Camels are remarkable animals that have evolved with a ruminant like digestive system to enable them to survive on low quality, fibrous feeds. Being browsers, camels are able to select high quality diets, which they can efficiently digest.

Camels have lower energy requirements than ruminants, and have evolved an efficient mechanism for nutrient recycling.

Camels have the ability to perform muscular functions such as racing at a level of intensity that exceeds the ability of horses. This unique capacity reflects the lower energy requirements for locomotion, the higher glucose supply, the lower oxygen demand, and preferential dependence on slow twitch muscle fibres which in turn rely on aerobic metabolic pathways.

For short distance, high intensity races, camels need high energy feeds to meet the additional energy demand. As with both horses and cattle, inclusion of high levels of grain in camel diets can cause metabolic disorders. Oil supplements provide energy, however the slow rate of metabolism of traditional polyunsaturated oils makes them of limited use in short distance, anaerobic metabolism races.

By comparison, tropical oils such as coconut oil are rich in medium chain fatty acids which are readily absorbed and metabolised providing an available source of cool energy.

The opportunity is to feed racing camels Cool Stance? to provide readily metabolisable energy, without causing carbohydrate overload. EzyCube? provides digestible fibre and cool energy.

1.   Background

Little research has been done on the digestive physiology and nutrition of camels. Camels are pseudo-ruminants, with a simple chambered forestomach, and is unlike the four chambered stomach found in cattle and sheep. Never the less, camels can digest high fibre feeds via fermentation pathways similar to those in true ruminants.

Camel racing is a major sport in the Middle East, with camel races over distances from over 5 to 40 km. Even though camels are pseudoruminants, the expectation is that they perform like a horse. Horses can sustain high levels of muscular exercise, because of the power to weight ratio, the balance of muscle fibre types (fast twitch and slow twitch fibres) and the forms of energy provided  by digestion.  Horses rely on energy sources which provide an immediate supply of ATP for explosive/intense muscular function. These energy sources include carbohydrates, oils, and muscle glycogen.

By comparison, ruminants rely primarily on volatile fatty acids from rumen fermentation to provide energy. These energy sources generally do not provide an immediate supply of ATP to support explosive muscular function for racing.

In practical terms, ruminants are unable to sustain intense muscular exercise and fatigue quickly. By comparison, horses can sustain both high levels of intense muscular exercise, and long term endurance exercise.

The challenge therefore is to feed camels (a pseudo-ruminant) to produce energy sources which support intense muscular exercise to enable them to perform like a horse.

2.   Camel racing

Camel race distances vary from 5km to over 40km. Camels naturally pace, and can maintain average speeds 35-40 km/hour for considerable distances, and for over 30-60 minutes. Camels can gallop at speeds well over 40km/hour, however they tire easily.

By comparison, the track record for the 3200m Melbourne Cup is held by Kingston Rule in 1990 - 3 minutes 16.3 secs, or 60km per hour.  Over a 10 to 40 km distance, horses would average approximately 20-25 km/hour.  Therefore even though camels are pseudo-ruminants, they have the capability to race at speeds similar to horses,  over longer distances, and for much longer times.

3.   Physiology

Camels are a member of the suborder Tylopoda, which is located between the suborders Suina (including pigs) and Ruminantia (including cattle).  Camels have adapted to the harsh arid environments inhabit allowing them to maximise the digestion of low quality feeds to a greater extent than ruminants. Through browsing, camels are able to select a high quality diet. There is a lack of research into camel nutrition and data is often extrapolated from ruminants (Ellard 2000, Manefield and Tinson 1997).

With racing camels, the aim is to feed a pseudo-ruminant to perform like a horse.  That is, to provide digestible energy (DE) to supplement the energy from roughage to meet the energy demands for high intensity exercise. In horses, the additional DE is traditionally provided by feeding grains together with digestible fibre. It is now known that feeding high levels of starch to both ruminants and horses is the main cause of temperament changes (fizzy or hot behaviour), and metabolic disorders including colic, laminitis and tying up. The effects of starch have been alleviated in most cases by replacement of dietary starch with digestible fibre and non starch, energy feeds such as oil. Anecdotal evidence suggests that camels also suffer from temperament changes and metabolic disorders on high grain diets.

