G.N. Egbunike and A.E. Ikpi
Departments of Animal Science and Agricultural Economics
University of Ibadan, Ibadan,
Nigeria
Introduction
Supply of agro-industrial by-products and crop residues
Livestock to benefits from agro-industrial by-products and crop residues
Constraints on the country-wide utilisation of research results on agro-industrial by-products and crop residues
Summary and recommendations
References
Nigeria is one of the countries where animal protein consumption per caput is still very low being about 9.36 kg/caput/year (Egbunike, 1988) without taking account of fish and game meat consumed. Yet every sector of the livestock industry is having serious setbacks mostly due to the escalating prices of feeds which normally constitute 60-80% of production costs depending on species.
Hitherto, Nigeria had depended almost exclusively on imported feed ingredients for the production of compound feeds and with the overvalued "naira" appeared to making some headway in livestock production especially in the poultry sector which utilised about 90% of compound feeds produced in the country. With the economic recession and the noncomitant ban imposed on the importation of the major constituents of livestock feeds, especially grains, many entrepreneurs in the livestock industry that are unable to withstand the tough competition have fallen by the wayside. Under this condition wide variations exist in feed supply and hence prices which have resulted in the present low level of productivity of the animals regardless of the system of management.
The capacities of livestock feed mills and average prices of poultry feeds are summarised in Tables 1 and 2 respectively considering that poultry feeds form about 90% of feed mill products. It can be observed that at 50 or 65% maize inclusion the amount of maize required cannot be met internally especially when viewed against the background that this commodity is in very high demand in other sectors of the economy viz for human foods and for industries like the breweries. Thus, Nigeria must look inwards for her feed resources. Fortunately, the pioneering work of Oyenuga (1966) paved the way for the understanding that agro-industrial by-products and crop residues could be economically used to supplement the erratic feed supply.
This paper assesses the potential of agro-industrial by-products and crop residues to meet the nutrient requirements and hence, support the growth and productivity of livestock in Nigeria.
Table 1. Capacities of livestock feedmills in Nigeria for 1987 ('000 metric tonnes).
|
Item |
Quantity | |
|
1. Total installed capacity |
2,015.00 | |
|
2. Utilised capacity |
735.89 | |
|
3. Percent utilised |
36.52 | |
|
4. Maize equivalent | ||
|
|
(a) at 50% |
1,007.50 |
|
|
(b) at 65% |
1,309.75 |
Source: Anonymous (1988)
Table 2. 1987 average prices of poultry feed in Nigeria (Naira per ton*).
|
Feed type |
Range |
Mean |
|
Broiler starter |
868.67 - 1160.00 |
1050.90 |
|
Broiler finisher |
863.00 - 1168.40 |
1017.30 |
|
Chick mash |
867.78 - 1066.50 |
960.12 |
|
Grower's mash |
721.00 - 1259.00 |
838.77 |
|
Layers mash |
796.00 - 974.62 |
906.77 |
*US$ 1.00 = 4 naira (1987)
Source: Akinwumi (1988)
As shown in Table 3 the supply of agro-industrial by-products is considerable being at least 738,271.6 tonnes per annum. Although their rate of utilisation is dependent on their chemical composition and the species of livestock in question, it is evident that wheat bran/offals were the most common followed by fresh or wet brewers' grains while maize bran and cassava chaff were the least.
It is worthy to note that some of these data may represent underestimations since they were collected from registered industry only. For example in the cases of rice and cassava by-products (especially the latter), the aggregate of rural producers could account for a very substantial amount of production. However, mention must be made of the chemical composition and physical form of these by-products which tend to limit their usefulness. For example a bulky product containing a high level of sugar would, due to high moisture content; deteriorate rapidly during storage due to fermentation and contamination by moulds (to produce mycotoxins) while oily products become easily rancid. These by-products can be classified as energy, protein and combined energy/protein sources.
Energy sources are rich in fermentable carbohydrates and low in protein. The best example is molasses traditionally used as a carrier for urea in ruminant feeding. Molasses is produced in the two sugar industries in Nigeria: Numan, in Gongola State, and Bacita and Jebba in Kwara State.
Protein sources are mostly the oilseed cakes. Palm oilseed cakes are produced in the southern part of Nigeria (Bender, Cross River, Imo and Rivers States) and form the most abundant and least expensive oilseed cake available. It is however notorious for being gritty and unpalatable. Cottonseed and groundnut cakes are also important although the latter had declined drastically about three decades ago and is only coming up again with this spirit of looking inwards.
