CALCULATING A FEED RATION Factors to consider • • • • • • • • • • • Present state of condition and health. Size and type. Age. Weight. Amount of work. Temperament. Ability of rider. Weather (horse in / out?). Cost-effectiveness. Availability of foodstuffs. Feed storage and ease of handling. Assessing condition in horses • The horse’s condition can be described as GOOD or BAD. Soft • Good condition Hard • Bad condition Underweight Overweight • Good condition - Carrying an appropriate amount of weight for the stage of training or work required. Thriving appearance. Signs of good health. • Soft - Well but not fit. Slack muscles. Slightly fat but not unhealthy. Incapable of sustained effort without sweating / distress. e.g. turned away / post injury. • Hard - Well and fit. Free from excess fat (internally & externally). Muscles hard / well developed and clearly defined. Limbs toned. e.g. hunter in regular work / competition horse. • Bad condition - Not carrying the correct amount of weight for the work required. Not thriving. • Underweight - No layer of fat under skin. Underdeveloped muscle. Neck, shoulders, quarters very thin. Bones prominent. Skin / coat dry & dull. Lacking energy. Cannot fight infection or withstand the cold. • Overweight - Gross, pads of fat. Neck, crest, shoulder, quarters. Moving is an effort leading to distress. Internal organs are covered in fat, causing excess strain. Limbs suffer due to extra burden. • Other terms to describe condition: • • • • Gross / Obese = Light = Poor = Emaciated = Fat Short of ideal Short of flesh, dull coat Skin and bone • Condition is assessed by using the “condition scoring” system. • This measures the weight distribution over the neck, back, ribs and quarters. Step 1. Calculating the horse’s weight • How big is the horse? Either measure or estimate. • Ideally, use a weighbridge. • Weightapes – measure around the girth and they give an approximate weight. • Formulae - Girth & body length measurements – measure around the girth (G) & from the point of shoulder to the point of hip (L) and use the following equation: • G(cm) x G x L(cm) = Bodyweight (kg) • 8700 • G(in.) x G x L(in) = Bodyweight (lb) • 241.3 or Table of approximate bodyweights: Type Height (h.h.) Approx. weight (KG) Approx. weight (lb) Pony 13.0 300 660 Large pony 14.2 425 950 Small hunter 15.2 500 1100 Medium hunter 16.0 575 1250 Large hunter 16.3 650 1500 Draft / shire 17.0 1000 2200 Step 2. Calculating total daily feed requirement • A horse can eat up to 2.5% of its bodyweight daily, although it does not have to eat the maximum. • Calculation used: • Bodyweight (kg) x 2.5 = Max. daily amount of food kg 100 • For example – a 15.2hh small hunter weighs approx. 500kg. • 500 x 2.5 = 12.5kg (28lbs) (to convert kg to lbs x 0.25) 100 • Quantity then needs to be adapted to suit the individual & the circumstances. Step 3. Roughage: concentrate ratio • Total daily feed intake is split into the hay / haylage / grass ration & the concentrate ration. • Based mainly on the horse’s workload. Work done Roughage Concentrates Resting 100% 0 Light work 80% 20% Medium work 65% 35% Hard work 50% 50% • The percentages then have to be converted into weights of feeds. • For example, the 500kg horse being fed 12.5kg food / day. • If being fed 75:25% R:C • 12.5 / 100 x 75 = 9.38kg roughage / day • 12.5 / 100 x 25 = 3.13kg concentrates / day EXERCISE • Individually, work out a ration for your own horse or one that you care for. • State the height & type & estimate the weight. • State the work done & temperament etc. • Calculate the total daily feed requirement & roughage : concentrate ratio. • Calculate the weights of the roughage & concentrates. • Suggest suitable types of feed & forage. Step 4. Protein requirements • Suggested protein levels in the total ration: • • • • Light work Medium work Hard work Strenuous work 7.5 7.5 8.5 8.5 – – – – 8.5% 8.5% 10% 10% • • • • • • • • Pregnant mares Mares in last trimester Lactating mares Foals Weaned foals Yearlings 2 year olds 3 year olds 8 – 10% 11-13% 14 – 12% (gradually decreasing) 16-18% 14.5 – 16% 12-14% 10 – 12% 8.5 – 10% Step 5. Calculating digestible energy requirements • Maintenance • Horses need 18MJ plus an extra 1MJ for each 10kg of bodyweight. • 18MJ + bodyweight (kg) 10 • e.g. a 500 kg horse • 18 + 500 = 68 MJ of DE / day 10 • Production • For work, add 1-8MJ for each 50kg of bodyweight, according to how hard the horse is working. • Work score x bodyweight + maintenance DE 50 • e.g. a 500 kg horse in medium work (some cantering): • 3 x 500 = 30MJ + 68MJ DE = 98MJ of DE / day 50 • (Add extra MJs for lactation, pregnancy and growth.) Scale points for level of work Category Light work Medium work Hard work Fast/ energetic Scale point Activity 1 1 hour walking 2 Walking & trotting 3 Some cantering 4 Jumping, schooling, dressage, driving 5 Eventing, cross-country, driving, hunting, endurance 6 Hunting 2 days / week, 3-day eventing 7 Racing 8 Racing Step 6. Allocating feed types • You have calculated the daily intake, the roughage: concentrate ration, and the energy requirements. • You now have to decide on what types of feeds to give. • Start with the roughage. Use this as your base and try to give the energy requirements as closely as possible through the roughage. • Any shortfall can then be made up with the concentrate portion of the ration. • Does the horse need high energy or low energy foods? • Does the horse need quick releasing or slow releasing energy? EXERCISE: Suggest a suitable daily diet for a 14.2hh horse doing 1 hour of walking / day: Feed type Quantity e.g. fed kg / day Hay DE / kg Haylage Cool mix Hi-fi Sugar beet Total DE / day in diet: DE total MJ / day EXERCISE: Suggest a suitable daily diet for a 16hh horse hunting twice a week : Feed type Quantity e.g. fed kg / day Hay DE / kg Haylage Total DE / day in diet: DE total MJ / day EXERCISE: Suggest a suitable daily diet for a 15hh race horse: Feed type Quantity e.g. fed kg / day Hay DE / kg Haylage Total DE / day in diet: DE total MJ / day EXERCISE: Suggest a suitable daily diet for a 15.2hh horse doing schooling & dressage: Feed type Quantity e.g. fed kg / day Hay DE / kg Haylage Total DE / day in diet: DE total MJ / day Step 7. Reconciling the ration • If the total DE content of the daily diet far exceeds the horse’s requirements, or vice versa, you could manipulate one or more of the following: • Maximum daily appetite from 2.5% of bodyweight to as little as 2% of bodyweight. • Roughage : concentrate ratio. • Choice of feed types. • Proportions of different feeds (particularly concentrates). • Workload. Step 8. Monitoring • Ongoing monitoring of the horse’s response to its diet is vital (i.e. condition scoring), to gauge whether she is loosing / gaining weight or maintaining a desirable body condition. • The diet can then be manipulated to take the response into account.