3.1.              Rumen

The mucosal membrane of the ?rumen? in camels is smooth, which is different to all other ruminants. The rumen sacculations contain accessory salivary glands which aid in recycling to the rumen during periods of water deprivation.  Like ruminants, the camel ?rumen? contains bacteria and protozoa.

The recycled saliva is very alkaline, and subsequently the pH of the rumen is normally pH 7.5. In the wild, the camels can browse most types of vegetation, and the rumen can operate as an efficient organ. With hand feeding grains and short chopped roughages however, the incidence of  rumen dysfunction is greater.

The omasum in camels is also very different to that in cattle. The mucous membrane is glandular, and is not packed in leaves as seen in cattle. It is joined directly to the abomasum, and the contents are moist. This contributes to the higher efficiency of digestion in camels.

Physiology of exercise

The energy cost of locomotion in camels is considerably lower than horses at moderate to high speeds. At 15km per hour, the horse requires 25% higher energy, and at 30km/hour, the horse requires 50% more energy than camels.  The energy cost of locomotion (ml O2/kg at 22 km/hour) was 85 in camels compared with 160 in horses.

The lower energy cost for locomotion in camels relates to the combined effects of

• musculoskeletal function. Unlike cattle, camels have less fusion in the bones of the lower leg which allows them to move faster and more efficiently (Ferguson 1997)
• camels pace rather than gallop,
• low oxygen requirement. The maximal capacity of an animal to exercise aerobically is determined by oxygen consumption. VO2max is a measure of aerobic capacity, and is the volume of oxygen consumed during a minute of exercise. The aerobic capacity of camels (VO2max) was 53ml/kg/min at 30km/hour, which is significantly lower than that in thoroughbreds (100-160 ml/kg/min). The VO2max in cattle was 55-60 ml/kg/min. This reflects the very low oxygen requirement of camels for rest and exercise in comparison with horses
• higher lactate threshold. Camels can perform at high levels of intensity before lactate accumulates in the blood. It is considered that 4mM/L of serum lactate represents the anaerobic threshold in many species, ie the level of exercise above which aerobic exercise is supplemented by anaerobic exercise. The Lactate Threshold is the level of exercise beyond which the rate of lactate production from pyruvate exceeds the rate that pyruvate is used in aerobic energy metabolism in the mitochondria. The accumulation of lactate causes a block to energy production, and rapid muscle fatigue. 

Camels will perform at up to 95% of VO2max before plasma lactate levels reach 4 mM/L, whereas this occurs in other species at 50-60% VO2max..  Elite horses, have lactate thresholds at or above 80% of VO2max. Camels can achieve this normally.

• At rest, the racing camel depends on lipid combustion to provide energy substrates. At low, submaximal speeds, carbohydrates are the dominant fuels, and there is a good balance between lactate metabolism and accumulation, because lactate does not accumulate until close to VO2max. Camel has extraordinarily high Krebbs cycle activity.

3.2.              Muscle fibres

There is a large variation between muscle types, and between camels in the proportion of Type I and Type II muscle fibres. Camels predominantly have slow twitch, slow contracting  fibres (Type I) suitable for endurance exercise. Type II, fast acting fibres (for explosive exercise) are not common. Camel muscles have very high levels of oxidative enzymes compared to horses. Camels can utilise various types of energy substrate for ATP production for muscular activity, ie glycogen, oil, glucose, lactate, and amino acids (Saltin et al 1994).

3.2.1. Endurance.

During endurance exercise (20km/hour for 90 minutes), camels preferentially use slow twitch muscles (Type I), which use aerobic metabolic pathways to supply ATP from glycogen and fat.

3.2.2. High intensity exercise

High intensity exercise in camels is in an 8 km race where speeds exceed 33 km/hour. During high intensity exercise, camels use fast twitch (Type II) fibres, and rely on anaerobic metabolism of glucose to produce ATP.  Once anaerobic metabolism is activated, metabolic acidosis due to lactate accumulation quickly occurs. Camels take longer than horses to clear lactate, however they can quickly restore muscle glycogen.

