H.B. Makobo and B.M. Mosimanyana
Department of Agricultural Field Services
Private Bag 003, Gaborone, Botswana
Abstract
Introduction
Drought relief measures
Agro-industrial by-products
Suggestions on future research priorities
References
With an estimated livestock population of 3.8 million, Botswana produced 903,905.1 tonnes of agro-industrial by-products in 1984. Currently, very little of these by-products is used to meet the nutritional requirements of livestock.
Because of the fodder deficit, the Government imported 5978.6 tonnes of roughage from neighbouring countries in 1984. Despite these efforts, livestock mortality was still as high as 20%.
Crop residues are not utilized efficiently as livestock feed, but could play a significant role in livestock feeding. The major quantities are cereal residues while legume residues are marginal.
Milling by-products are from cereal sources as there is no factory producing oilseed cakes or the equivalent. Major animal byproducts consist of bone, blood and carcass meals and chicken litter. These can be used by the dairy industry which is still in its infancy. There is endless competition for bonemeal by the cattle, pig and poultry subsectors.
There are two sources of industrial by-products and all of them are used by the dairy industry.
It is suggested that future research address itself to inventory, documentation and dissemination of information on available feed resources.
The livestock population in Botswana is estimated at 2.7 million cattle, 0.9 million goats and 0.2 million sheep (ASU 1984). These are kept under two production/management systems, namely the commercial system and the communal system. About 85% of the national herd is found in communal areas, where the majority of farmers are small/livestock producers. Botswana has an area of 576,000 km² of which 77% is grazing land.
Livestock in Botswana have customarily been maintained on feedstuffs that come from natural rangeland. Rangeland utilization within the communal zones is uncontrolled, while the commercial system follows "reasonably acceptable levels of management" (APRU 1980). Unfortunately, there is considerable evidence to indicate that the productivity of the range is declining rather than increasing to match the steadily increasing livestock population. In 1978 the average stocking rate in communal areas was 14.4 ha/LU (Field 1978) which by 1983 had decreased to 11.0 ha/LU*. Large grazing areas have lost their plant cover as a result of overgrazing and the four-year-old drought. It is perhaps now evident that the country's current rangeland production under the two management systems may not provide the animal feedstuffs required by small livestock producers as well as the entire national herd.
*The figure was arrived at by dividing the total communal grazing land area (41,290,000 ha) by the estimated number of livestock units (= 3.75 million) derived from multiplying the number of cattle (= 3.0 million) by a factor of 1.25 LU per 350 kg animal.
It is therefore, inevitable that some districts in the country will soon have to resort to agro-industrial by-products to augment the disappearing range resource and to meet feed requirements of their livestock.
To achieve efficient utilization of the available feed resources, it is essential to have a good knowledge of their production and availability. With this in mind, this inventory has been undertaken to ascertain the national production of animal feed resources available for utilization by the small livestock producer other than from the natural rangeland.
Botswana's livestock industry is one of the heavily subsidized sectors in the country. There has been an intensified drought-relief programme geared to providing fodder from the livestock industry. Lucerne, pandamatenga grass, **nyle grass of Acroceras macium teff, maize and sorghum stover have been provided at subsidized prices (Table 1). Peak demand period is from mid-winter to mid-summer. Sale of these feedstuffs has fluctuated since the inception of the programme in 1983. The 1984/85 sale estimates are shown in Table 1.
**A bale containing a mixture of Hyparrhenia spp., Setaria sphacelata and Ischaemum brachyatherum
During this period, livestock mortality was 20% and this amount of fodder did not have a significant effect on reducing mortality.
There are large amounts of by-products which can be used as feed for ruminants They result from the processing of food crops and as animal byproducts.
Table 1. Drought-relief sales in 1984/85
|
Feed type |
Production sales (tonnes) |
|
Pandamatenga grass |
568.6 (locally produced) |
|
Nyle grass |
1,180.9 |
|
Lucerne |
367.5 |
|
Teff |
877.1 |
|
Wheat straw |
18.0 |
|
Millet stover |
136.2 |
|
Peanut stover |
148.2 |
|
Maize stover |
1,649.5 |
|
Sorghum stover |
1,601.2 |
|
Total |
6,547.2 |
Source: Livestock Advisory Centre, Gaborone
Crop Residues
Maize and sorghum are the major cereal crops in Botswana, followed by millet, beans and groundnuts. They provide considerable amounts of grain and crop residues. With a cattle population of 2.7 million and each animal consuming about 2.5 tonnes of dry-forage equivalent per year, crop residues could play a major role in supplementing natural grazing. A previous study (Mosimanyana 1983) revealed substantial residue-production levels per hectare (Table 2).