Combined energy and protein sources by-products considered under this category are cereal and brewers' grains. Until the ban on wheat importation, wheat bran was the most important cereal bran in the country. However brans from traditional grains (sorghum, millet, rice and maize) are growing rapidly in quantity. As regards brewers' grains, most of the 32 breweries originally produced wet grains that were available for the asking. As the usefulness of the grains in livestock feeding became increasingly clear, some of these breweries started to dry some of their grains for sale. These dried grains constitute only 5% of the total produced (Table 3).
With the advent of the oil boom in the mid sixties in Nigeria came an unfortunate neglect of agricultural production which hitherto yielded about 80% of Nigeria's export earnings. This had an unparalleled drop in crop production and a concomitant increase in imports to meet the needs of the fast growing human population. All these led to a drastic reduction in the quantity of available crop residues. However with economic recession there is now an upward turn in the production of crops and hence in the availability of residues.
It is known that most of the ruminants in Nigeria are found in the Guinea savanna and Sahel zones where they are managed by pastoralists. These zones are the major cereal (sorghum, millet and maize) growing areas of Nigeria. The amount of straws and leaves left in the cereal plants after harvesting can be estimated. For example in the case of sorghum which is the most abundant of the cereals in these areas, the ratio of grains to straw is 1:4 at the time of harvest. Thus with a production of about 6 million tonnes of sorghum in Nigeria 24 million tonnes of straw would be available for use in livestock production annually. Also with a ratio of 1.3:1 for leaves and grains 5.2 million tonnes of leaves would be left behind. With the recent FAO figures it must follow that this tremendous tonnage will be more than equalled by total amount of maize, millet and rice straws, giving a modest annual estimate of more than 52 million tonnes of crop residues in this zone alone. In addition to this, there is an estimated amount of over 400,000 tonnes of maize cobs available for livestock feeding after the necessary treatment.
Table 3. Supply of major agro-industrial by- products by registered companies in Nigeria (1985).
|
Type |
Production (tonnes/yr) |
Price (N/ton) |
|
Wheat bran/offals |
382,666 |
139-180.00 |
|
Cottonseed cake |
6,707 |
315.00 |
|
Groundnut cake/pellets |
6,970 |
550.00 |
|
Palm kernel - meal |
50,000 |
60.00 |
|
Palm kernel - cake/pellets |
33,000 |
65.00 |
|
Molasses |
24,000 |
51.00 |
|
Molasses - fresh |
190,000 |
n.a** |
|
Brewers grains - dried |
10,182 |
30-100 |
|
Brewers grains - bran |
23,800 |
150.00 |
|
Rice - husks |
6,530 |
n.a |
|
Rice - chaff |
59.60 |
|
|
Cassava - peeling |
2,943 |
|
|
Maize bran |
450 |
n.a. |
|
Total |
738,271.60 |
|
* US$ 1.00 = 2 naira (1985)
** n.a. = not available.
Source: Reddish and Scarr (1987)
Because of the poor quality of these materials, it is normally thought that only ruminants can benefit from them. However, it is now known that they can be beneficial to non-ruminants as well after having been properly processed as shown later. For example, we have consistently used the items on Table 4 with the exception of molasses, sorghum and maize stovers. The only difference in the utilisation of these materials for ruminants and non-ruminants would be the levels of inclusion in the diets. In cattle production, these materials have been used for a long time for fattening as was developed by the Livestock Project Unit for smallholder farmers over a 120-day period. In this scheme cattle of 200-340 kg liveweight are introduced to rations made up of a combination of these materials as shown in Table 5. It is obvious that the dried brewers' grains and molasses combination is the cheapest. Average daily gains (ADO) of 0.38 - 0.85 kg have been reported with fattening periods of not more than 160 days recording higher values. This makes it possible for two complete fattening cycles per annum. If, for example, 30,000 additional tonnes of dried brewers' gains were made available from the breweries and used for fattening cattle, 100,000 cattle would, fed at 3 kg/head/day for 100 days, gain 5 million kg in liveweight. At 60% dressing weight, this would give an additional 3,000 tonnes of saleable meat.