In horses sprinting over short distance races, the aerobic energy system still provides up to 70% of the total energy (Davie, 1999). This emphasises the importance of the type of energy substrates supplied to support the aerobic energy system and anaerobic energy systems.

4.   Energy metabolism

4.1.              Energy systems to provide energy for exercise

Camels have a continual energy demand for maintenance and muscular performance.  The form of energy in the muscle cell is adenosine triphosphate (ATP), and is the only energy source that can be used for muscular contraction. ATP is stored only to a limited extent in cells, and so ATP must be produced from other sources by chemical reactions . These sources of ATP include creatinine phosphate (which is converted directly to ATP) or feed sources (glucose, fats and proteins). ATP is supplied  from the feed sources either by aerobic or anaerobic chemical pathways (from Davie 1999).

4.1.1. Aerobic metabolism

Aerobic metabolism is the use of oxygen to burn fuels (carbohydrate/fat) to supply ATP.  This energy source yields high levels of ATP, but more slowly than the anaerobic system. This is the main energy source for endurance and low intensity exercise.

4.1.2. Anaerobic metabolism

Anaerobic metabolism produces ATP very rapidly from glucose/ glycogen without the use of oxygen, and produces lactic acid. Lactic acid production of the muscle causes muscle fatigue. The rate of energy production is very high, and is the main energy source for explosive or sprint energy. The total contribution of the anaerobic system even under intense exercise is only 30%.

Camels have an inherent capacity for anaerobic activity, and can clear lactate efficiently.  The challenge is to increase glucose supply to the racing camel, without causing starch overload, and metabolic disorders. ATP sources such gluconeogenic amino acids, and medium chain fatty acids provide an alternate to starch based diets.

5.   Nutrition

5.1.              Feed intake and digestibility

Camels have a lower dry matter intake than cattle or horses. Camels typically consume only 1.7% of bodyweight as dry matter, compared with 3-4% bodyweight for horses and cattle. Camels require 70% of dry matter intake as roughage. Camels typically have higher digestibility coefficients compared with ruminants.

Camels can efficiently digest low quality roughage?s because of the wide range of ruminal microflora which can adapt to a range of forages, active rumination, and high levels of urea recycling.

5.2.              Fermentation

Camels produce the volatile fatty acids acetate, propionate and butyrate from fermentation in their forestomach, in similar molar proportions to ruminants given roughage based diets. Compared with ruminants, camels can extract more energy from the food they consume. This has been attributed to their specialised metabolism of glucose and urea recycling (Abdel Fattah et al 1999).

5.3.              Energy

The ME requirement for maintenance in camels is lower than for cattle. A 450kg camel requires only 37 MJ ME for maintenance compared with 52 MJ ME for cattle.  The DE requirement for a 450kg horse is 48 MJ DE/day, which approximates 40 MJ ME/day. Camels therefore have an energy requirement similar to horses for maintenance.

Racing camels have an energy requirement of 2 MJ ME/ km travelled, ie an additional 20 MJ ME for an average 10km race. For feeds with an energy density of less than 10, this represents an additional feed intake of over 2 kg/day, which is a 25% increase in feed intake. The challenge therefore is to increase energy intake without increasing the amount of bulky feed, and without causing rumen dysfunction by feeding excess grain.

Camels, like horses have an increased energy demand for muscular function for racing, which requires supplementation of the basal diet with an additional energy source (Manefield and Tinson 1997) from hay or grain.

5.4.              Glucose metabolism

The blood glucose concentrations (130 mg/100ml) in camels are much higher than in ruminants (63 mg/100ml) and horses (90 mg/100ml) (Table 1), despite having a ruminant pattern of digestion which does not yield glucose for absorption.

Although the glucose turnover rate is similar between camels and sheep (1.7 mg/min/kg bodyweight), when corrected for metabolic body size, camels have a glucose entry rate at least 60% greater than in sheep (4.3 and 2.6 mg/min/kg Bwt0.75) (Chandrasena et al 1979).

