Wildlife Nutrition: Facts or

Fiction

Hinner Köster (Ph.D.)

Introduction

• Game have survived Southern Africa's harsh and variable

environments

• Able to have migrated from one area to another

• Found indigenous vegetation of high nutritional

quality

• Grass, shrubs and bushes

• Supplied their requirements for growth and reproduction

Introduction

• Modern times these migration routes have been

largely fenced off

• Preventing animals from being able to move to

areas where the grazing or forage would be

better

• Selection limited especially during the drier

season

If it's impossible to migrate or the whole area is in a

drought the animals will lose condition

• Measures of fat stores (body condition)

– Primary mode of storing energy in vertebrates

• Play important roles in reproduction, migration,

and thermoregulation

– Good indices of nutritional status

Body condition

Phenotype = Genotype + Environment

Dry

Ideal

Cold

Profitability

• Profitability of modern intensive game farming practises

affected by:

• Reproduction

• Amount of offspring produced within a specific specie’s

reproduction cycle

• Performance of offspring

• Milk production of dams

• Growth after weaning

• Phenotypic condition and features of animals

• Body condition, hair coat

• Health, immune system

• Legs, feet (hooves), horn size

Precision Feeding

• Game farmer has unique challenges

• Supply all specific species of animals

• with the nutrition they require

• in a specific defined area

• at specific time periods of the year

Grass

Leaves

Selection intensity

Specie specific nutrition

Area specific – unique characteristics

Summer WinterP

rote

in

Oct Oct

Supply

Requirement

Season specific - Protein

Summer WinterE

nerg

y

Oct Oct

Supply

Requirement

Season specific - Energy

Summer WinterP

ho

sp

ha

te

Oct Oct

Supply

Requirement

Season specific - Phosphate

Approach when

developing dietary/

supplementary feeding

programs for wild animals

–Dietary habits in the wild

–Oral and gastrointestinal morphology and

physiology

–Needs of similar domestic species whose

requirements are known

–Environmental features that affect energy

and nutrient need

Consider

Oral anatomy and gastrointestinal

tract morphology

• Oral anatomy and gastrointestinal tract

morphology have a high correlation with

natural diet

• Presence of a ruminoreticulum

–Qualitative nutrient requirements are

similar to those of cattle and sheep

Oral anatomy and gastrointestinal tract

morphology

• Gut has a cecum and sacculated colon

–Capacious enough to support microbial

fermentation

–Nutrient needs are likely to be similar to

those of the horse

• A simple stomach with limited lower gut space

for microbial activity

–Similar to a pig (Ullrey, 1988)

Oral anatomy and gastrointestinal

tract morphology

• Can extrapolate nutrient requirements

from domestic species with known

needs to wild species

–Similar in dietary habits and

gastrointestinal structure and

function

• Beyond food habit studies, wildlife

biologists have used captive animals

–Made detailed studies of nutritional needs

•Associated with physiological functions such

as:

–reproduction

–growth

–horn development

Captive animal requirements

• Relationship between nutritional status and

reproductive rate is thoroughly documented

– Good to know what the reproductive response of

animals to improvements in the supply of selected

nutrients is

– Animals in good physical condition generally have

higher rates of reproduction

• More resistant to all forms of mortality than are

animals in poor condition

Nutritional status vs reproductive rate

Effect Of Weight Loss On Reproduction

(Estrus-activity)(Adapted From Louw, Thomas & Lishman, 1988)

Weight loss = 103 kg

(21%)

CS = 2,77*

CS = 1,72

CS = 2,23

Estrus Activity stopped

Weight Increase = 47kg

(13%)

Resumption of

Estrus Activity

*CS = Condition Score

Economic

traits

Horns

• Length

Hair Coat

• Shiny

Horn growth

Heritability of Male Horn Volume = 0.32

Canadian Researchers assessed the effects of resource availability on

body mass and horn growth of bighorn rams at Ram Mountain,

Alberta, Canada over 30 years

They showed:

• Horn growth was positively correlated with feed availability

• Compensatory horn growth does not occur

• University of Zürich (2015) measured 8043 Ibex from 1967

• No evidence was detected for compensatory horn growth

• Late-life horn growth was positively depended on early-life

horn growth in males

• Horns are dead tissue with no blood flow

• Require continuous levels of sufficient nutrition

• Horn growth rates continuously increased due to earlier and

higher spring-time temperatures

Alpine Ibex

Annuli

Nutrient

requirements of game

Nutrient requirements of game

• Most herbivore game species on farms are ruminant

animals

• Exception: zebras, rhinos, hippopotamus, elephants, bushpigs,

warthogs

• Differences in eating habbits and alimentary tracts of

game within the same environment

• Makes supplementation aimed at the same specie impossible

• Supplementary feed for game still based on requirements

of similar domesticated animals (cattle, sheep, horses, pigs)

• Response of such domesticated species to spesific supplemental

feeds in a specific area to achieve a specific performance target

• Game species would (in the habitat to which they

are adapted) select a diet

– With a digestibility in accordance with their feeding

habits and are thus classified accordingly (Hofmann

(1973)

• Bulk and roughage grazers

– Large, essentially grazing animals

– Not high degree of selection

– Capacious stomachs normally filled to capacity

– Relatively low-quality feed composed mostly of grass

Nutrient requirements of game

• Browsers (Selectors of juicy, concentrated herbage)

– Feed mostly on the leaves, flowers and fruits of forbs, shrubs and

trees (Concentrated food)

– Small stomachs (usually <200 kg mean individual live weight)

– Include grazing animal which exercises some form of extreme

selective defoliation (white rhino - area selection)

– Normally filled to only 50-60% of their capacity

• Intermediate feeders (herbivores that eat both grass and

leaves)

– Have the ability to adapt in different seasons and places towards

grasses and leaves

– Have greater ability to tolerate variations in the quality of their diet

Nutrient requirements of game

Factors affecting nutrient levels and

quality in natural forage

• Every game farm or reserve has a unique system

• Either intensive or extensive camps

• Game need a particular amount of nutrients

• Correct ratios at different levels during the physiological

changes of their life

• Lactation, pregnancy, maintenance, growth, etc.

• Specific but different daily nutrient requirements for:

• Protein, energy, macro- and trace minerals and

vitamins

• Certain natural forages may be suitable for some animals

but not for others

Supplementation

• Nutrients that can in particular be limited on low-quality pastures:

• Energy

• Especially where pastures have been deteriorating and competition of game

increases

• Droughts

• Protein

• Rumen Degradable Protein in ruminant game

• Especially to utilise low-quality pastures and shrubs during the dry season

• Minerals and trace minerals (all species)

• Most areas require supplementary minerals and trace minerals throughout

the year

• Roughage (all species)

• High quality roughage supplementation (e.g. lucerne) would supplement

roughage, protein, energy and certain mineral shortages

Economic feeding strategy for

breeding game on pastures

• Maximize use of nutrients in natural and established

pastures/stover/hay/silage1. Supplementation must complement roughage source

2. Critical to understand the effect of supplemental nutrients on the

intake and digestion of the roughage source • Low quality roughage – goal to increase intake and digestion

• Ensure optimal feeding conditions:

2. During breeding season

3. Shortly before calving/lambing (late pregnancy)

4. When calve/lamb suckles (lactating animal)

1. For maintaining live weight and condition during the dry, pregnant

phase• Supplementation before calving/lambing can have a larger impact on pregnancy

% than supplementation after calving/lambing (Marston et al., 1995)

Why supplementation?

• Supplementation focuses on supplying

animals with the necessary nutrients that the

forage available to them cannot supply

• Supplementation is critical to:

• Ensure optimal degradation and digestion of

available forage

• Prevent nutrient imbalances

• Improve/maintain condition score, production

and reproduction

Degradation and digestion

of available forage

• The most important facet of ruminant

feeding

• Understanding the nature and behaviour of

the microbial population in the rumen

during the different climatic seasons

• Focus on feeding the rumen microbes

– Ensure optimal intake and degradation of dry

forage/ roughage

Entodinium parvum

species, 30 to 70% in

Springbok, with a

shorter generation time,

multiply rapidly utilizing

starch and other readily

available substrates.

