HKHPE 07 03

Where is the elephant able to live now, and where not? How much dry plant matter, energy, and protein does the elephant need, in order to maintain its body weight, to grow and to nurse its young? How much aboveground dry matter and crude protein must grow, where the elephant is still able to live comfortably on its normal range? How much food must grow, where the elephant is still able to live, at the lower limit of its range? And how much food has grown, where the elephant is starving to death? What have some of the world’s leading elephant experts found out about this now?

Ellen S. Dierenfeld, Department head, Nutrition, Wildlife Conservation Society, Bronx Zoo Wildlife Conservation Park, U.S.A., is also nutrition advisor at the Elephant Research Council. She writes about "Nutrition composition": "Based on averages from 41 plants listed by Sukumar (1989) and stomach contents from over 700 elephants sampled in Uganda (McCullagh, 1969), diets consumed by elephants contained 8 to 13% crude protein (range 2-26% of dry matter). These numbers are similar to those listed by Williamson (1975) for plants eaten by elephants in Zimbabwe, Bax and Sheldrick (1963) in Kenya, and Meissner and colleagues (1990) in South Africa.

"Browses and herbs eaten by elephants contained higher protein levels (12 to 18%) in all seasons, whereas grasses varied from 3 to 12% crude protein throughout the year. Crude, rather than available protein was reported in these studies; true protein values of browses may be considerably lower (up to 50%) due to chemical binding of nitrogen. While diets containing a yearlong average of 8% crude protein have been shown to be at least marginally adequate for elephants, growth appears inhibited seasonally below that level, with possible protein deficiency (McCullach, 1969)." (1994:70).

"Elephants digest only about 40-50% of dietary matter. Thus total diets eaten should contain at least 4.0 Mcal/kg dry matter as gross energy to provide the 2.0 Mcal/kg required by domestic equids. Diets for young growing animals should contain at least 2.45 Mcal/kg of digestible dry matter, obtained from milk and forages.

"African and Asian elephant diets: mature, maintenance: Digestible energy: 2.0 Mcal/kg. Crude protein: 10-12%. "Dietary crude protein requirements (dry matter basis) for horses range from 8% for mature maintenance up to 15% for young growing animals. These numbers fit well with derived protein requirements for elephant in Table 1 (elephant milk would provide 9-15% digestible crude protein on a dry basis). Absolute minimal digestible dietary protein for adults would thus be set at about 4% of diet dry matter intake (8% crude protein in diet x 50% digestibility of that protein), providing 1300-2080 g of protein per day (32.5-52.0 kg dry matter x 4.0% (digestible) crude protein).

"Protein malnutrition was assessed in a group of young elephants fed a diet comprising timothy hay, sweet feed, and supplemental minerals and vitamins; the diet contained 5.5% crude protein, well below the known requirements to support growth in any mammal (Ullrey, 1985). Diets were corrected by following nutrient guidelines for growing horses (see Table 1), and most animals recovered." Most of these young elephants were saved, when one gave food to them, containing 12-15% crude protein. – Dierenfield, E. S. (1994:70-75).

How much food does the adult Asiatic elephant need per day, in order to maintain its body weight? How much dry matter, digestible and metabolizable energy, and digestible crude protein does it need?

Francis G. Benedict, Director, Nutrition Laboratory, Carnegie Institution of Washington, D. C. has studied the nutritional requirements of the Asiatic female elephant, named "Jap". She was then about 40 years old and weighed 3672 kg. Jap ate 45.89 kg dry matter a day. Thus she needed 97.28 g DM/kg^0.75 per day for maintenance. Her food contained 1.133% nitrogen. And 1 gram dry matter contained 4.5 kilocalories of gross matter. She digested 43.8% of the dry matter, 48% of the nitrogen, protein, and 40.0% of the gross energy.

Basal metabolism of Jap lying down: 49 000 kcal per 24 hours. Thus, the basal metabolism of Jap, when lying down, was 104 kcal/kg^0.75 per day. How much digestible and metabolizable energy did this non-lactating elephant cow need, in order to maintain her body weight, when standing, feeding, and walking around a little?