Table 2. Dry-matter yields and dry-matter digestibility of sorghum, millet and maize residues
|
Type of residue |
DM yield range (tonnes/ha) |
Average DM yield (tonnes/ha) |
Dry-matter digestibility (%) |
|
Sorghum |
0.60-10.40 |
5.50 |
60.93 |
|
Millet |
1.15-4.95 |
3.05 |
55.65 |
|
Maize |
1.66-5.81 |
3.73 |
63.60 |
Source: Mosimanyana 1983.
It was concluded that a herd of 50 cattle could be maintained for at least two months on the residues from 6 hectares. It was also concluded that dry-matter yield of the plant residue decreased by 28.34% and dry-matter digestibility by 11.17% from April to May. This means that early harvesting would result in higher quality fodder.
Average residue-production values per hectare (Table 2) were used to compute the 1984 production estimates (Table 3), given the area planted (ASU 1984).
Table 3. Estimated 1984 season sorghum, maize, and millet crop residues*
|
Type of residue |
Area planted (000 ha) |
Total production (000) tonnes |
|
|
Sorghum |
|||
|
|
Traditional |
107.6 |
591.8 |
|
|
Commercial |
6.8 |
37.4 |
|
Maize |
|||
|
|
Traditional |
43.9 |
163.8 |
|
|
Commercial |
4.0 |
14.9 |
|
Millet |
|||
|
|
Traditional |
16.6 |
50.6 |
|
|
Commercial |
0.1 |
0.3 |
|
Total |
179.0 |
858.8 |
|
*1984 was a drought year.
Under traditional husbandry considerable quantities of crop residues are left to be trampled by livestock or ploughed under (Table 3). These could have an important impact on animal production if they were preserved as soon as possible after grain harvest when both the yield and nutritive value are relatively high (Mosimanyana 1983).
Though there are several options open to small-scale producers on how to utilize crop residues for livestock, in Botswana the popular method is to have them grazed by uncontrolled animals. The current extension packages emphasize cutting the residues during grain harvest and drying and transporting to a safe place next to a kraal from where they can be fed to a selected group of animals.
Legume Residues
Production of legumes in Botswana is primarily done on a commercial basis, therefore these crops do not play a significant role in small-scale livestock production systems. The few small-scale producers who do grow legume utilize them by grazing livestock after harvest.
Milling and Animal By-Products
As energy resources become scarcer, there is an ever-increasing need for efficient utilization of food by-products and animal and plant waste. Because techniques of integrating them into animal-feeding systems are often unknown or uneconomic, millions of tonnes of potentially valuable feed are discarded annually. Both concentrate and roughage by-product feeds are available in Botswana, though utilization by small-scale producers is very limited.
Milling By-Products
There are a number of sorghum-milling factories in Botswana. A recent inventory revealed the existence of one large milling factory in the south, one medium-sized factory in central Botswana and about ten smaller units scattered throughout the country.
Since Botswana is not yet self-sufficient in food grain production, there is heavy reliance on grain imports. Over the past two years, Botswana imported about 19,000 tons of sorghum represented about 3,800 tons of additional sorghum bran that could be used as feed.
The figures in Table 4 were arrived at by adding the estimated production levels of milling factories to 20% of sorghum grain imports. Wheat bran production figures were provided by producers. The third source of sorghum bran relates to individual household production. This level of production has not been estimated, though the production capacity cannot be discounted. The high-energy feeds produced include rice and wheat bran.
Table 4. Estimated production levels of milling by-products
|
Type of by-product |
Estimated production (tonnes/year) |
|
|
Sorghum bran (moroko) |
||
|
|
Local |
11,000 |
|
|
Imports |
3,800 |
|
What bran |
6,000 |
|
|
Total |
20,800 |
|
Wheat bran is produced by the flour milling company in the south, while rice bran is localized in the north-western part of Botswana (Ngamiland).
Considerable but undocumented quantities of glumes (moko) are wasted annually during threshing. These are generally disposed of by burning-another untapped source of livestock feed.
Animal By-Products
Recycling animal waste as livestock feed is a well established practice. Broiler or layer-house litter is currently being used as a protein and energy substitute in other parts of the world. Botswana has an estimated 770,000 mature birds (broilers and layers) producing 6,183.1 tonnes of chicken litter per year - based on 0.022 kg dry-matter production per day by a 1.8 kg bird (North 1978). Currently Botswana does not use chicken litter for livestock feeding but occasionally as fertilizer.
