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| Hay for Performance Horses |
Introduction
AlternativesAlthough concentrating on "straight hay" a brief referencemust be made to the questions of silage & treated hays.Silage has not been popular with horse owners, but goodquality silage is a suitable feed. Problems occur withsilage of poor quality; if the pH of a made silage crop isnot below 5.5 the bacterium Botulinum Clostridium, which isendemic in soils, is able to produce an endotoxin thatcauses Botulism. Each year several horses die in the UK dueto Botulism. This can often be traced back to "Big BaleSilage" that has not been treated with a preservative andwhose pH is circa 6.Interest has arisen in treating hay with a mixture ofvolatile fatty acids, to act as a preservative. Illinois &Cornell Universities carried out a study treating hay with amixture of 80% propionic acid, 20% acetic acid (details asin Table 1). Horses given a choice preferred the untreatedhay, however when given no alternative, they ate their fullration in treated hay & with no adverse effects.
Thus, not only was preservation of the hay improved but alsosince the hay could be harvested with a higher moisturecontent, this may be an extremely useful technique in poorsummers as an alternative to barn drying.An alternative treatment yielding similar results is CiderApple vinegar. Major Species involved during hay conservation.The following groups may be considered as the majorcontributors towards hay production :Ryegrasses, Fescues, Timothy, Cocksfoot, Meadow Grass,Legumes, Cereals.For a typical analysis of hay made from these, please seeTable 2. The basic characteristics of the main species chosen forhorse pasture are as follows : [a] Perennial Ryegrass (Lolium Perenne)is very persistent in good rich soils but tends to declineafter 2 to 3 years on poor light soils unless it is keptwell fertilised. Since it is a useful base for seedmixtures, it is found worldwide.Red Fescues (Festuca Rubra)have a large variation of quality but the best are palatable& have good nutritional quality. They have poorestablishment ability but are hard wearing. For this reasonthey are popular for sports fields & the seed isappropriately expensive.[c] Rough Stalked Meadow Grass [Poa Trivialis]has a close growing habit. It is best grown on moist soils &in sheltered conditions. Due to its close growing habit itfills the bottom of the pasture & thereby keeps out weedspecies.[d] Smooth Stalked Meadow Grassprobably best known as Kentucky Blue Grass, is useful onlight & sandy soils since it is stoloniferous and resistantto severe drought.[e] Timothy (Phleum Pratense)produces possibly the most palatable hay for horses. It'sseed is relatively cheap due to the abundant seed productionof each plant. Moist soils are preferred, such as : heavyloams, clays & peat soils.[f] Wild White Clover (Trifolium Repens)Deep rooted & drought resistant. Low levels of cloverinclusion are often required but high inclusion rates mayprovide an excess of protein. This wild white clover is tobe generally preferred over the more vigorous cultivatedvarieties.
Cost & AvailabilityBoth of these factors vary widely with season & weatherduring that year. There are only a few specialist growerswho cater specifically for equine needs; most forage musttherefore be purchased from farmers & dealers whose mainconcern is for other agricultural animals. It is often thecase that the most available & cheapest hays have a highmeadow grass content. More specific ryegrass / timothy haystend to command a significantly higher price. In order toobtain lucerne, fenugreek or other specialist crops one maybe able to buy the prepacked & chopped product from thelocal feed merchant. If not, the crop may be obtained byfostering a relationship with a specialist producer; forexample. Lucerne hay may be purchased by the bale in theNewmarket district, straight from the producer. PalatabilityDespite the importance of this characteristic [if a horsewill not eat the hay, then the hay is of no use] very littleresearch has been carried out to study this. In fact, to myknowledge, no grasses have yet been bred with this specificcharacteristic in mind. However, in 1980, Mrs M. Archerpublished a paper on her preliminary findings carried out atthe Equine Research Centre, Newmarket, England. The work wascarried out with grazing horses, the results beingsummarised as follows :
However, 3 points should be noted when considering theresults : all grasses were grazed at a fixed height and thus atdifferent growing stages, yet palatability is known to varywith growing stage. [ii] Palatability and therefore the horses preference willprobably vary between the growing crop & hay. Could thisexplain why Timothy is not favoured here but is consideredfavourably as hay. [iii] A further variation may be caused by exogenous factorssuch as soil type or climatic variation. Adverse EffectsProviding that the hay to be fed is free from toxic plantssuch as Ragwort (Senecio Jacobeae) then few adverse effectsare normally noted when feeding good quality hay. However, afew points should be made : [A] If contamination with fungal spores is suspected thenhay may be soaked in water or a water/molasses mix, in orderto reduce any respiratory risk. The reasoning is as follows;soaking will swell any spores to a greater diameter thanthat of the bronchioles within the horse's respiratorytract. The cilia {fine hairs} within this region can thenremove the spores before they can causes blockages withinthe lungs. To swell the spores sufficiently, soaking shouldbe carried out for at least 12 hours. It appears that leafyhays made from meadow grass are more susceptible to thisproblem than are the coarser ryegrass hays. [B] Photosensitisation of predominantly chestnut horses hasbeen noted as below :A susceptible horse {perhaps carrying a gene predisposinghim to the condition} is fed upon hay containing high levelsof