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Nutrition 101

management & production

DIRE STRAITS by Craig Shepstone Photos by Quintus Strauss

WILDLIFE RANCHERS HAVE TO MANAGE NUTRI-TIONAL CHALLENGES THAT VARY OVER DIF-FERENT SEASONS AND WHICH ARE CURRENTLY AGGRAVATED BY DROUGHTS IN SOME REGIONS IN SOUTH AFRICA.

SOUTH AFRICA'S CURRENT DROUGHT IS THE WORST IN 23 YEARS, WITH LIMPOPO, MPUMALANGA AND NOW KWAZULU-NATAL AMONG THE MOST AFFECTED PROVINCES.

Photo by Louis Strauss.

PRACTICAL APPROACHES TO WHAT TO DO IN TIMES OF DROUGHT OR LACK OF NATURAL FORAGE

Drought has affected large parts of southern Africa in the past year (and, in some areas, the past two to three years). Periods of drought are characterised by far below normal average rainfall. This water shortage has a direct effect on the nutritional quality and quantity of available forage.

High-quality forage supplies an-imals with the necessary energy, protein and other essential nutri-ents to maintain their health status. Initially, drought affects the quality of the forage: the plant’s main aim is to survive into the future, so some plants dry out, storing nutrients in their roots, tubers, bulbs and seed. Others simply throw seed and die.

A prolonged drought forces an-imals to consume the available forage. With limited or no sea-sonal rain, the natural forage will be depleted by the resident animals,

resulting in a crisis. Animal produc-tion decreases rapidly if high-quality forage is not obtained in adequate amounts. Production parameters af-fected are body condition, growth, milk production, weaning percentage and body weight, reconception and general health. Uncontrolled fires and overstocking have similar dev-astating effects on the quantity of forage available to maintain animal production and health.

Worst-case scenarios need to be kept in mind and planned for. When estimating how much forage needs to be produced/purchased and stored, the following is needed:• Species and number of animals.• Sex ratio and age.• Average weights of respective

species on the farm.• Size of the farm or area where

animals are housed.• Carrying capacity of area.• Stocking rate of the area.

It is necessary to estimate for worst-case scenarios when there is no available roughage on the farm. When considering purchasing

It is necessary to estimate for worst-case scenarios when there is no available roughage

on the farm.

and storing roughage, accurate estimates of the volume of roughage needed is necessary over a specific period of time. If you know the species, sex, age and number of animals, it is possible to calculate how much dry forage you need.

Animal forage requirements are expressed on a moisture-free basis (dry matter or DM basis), so prior to purchasing it is important to determine the ‘as fed’ value: forage DM value x by the moisture value of the given forage.

For example, grass hay with a DM value of 88% has a moisture value of 12% (100 - 88 = 12% moisture).

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Therefore 120kg of forage = 120kg x 88% = 105.6kg of forage on a DM basis.

When it comes to the intake of dry forage during the dry season, bear the following in mind: animals heavier than 100kg live body mass eat approximately 2% of live body mass and animals smaller than 100kg live body mass eat

approximately 3.5% of live body mass. For example, a 530kg buffalo cow will need 530 * 2% = 10.6kg dry forage.

Moisture value impact on dry forage required

Example: forage moisture % on a DM basis of 12%:

So correcting for moisture, the buffalo needs:

10.6 x 1.12 = 11.87kg of forage on an ‘as fed’ basis.

Take the total calculated volume and add 15% for wastage.

MAINTAINING AND/OR IMPROVING PRODUCTION

To maximise production in times of drought, or times of lack, it is

THE LIKELIHOOD OF SOUTH AFRICA’S EXPE-RIENCING DRIER AND WARMER CONDITIONS TOWARD THE SUMMER SEASON IS CAUTIOUSLY HIGH (http://www.weathersa.co.za).

Photo by Jaco van Rensburg.