Table 4. Chemical composition of some agricultural by-products and crop residues.
|
Product |
DM (%) |
Crude protein (% or DM) |
Metabolisable energy (MJ/kg.DM) |
|
Wheat bran |
90 |
17.20 |
10.10 |
|
Cottonseed cake |
90 |
26.90 |
11.00 |
|
Groundnut cake |
90 |
48.60 |
12.00 |
|
Palm kernel cake |
90 |
18.60 |
12.60 |
|
Molasses |
75 |
4.10 |
12.70 |
|
Dried brewers, grain |
90 |
20.40 |
10.30 |
|
Rice bran |
89 |
10.60 |
10.80 |
|
Sorghum stover |
93 |
4.75 |
6.28 |
|
Maize stover |
94 |
5.60 |
- |
Table 5. Typical rations formulated from agro-industrial by-products and crop residues for cattle fattening.
|
|
Rations | ||
|
Ingredient |
1 |
2 |
3 |
|
A. Quantities (kg) | |||
|
Wheat offals |
3.00 |
3.00 |
- |
|
Groundnut cake |
0.25 |
- |
- |
|
Molasses |
1.00 |
1.00 |
1.00 |
|
Crop residue/grazing |
2-3 |
2-3 |
3.00 |
|
Cottonseed cake |
- |
0.50 |
- |
|
Dried brewers' grains |
- |
- |
3.00 |
|
B. Chemical composition | |||
|
Metabolisable energy (MJ) |
57.19 |
57.88 |
58.98 |
|
Crude protein (g) |
615.00 |
623.00 |
657.00 |
|
C. Cost/head/100 days (N) |
68.50 |
74.00 |
46.00 |
These materials have been used, when available, to avoid the annual weight loss of cattle during the 5-6 months dry season in the northern parts of Nigeria. This prevents the drop in fertility while reducing both calf and herd mortalities. In addition, heavier weaning weights would be achieved. It could thus be construed that the benefits of dry season supplementation far outweigh those of fattening.
As for small ruminants, agricultural by-products and crop residues are also used for fattening and dry season feeding. For example, Adebowale (1985) and Ademosun et al (1987) have shown that inclusion of dried brewers' grain at 25 and 50% levels gave weight gains in goats of 38.4 and 29.2 g per day respectively. As regards poultry and pigs, which are more abundant in the south and which have to be intensively fed throughout the year, by-products and crop residues with or without cassava peels (Tewe and Egbunike, 1988) have virtually kept the industries going without much loss in the level of production even at lower costs.
Lack of appropriate terms.
Lack of biological screening
Contrasting responses of animals of different species, physiological states and ages.
Composition differences of crops
Conflict between the goals of the researcher and the farmer
Constraints on the use of by-products and crop residues include, according to El Hag and Kurdi (1986), bulkiness, location in areas with lower animal population density, poor nutritive value and unsuitability for direct animal use. In Nigeria today, the issue of the bulkiness and location in areas far from those where the materials are needed has been partially solved by the development of a good network of roads and the opening up of the rural areas for development since the establishment of a directorate charged with this function two years ago. As regards the poor nutritive value and non-suitability for immediate animal use, research results have shown that supplementation with molasses, non-protein nitrogen (urea and poultry excrete) and chemical (NaOH) and physical (grinding and pelleting) treatments improve the nutritive value and intake and hence the response of animals to some of these by-products. El Hag and Kurdi (1986) concluded that physical treatment was more useful in improving the nutritive value of these products and was also economically more feasible than the chemical treatment. On the other hand constraints on the use of research results on the by-products and crop residues include the following:
As pointed out by Kayongo-Male et al (1986) the use of different local names in different localities and by researchers constitutes a problem calling for the adoption of a standard system for describing crop residues and by-products. An example is the use of "cassava peels" to describe a mixture of the peel, flesh and some discarded tubers most of the time.
It is known that some of these products contain some abnoxious materials that may be harmful to animals when used for a long time. Because most of the experiments have been on short-term basis, it has not been easy to adopt some of the recommendations arising from research results blindly. Theobromine and hydrocyanic acid contents in cocoa husks and cassava peels/leaves, respectively, tacitly caution against long-term utilisation of these products especially for breeders. For example, Osuagwuh (personal communication) has shown that the long-term feeding of cassava peels to breeding nanny goats causes abnormal embryogenesis resulting in the birth of stunted neonates that have very little chance of surviving.
