearing in mind that laboratory analysis of feed samples are needed for reasonably accurate assessment of DE content. Regardless of the method used, it is important to realize that these estimates only provide a starting point for ration development; regular assessment of body weight and condition will inform the need for adjustments in DE provision. Underfeeding of DE in relation to workload, etc., will result in weight loss, lethargy and poor performance, while horses provided too much DE will gain weight and may become hyperactive.3,10 The relationship between body fatness, fat free mass (FFM) and running performance has not been studied in great detail in the horse. Ultrasound-measured depth of subcutaneous fat over the rump was used to estimate percentage body fat and FFM, and then examine the relationship of these variables with maximum aerobic capacity (VO2max) and running performance.11–13 Both sprint and endurance performance were inversely correlated with estimated body fat in these studies; however, it should be recognized that measurement of rump fat depth has not been fully validated for estimation of body fat and FFM in the horse.14 The concept of optimal BW has been proposed for racehorses; Lim15 reported that race performance was negatively affected by deviations >1.5% from optimal BW, with performance less affected by the horse being overweight as compared to being underweight. The amount of energy needed for athletic activity is directly related to the weight being moved (horse, rider and tack) as well as the speed of running, the incline, jump efforts, etc.16 Therefore, a change in total weight will affect the energy cost of locomotion. The addition of a 10% load to horses exercising on a horizontal treadmill increased oxygen consumption by 15%,17 the administration of furosemide resulted in decreased anaerobic energy expenditure during brief high-intensity work at least in part due to an acute BW reduction.18 For endurance-type events (e.g. endurance racing, three-day event), being ‘thin’ (i.e. body condition score, BCS ≤ 3/9) might be a disadvantage because of lower energy reserves (and potentially lower muscle mass) when compared to a higher BCS. Over-conditioning (BCS ≥ 6/9) also could adversely affect performance due to the insulating effects (and potential impairment to heat dissipation) of excess subcutaneous adipose tissue. For most athletic activities, therefore, a BCS of 4–5 should be targeted and monitored regularly, with DE intake adjusted as needed. The authors recommend use of the Henneke BCS system19 as modified by Kohnke.20 • hydrolysable carbohydrates, e.g. simple sugars and starch • fermentable fibers, a component of dietary fiber, e.g., cellulose, pectins, hemicelluloses • protein (note, however, that protein should not be included in the ration as an energy source). Figure 36.1 is a schematic that depicts how energy is provided to the horse by the three principal dietary sources. The efficiency conversion of these energy sources into useable or NE varies considerably.3,21 In general, cereals provide more NE than hay, and hay provides more than twice the NE of straw. Vegetable oils contain proportionally more energy than cereals (~2.5 times as much DE as maize/corn and three times as much as oats). The art and science of feeding the performance horse depends to a large extent on the relative proportions of the energy sources provided to the horse and the feedstuffs used. Different athletic disciplines will require different strategies, e.g. the provision of a high-fiber, roughage-based diet may be advantageous to an endurance horse as it is likely to provide an ongoing supply of energy during a race. Additionally, this type of ration is thought to increase the size of the fluid and electrolyte reservoir in the hindgut (which may help offset sweat fluid losses during exercise). However, excess gut fill may be energetically disadvantageous during high-intensity, short-duration exercise. Nonetheless, forage provision should be the starting point in designing any ration for an athletic horse. As non-ruminant herbivores, horses are well adapted to eating high-fiber feedstuffs that undergo microbial fermentation primarily within the caecum and colon with production of short-chain or volatile fatty acids (SCFA). The SCFA propionic acid is an important precursor for gluconeogenesis, acetate is important in the production and storage of long-chain fatty acids, while butyrate is a primary energy source for the hindgut mucosa.22,23 The inclusion of some long-stem forage in the diet is thought to be important for maintenance of hindgut function and health, and also may reduce risk of gastric ulceration and abnormal behaviors.24 The continual fermentation and absorption of SCFA (predominately acetate and propionate) also means that fiber can provide ongoing energy during prolonged exercise. Most equine feedstuffs contain some fiber but forage is the primary source. For most horses, the daily forage intake will be based around fresh or dried/preserved ‘grass’. Preserved forages should be as free as possible of contaminants such as molds. Hay that is baled at high moisture content is likely to heat and become heavily contaminated with molds that can exacerbate chronic airway diseases such as recurrent airway obstruction and inflammatory airway disease. In areas with high rainfall during the growing and haymaking season (e.g. the UK), the feeding of ensiled hay or ‘haylage’ is increasingly practiced. Haylage can be a suitable alternative to hay providing that it is stored correctly and fed in sufficient quantity to ensure adequate fiber intake. One concern with especially large bale haylage is the potential for clostridial growth and production of botulinum toxin.25 Haylage, unlike properly made silage, can still have a high WSC content (average 21% in a recent UK survey – Briars, personal communication 2013) and nutritionally very variable. Haylage should be examined carefully for the presence of mold and other contaminants before feeding, and sealed haylage bales should be fed within a few days of opening. Recently, there has been increased use of small hay-bale steamers that significantly reduce the fungal spore count of the hay.26 Comments on the main types of preserved forage are provided in Table 36.2. Table 36.2 A guide to the main types of forage available and their nutrient content. Please note that this is only a general guide as forages vary between countries and even from field to field
Nutrition for the equine athlete
Nutrient requirements and key principles in ration design
Introduction
What nutrients does an athletic horse need?