AFRICAN BUFFALO OR CAPE BUFFALO (SYNCERUS CAFFER).

important to ensure optimal di-gestion of the dry forage. This is achieved by supplementing the animals with the necessary nu-trients, supplying the microbes (ruminants) with the necessary di-gestible protein, energy and min-erals to multiply to optimal numbers, and facilitating the degradation of the available dry forage for further

digestion in the animal’s gut.Animals in this state have the

ability to consume more dry grass, similar to the amounts eaten in the green growing season:

animals heavier than 100kg live body mass eat approximately 2.5% of live body mass while animals smaller than 100kg live body mass eat approximately 4%

of live body mass. When calculating, it is suggested

the average between the worst dry season and the wet season values are used (2 and 2.5% – average 2.25%).

For example, a 530kg buffalo cow will need 530 * 2.25% = 11.93kg dry forage. Forage moisture % on a DM basis is 12%.

Purchase roughage early in the season, as costs of roughage escalate as the dry season progresses

and the supply becomes scarce.

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So correcting for moisture, the buffalo needs:

11.93 x 1.12 = 13.36kg of forage on an ’as fed’ basis.

Take the total calculated volume and add 15% for wastage.

This group of animals will be supplemented with either pellets, cubes, licks and self-mixed feed.

The predetermined amount (company intake table) supplied to the animals needs to be subtracted from the calculated amount of forage on an ‘as fed’ basis. The difference is the amount of roughage the animal needs per day. Knowing the

‘as fed’ requirement of forage, and the ‘as is’ amount of supplement, it is possible to calculate how much of either is needed for a fixed period of time. This allows us to budget for and purchase raw materials before they become expensive or scarce.

STORAGE OF ROUGHAGE (ANY FEEDSTUFF)

It is strongly suggested that suitable storage barns or stores be constructed on the farm, so that the purchased roughage can be stored under a roof.

NYALA (TRAGELAPHUS ANGASII).GREATER KUDU (TRAGELAPHUS STREPSICEROS)

Vir verdere inligting besoek ons webtuiste by www.epol.co.za.

THABA THOLO “Enige wildsboer wat ernstig is oor dieregesondheid en volgehoue opbrengs

behoort EPOL te gebruik.”

36338_epol_game_afrik_ad_FA.indd 1 06/05/2013 13:29

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For more information, contact Craig Shepstone: craig.shepstone@gmail.com

A well-constructed store en-ables moisture/mould and pest-free storage of raw materials. All roughage or feedstuffs need to be kept off the ground – this will pre-vent moisture from being absorbed, creating a suitable environment for possible fungal growth. Purchase roughage early in the season, as costs of roughage esca-late as the dry season progresses and the supply becomes scarce. Roughage and feedstuffs that are stored should be used on a ‘first in equals first out (used)’ basis. This will prevent the new feed from being used up before the old feed.

If it is necessary to store roughage outside. Place it on pallets, or on top of logs of wood, under a moisture-tight tarpaulin.

When feeding, note that the lack of roughage management is possibly the biggest reason why

our game farmers’ feed bills are so high. It is estimated that up to 30% of the roughage purchased is thrown away, due to handling, poor storage, badly designed hay racks/bins and animal wastage.

particularly square bales, store on pallets – bales in direct contact with concrete absorb moisture, resulting in possible fungal growth and mycotoxicosis.

Feeding roughage should be placed in hay racks or bins. Hay racks/bins should be moved regularly and hay that falls on to the ground should not be eaten as it is often contaminated with soil, urine and faecal matter.

Hay bales placed directly on the ground are also often used as bedding. To make matters worse, moisture often gets absorbed from the soil surface, creating a suitable environment for possible fungal growth, which results in possible mycotoxicosis. If hay is contaminated with fungus, mycotoxins, soil, urine and faecal matter, it is strongly suggested that it be destroyed.

...note that the lack of roughage management is

possibly the biggest reason why our

game farmers’ feed bills are so high.

It is not advisable to place the roughage on the ground; rather, place all roughage in hay racks, or hay bins. When it comes to storage,