The Botswana Meat Commission has three slaughter and canning factories which currently produce bonemeal, meatmeal and bloodmeal. Production levels vary from year to year depending on the number of animals slaughtered. Table 5 gives the 1984 production levels of the three animal processing byproducts.
Bonemeal is highly subsidized to encourage small livestock producers to utilize it, though supply is below national requirements. The cattle, pig and poultry sub-sectors are currently competing for the scarce bonemeal feed. Fish meal is imported in small quantities for pig production.
Table 5. Production of animal by-products in 1984
|
Type of by-product |
Production (tons/year) |
|
Chicken litter |
6,183.1 |
|
Bonemeal |
2,528.0 |
|
Meatmeal |
4,361.0 |
|
Bloodmeal |
533.0 |
|
Total |
13,605.1 |
Source: Botswana Meat Commission 1984
Brewery By-Products
There are at least three sources of brewer's grains in Botswana. On average both Kgalagadi and Chibuku Breweries produce 700 tons of dry matter per year. Brewer's grains have 20-25% crude-protein content on a dry-matter basis (Huber 1980).
Concentrate Feed Production
Like most of the developing countries, Botswana often experiences a shortage in grain production for human consumption. Concentrate feeding is therefore not practiced in Botswana except for one feedlot and a handful of commercial farmers. On average there is production of 10,000 tons of hominy-chop, maize bran mixed with coarse particles of grain, which is also utilized by the growing pig industry. Nutrient values for some of the agro-industrial products mentioned are given in Table 6.
From Table 6, it can be seen that some agro-industrial byproducts have adequate crude protein but cereal stovers are marginal to deficient.
Table 6. Nutrient values for some agro-industrial products
|
By-product |
CP |
CF |
Ca |
P |
|
Groundnut hulls |
10.11 |
20.32 |
2.36 |
0.077 |
|
Rice bran |
12.63 |
- |
0.202 |
0.531 |
|
Sorghum bran (Moroko) |
12.00 |
6.17 |
0.038 |
0.036 |
|
Sorghum stover |
6.35 |
31.46 |
0.35 |
0.11 |
|
Maize stover |
8.54 |
30.85 |
0.35 |
0.10 |
|
Millet stover |
3.98 |
37.02 |
0.19 |
0.03 |
|
Brewer's grains |
12.15 |
43.94 |
0.77 |
0.46 |
|
Bonemeal |
45.80 |
- |
5.67 |
0.49 |
|
Bloodmeal |
90.51 |
- |
0.004 |
0.005 |
|
Meatmeal |
59.52 |
0.17 |
11.34 |
7.84 |
Source: APRU (unpublished data), Gaborone.
Forage from natural rangeland in Botswana is of very how nutritive value, being characterized by high crude fibre, low crude protein, low dry-matter digestibility and low calcium and phosphorus values at all times except for the immature herbage produced after the first rains. Consequently beef cattle and range research in Botswana has concentrated on improving the utilization of extensive natural rangeland and thus the nutritional status of the grazing ruminant. There is, therefore, a need to focus research priorities on other sources of livestock feeds. With this in mind, the following priorities are suggested:
1. Documentation of total production (traditional and commercial) and availability of agro-industrial by-products, and the designing of suitable utilization methods under both the communal and commercial systems;2. Characterization of nutritive value and inventory of local feed resources;
3. Production of continuous publications/handouts on nutritive values of such by-products for extension staff.
ASU (Agricultural Statistics Unit). (1984). Botswana Agricultural Statistics, Ministry of Agriculture, Gaborone, Botswana.
APRU (Animal Production Research Unit). (1980). Ten years of animal production and range research in Botswana. Ministry of Agriculture, Gaborone, Botswana.
Botswana Meat Commission. (1984). Annual Report, Lobatse, Botswana. Field, D.I. 1978. A Handbook of Basic Ecology for Range Management in Botswana. Ministry of Agriculture. Gaborone, Botswana.
Huber, J.T. (1980). Upgrading Residues and By-Products for Animals. Florida: CRC Press, Inc.
Mosimanyana, B.M. (1983). Crop residues for animal feeding. Bulletin of Agricultural Research in Botswana, Ministry of Agriculture, Gaborone, Botswana.
North, M.O. (1978). Commercial Chicken Production Manual. Westport, Connecticut: AVI Publishing Company, Inc.