NUTRIENT
REQUIREMENTS BASED ON NRC 2007 (VALUES IN PARENTHESIS REPRESENT THE AUTHORS’ CURRENT RECOMMENDATIONS)
HIGH SOURCE
MODERATE SOURCE
LOW SOURCE
COMMENTS
Energy –
Is not a nutrient per se
Units MJ or Mcal
I Mcal = 4.184 MJ
DE: Based on one of 4 levels of exercise: 20–34.5 Mcal
(Base on NRC but adapt to the individual)
Vegetable oils
~35 MJ/Kg as fed
Oats ~10–12 MJ/kg
Barley ~13 MJ/kg
Corn ~14 MJ/kg
Mature grass hays ~6–12 MJ/kg
Wheat straw ~6 MJ/kg
Rice hulls ~2 MJ/kg
Essential to all cellular functions. Important to consider source of energy as well as quantity. Base intake on previous diet or NRC and then adapt to the individual. Need to continue to monitor (body condition, behavior, etc.) as requirements will change with environmental conditions, availability of grass during any turnout, nature of the forage, body condition, etc.
Protein – Expressed as crude protein (CP) or digestible protein (DP varies from ~40 to 80% CP)
699–1004 g (750–1500 g)
Oil seed meals
~22% sunflower seeds whole
~45% soyabean meal
Alfalfa hay
~15–20%
Grass hays
~8%
Grains variable and influenced by growing conditions
~6–12%
Maintaining building and repairing body tissues. Too little and too much protein may be detrimental to performance. Especially with higher amounts need to ensure adequate water intake and good stable hygiene
Amino acids
e.g. Lysine: an essential amino acid which must be provided by the diet as cannot be made by the horse
30–43 g
(30–50: allow up to 0.1 g/kg BW in hard/intensive work).
Threonine possibly 80% of the lysine level
Soyabean meal
~28 g/kg lysine
~20 g/kg threonine
~6 g/kg methionine
Linseed
~12 g/kg lysine
~11 g/kg threonine
~4 g/kg methionine
Cereals ~2–3 g/kg lysine
Grass /cereal hay <2 g/kg lysine
Protein quality. i.e. Amino acid profile may be more important than total protein intake.
Lysine is thought to be the first limiting amino acid in typical horse rations and if the lysine requirement is met, unless synthetic amino acids are used to supplement the diet, then it is believed the requirement for other amino acids will most likely be met. Requirements for the other amino acids have not been established for the horse
Fats/fatty acids
There may be a need for certain fatty acids such as linoleic acid but actual amount required unknown in the horse although a guide of 5 g/kg DM given by NRC
(Up to 1 ml/kg BW without additional nutritional advice but around 5–10% of the diet may be advantageous for some performance animals)
Vegetable oils ~99%.
Corn oil/soy oil more commonly used.
Possible advantage of including some linseed/fish oil but yet to be fully proven
Whole oil seeds ~20%
Rice brans ~25%
Grains ~1–3%
Hays ~2%
Beans ~1%
Concentrated starch free source of energy. Add gradually, consider the vitamin (esp. vit E) and mineral balance of the final diet. Only use fresh non-rancid oils. Fatty acid profile may be important but not known for the horse.
For practical purposes 450 ml of oil (~420 g) provides about 14 MJ (3.4 Mcal) of DE.
Sodium – Na
Mineral
Electrolyte
14–41 g: May be higher if undergoing prolonged endurance work (15 g + 1.2–2 g/kg sweat loss). Exact amount is controversial and needs to be adapted to the individual and take into account core ration – especially for endurance horses
Salt
~11 g Na/28 g salt or ounce
Sugar beet molasses can be high from ~20–50 g/kg
Sugar beet pulp (un-mollased)
~4 g/kg DM
Cereals
Usually <0.3 g/kg
Major extracellular cation essential for nerve and muscle function plus water balance.
