WINDHOEK – Desperate, drought-stricken Namibian farmers have launched a resurgence of the importance of studies which indicate that poultry litter has carried many southern African livestock producers through the previous droughts.
Poultry litter is a safe source of proteins, minerals and energy for cattle raised for beef. In addition, processed litter makes a good protein supplement for both cows and growing calves.
Dr Silas Obukosia, a South African agricultural biotechnologist says although feeding animal waste to beef cattle had at some point been wrongly associated with causing mad cow disease, the only known poultry disease that is zoonotic is salmonella.
He explained that chicken litter desirable for feeding to cattle should contain 20 to 30 percent moisture and crude protein. “The litter should also be low in ash (soil) and should be free of hardware, glass, and other foreign material. Processed turkey, broiler breeder, and hen litter have also been successfully used as a feed,” he said.
Straight after rain, ephemerals (opportunistic plants or opslag) high in salt and minerals appear almost overnight. These are followed by fast-growing plants rich in energy and vitamins, which, as they reach maturity, undergo an increase in protein, fibre and dry-matter content.
The opposite happens during a drought. Plants turn from green to brown and later to black. When the “opslag” disappears, it becomes necessary to add energy, fat and especially fat-soluble vitamins (Vitamin A) to the diet.
In an advanced stage of drought, plants are critically short in protein, dry matter and fibre. The calcium concentration increases, as it does in winter. Usually, high calcium or iron concentration in plants is the main reason for the poor absorption of energy, minerals and vitamins from the digestive tract to the blood and liver.
This occurs due to a more alkaline digestive tract and an insoluble compound of calcium, phosphorus and magnesium, which leads to a deficiency of phosphate and magnesium, as these minerals are excreted in manure and urine.
In overgrazed veld where fodder is scarce, lucerne and drought pellets will be the best supplementary feed. But in the veld in reasonable condition, a tailor-made lick could be better. Drought pellets are high in fibre, calcium and perhaps iron, but the overall nutritive value is lower than needed for maintenance. Lucerne supplies protein, but contains too much roughage and calcium, while energy is too low for production. Feeding lucerne only is thus not the best option. Much of the fibre available in the vegetation is wasted because of injudicious supplementary feeding. This is a great problem throughout South Africa. While adult ruminants need 20 percent fibre, and growing ruminants require 15 percent in their diet, the veld provides more than 30 percent. This can increase even further during a drought.
This means that, under normal conditions, each adult ruminant will use the fibre of 1.5 animals, while each growing ruminant (lamb or calf) will excrete that of two animals. With a lick tailor-made for farm and animals, fibre use will be more effective and will be available for longer in any specific grazing camp during drought.
Rumen microbes can produce protein from non-protein nitrogen (NPN), as well as vitamins, enzymes and other vital compounds, via essential amino acids and fatty acids. The problem is that these nutrients are not enough for production or to maintain fertility.