Camels have higher concentrations of the hormone glucagon compared with other mammals. The role of glucagon is to increase glucose output from the liver by increasing glycogenolysis (glucose from glycogen) and gluconeogenesis (glucose from amino acids) (Abdel Fattah, 1999).

Camels therefore produce greater quantities of glucose compared with true ruminants, presumably as a survival mechanism. This also allows camels to produce higher levels of ATP from glucose for muscular function, and highlights the importance of feeds that can provide glucose or glucose forming substrates (gluconeogenic amino acids).

5.5.              Oil

Camels can store fat efficiently in their hump, and in the adequately fed camel, the hump can represent 20% of the camel?s total body weight (Mirgani 1981).  The oxidation of fat in adipose tissue yields more energy (1g fat=9.3 kcal) than the oxidation of carbohydrates (1g=4.2 kcal).

Racing camels require an additional 2.0 MJ ME /km travelled (Manefield and Tinson 1997), and therefore require an additional energy dense feed in addition to roughage. It has been suggested that inclusion of energy dense oils in racing camel diets may be beneficial. Up to 200g/day of protected fat has been fed without causing metabolic and nutritional disorders. Little research has been conducted however into the type and nature of dietary oil (Manefield and Tinson 1997).

Oils are useful feed supplements to provide slow release energy for endurance exercise, or long distance races.  It is believed that camels don?t begin to metabolise fat stores until after a period of 1.5 hrs of submaximal exercise (20km) suggesting that energy provided by fats is only of importance for endurance races (Manefield and Tinson 1997). It is further suggested that oils are of no value for short races (8-10km) because of the slow metabolism of oils.

Research suggests that the maximum oil inclusion in camel diets is 3%, because of the effects of oil on reducing fermentation. There is no information available on feeding different types of oils to camels.

In cattle, it is the free fatty acid concentrations that impact on rumen fermentation, and not the total fat concentration. In ruminants, rumen function is impaired at free fatty acids (FFA) at levels greater than 3-4% in the diet. For example, polyunsaturated oils such as canola and soybean contain approximately 80% FFA, and so can only be fed at 3-4% of the diet. By comparison, saturated oils such as coconut oil contain only 30- 35% FFA, and so can be fed up to 9-10% of the diet.

In horses, polyunsaturated oils which are long chain (C18) are slowly absorbed into the lymphatics and then slowly metabolised in the liver. By comparison, medium chain fatty acids (C12-C14) such as in coconut oil are readily absorbed into the portal blood and metabolised in the liver.

Saturated oils such as coconut oils have been shown to be beneficial energy sources to both cattle and horses, and may well be beneficial to racing camels as an energy substrate. Coconut oils can be fed at higher levels, and are more readily digested and absorbed compared to polyunsaturated oils.

5.6.              Protein

Basal protein requirements in camels (450 kg bodyweight) have been estimated at 300g DCP / day for adult working and racing camels.

Nitrogen retention in camels is greater than sheep given a diet of 4% crude protein. During a state of dehydration the camel?s nitrogen retention is increased by 150%, whereas in sheep it is only increased by an increment of 34% (Manefield and Tinson 1997). Supplementation of urea has found to have a variable effect on the VFA producing microbes in the camel. (Mostafa et al 1984).

Camels recycle greater quantities of urea to the rumen, which in turn would support higher levels of digestion. It is reported that young camels given low protein diets respond well to supplements of bypass protein, as shown with weaner sheep and cattle. Proteins with a high biological value give the best results.

6.   Grain feeding

The main source of roughage for the racing camel is fresh cut alfalfa. Typically, much of the camel?s energy is derived from barley. A normal diet for the racing camel consists of ?10kg of alfalfa tops, 3-4kg of soaked whole barley, 1kg dates, 2L of fresh milk, occasional hay, and some electrolyte, vitamin and mineral supplements? (Manefield and Tinson 1997).

Although camels perform well on these diets, they often suffer digestive upsets including colic and rumen dysfunction, similar to grain poisoning in cattle.  Cool Stance? could be fed to replace the grain.