She ate 45.89 kg DM (hay) x 4.5 kcal/g GE = 206 496 kcal/day. She digested 43.8% of this dry matter. Thus, she took in then 90 445 kcal digestible energy per day. That is 192 kcal DE/kg^0.75 per day for maintenance.

The metabolizable (changeable) energy is the digestible energy x 0.82. Thus, Jap took in 74 165 kcal ME/day. That is 157 kcal ME/kg^0.75 day for maintenance. The lowest value for standing, feeding, and minimum activities was 64 800 kcal per day. That is 137 kcal ME/kg^0.75 per day.

We may even calculate the metabolizable energy, Jap needed, still more accurately: She weighed 3672 kg and took in 206 500 kcal gross energy (GE) per day, digesting 43.8% of this gross energy. Hence, she needed 192 kcal DE/kg^0.75 per day to maintain her body weight.

Jap metabolized 33% of the gross energy (GE). That is 68 145 kcal ME per day and 144 kcal ME/kg^0.75 per day for maintenance.

Comment: There were 4.5 kilocalories, not 4.5 calories per gram in Jap’s food (dry weight), as Francis G. Benedict wrongly stated in his book, The Physiology of the Elephant (1936) page 165. The gross, digestible, and metabolizable energy, given by Benedict, is, therefore, kilocalories, not calories.

Francis G. Benedict, Director, Nutrition Laboratory, Carnegie Institution of Washington, with Jap, the Indian female elephant. She was then about 40 years old and weighed about 3672 kg. Benedict, The Physiology of the Elephant (1936) found out, how much digestible crude protein and metabolizable energy she needs per day, to maintain her body weight. Jap needs 3.228 g DCP (gram digestible crude protein) and 144 kcal ME/kg ^0.75 per day (kilo calories metabolizable energy per kilogram of metabolic body weight) per day.

How much digestible crude protein did the non-lactating Asian elephant Jap need, to maintain her body weight? What do we learn from F. G. Benedict’s findings, published in 1936?

Jap took in 3.152 kg crude protein (dry wt) a day, digesting 48.3% of this crude protein. That is then 1.523 kg digestible crude protein (dry wt) a day. Thus, the adult elephant Jap needed 3.228 g DCP/kg^0.75 per day for maintenance.

How much digestible crude protein does the young elephant need per day, so that it will be able to grow up properly?

The young growing elephant needs about 13.5% CP (12-15%) crude protein (dry wt) in its food. Instead of digesting 48.3% of the crude protein, as the adult elephant Jap does, the young growing elephant is digesting here only about 47% of the crude protein. It needs then 6.154 g DCP/kg^0.75 per day for growth. That is 1.9 times more, than the adult elephant Jap needs for maintenance.

Jap, the adult, non-lactating elephant cow, weighs 3672 kg. She needs 97 g DM, 192 kcal DE, 144 kcal ME and 3.228 g DCP/kg^0.75 (dry wt) per day for maintenance. The food of the young growing elephant must contain 13.5% crude protein and 6.154 g DCP/kg^0.75 (dry wt) per day.

How much protein and energy does the African elephant need, to maintain its body weight? – J. M. Roehrs and co-workers, in the elephant enclosure of the Zoo in Toledo, Ohio, U.S.A., have studied two young African female elephants, 6 years old. They used them in summer and winter trials, to determine the apparent digestibility of timothy (Pleum pratense) hay. After 12-14 days of dietary adjustment, dry matter intake and fecal excretion were quantitatively measured for 7 days. Dry matter of timothy hay contained 8.6 and 7.7% crude protein. Estimates of apparent digestibility during summer and winter, respectively, were 39 and 35% for dry matter, 43 and 32% for gross energy (GE), 45 and 30% for crude protein (CP). Dry matter intake was 1.4-1.6% of body weight (BW), providing an average 144 kcal of digestible energy per kg BW^0.75. (1989).

