Mon, 21 Aug 2017 13:56:00 +0000
By Makeli Phiri
IN ORDER to feed the ever rising Zambian population of this country, there must be a corresponding increase in food production if famine and its consequences are not to become a very big problem within the years to come.
The acreage of crop production and other basic foodstuffs must be increased and the methods of cultivation interfiled.
The need to increase production applies equally to domestic animals. It can be met by an increase in the size of the herds or flock and their pastures, by the rise in their productivity and by the control of animal diseases.
Prevention and treatment of diseases must therefore be complementary to other measures to increase food production.
The animal owner must be provided with information necessary to prevent and cure diseases, for it is only with help that animal production can be extended.
Let us look at climate and stress how these can affect animal production in the quest to increase food production.
WEATHER CONDITIONS
Climate has to do with changes in weather conditions that is dryness, wind, light etc. sudden changes in weather pattern can have a very bad effect on the animals’ production system. It means an animal may go through stress which in turn affects the potential production of that particular animal.
In some animals especially sheep if they are exposed to heavy rain with no proper shelter, this may cause fleece rot. Therefore, the general effects of climate should be looked into to avoid such a condition developing and this can add to the general burden of stress on such animals.
Continuous high temperatures in animals under high productivity for example big milk yields, this involves an intense activity of body functions.
Food intake, rumen fermentation digestion, absorption, liver function, chemical synthesis, transportation of nutrients is all increased.
This increased metabolic activity in turn tends to increase the heart rate and oxidation processes. In order to produce intensively the animal produces a lot of excess heart, like a petrol engine running at high speed.
Thus the ability to lose heat becomes a limiting factor in our local climatic conditions. This is even worse especially with important high yielders which were bred for their good performance under their conditions in other countries such as cool temperate conditions.
We have such animals especially in milk production where high yielders are or have been purchased from countries where conditions are different from Zambia.
Kalundu Dairy under Zambeef have some animals which need comfort zone for them to continue yielding high production. Such animals are put under a good shed under which they are sprayed with a fine mist to cool them before milking.
Other farmers in the dairy farming should emulate such a practice especially that we are now approaching the hot season.
HIGH HUMIDITY
High humidity further decreases the ability of an animal to lose heat. Sweating is less effective because any air that is already saturated is not able to receive any more water vapour by evaporation. Likewise, heat loss via respiratory evaporation is lowered.
Under humid conditions it is almost impossible to keep high yielding dairy cows. The country is looking at quick food production in both cereals and livestock to feed the people.
Therefore, the importation of high yielders in terms of milk production would need that the animals so brought into the country must adapt to local Zambian climatic conditions.
What would be expected is that these animals for them to acclimatize to our situation or conditions in order to assist in heat loss, there will be need to increase number of sweat glands, increasing capillary network in the skin and creating large loose folds of skin.
For this to happen would mean adaptation through breeding new anatomical or physiological features.
For animals that have to be imported for cross breeding purposes may not do so well looking at the sunshine in this country.
A white surface yes reflects more radiation than a black surface, hence the thought would be a white skin would be best for places with a lot of sun.
In fact, the skin needs black pigment to absorb the sun’s rays, carry the heat away and this prevent burning.
Furthermore, animals in the tropics with unpigmented skins are susceptible to photosensitization as well as sun burn.
EYE-CANCER
Also a form of eye – cancer is found in eyelids of certain animals e.g. Hereford cattle which are imported into the country, which have no black pigment around the eyes.
Therefore, for these animals to be imported for breeding or to improve the local breeds should have an ideal coat for conditions in the tropics and to Zambian conditions for that matter.
Therefore, the following would do:
1. Animals have the skin with black pigment
2. Hair that is white, grey or silvery (these are least absorbent colors)
3. Hair that is thin closer to our local breeds (not thick or curly to insulate)
4. Hair that is sleek and shiny, lying flat, making reflecting surface. For example, the Boran.
During continuous cold weather problems also are seen in this care has to do with insulation. Energy needed for maximum productivity or growth will be lost as heat.
During summer when high rainfall is experienced, it is time when humidity increases, the air is moist (presenting real humidity).
High rainfall predisposes the animals to skin diseases for example Senkobo in cattle and also adds to general stress burden usually wind and rain are a worst combination.
With wind would mean evaporation will increase, temperature (high), wind will carry more heat from the animals’ skin.
In some parts of the country like some parts of Western Province the desert like condition often have very hot days with somehow intense sunshine, followed by very cold nights.
The cooling off does give some relief after the heat, but generally such changes greatly add to the stress burden especially on imported animals.
Strong winds and rain showers will also worsen the effects of cold and produce more stress. All in all, animals will adapt themselves (become used) to a new climate, even if this involves a reduction of maximum productivity.
It is the newly introduced animal which suffers the greatest stress. Therefore, our livestock farmer in venturing into improving his stock for higher production should consider the comfort zone for the stock to be reared and at least have the least stress on them.
Stress can have retrogressive effect on any animal introduced in a new area. Therefore, any farmer bringing animals in a new area must be wary of what the animal may go through before it can really settle down.
Stress can reduce profits in high productive animals and must be avoided at all cost if the farmer is to maintain good income from the animals being reared on the farm.
Good farmers always are very observant when weather conditions change and are on the lookout for changes that may affect their animals, and precautions are put in place to protect the farm animals.
It is the farmer who needs that extra income from what is kept therefore must make sure that these animals are exposed to minimal stress if it is possible.
Be on the lookout for stress signs.
