Default Re: Grainless dod food



Maintenance. A greyhound requires approximately 132 kcal ME/kg body weight0.75 daily under temperature (15 to

25˚c or 60 to 77˚F) conditions.9. For greyhounds weighing between 25 and 35 kg, this equates to 55 to 60 kcal per kg

body weight. An average 30kg (66 pound) racing greyhound housed under temperature conditions requires

approximately 1700 kcal ME/day.2, 3. An excitable greyhound or one housed in a larger enclosure will have a higher

basal metabolic expenditure because of panting, barking, or hyper-activity in the kennel, and may require up to 2100

kcal ME daily additional fat included in the diet will increase energy input without significantly increasing ration bulk.2.

A weight check once weekly will enable adjustment of the fat intake to maintain body weight.

Thermoregulation. A greyhound housed and raced under cold weather conditions, between 10 and 15˚c, will require

an increase in energy at low range ambient temperatures to maintain body warmth.2, 5-7.

As a guide, for every 1˚c (2˚F) decrease in ambient temperature below 15˚c (60˚F), add 3 kcal ME/kg body weight0.75,

or approximately 40 kcal ME daily for a 30kg (66 pound) greyhound.6.

Under cold conditions increasing the amount of dry food (see energy equivalents above) relative to the decrease in

the ambient temperature will help to maintain body heat and body weight. Most greyhounds can consume up to a

maximum of 100 gm extra dry food (about 3 1/3 oz) daily without exceeding bulk or appetite limits. The greyhound

should be weighed at least once weekly to ensure that it is maintaining body weight. If a greyhound loses weight or

requires more energy under cold conditions, extra fat should be added to boost energy intake so as to avoid a

significant increase in the volume of feed the animal has to consume above the additional 100gm of dry food.2, 6. The

housing should be heated to a more comfortable temperature and a rug and adequate bedding provided under very

cold ambient temperatures.

During hot, and especially humid, weather, the energy expended by panting to eliminate excess heat may increase

daily requirements up to 3000 kcal ME for a 30kg greyhound.2. Exercise under these conditions may deplete glycogen

stores more rapidly.3. In addition, hot climates suppress appetite, and a more energy-dense diet boosted with fat will

help limit the ration volume, provide a useful source of metabolic water and minimise heat production from hindgut

fibre fermentation.6, 7.

High ambient temperatures for longer than 4 hours a day when a greyhound is panting will increase energy

requirements. As a guide, for a 30kg (66 pound) animal, each 1˚c (2˚F) increase between 26 and 30˚c (70 and 86˚F),

will require an extra 130 kcal ME daily and 160 kcal ME daily for a similar rise between 31 and 35˚c (88 and 95˚F).

Feeding the Racing Greyhound for Performance Page 6

Thermoregulation (cont.)

Under hot conditions, up to a maximum of 100 gm dry food will provide energy as well as fibre to maintain hindgut

water reserves against panting losses.6. However, for energy needs in excess of this input under hot conditions, as

appetite and feed intake are often reduced, additional fat will meet the shortfall in energy requirement and provide a

metabolic source of water to counteract dehydration.2, 6. A weight check once a week will enable dietary adjustment,

which should also be matched to weather conditions. 2, 6. Adequate electrolyte and fluid replenishment is also

essential during hot weather to avoid dehydration and weight loss.

Racing Expenditure. Total energy expenditure for a greyhound in training and raced under temperature conditions

ranges from 150 to 190 kcal ME/kg body weight0.75, or approximately 1890 to 2390 kcal ME for a 30kg (66 pound)

greyhound.5. It has been estimated that an additional 75 kcal ME is expended in each 30 second trial or race, or 4 –

5% increase over maintenance requirements. Under temperature conditions the expenditure for racing can be

provided by the standard diet.

Behavioural Influences. Excitable, barking and “hard-walking” or hyperactive greyhounds may expend valuable

energy reserves and dehydrate during training and particularly during traveling or when kennelled in the pre-race

period. Although the amount has not been quantified scientifically, a diet boosted with 30 to 60 gm (1 to 2 oz) of fat

or vegetable oil in the pre-race meal about 6 to 8 hours before racing will provide extra energy expended in pre-race

anticipation. Additional fat is recommended for nervous or hyperactive greyhounds that lose body weight, dehydrate,

or perform below optimal levels.2. Regular body weight and condition assessment with appropriate dietary

adjustment are essential to maintain racing weight limits.

ENERGY SOURCES

Carbohydrates, proteins and fat included in the ration blend provide the major sources of energy to meet

requirements.