In order to keep these two young African elephants easier apart, I am calling the one, "Elephant A" and the other one "Elephant B".

How much energy does the young African female Elephant A need per day, to maintain her body weight, while standing, eating, and walking around a little in the elephant enclosure of the Toledo Zoo?

Summer trial: Elephant A weighed 1237 kg in summer. She was gaining no weight during the trial. She took in then 32.6 Mcal DE per day. That is 156 kcal DE/kg^0.75 per day for maintenance. 156 kcal DE x 0.82 = 128 kcal ME/kg^0.75 per day for maintenance.

Winter trial: In winter the young African female Elephant A was weighing1435 kg. Also during the 3 weeks of trial in winter, she did not gain any weight. She took in now 30.8 Mcal DE per day. That is 132 kcal DE/kg^0.75 per day for maintenance. 132 kcal DE x 0.82 = 108 kcal ME/kg^0.75 per day for maintenance. That is 19% less than in summer.

How much protein does the young African female elephant need, to maintain her body weight, in summer and in winter?

Summer trial: Elephant A weighed in summer 1237 kg. The hay contained 8.6% crude protein (dry wt). She digested 45.1% of this crude protein. And she ate 15.6 kg dry matter a day. Thus, she needed 75 g DM/kg^0.75 per day, to maintain her body weight. Because she did not gain any weight during this summer trial. She took in then 1.342 kg crude protein a day, and 0.605 kg digestible crude protein (dry wt). Hence, this young African female elephant needed 2.901 g DCP/kg^0.75 per day for maintenance.

Winter trial: At the beginning of the 3 weeks of trial in winter, the young African Elephant A weighed 1435 kg. She did not gain any weight during this trial either. Thus, she was on maintenance. The hay contained now 7.7% crude protein (dry wt). She digested 30.1% of this crude protein. And she ate 21.1 kg of dry matter per day. She needed then 90 g DM/kg^0.75 per day for maintenance. She took in 1.625 kg crude protein and 0.489 kg digestible crude protein (dry wt) a day. She needed 2.097 g DCP/kg^0.75 per day for maintenance: That is 28% less than in summer.

How much energy did the other young female African elephant need, in order to maintain her body weight?

Summer trial: At the beginning of the summer trial, the young African female elephant, also 6 years old, weighed 1042 kg. During the 3 weeks of trial, she did not gain any weight. She was on maintenance. She took in 32.6 Mcal digestible energy per day in summer. Thus, she needed 178 kcal DE/kg⁰⁷⁵ and 146 kcal ME/kg^0.75per day for maintenance (DE x 0.82 = ME).

Winter trial: At the beginning of the 3 weeks of trial in winter, the young Elephant B weighed 1205 kg. She did not gain any weight during this trial. She took in 30.8 Mcal digestible energy per day. Thus, she needed 150 kcal DE and 123 kcal ME/kg^0.75 per day to maintain her body weight. That is 15.7% less than in summer.

How much protein did the Elephant B need in summer and in winter, to maintain her body weight?

Summer trial: When the 3 week-long trial began in summer, she weighed 1042 kg. She did not gain any weight during this trial. She took in 15.6 kg dry matter per day. This dry matter (hay) contained 8.6% crude protein. And she digested 45.1% of this crude protein. Hence, she needed 85 g DM/kg^0.75day for maintenance in summer. She took in 1.342 kg crude protein (dry wt) a day, or 0.605 kg digestible crude protein. Therefore, she needed 3.299 g DCP/kg^0.75 day, to maintain her body weight.

Winter trial: When the 3 week-long trial began in winter, the young Elephant B weighed 1205 kg. She did not gain any weight during this trial either. She took in 21.1 kg dry matter per day. This dry matter (hay) contained 7.7% crude protein. And she digested 30.1% of this crude protein (dry wt) in winter. Thus, she needed 103 g DM/kg^0.75 per day, to maintain her body weight in winter. That is 18% more than in summer. The young African female Elephant B took in during the winter trial 1.625 kg crude protein a day, and 0.489 kg digestible crude protein. Hence, she needed 2.391 g DCP/kg^0.75 per day, to maintain her body weight.