For many in light work, providing free salt or an equine-specific salt block may be adequate but for those in harder work higher levels may be required. Authors’ current general advice is to provide reasonable levels in the core daily diet and then provide during / immediate post competition ~1/3 of estimated losses but this needs to be adapted to individual circumstances. Continue with a fortified diet post exercise
Potassium – K
Mineral
Electrolyte
28.5–53 g: NB may be higher if undergoing prolonged endurance work (minimum of 35 + at least 0.5 g/L sweat)
Sugar beet molasses – variable ~10–35 g/kg
KCl ~ 14 g/28 g or ounce
Forages
~15–25 g/kg – in hay
Grains
<5 g/kg
Major intracellular cation essential for normal cellular function including heart and muscle.
Potential risk of a reduced or even deficient intake when on low forage intakes, especially if the forage fed is haylage/silage
Chloride – Cl
Mineral
Electrolyte
47–93 g (40 + ~3 g/L sweat)
Salt ~17 g Cl /28 g or ounce
Sugar beet mollases
~10 g Cl/kg DM
Cereals ~<1 g/kg DM salt ~0.6 g Cl/kg
Closely interrelated to sodium plus osmotic pressure
Calcium – Ca
Mineral
Electrolyte
30–40 g
(45 g + 0.2 g/kg sweat loss)
Limestone flour
(~40% Ca – 400 g/kg)
Legumes
e.g. alfalfa ~1.2%
Sugar beet pulp ~0.6% (DM basis)
Cereals
~0.15% some very low less than 1 g/kg
Bone formation, nerve and muscle function, blood clotting, etc.
May need to provide higher amounts when first go into training and and during ‘lay off’ periods
Phosphorus – P
Mineral
Electrolyte
18–29 g (25–30+ in proportion with the Ca intake)
Dicalcium phosphate
~23% Ca and 18% P
NB high content in most cereal brans (~11 g/kg) but due to high phytate level limited bioavailability estimated ~2 g/kg
Legume hays ~2 g/kg
Cereals
(0.3–0.6% P)
NB still high relative to Ca content
Bone formation, energy metabolism, essential component of cell membranes.
Ratio of Ca: P may be as important as total amount – aim for a ratio of Ca:P between 1.5 and 2.1.
Potentially need to provide higher amounts when first go into training (e.g. 35 g/500 kg horse)
Magnesium – Mg
Mineral
Electrolyte
9–5 − 15 g (15 g + 0.125 g/kg sweat loss)
Rice brans ~0.9%
Wheat bran ~0.55%
Canola seeds ~0.55%
Sugar beet molasses ~0.23%
Oil seeds ~0.3%
Timothy mature hay ~0.08%
Oats ~0.8%
Bone, muscle contraction, metabolism.
Claims for behavior-modifying effect when fed in moderately increased amounts have not been confirmed but large amounts given iv will be sedative.
Availability from synthetic sources will be highly variable – i.e. low from MgO and higher from sources such as magnesium aspartate
Copper – Cu
Micromineral
100–125 mg (125–175 mg)
Synthetic sources
Molasses can be ~50 mg/kg
Legume hays
~10–16 mg/kg
Some cereals
may have ~10 mg/kg
Many cereals and hays
<4 mg/kg
Cofactor for many enzymes associated with energy metabolism collagen and elastin synthesis – bone formation, immunity.
Copper to Zn ratio in the diet may be important – current advice is to try to maintain around 3.5–4.5 : 1.
Authors’ advice is not >33% of the intake comes from chelated sources
Zinc – Zn
Micromineral
400–500 mg (500–700 mg)
Synthetic sources
Inorganic sources
Synthetic sources
Chelates and bioplexes
Full-fat soya ~50 mg/kg
Legume hays and cereals ~20–25 mg/kg
Component of many metalloenzymes involved in protein and carbohydrate metabolism, important to several hormones including insulin, immunity.
Authors’ advice is not >33% of the intake comes from chelated sources
Manganese – Mn
Micromineral
400–500 mg (500–700 mg)
Synthetic sources
Legume hays
~30–60 mg/kg
Oats can be high 35 mg/kg or low
Grass hays
Corn ~5 mg/kg
Barley intermediate
Cartilage (formation chondroitin sulfate)
Metabolism
Authors’ advice is not >33% of the intake comes from chelated sources
Iron – Fe
Micromineral
400–500 mg (500–625 mg)
Inorganic supplements
Oaten chaff
~350 mg/kg
Some mineral sources contain high levels of iron contamination
Legume hays
140–210 mg/kg
Cereals <100 mg/kg
Incorporated into hemoglobin, myoglobin, certain enzymes; oxygen transfer; metabolism.