Carbohydrates

Energy Yield and Food Content. Carbohydrates (sugars and starches) yield 3.5 kcal ME gm,3, 9. and on average,

contribute 40 - 45% of the energy in traditional racing diets.2 Meat is low in carbohydrates, contributing only to 5% of

the total carbohydrate intake from the traditional 70% meat by weight diets.2. Dry foods contribute varying amounts

of carbohydrates, mainly from cereal grains, ranging from 35 - 40% carbohydrates in dry foods containing 27 - 30%

crude protein and 15% crude fat, to 55% carbohydrates in lower protein (13% crude protein, 2 - 3% crude fat), dry

foods or kibbles.2.

Excess Carbohydrates. Excess intake of carbohydrates in the form of cereal grain starches can have a number of

adverse effects in racing greyhounds. High starch intake may increase potential glycogen over storage in muscles,

with resultant accumulation of higher lactate levels and lower clearance rates, and ultimate earlier onset of metabolic

fatigue and risk of exercise rhabdomyolysis or cramping.1, 2, 5, 8.

High intakes of poorly digested carbohydrates, particularly in the form of cereal-based lower-protein human breakfast

or dry dog foods, may also reduce protein and fat digestibility and uptake of sodium, potassium, and calcium because

of their higher fibre content.5. The higher fibre, while helpful in maintaining faecal bulk, increases iliocecal water flow

and results in wetter faeces,5, 6. with less retained as an intestinal reservoir against dehydration during hot weather.6.

Feeding pre-race snacks provide soluble short-chain sugars, such as sucrose (sugar) and glucose (dextrose) and can

lead to increased insulin sensitivity.2, 7, 10. When excess amounts are ingested in the immediate pre-race period,

rebound hyperinsulinemia may be triggered, leading to lowering of blood sugar levels. The combined hypoglycaemia

and the effect of insulin decrease on mobilisation of fatty acids and glycerol from lipid stores may also delay liver and

muscle glycogen replenishment during the pre-race kennel period.2, 7, 10. Both these effects, in theory, can cause a risk

of earlier metabolic fatigues and reduced race performance. In practice, it is widely recommended to avoid feeding

large amounts of soluble sugars in a pre-race “snack” feed, limiting to 15 gm (½ oz) glucose or 60 ml (2 oz) honey

within 4 to 6 hours before racing.2, 6, 7, 10.

Feeding the Racing Greyhound for Performance Page 7

Proteins

Energy Yield and Food Content. Proteins yield 3.5 kcal ME per gram.3, 9. Proteins provide a source of energy, as well

as essential amino acids, for protein synthesis. As a source of available amino acids, greyhound diets should contain

30 - 35% high quality crude protein on a dry matter basis.2, 4. Protein sources contribute, on average, between 35 -

40% of the total energy needs for a racing greyhound.2, 4. Lean meat ranges from 17 - 21% crude protein on an as-fed

basis, or approximately 60% crude protein on a dry-matter basis.2, 9. Dry foods contain a wide range of crude protein,

depending on the content of meat by-products and oilseed protein sources, and commercial products range from 17 -

35% on a dry-matter basis.2. Most greyhound diets based on meat and/or dry foods to satisfy energy demands

contain adequate protein to meet daily requirements.

Excess Protein. High intakes of protein increase the cost of the ration blend, and the elimination of excess poorquality

protein, such as contained in cereal-based dry foods, is an energy-consuming process. It is much more

economical, and metabolically more efficient, to feed a diet containing adequate protein, with additional energy

provided by fat to greyhounds, during hot weather or those competing in longer-distance races.2.

Fats or Lipids

Energy Yield and Food Content. Fat or lipids yield 8.5 kcal ME/gram, or approximately 2.25 times that of

carbohydrates or protein.3, 9. Fats are a useful energy-dense feed that provide an energy boost without adding

excessive volume or weight to the ration.2. The lipids in fats and oils are a palatable, highly digestible source of

energy; greyhound diets should contain at least 12 – 15% fat on an as-fed basis, and greyhounds can tolerate up to 25

– 30% fat on a dry-matter basis.2. Higher fat intake is recommended for excitable, hyperactive greyhounds and during

hot or very cold weather conditions.2.

Both animal and plant oils and fats are highly digestible. Lipids with a high percentage of short-chain (unsaturated)

fatty acids remain liquid (oils) at room temperature.2. As the percentage of long-chain fatty acids increases, the lipid

becomes solid at room temperature as a fat and digestibility is reduced in fats with high long-chain saturated

content.2, 6. Short to medium chain saturated triglycerides, as contained in coconut, canola, palm, and copha are

considered better utilised, as these lipids are digested by pancreatic enzymes without need for bile emulsification.4.

Although it is suggested that up to 25% of the total fat be provided by these sources of short to medium chain

triglycerides,4. greyhounds may not readily accept these items in their diet. Stepwise introduction over 7 to 10 days

may be necessary to obtain acceptance.6.

Excess Fat. High intakes of long-chain saturated fats, such as beef and mutton fat (trimmings or suet) or butter fat,

can reduce overall lipid digestibility, although greyhounds find these animal fats naturally more acceptable. 2, 4.