When growing, the young elephant would have needed much more energy and protein, than when only maintaining its body weight. And when roaming around in the wilderness, also the adult elephant will need more energy and protein, than, when only standing, eating and walking around a little in the elephant enclosure.

How much energy does the elephant need, when roaming through the wilderness or through a game preserve, when it is walking, climbing, grazing and browsing? What have scientists found out about this?

H. H. Meissner and co-workers (1990) have studied free roaming male elephants in private game reserves bordering the Kruger National Park, in South Africa. Voluntary intake was calculated by dry matter (DM) excreted divided by the indigestible DM fraction. Crude protein of the plant material, which the elephants selected, ranged from 6.7% in the dry season to 10.7% in the wet season. DM digestibility ranged from 29.7% to 44.7%, and food DM intake from 67 to 54 kg/day.

DM digested	25%	30%	35%	40%	45%	50%
ME MJ/kg^0.75	0.50	0.56	0.60	0.64	0.65	0.66
ME kcal/kg^0.75	119	234	251	268	272	276

How much metabolizable energy does the South African elephant need, when roaming around freely in the wilderness?

The adult male and non-lactating female needs 0.65-0.67 MJ (155-160 kcal) ME/kg^0.75 day for maintenance. The lactating female needs 30% more metabolizable energy, than the male and non-lactating female. Meissner, H. H. et al. (1990).

How much food has the elephant in Tsavo East National Park, in Kenya, East Africa, south of the Galana River, needed from 1969-1972, in order to grow and to maintain its body weight? How much above ground dry matter (DM) and crude protein (CP) per square meter per year (and per month) had to grow there at least?

Year	1969	1970	1971	1972
Monthly food needed (g.m².mth)	1.8	2.0	2.1	2.4
Monthly growth needed, if elephants are using only 8% (g.m².mth)	22.5	25.0	26.3	30.0
Total food per year (dry wt.)	554.3	302.6	232.6	483.3

Monthly food, the elephant needed south of Galana River, and above ground plant growth per month. After: Phillipson, J. (1975:184) Table 3.

How much food have the elephants in Tsavo East N. Park, in Kenya, south of Galana River, needed in 1970, for example? – 302.6 g m² above ground dry matter had to grow there per year. Rounded up 300 g m².a. That is 25 g m² per month, when divided through 12 months. Of these 25 g DM/m², growing there month by month, the elephant is able to use up to 8%. That is 2 g DM m².mth. Normally, the wet season in Tsavo East lasts 8-9 months. Only 3-4 months of the year are dry. There is then no fresh green food growing at all (or not enough). These 300 g above ground dry matter per square meter per year have grown from 352.5 mm of rain. That is 0.851 g DM per 1 mm of rain. - Phillipson, J. (1975:176).

Not only the quantity, also the quality of the food is important. How much crude protein does the grass in Kenya contain during the first wet month, when growing up? And how much does it contain during the second and third month, when drying up? How much protein does the fresh green grass contain during peak vegetation per square meter?

J. T. Cassady (1973) has studied the grasslands in Kenya. During the first month of growth, the grass in Kenya contains an average 8.98% crude protein (dry wt). At 8.98% CP (dry wt) the 300 g DM m².a contains 26.94 g crude protein per square meter. J. T. Cassady (1973) found also out: If the above ground vegetation in Kenya’s grasslands is being used too much, the plants will die within a few years.

How much does the elephant eat during the dry season and the wet season? When is the elephant normally eating more in the wilderness: during the dry or the wet season? What have the experts found out about this?

The East Indian zoologist R. Sukumar (1989:78) found out: The 2700 kg adult elephant is taking in within 12 hours 33.6 kg dry matter during the dry season and 44.4 kg (dry weight) during the wet season. That is 1.5% of its body weight during the dry season and 1.9% during the wet season. This means: The elephant is eating 1.321 times more dry matter during the wet season, when the food is fresh and green, when it contains much protein and little fiber.