trifoliates [esp. clover, alfalfa & fenugreek].The horse is then wormed with a thiobenzadole wormer.Shortly afterwards the horse may break out in sores thatsecrete pus, particularly on the lower leg & face. Eventreatment with cortisone creams will not cure the sores yet2-3 days after removal of the trifoliate forage, the soresdry up & heal. While not common this condition may be severeand is therefore worth noting. [C] The inclusion of herbs that broaden a horse's diet[e.g.. wild garlic] is considered beneficial; thus a haylacking in herbs may not provide the best possible foragefor the horse. However it may in certain cases be helpful tohave a straight monoculture hay. For example, when trackingdown possible allergies. [D] Fescues are commonly used to give "bottom" to a sward &to increase its drought resistance, however, high levels ofFescue encourage an increase in its associated parasiticfungus, Epichloe Typina. This is toxic to horses, if eaten.Its mode of action is two fold; firstly it depresses therelease of prolactin, thereby inhibiting mares in theirproduction of milk. Furthermore, it also produces achemical, Chonoclarine I, this depresses levels of cortisoland inhibits mammary gland development. Thus foals cansuffer or even die due to lack of nourishment from theirmothers. [E] Photosensitisation has also been noted due to Aslikeclover being fed, particularly in areas with high copper orselenium levels. Aslike contains a toxin which damages theliver so that it does not drain correctly into theintestinal tract. The obstruction causes the metabolicby-products of chlorophyll to build up in the bloodstream.When exposed to light in the less pigmented areas of a horsee.g.. a white sock , the activated residues cause skin cellsto die in large numbers. [F] Alfalfa & certain clovers have oestrogenic activity,there is no specific evidence that this causes problems,however it is possible that high levels may be associatedwith abnormal oestrus in mare's breeding cycles. [G] Where home production of a conservation crop is to bepractised, it should be noticed that care must be taken withartificial fertilisers. High levels [partic. of Nitrogenfertilisers] have been noted to cause metabolic disorders ingrazing horses. It is also suspected that high nitrogenlevels in forage may adversely effect the development ofbone in young horses.Having decided upon which fields to conserve pH should beconsidered. pHThe pH of ones soil will effect which grasses are mostsuccessful at growing on your land, see table 4 below.
* Below this pH growth is restricted. Control of species within the sward may be assisted by pHcontrol, such as the addition of lime to the land. Feeding CharacteristicsA brief comment about hay & equine nutrition.As the general level of physical performance required from ahorse increases then so should the energy density of thehorses feed ration. This normally means a move away fromhay, towards concentrate.The following table demonstrates typical energy & proteinrequirements of a 500kg Thoroughbred mare, daily.
DE = Digestible Energy - DP = Digestible Protein An adult horse requires between 7 & 8.5% Crude Protein perday and can thus receive his entire quota from hay. Howeverdue to the high energy levels required by a performancehorse, much protein is actually supplied by the concentrateand hay @ 7% CP is quite sufficient. Contrastingly the lactating broodmare & the growing foalwill need higher levels of protein, as above and in general: Foals: 18% CP dropping to 16% CP @ 6 months Weaned foals : 16% CP dropping to 13.5%CP @ 1 year Yearlings : 13.5% CP dropping to 10% CP @ 2 years Initially the CP is provided by concentrate since the foalcannot consume large quantities of hay, but by 2 years ofage most can be supplied by a suitable high protein hay.Thus referring back to Table 2 one can select the correctsward type according to the requirements of the stock to befed. If looked at in slightly more detail then; on a Dry Matterbasis yearlings require 0.4% Phosphorous at a Ca to P ratioof 1.7 : 1. This is similar to the requirements of lactatingbroodmares. Now compare back to table 2 again; it shouldbecome clear how Legume/grass mix hays may provide a goodbalanced basis for the diet of many stud horses. Also notehow partly conserved ryegrass hay could be used as asubstitute {its DM content of circa 55% is slightly drierthan that of haylage hence the term "part conserved"}. ConclusionHorses performing via physical endeavour will perform quiteacceptably when fed on top quality meadow hay though I wouldin preference choose an Italian ryegrass / Timothy mix. Inselecting a meadow hay particular attention should be paidto the actual grass varieties within the crop a mixture ofryegrasses and meadow grasses with some clover being typicalof a good example.However, Broodmares & youngstock could benefit fromreceiving a different type of hay from the competitionhorses above. Grass / Legume mixes are traditionally themost suited however the use of partly conserved forages mustalso be seriously considered. Below are two typical seed mixes {by weight} to provide agood quality multipurpose sward for both equine grazing &conservation. Mix A 50% late perennial ryegrass - multiple varieties 25% standard perennial ryegrass 10% Creeping Red Fescue 5% each - Crested Dogstail, Rough Stalked Meadow Grass, and herb mix incl. white clover Mix B 20% Italian Ryegrass 20% Hybrid Ryegrass 20% Tetraploid Perennial Ryegrass 10% Late Variety Ryegrass 15% Creeping Red Fescue 10% Timothy 3% General Herb mix 2% Wild White Clover BibliographyPasture Management - Gillian Mcarthy Equine Nutrition - AC Leighton Hardman Horse/Stable Management - J Houghton-Brown & V Powell-Smith Equine Injury & Therapy - Mary Bromley Nutrient Requirements of Farm Livestock - various The Thoroughbred Breeders Association M Archer - Equine Research Centre |
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