Animal fat sources are generally cheap to purchase as trimmed fat or omental fat from carcasses. However, if more

than 60 gm (2 oz) of animal-derived fat is required to boost energy content in the ration during hot weather, or in

dehydrated greyhounds, it is preferable to provide additional fat in the form of vegetable oil.2.

Essential Fatty Acids. Greyhounds require essential fatty acids. The diet should contain at least 1% of linoleic acid, an

omega-6 fatty acid, on a dry matter basis, or 2% of ME intake, to prevent the characteristic dry, flaking dermatitis

associated with a deficiency in dogs.11. Linoleic acid is the precursor of other linoleic acid family members, linolenic

and arachidonic acid, if adequate linoleic acid is available in the diet.11.

CONCLUSION

Greyhounds are elite athletic animals which are subjected to extreme physical exertion during racing and the

cumulative effects of environmental, metabolic and physical stress when trained and raced on a regular basis. They

must be provide with a palatable, low bulk, high energy-dense ration, with a medium crude protein and fat content to

maintain competitive speed and stamina within set limits of body weight. An adequate intake of minerals, trace

minerals, electrolytes and vitamins to correct low, imbalanced or inadequate levels in meat-based diets, in particular,

is essential to maintain musculo-skeletal soundness, optimum metabolic activity, strong immune status and overall

health in greyhounds racing between a relatively young age of 15 months to a mature age of between 3 and 4 years.15.

Feeding the Racing Greyhound for Performance Page 8

Table 2: Recommended daily intake (RDI) for a 30 kg resting and racing greyhound on a combined meat and dry

food diet. Updated from Kohnke 2002.15.

Nutrient

Recommended daily intake

(RDI) Practical guidelines for feeding racing greyhounds.

Resting Racing

Calcium 3570 mg 600-800 mg Supplement meat-based diets to 75% of RDI, dry food

diets to 30% RDI: essential in all young greyhounds in

training for musculo-skeletal development.

Phosphorus 2670 mg 5000 mg

Magnesium 246 mg 800-900 mg Add 50% RDI to the diets of nervous or cramping

greyhounds or hot weather.

Iron 20 mg 60 mg

maximum

Add 50% RDI, especially to chicken or fish-based diets

that are inherently low in iron.

Copper 1.8 mg 5 mg Add 50% RDI, especially to chicken or fish-based diets

that are inherently low in copper.

Zinc 21.6 mg 65 mg

maximum

Add 50% RDI to dry foods if calcium is supplemented.

Manganese 3.0 mg 6.0 mg Add 50% RDI to meat-based diets.

Selenium 100 ug/kg diet 200 ug/kg diet Add 100% RDI to high meat diets, 50% to dry food diets

(fish has high Se concentrations).

Iodine 0.36 mg 1.0 mg Add 50% RDI to high carbohydrate diets to optimize

metabolism.

Sodium 330 mg 3000-5000 mg

maximum

Do not add extra if more than 300g dry food with 1%

salt is fed; add 50% RDI to diet in hot weather.

Potassium 2670 mg 4500 mg

maximum

Add 50% RDI in hot weather, cramping, nervous

greyhounds.

Vitamin A

(retinal)

2250 IU

(0.675 mg)

3375 IU

(1.0 mg)

Add 50% RDI to lean-meat diets.

Vitamin D

(cholecalciferol)

240 IU

(0.06 ug)

260 IU

(0.09 ug)

Add 50% RDI to lean meat diets, or 360 IU (1.2 ug) when

calcium is included in cereal-based dry food.

Vitamin E

(tocopherol)

15 IU

(15 mg)

30-100 IU

(30-100 mg)

Freezing meat destroys vitamin E: add 50% RDI to meat

diets and up to 100% RDI in fat-boosted diets or high fat

dry diets. Do not exceed 400 IU daily as it may affect

performance (Marshall 20002 – optimum 100 IU daily,

pre-race 150-200 IU).

Thiamin

(Vitamin B1)

600 ug 1.8 mg Add at least 50% RDI to meat-based diets.

Riboflavin

(Vitamin B2)

1.5 mg 4.5 mg Add 100% RDI to fat-boosted diets.

Niacin 6.75 mg 20 mg Add 50% RDI daily when racing regularly on high energy

diets.

Pantothenate 6.0 mg 18 mg Add 50% RDI to diets containing cooked foods (stews)

Pyridoxine

(Vitamin B6)

0.6 mg 2.0 mg Add 50% RDI to high protein dry foods.

Cyanocobalamin

(Vitamin B12)

15 ug 45 ug Add 100% RDI to chicken or fish-based diets, which are

inherently low in vitamin B12.

Folic acid (folacin) 120 ug 360 ug Add 50% RDI to all racing diets.

Vitamin C Internally

synthesised

250-300 mg

can be

supplemented