There is, though, one exception: During the great drought of Tsavo East, in 1970-71, the elephants were using 8-12% of the annual above ground plant growth. During normal years they have used only up to 8%. But eating more of this poor food, low in protein and high in fiber, did not help them much. Because the food, they were eating then, was not food to them anymore. It was dead food. They were starving to death with a full stomach, because the microflora in their digestive tract was not able to digest it anymore.

How much crude protein does Kenya’s grassland contain during the second and third month? Is the elephant still able to eat it then? Is this "old" grass then still food to the elephant?

During the second month of the wet season, Kenya’s grassland still contains 6.14% crude protein and 31.5% crude fiber. The grass is then dry and straw-coloured. - Cassady, J. T. (1973).

Also, when the grass contains only 6.14% crude protein, the adult elephant is still able to maintain its body weight, by eating then 1.462 times more of this grass. This will give him then 8.5% CP, compared to its normal maintenance intake of dry matter per day. Or the tusker will have to leave then the grassland and to browse on the leaves and twigs of bushes and trees, still containing more protein, than the grass does now.

During the third month of growth, Kenya’s grassland contains only 3.78% crude protein and 32.9% crude fiber, as J. T. Cassady (1973) found out. That is now far below the adult elephant’s level of maintenance. It will not help him now at all, if he tried to eat much more of this dead grass, low in protein and high in fiber. Because the microflora in its digestive tract is not able anymore to digest it at all, or not enough. The elephant will lose now condition and will slowly starve to death – with a full stomach.

The elephant will usually only graze in the short grassland during the wet season, when there is much surface water and much fresh, green grass. During the dry season, the animals will move into the shade of the forest and feed on the leaves and terminal twigs of trees and bushes. They do contain then more protein than the grass. Or the elephant may have to stay now near its dry-season-range, close to permanent water – at the shore of lakes and ponds, or at the banks of rivers, feeding there also on aquatic plants.

During the third month of plant growth, the elephant is not able anymore to balance the deficit of crude protein intake, by eating more each day, as it did during the two first months of plant.

The elephant eats with its trunk. First, it tears off the grass. Then it piles this grass up into a small bundle and pushes it with its trunk into its mouth. From Grzimeks Enzyklopädie Vol. 4 (1987)

The elephant in Tsavo East, south of Galana River, would still have been able to live normally in the year 1970, if these 300 g above ground dry matter had grown regularly month by month from 352.5 mm of rain per year. This fresh green grass had to grow (in this model) during the 8 wet months of the year. Hence, 37.5 g DM m² had to grow then during each one of the 8 wet months of the year. And these 37.5 g DM m² mth contained then (at 8.98% CP) 3.367 g crude protein (dry wt) per square meter. It is here now important, to understand this: This is living grass and browse, the elephant is able to eat, to digest and to metabolize (to change into other substances). And in this living grass, there is 3.367 g crude protein per square meter at peak plant growth, during each one of these 8 wet months.

But this is not the only above ground dry matter and crude protein on the elephant’s pasture. There is also much old, dry grass. And this does also still contain some crude protein. But this old grass is dead. The elephant is not able to eat, to digest and to metabolize this old grass. Because it is waste, containing too much fiber and too little protein. An example from the dry steppe (short grassland) in West Siberia shall show this.

The dry steppe in West Siberia and the Altai region contains in summer during peak plant growth, 300 g above ground green vegetation (dry wt) per square meter. At 8.75% CP, there is then 26.25 g CP m² in this living grass. That is, in the food, the large mammal is able to eat. – Walter, H. and S.-W. Breckle (1986:191).

But at the same time, on this same square meter of West Siberian dry steppe there is also much old dead grass: 1900 g DM m² during peak vegetation time. That is 6.3 times more, than the living grass (dry wt). This waste contains 58.1 g CP m². That is 2.2 times more than the crude protein, contained in the living grass, on the same square meter of dry steppe. But this old dead grass, the large mammal is not able to eat, because it contains too many fibers and too little protein. The dead grass contains only 3.058% crude protein (dry wt). So, we must keep here the fresh, green, living grass (with 8.75% CP) and the dry, gray, dead grass (with only 3.058% CP) apart. The living grass is food to the large mammal. The dead grass is no food.