Eudiplodinium sablei

species, unique to

Sable antelope.

Entodinium taurinus n.

species unique to Blue

Wildebeest.

Challenges of microbial diversity

within game

• Thriving on different nutrients

NH3

urea

MCPAA

NH3

Dietary

crude

protein

A

B1

B2

B3

C

Pep

Supplemental nutrition on low quality

roughage sources

• Dry pastures, standing hay, stubbles, stover

– Contains insufficient protein – first limiting• Insufficient protein for rumen microbes, especially where no

green material is present

– Microbes take >48 hours to degrade the available forage

– Decreased supply of nutrients from the rumen to the rest of

the animal's body

– Animal mobilizes stored reserves (e.g. fat and protein)

• Produces energy for survival

• Results in loss of condition and muscle mass

– Low digestibility• Proper digestion of consumed material cannot take place

– Results in lower intakes and digestibility values

• Animals that do not receive any supplementation during the dry season

– Intake of forage is ±0,3-0,5% less of their live body mass (DM basis)

than animals that receive supplementation during the dry season

• Intake of forage in wetter months is:

– ±0,3-0,5% more of their live body mass (DM basis) than animals that

receive supplementation during the dry season

Requirements and Intake

–Governed by Metabolic BW (W0.75)

and not BW per se

–Within a feed type, small animals

eat more on a BW basis than large

animals

Maintenance Energy

Requirement (all species)

Based on non-pregnant,

mature female

0.55 MJ ME/kg W0.75

EXAMPLE : INTAKE CALCULATION

•Buffalo female, 530 kg BW, maintenance

• W 0.75 = 530 0.75 = 110.46 kg W0.75

• MER = 110.46 kg W 0.75 *0.55 MJ ME/kg W 0.75 = 60.75 MJ

ME/day

• Feed quality (ruminant, grazer) = 7.4 MJ ME/kg DM @

88% DM = 6.51 MJ ME/kg AF

• Feed Intake = 60.75 MJ/6.51 MJ/kg = 9.33 kg

• FI (% BW) = 9.33 kg/530 kg * 100 = 1.76%

• Intake for other objectives relative to maintenance• For growth & general well-being = +10% (1.75% * 1.1 = 1.9%

BW)

• For lactation = +30% (1.75% * 1.3 = 2.3% BW)

0

5

10

15

20

25

30

35

40

0 1 2 3 4 5 6 7

Total DIP Intake, g/kg BW .75

To

tal

DO

MI,

g/k

g B

W.7

5

DIP Requirements

= 4.01/36.15

= 11.1% of DOM

Forage DIP = 53%

Estimating DIP Requirements using the

One Slope, Broken-Line Model (Köster, 1996)

Breakpoint = 4.01

530 kg animal

= 5300.75 x 4.01

= 110.46 x 4.01

= 443 g RDP/day

RDP requirements and supplementation of

game on low quality pastures

• Assumptions:– Animal: Dry pregnant buffalo

– Weight: 530 kg

– Forage quality: 5% CP (AI basis)

– Degradability of CP from grass: 55%

– Grass intake: 9.3kg

• Requirements:

– 5300.75 kg x 4.0 = 110.5 x 4.0

= 443 g total DIP/animal/day

RDP requirements and supplementation

of game on low quality pastures

• DIP from grass:

– Grass intake: 9.3kg

– Total CP intake from grass = 9.3 kg x 5% = 465g

– DIP intake from grass = 465 g x 55% = 256g

• DIP that needs to be supplemented to optimize

utilization of the grass:

– 443g total DIP/cow/day - 256g DIP from grass

= 187g DIP/530 kg animal/day from supplement

Effect of different levels of urea on True OM

Digestion of hay in the rumen – Cattle

(Köster, 1993-1995)T

rue

OM

dig

esti

bil

tiy,

%

Effect of different levels of urea on DOMI of

hay in the rumen – Sheep (Nolte, 2001)