Recommendations drawn from some results tend to ignore the fact that different species or classes of animals e.g. ruminants and non-ruminants) respond differently to agricultural by-products and crop residues. Also animals of different physiological status (pregnant or not) and ages would obviously respond differently to these materials. Often the ages and liveweight of experimental animals are not indicated while sometimes pregnant or sick animals are used thus making adoption of results therefrom difficult.
It is continuously becoming clearer that varietal differences exist in the morphological and chemical compositions of plants. Except in experiments where the varieties of crops involved are clearly stated, adoption of results may be jeopardised.
In many instances the researchers work in complete isolation of the end users of their results, the farmers. Under such circumstances these results are a clear wastage of time and funds as they are not normally adopted by the farmers. In a few cases their adoption has been a failure. This may partially explain the almost regular non-repetition of research results at the farm level and calls for a proper exchange of ideas between the researcher and the farmer and the development of proper packages for the transfer of research findings from the researcher to the farmer by extension experts.
The tremendous potential of agro-industrial by-products and crop residues in upholding the aims of livestock production has been indicated in this report. There is a supply of at least 738,271.6 tonnes of agro-industrial by-products nationally and 52 million tonnes of crop residues in the cereal belt of Nigeria. Judicious use of these in conjuction with the grass/pasture carryover from the rainy season in the form of hay or silage will minimise the dry-season weight loss in our animals, especially ruminants, and encourage acceptable weight gains while reducing calf and herd mortalities. In the case of non-ruminants, the ban placed on the importation of feed resources has been partially contained by the use of these non-conventional feed resources.
However, there is need for more research to arrive at the optional utilisation of agro-industrial by-products and crop residues for livestock production in Nigeria. Emphasis should be continuously placed on farming systems research so as to achieve optimum production of both crops and livestock. The investigation and development of alternative legumes and browse species for supplementation of agro-industrial by-products and crop residues should also be emphasised.
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Ademosun, A.A., Bosman, H.G. and Jansen, H.J. 1988. Nutritive studies with West Africa Dwarf goats in the humid tropics. In: O.B. Smith and H.G. Bosman (eds) Goat production in the humid tropics. Pudoc Wageningen. pp. 51-61.
Akinwumi, J.A. 1988. Economics of large scale use of alternative feed resources to replace conventional ingredients in livestock production in Nigeria. Proc. National Workshop on "Alternative Formulation of Livestock Feeds in Nigeria". ARMTI, Ilorin, 21-25 November, 1988.
Anonymous. 1988. Second national poultry survey. Egbunike, G.N. 1988. small-scale investment opportunities in livestock and related enterprises. Proc. National Workshop on "Investment Opportunities in small-scale Enterprises in Nigeria". NISER and Friedrich-Ebert Foundation, Lagos, 21-23 November, 1988.
El Hag, M.G. and Kurdi, O.I. 1986. Prospects of efficient utilisation of agro-industrial by-products and crop residues for ruminant feeding in the Sudan, with emphasis on quantification, nutritional composition, constraints and research results. In. T.R. Preston and M.Y. Nuwanyakpa (eds), Towards optimal feeding of agricultural by-products to livestock in Africa. Proceedings of workshop held at Alexandria, Egypt, October 1985. ILCA, Addis Ababa. pp. 22 - 23.
Kayongo-Male, H., Said, A.N. and Kategile, J.A. 1986. Use of INFIC nomenclature on crop residues and by-products produced in Kenya. In. T.R. Preston and m.Y. Nuwanyakpa (eds), Towards optimal feeding of agricultural by-products to livestock in Africa. Proceedings of a workshop held at Alexandria, Egypt, October 1985. ILCA, Addis Ababa. pp. 42-49.
Oyenuga, V.A. 1966. Nigeria's feeds and feeding stuffs. University of Ibadan,. Press, Ibadan, Nigeria.
Reddish, P.M. and Scarr, M.J. 1987. Subsiding industries for the livestock subsector. Proc. 11th Conf. Nigerian Soc. Anim. Prod., Zaria. pp. 12-23.
Tewe, O.O. and Egbunike, G.N. 1988. Utilisation of cassava in poultry and pig feeding. Proc. Workshop on "The Potential of Cassava as Livestock Feed in Africa", IITA, Ibadan, 1418 November 1988. International Institute of Agriculture, Ibadan, Nigeria.