Where is the elephant still able to live? What is the poorest range, where the elephant is still able to survive? How much aboveground dry matter must grow there at least per year and per month? And how much must it rain there at least in one year, so that this food will be able to grow? And how much crude protein (CP) must grow there at least per square meter per year?

The British zoologist R. M. Laws, University of Cambridge (1970:3): reports The elephant is still able to live in the semi-desert, where there is at last 300 mm of rain per year. These 300 mm of rain per year are producing in East Africa 255.33 g DM m² per year. The adult elephant needs about 8.5% CP, to maintain its body weight. Thus there must be 21.703 gram crude protein per square meter per year. And of these 21.703 g DC m².a, the elephant is using up to 8%. That is 1.736 g CP m².a.

How much food has grown in Tsavo East National Park, south of Galana River in the year 1970, when the elephant was starving there to death with a full stomach? How much above ground dry matter and crude protein has grown there per year and per month per square meter?

John Phillipson, Animal Ecology Research Group, University of Oxford (1975:171, 176) found out: "The distribution limits of elephants death during 1970-71 showed a good correlation with the annual 200 g m².a contours." Figure 3 in his article shows that "during the drought years 1970 and1971, the area of the southern section of Tsavo (East) with an estimated primary production of <200 g dry wt m² became much enlarged and in 1971 covered 80% of the 4200 km². In particular those regions classified as having a net primary production above ground of <100 g dry wt m² should be noted.

"In the years of good rainfall, 1969 and 1972, the influence of the two rainy seasons is apparent over 4-5 months in each of the periods, hence the dry season in these years did not exceed 3-4 months. In the drought years, 1970 and 1971, the so-called rainy seasons were characterized by sporadic rainfall and lasted approximately 2 months each. This gave rise to a non-productive dry season of 6-8 months, which is double that of the good rainfall years."

"Drought conditions continued into 1971 and an estimated 5000 elephants died in Tsavo; the deaths south of the Galana were not confined to the north-eastern sector, but spread over much of the southern section of Tsavo (East). Corfield (1973) showed a relationship between the overall distribution of elephant deaths during 1970 and 1971 and the 10 in(ch) (254 mm) 10% rainfall probability isohyet. A much closer correlation appears when Corfield’s contours of elephant death densities are considered in conjunction with the primary production estimates for 1970 and 1971 (Figs.8 and 9 in his article). Elephant deaths occurred in those areas with a primary production <200 g dry wt m².a, the highest mortality being in the region with <100 g dry wt m².a. ... Starvation was probably the main mortality factor; however, the question arises as to why a net primary production above of 200 g dry wt m².a (equivalent to 235 mm rain.a) is the level of production below which the Tsao (East) elephant population, and possibly other animal populations can no longer be supported without suffering heavy mortality. The answer must take account of the numbers, biomass and food requirements of the fauna." - Phillipson, J. (1975:181, 182).

"Clearly, consumption in the non-drought years (1969 and 1972) did not exceed 6.4% of the annual primary production, whereas in the drought years (1970 and 1971) it was of the order of 8-12%. On this evidence it could be suggested that only 8% or less of the primary production can be utilized by elephants; however this would be tenable only if primary production was even throughout the year.

"Table 3 shows the monthly food requirements of the elephant population south of the Galana River in each of the years 1960-72... Depending on the density, the food requirements of the elephants south of the Galana varies between 1.8 and 2.4 g m².mth (= when divided by all 12 months of the year).

"Thus although annual primary production is not the most important factor but rather the month to month production, a level of 200 g m².a is probably a useful indication of a poor month to month rainfall. The figure of 3 g m².mth was selected because the maximum estimate of elephant food requirement was 2.4 g m².mth whilst ... the remaining large fauna was estimated to require a further 0.5 g m².mth." - Phillipson, J. (1975:183, 184).