10

15

20

25

30

35

40

0 25 50 75 100

% N from from Urea

Ha

y D

OM

in

tak

e, g

/kg

BW

0.7

5

Urea supplementation of game on low quality pastures

• Larger ruminants

– CP can be derived 100% ex NPN

• Game preferably 75-80%

• Small ruminants

– >25% of CP as NPN

• Not effectively used but still safe

• Non-ruminants

– NPN not useful

– Yet not lethal

• Zebras grazing in a mixed species camp

– Dietary protein deficit not covered by protein supplements ex NPN

– Yet not lethal

Higher performance is dependant

on individual amino acid supply

-Rumen Non Degradable Protein-

IDEAL

First limiting nutrient allowable growth

Protein

High Min + Fat

Horn Growth

Supplemental nutrition on green

pastures• Sufficient protein

–Sufficient protein for rumen microbes and often also to maintain

certain level of animal production

•Microbes take ± 12 hours to degrade the available forage

–Supplementing rumen non-degradable protein (amino acids) to

maintain higher production

•Lactating and late pregnant animals, pregnant young

animals, growing animals

– Can result in positive response

– Depends on performance target and economy

– Colostrum quality (calf health)

• Problem:– Mainly Minerals

Effect of different types and levels of energy on digestible

OM intake of low quality hay (Le Roux, 2002)

34,3 33,6

30,8

34,2

36,9

20

25

30

35

40

Starch Cellulose Sucrose 1MJ

ME/d

7MJ

ME/d

Hay

DO

MI,

BW

0.7

5

DIP = 4.67 g/kg BW0.75

Energy types Energy levels

(Molasses)(Bran)(Maize)

Energy Supplementation on low

quality pastures and/or roughage

•Feed grain and other energy sources if:

–Goal of energy supplementation •Achieve additional production above maintenance on

pastures

–Production licks/blocks or pellets/self mixed feeds•Female animals with calves/lambs in winter

•Dry, pregnant female and male animals at any stage

not in optimal body condition

•Young animals

Mineral and Vitamin

supplementation

• Required in small quantities

• Essential for all physiological systems

• Especially critical for growth, reproduction, milk,

development, immunity, enzyme functions, cell

regulation, etc.

• Subclinical shortages biggest problem

– More important than acute problems

• If there are no symptoms beyond an inexplicable drop in

reproduction efficiency, growth rate or condition score

– Makes the identification of which mineral it is that is

deficient very difficult

Minerals

Mineral interactions

Organic vs Inorganic trace minerals

• Bio-availability

• Organic sources high

• Inorganic sources differ substantially

• Reduced interaction (antagonistic) problems with organic sources

• Organic substantially more expensive

• Supplement selectively

• Normally not required for grazing animals

• With problems like osteochondrosis, hoofs (horn growth), reproduction, etc., also strong consideration

Typical observations on farm with trace mineral

shortages

• Cu and Zn especially are important for strengthening

hoofs and stimulating horn growth• Organic Zn is especially used world-wide to improve hoof

integrity of livestock

• Zn is also used: • Proper keratin formation

• Important for wound healing, skin health, hoof/horn

structures

• Limtation of Zn in male animals

• Spermatogenesis, Inhibits maturing of spermatozoa,

Atrophy of the semen carrying tubes, Testicle size , Libido,

Retards puberty

Hoof Integrity, Horn Growth, Skin

Health and Reproduction

Analyse Water!

Vitamins• Important vitamins needed by herbivores are:

– Vitamin A, D, E (Browsers), K, B12, Thiamin,

Niacin, etc.

• Most of the deficiencies have been detected in

captive animals

• Free-ranging wildlife continually adapt their food

habits to avoid diets deficient in one or more of the

vitamins

• Biotin

• Safe water soluble B vitamin

• Very important in growth and strengthening of

the cartilage in hoofs and horns

• Supplementation in game:

• Directed towards strengthening hoofs and

horn growth

• Achieving maximum hoof strength and horn

length

HOOF INTEGRITY AND HORN

GROWTH

Future Directives• A combination of basic and applied research is essential

– Conducted on both free-ranging and captive animals

– A cross-disciplinary approach must continue

• Combine qualitative information on natural feeding habits with

quantitative data on food nutrient composition and utilization

– Can provide direction for further development of optimal diets for

captive/confined game animal management

Thank

You