Rare to have an inadequate intake of iron and therefore iron deficiency anemia is very rare in the horse. Anemia in performance horses is commonly associated with inflammation
Cobalt – Co
Micromineral
Vitamin B12 contains about 4% cobalt
Unknown
Synthetic sources
Legume hays up to ~0.4 mg/kg
Cereals <0.15 mg/kg
Oats tend to be low ~0.05 mg/kg
Involved with hemoglobin formation and metabolism
Selenium – Se
Micromineral
1–1.25 mg (2–3 mg)
Synthetic sources
Certain selenium accumulating plants
Selenium yeast
Cereals and hays – but variable some plant species can have very high levels.
Cereals <0.2 mg/kg
Part of the cellular antioxidant defeness.
Toxicity can occur. Recommended not more that 1 mg/100 kg BW, i.e. <5 mg/500 kg horse
Iodine – I
Micro-mineral
3.5–4.4 mg (2–3 mg)
Seaweed meal
Iodized salt
Potassium iodate
Legume hay ~0.15 mg/kg
Cereals usually <0.1 mg/kg
Essential component of thyroid hormones.
Very difficult to assess iodine levels from organic materials. Seaweeds contain very variable and sometimes high levels of iodine
Vitamin A – fat soluble
Main source is β-carotene from green herbage.
Toxicity is unlikely to result from high intakes of β-carotene as the horse is thought able to reduce the conversion of β-carotene to vitamin A
22 500 iu (50 000 iu as mix Vit A and β carotene)
Leafy green plants
Vitamin A equivalents ~200 000 iu/kg but will vary with plant maturity, season, etc.
Cod liver oil
~200 000 iu/20 ml
Different synthetic sources may have different availabilities
Yellow maize
~2000 iu/kg
Legume hays early stage
50 000 iu/kg
‘Aged’ preserved forages – rapid loss in cured hays
Oats <500 iu/kg
Barley <1000 iu/kg
Normal growth, vision, maintenance of skin and epithelial tissue, support for infection resistance.
Requirements for exercising horses in the literature vary between ~45 and 200 iu/kg BW – the authors’ currently recommend a more optimal intake level of 100 iu/kg BW
Vitamin D
A hormone
Fat soluble
Synthesized in skin under exposure to sunlight
3300 iu (5000 iu)
Action of sunlight on the skin
Synthetic sources
Cod liver oil ~2000 iu/20 ml
Sun-cured forages
Alfalfa hay ~1500 iu/kg
Little or none in cereals & preserved aged forages
Normal bone growth. Believed involvement in Ca metabolism may not be as great under normal conditions as in other species.
Currently levels between 5 and 13 iu/kg BW suggested for exercising animals. The authors’ recommend around 10 iu/kg BW. Higher levels may be required for stabled animals and young animals entering training; BUT toxicity possible.
Recent research into Vit D in other species suggests has a much broader role in immunity, metabolism, etc.
Vitamin E
Fat soluble
1 mg ~ 1 iu
800–1000 iu (1500–2500 iu – plus 1–2 iu/ml of additional oil)
Synthetic or natural concentrated tocopherols. Supplementation most beneficial if given orally daily
Oils of some grain seeds
e.g. wheat germ 2.1 mg/20 ml
Green forage 100–450 iu/kg
Cereals <30 iu/kg
Alfalfa hay 10–30 iu/kg
Haylage and hay levels may be very low
Antioxidant, normal muscle metabolism, promotes immune function.
Higher intakes may be advantageous re the oxidative stress and immunity challenges associated with exercise.
Levels in the literature typically vary from 1.5 to 5 mg/kg BW but as high as 11 mg have been suggested. The authors’ recommend from 3 to 5 mg/kg BW depending on work load plus 1–2 iu/ml additional oil depending on the oil and the background level of Vit E in the oil.
Recommend other than for specific clinical reasons not >10 iu/kg BW
Vitamin K
Fat soluble
Synthesized by intestinal bacteria and sourced from good-quality hay and pasture
Unknown
Synthetic sources
Some suggestion that certain synthetic sources (e.g. injectable menadione) may have increased toxicity
Most forages and hays are thought to be adequate sources
Blood clotting/bonemetabolism.
Typically thought not to be required in the diet as synthesized in hind gut.