"It was stated earlier that food shortage is likely when 2 consecutive months each fail to reach the monthly requirements of the fauna. Allowing 1 or 2 months of further low primary production, in which general deterioration of the faunal condition will occur, it follows that 4 consecutive months will cause severe hardship of the animals. Demonstrably, 5 consecutive months with a primarily production <3 g m².mth will result in deaths of the type recorded for elephants in 1970." - Phillipson, J. (1975:185).

In 1970, the rainy season (and new plant growth) began in January, and ended four months later, in May. During these 4 wet months there was 235 mm of rain, producing 199.7 g above ground dry matter. At 0.851 g DM per 1 mm rain. Then 6 continuous dry months followed, till the end of November. And many elephants were starving then to death with a full stomach.

The next rainy season south of Galana River began in December 1970. It lasted 5 months. Most of the rain then fell in December 1970 and April 1971. In between, it rained only a little. By the end of April 1971, 210 g above ground dry matter had grown, from 247 mm of rain. Then, 6 very dry months followed in a row. And many elephants were starving again to death with a full stomach – till the end of October 1971.

The next rainy season began in November 1971. And it lasted till May 1972. Then 3 dry months followed in a row (June-August). In September it rained again a lot. But no elephants were starving to death in 1972 south of the Galana River. From November 1971 to May 1972 261.7 g above ground dry matter had grown from 307 mm of rain. This shows us: The elephant has starved to death with a full stomach, where only 200 g DM m² had grown per year.

The elephant will starve to death with a full stomach, due to lack of protein and energy, where only 200 g DM m² has grown per year, at 235 mm of rain. There is then only 17.96 g CP m². It has grown there during the 8 wet months of the year. The elephant will starve to death with a full stomach, where only 25 g DM m² has grown during each one of the 8 wet months, containing 2.245 g CP per month.

Angry Black rhino facing its foe. From: Grzemiks Enzyklopädie (1987:628) Volume 4.

The elephants at Tsavo East National Park have starved to death with a full stomach during the great drought of 1970-71, after there had been 3, 4 and 5 dry months in a row. – How large has been then their intake-deficit of digestible crude protein (dry wt), compared to their body weight and to their level of maintenance and growth? The following report (already briefly mentioned), will help us, to find the answer.

"Duana E. Ullrey at the Department of Animal Sciences, Michigan State University, and E. R. Jacobson and co-workers, College of Veterinary Medicine, University of Florida (1985:75) report about captive African elephant calves. Some of these small calves were starving to death, when eating food, containing only 5.5% crude protein (dry wt).

"Sixty-three young elephants were captured in Zimbabwe and imported into Florida in 1984. They were held in a 1.6 HA lot divided into 4 pens of equal size. Many of these elephants had been nursing their mothers and were 2 years old or less. Over the next months, illness was noted in a number of younger individuals, 8 of them died and 1 was euthanized terminally. ... Nine elephants were necropsied at the University of Florida Veterinary Medical Teaching Hospital. Their age was estimated to be about 2 years, and weights ranged from 180 to 250 kg." All of these elephants had no subcutaneous or omental fat. - Normally, the average African elephant calf (male and female, about 2 years old), kept in a zoo, weighs an average 500 kg. (K. Eltringham, written comm. 21 February 1984).

These small African elephant calves had received for about 6 months in a row food, containing only 5.5% crude protein (dry wt). After about 6 months, 8 of these calves died, and one was euthanized [killed] with signs of kwashiorkor and marasmus. They state: "... crude protein concentration of the diet was approximately 5.5%. This level is below known requirements to maintain nitrogen balance in an adult mammal, let alone support growth of the young. In addition, the smaller, younger elephants did not compete effectively for their share of the sweet feed, thus limiting their digestible energy intake."