7.   Comparison of camels with cattle and horses

Table 1.      Comparison of camels with cattle and horses (450kg)

8.   Role of copra meal  in the nutrition of racing camels.

? The successful racing camel feeder must walk a fairly fine line between a ration which is to bulky and gut filling to allow the camel to produce optimum performance, and one which is too energy concentrated and low in fibre to permit healthy rumen function? (Manefield and Tinson, 1997)

Racing camels require energy to meet the short term, high energy demands for explosive exercise for short distance races. This is similar to the energy demands of high performance horses, including race horses. In horses, the demand for energy sources that yield high levels of ATP for rapid muscular function is usually met by feeding starches, which are readily digested in the intestines to yield glucose. Horses have a limit to the amount of starch they can digest, and can suffer starch overload as exhibited by laminitis, colic, tying up and fizzy behaviour.

Being ruminants however, camels rely on energy supply from the fermentation of roughage?s to yield volatile fatty acids. Normally in ruminants, there is little starch digested in the intestines. Feeding high levels of starch to increase energy supply can cause acidosis in the rumen and hind gut of ruminants, causing acidosis and laminitis. Similar effects have been observed in grain fed camels.

Oils are energy dense feeds, and can be fed to both ruminants and horses to avoid the metabolic disorders associated with grain feeding. Not all oils behave the same however. Polyunsaturated, long chain oils including maize, canola, and soybean oil will disrupt rumen function when fed to cattle above 3%. In horses, these oils are slowly digested, absorbed into the lymphatics and slowly transported to the liver and metabolised. Polyunsaturated oils are not a source of energy for explosive exercise.

By comparison, saturated oils such as coconut oil can be fed to ruminants at much higher levels without disrupting rumen function, because they have a lower FFA content. Further, coconut oil is unique in that is contains high levels of the medium chain fatty acids (MCFA) (lauric and myristic) which are absorbed into the portal blood and transported directly to the liver. For this reason, coconut oil is used as a source of ?Cool Energy? for explosive exercise in high performance dogs and horses.

9.   KEY ADVANTAGES OF copra meal for racing camels:

Cool Stance is derived from the white part of the coconut, after the coconut oil has been extracted. Cool Stance? typically contains 22% crude protein, very little starch, 10% oil, and 15 MJ DE for horses, and 12.5 MJ ME for cattle.

9.1.        Palatable and dust free

Cool Stance? is palatable to both horses and cattle. It can be fed dry or as a wet mash.

9.2.              Feeding rates

Cool Stance? can be fed together with roughage as the sole feed for most performance horses. With high intensity exercise such as with  pacers, trotters and race horses, there is need for some starch to augment the supply of ATP for explosive muscular activity.

Feeding rates are 1-4kg/day, together with a supply of medium quality roughage.

9.3.                 Energy

Cool Stance contains high levels of Digestible and Metabolisable Energy from the oil and digestible fibre. It contains very little starch, and does not cause metabolic disorders in cattle or horses.

9.4.              Oil.

Cool Stance contains 10% coconut oil, which is saturated and has 40% lauric and 20% myristic acids (MCFA?s). These provide readily available ATP for both explosive and endurance exercise.  Cool Stance is widely used as a horse feed to provide Cool Energy for performing horses.

9.5.              Protein

Cool Stance contains 22% crude protein of which at least 70% bypasses rumen fermentation, that is 140g protein/kg Cool Stance passes to the small intestines. The protein in Cool Stance contains high levels of the gluconeogenic amino acids glutamine, alanine, glycine and serine which are readily converted to glucose to provide energy.  The bypass protein in Cool Stance therefore could be an important source of glucose for racing camels, and could supply 75g glucose/ kg Cool Stance fed.

9.6.              Storage

Cool Stance stores well, even in hot climates provided that it is stored under cover. The oil in Cool Stance is saturated, and therefore wont go rancid. Further, since Cool Stance contains very little starch, it does not ferment, and does not attract rodents.