Whether additional Vit K is required on top of a forage-based diet has not been proven but some recent work suggests that it may not be as bioavailable from forage as previously thought and supplementation may be of value for young growing /exercising animals
Thiamine
Vitamin B1
Water soluble S
30–62.5 mg (60–65 mg)
Brewers’ and bakers’ yeast contain 150–160 mg/kg. Yeast is a good source of thiamine as well as other B vitamins
Synthesized by bacteria in the GIT
Cereal by-products 10–15 mg/kg if contain the scutellum and germ which is rich in thiamine
Legume hays ~3 mg/kg
Cereals ~5 mg/kg
Hays 0.2–4.5 mg/kg DM
Growth, energy production, nerve function.
In the literature 0.07–0.13 mg/kg BW/day have been suggested. Potential for increased requirements in animals with reduced appetite or reduced forage intake depending on the core ration
Biotin
(15–25 mg – depending on hoof quality)
Synthesized by bacteria in the GIT
Brewers’ yeast ~1 mg/kg dried yeast
Reasonably good
Sugarcane molasses ~0.7 mg/kg
Wheat bran ~0.4 mg/kg
Oats ~0.3 mg/kg
Peas ~0.2 mg/kg
Involved with maintenance of hoof, skin, hair, and other tissues.
Metabolism.
Suggested that 2–3 mg/100 kg BW/day required to maintain healthy hooves and 3–5 mg/100 kg BW to improve hoof quality or for those with hoof problems. NB not all hoof problems respond to biotin supplementation. Response may take up to 9 months or more to have an effect, if at all
Folic acid
Unknown
Brewers’ yeast (10–15 mg/kg)
Synthesized by bacteria in the GIT
Wheat bran 0.8–1.8 mg/kg
Alfalfa meal dehydrated ~1.6 mg/kg
Rice bran ~1.6 mg/kg
Cereal grains variable
~0.1–0.6 mg/kg
Associated with vitamin B12 and blood cell production.
Increased erythropoiesis during training may increase requirements of folate to support the cell turnover. Serum concentrations may be reduced in hard working/stabled animals. Intakes of 0.012–0.043 mg/kg BW suggested in the literature
Vitamin C
Ascorbic acid
Water soluble
Synthesized in the liver
(5 g – respiratory support)
Manufactured within body – absorption from synthetic sources not always good and individually variable
Pasture contains variable amounts
Formation of cartilage and bone, antioxidant, Immune system and wound healing.
Additional vitamin C may be of value in certain conditions, e.g., infections, ‘stress’ especially respiratory challenge. Levels of 30–40 mg/kg BW have been recommended in such instances. The authors’ currently recommend ~1 g/100 kg BW for exercising or stabled animals (of a stable biovailable form). Advise that vitamin C supplementation should not be stopped abruptly
Building a ration for an individual horse
Which units and requirements to use?
Calculation of energy requirements
Sources of dietary energy
Forage
GENERAL COMMENTS
PROTEIN/ENERGY
MINERALS
SOME COMMENTS SPECIFIC TO ATHLETIC HORSE
Meadow hay
10–15% Moisture
Typically from permanent pastures with a range of grass species (plus often herbs and other plants). Resulting in plants at different stages of maturity when cut – so can be referred to as ‘soft’ hay. Note: due to different growing conditions late harvested hay from one region may have higher nutrient value than an early cut from another region
Provide higher protein (typically 8–12% DM) and digestible energy levels (typically around 2–2.5 MCal/kg DM: 8–11 MJ/kg DM) than most seed hays.
Lysine values vary but can be up to 4.5% of the CP values
The Na content will be low in all forages & Na and Cl supplementation will typically be required for performance horses on forage-based diets.
Cu, Zn and Se contents can be low in hays.
Ca/P vary
Energy and nutritive value will vary mainly due to fiber content and fiber quality. Younger less mature hays tend to be more digestible and suitable for the exercising animal – but the reduced fiber content may be an issue if low levels of forage are fed
Seed hay
10–15% Moisture
Produced from specially seeded leys, usually 1–3 years old, and contains predominantly one or two grass species (often rye grass or timothy)
Typically, seed hay has lower energy (for example around 1.5–2 Mcal: 7–9 MJ/kg DM) and protein levels (around 4–8% DM) and a lower digestibility than meadow hay
The mineral levels in seed hay also tend to be lower than for meadow hay, although this will depend on the soil upon which the hay was grown
For all hays the hygienic quality (dust, molds, etc.) is important. Soaking or more recently steaming hays may improve hygiene status
Legume hay
10–15% Moisture
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