The surviving small African elephant calves were given then coastal Bermuda grass, containing 10% CP, and alyce clover, containing 13% CP, and a pelleted diet, containing 17% CP (dry wt). – Ellen S. Dierenfeld (1994:74) remarks about this: Most of the other elephant calves were saved, when given food, containing 12-15% protein, or an average 13.5% CP (dry wt), as needed for growth.

Duana E. Ullrey and co-workers than add: "No further death losses have occurred, body weight has increased and body condition has improved. It appears that inadequate intake of protein and digestible energy were major contributors to the illness and death of these baby elephants and that a dietary program designed to meet the nutrient needs of young herbivores with hindgut fermentation effectively reversed the problem."

At which intake-deficit of digestible crude protein (dry wt) have these baby elephants starved to death, when eating food that contained 5.5% crude protein for about six months? How large was then their critical DCP-intake-deficit compared to their body weight?

African elephants tearing off the bark from tree trunks, tearing off branches and twigs, pushing over trees. They eat the leaves, twigs, fruit, and bark of the trees. By pushing over the trees the elephant enabled the grassland, the savannah with islands of trees and shrubs in a sea of grass to exist. In this way the elephant prevented the forest to cover the whole land. From: Grzimeks Enzyklopädie (1987:508) Vol. 4.

In this model I do try to find out, at which deficit of digestible crude protein (dry weight), compared to its body weight, below its level of growth, the 500-kg elephant will starve to death. The 500-kg elephant, about 2 years of age, is getting only about 5.5% crude protein (dry weight) with its food for 6 months, as reported by Professor Dr. E. Ullrey (1985) and E. S. Dierenfeld (1994). This table you will find in The Mammoth and the Flood (1996) Volume 1 page 74.

Month.: This table begins at the beginning of June and ends at the end of December.

%CP dry wt: In June, the 500-kg elephant calf, 2 years of age, is still at its intake level of growth. Its food contains still 13.5% crude protein (CP) = 4.86% digestible crude protein (DCP) (dry wt). During each one of the following 6 months (till the end of December), the food of the elephant calf contains only 5.5% CP. That is far below maintenance and growth. At 5.5% CP the elephant’s food contains then only 1.925% DCP (dry wt).

DCPI g/kg^0.75 d: The young elephant needs 6.154 gram digestible crude protein (dry wt) per kilogram of metabolic body weight per day for growth (6.154 g DCP/kg^0.75 d). But during each one of the following 6 lean months (when its food contains only 5.5% CP), it is taking in then only 2.437 g DCP/kg^0.75day.

DCPI g/day: During the last normal month, with 13.5% CP in its food, the 500-kg elephant calf is taking in 651 g DCP per day. But during each one of the following lean means, only 258 g DCP/day. The animal is losing condition. It is slowly starving to death.

DCPI g/month: In June, the last normal month, the 500-kg elephant calf is taking in 19,521 g DCP. During each one of the following six lean months, only 7988 or 7740 g DCP (dry wt).

DCP g/month needed: In June, with its 30 days, the last month with normal food intake, the 500-kg elephant calf needed 19,521 g DCP per month for growth. And in July, with its 31 days, 20 172 g DCP.

DCP deficit g/month: In July, the first lean month, the 500-kg elephant calf has taken in 12,184 g DCP too little for growth, while its food contained only 5.5% CP and 1.925% DCP. At the end of these six lean months, at the end of December, the elephant calf has taken in then 72,298 g DCP too little. Then it starves to death, due to lack of digestible crude protein. That is, when its DCP-intake-deficit has reached 14.46% of its body weight.

In other words: When eating food for six months in a row, containing only 5.5% crude protein (dry wt), the 500-kg African elephant calf, about 2 years of age, starves to death, due to lack of protein. Its intake-deficit of digestible crude protein has reached then 72,298 g. or 14.46% of its body weight.

African Black rhinoceros (Diceros bicornis). It has the pointed upper lip of the browser. It is feeding mainly on the terminal twigs of shrubs and on herbs. From: H. Haltenorth and H. Diller (1977) Plate 22. During the great drought in Tsavo East National Park (1970/72) also many black rhinos starved to death with a full stomach.