9.7.              Feeding rates

It is recommended that Cool Stance could be fed at rates from 1- 3 kg/day to racing camels in place of grains such as barley.

10.        Copra meal and Date pip's for camels.

10.1.           Composition of copra meal and date pips.

Source: www.hort.purdue.edu

10.2.           Dates

Dates traditionally form part of the diet for camels, and provide a good source of metabolisable energy (ME) from the oil and carbohydrate.

The oil in dates is primarily long chain, unsaturated fatty acids (LCFA), which are slowly metabolised, and prone to rancidity.  The carbohydrate in dates will ferment, and become unstable if not stored correctly. Dates provide little protein, and no bypass protein.

10.3.           Copra meal .

Copra meal contains  only 11% NSC, and provides the energy from oil and digestible fibre.  Over 90% of the oils in coconut oil are saturated, and 75% are medium chain fatty acids (MCFA). The significance of MCFA is that these oils are absorbed and transported directly to the liver, and rapidly metabolised. By comparison, LCFA are  absorbed and transported by the lymphatics, and slowly metabolised.  Cool Stance? contains reasonable levels of bypass protein, which is essential for the performing ruminant animal such as racing camels.

10.4.           Feeding Copra meal  and Dates

Copra meal provides an ideal complimentary feed to dates for performance camels. Cool Stance? can be fed to replace grain.

Dates provide

• explosive energy from the carbohydrates,
• endurance energy from the LCFA.

Copra meal provides

• additional explosive energy from the MCFA,  without causing carbohydrate overload
• the MCFA in copra meal compliments the LCFA in dates.
• a source of bypass protein
• a source of amino acids and glucose from the bypass protein
• digestible fibre

11.        References:

Abdel-Fattah, M., Amer, H., Ghoenim, M.A., Warda, M. and Megahed, Y. (1999) Response of one-humped camel (Camelus dromedaries) to intravenous glucagon injection and to infusion of glucose and volatile fatty acids, and the kinetics of glucagon disappearance from the blood. J. Vet. Med. 46; p473-481.

Bhattacharya, A.N., Al-Mutairi, S., Hashimi, A. and Economides, S. (1988) Energy and protein utilisation of lucerne hay and barley grain by yearling camel calves. Anim. Prod. 47; p 481-485.

Cahill, L.W. and McBride, B.W.( 2003) Effect of level of intake on digestion, rate of passage and chewing dynamics in hay-fed Bactrian camels (Camelus bactrianus).

Chandrasena, L., Emmanuel, B. and Gilanpour, H. (1979) A comparative study of glucose metabolism between the camel (Camelus dromedaries) and the sheep (Ovaris aries). Comp. Biochem. Physiol. 62A; p837-840.

Davie, A (1999). A Scientific Approach to the Training of Thoroughbred Horses. Norsearch Reprographics ISBN 0646382802

Ellard, K. (2000) Development of a sustainable camel industry, Part 1. Western Australia. RIRDC publication no 99/118.

Faye, B., Saint-Martin, G., Cherrier, R. and Ruffa Ali. (1992) The influence of high dietary protein, energy and mineral intake on deficient young camel (Camelus dromedaries)-I. Changes in metabolic profiles and growth performance. Comp. Biochem. Physiol. 102A; p409-416.

Faye, B., Saint-Martin, G., Cherrier, R. and Ruffa, Ali. (1992) The influence of high dietary protein, energy and mineral intake on deficient young camel (Camelus dromedaries)- II. Changes in mineral status. Comp. Biochem. Physiol. 102A; p417-424.

Manefield, G.W. and Tinson, A.H. (1997) Camels, a compendium. The TG Hungerford, Vade Mecum series for domestic animals, series C, No.22. University of Sydney Postgraduate Foundation in Veterinary Science.

Mostafa, M.A., El-Hindy, H., Abd El-Aziz, S.A., Abd El-Salam, S.A. and Wasfy, M.A. (1984) The in vitro utilisation of urea and its effect on volatile fatty acids in ruminal fluid of Egyptian camel supplemented with protein-free diet. Indian Vet. J. 61; p922-925.