Chapter 3: Feed Resources

INTRODUCTION

A regular supply of low-cost feed, over and above maintenance requirements, is essential for improved productivity in the three farming systems used in family poultry production:

• free-range - poultry roost in trees at night;

• backyard - poultry are confined at night; and

• semi-intensive - poultry are enclosed during the day in a very limited scavenger resource base.

When feed resources are inadequate, a few birds in production are better than more birds just maintained, but without enough food for production.

Extensive Systems

Farmers attempt to balance stock numbers according to the scavenging feed resources available in the environment in each season. Under the free-range and backyard systems, feed supplies during the dry season are usually inadequate for any production above flock-maintenance level. When vegetation is dry and fibrous, the scavenging resources should be supplemented with sources of minerals, vitamins, protein and energy. Under most traditional village systems, a grain supplement of about 35 g per hen per day is given.

There have been various approaches to utilising a wider base of feed resources for the flock. One is the use of poultry species apart from chicken. Waterfowl, especially ducks, may be distributed throughout the wetland rural areas, where they can feed on such resources as snails and aquatic plants in ponds and lagoons. Another approach is the integration of poultry with the production of rice, vegetables, fish and other livestock. An example is the combination of chicken with cattle, as practised by the Fulani of Nigeria, where the chickens feed on the ticks on the cattle as well as on the maggots growing in the cattle dung. Chickens raised in the cattle kraal (compound) weighed an average of 500 g more than those in the same neighbourhood but outside the kraal (Atteh and Ologbenla, 1993).

Semi-Intensive System

Under the semi-intensive system, all the nutrients required by the birds must be provided in the feed, usually in the form of a balanced feed purchased from a feed mill. As these are often expensive and difficult to obtain, smallholders use either unconventional feedstuffs or “dilute” the commercial feed by supplementing it with grain by-products (which supply energy and some protein). A well-balanced feed however is difficult to achieve, as grains and plant protein sources (the by-products of a few oil seeds) are becoming increasingly unavailable for livestock, and premixed trace minerals and vitamins are usually too expensive for smallholders. Phosphorus and calcium can be obtained from ashed (burnt and crushed) bones; and calcium from snail shells, fresh or seawater shellfish shells, or limestone deposits. Salt to supply sodium can come from evaporated seawater or land-based rock salt deposits. These mineral sources are rarely used. Feed provided for birds kept under this system is therefore of a much poorer quality (unbalanced by dilution with crop by-products) than under either the extensive or fully intensive system.

AVAILABLE FEED RESOURCES

The size and productivity of the village flock ultimately depend on the human population and its household waste and crop residues, and on the availability of other scavengable feed resources. There is a clear relationship between egg production and nutrient intake. This is demonstrated in Bangladesh, where fewer eggs are laid in the rainy season from August to September, but when snails are available in January and February, production increases (ter Horst, 1986). A list of feed resources available to smallholders was compiled from surveys undertaken in Nigeria (Sonaiya, 1995). These feedstuffs were mostly by-products of home food processing and agro-industries, and were similar to those found in other tropical countries.

The Scavengable Feed Resources Base (SFRB) include:

• household cooking waste;

• cereal and cereal by-products;

• roots and tubers; oilseeds;

• trees, shrubs (including Leucaena, Calliandra and Sasbenia) and fruits;

• animal proteins;

• aquatic plants (Lemna, Azolla and Ipomoea aquatica); and,

• commercially prepared feed.

These resources are described in greater detail in the following section.

The Scavengeable Feed Resource Base

Gunaratne et al. (1993; 1994), Roberts and Senaratne (1992), Roberts et al. (1994) and Roberts (1999) have researched and classified the feed resources available for scavenging poultry in Southeast Asia, which they named the Scavengeable Feed Resource Base (SFRB). The SFRB was defined as the total amount of food products available to all scavenging animals in a given area. It depends on the number of households, the types of food crops grown and their crop cultivating and crop processing methods, as well as on the climatic conditions that determine the rate of decomposition of the food products. Seasonal fluctuations in the SFRB occur due to periods of fallow or flooding, cultivation, harvesting and processing. The SFRB includes termites, snails, worms, insects, grain from sowing, harvesting by-products, seeds, grass, fodder tree leaves, water-plants and non-traditional feed materials. The SFRB can only be harvested by scavenging animals, of which poultry are the most versatile, although this varies with species. Several types of poultry scavenging together can make more effective use of this resource.

Keeping poultry under the free-range and backyard systems depends to a large degree on the quality of the feed available from scavenging. Therefore it is essential to know what feed resources are available. For example: a flock of 12 young growing chickens with five productive hens have access to an SFRB of 450 g (dry weight) containing nine percent protein and 2 300 kcal of metabolizable energy (ME)/kg. This supports about 22 percent daily egg production, with about three eggs/clutch, assuming 80 percent of the SFRB was utilized.

Methods of estimating SFRB

The value of the SFRB can be estimated by weighing the amount of daily food product/household waste generated by each family as parameter “H”, which is then divided by the proportion of food product/household waste found in the crop of the scavenging bird (assessed visually) as parameter “p” (Roberts, 1999). This is then multiplied by the percentage of households that keep chickens (parameter “c”):

SFRB = H/p©

For example, an SFRB measured using the above method in Southeast Asia ranged from 300 to 600 g on a Dry Matter (DM) basis, containing eight to ten percent of vegetable protein and 8.8 to 10.4 megajoules (MJ) of metabolisable energy (ME) per kg (2 100-2 500 kilocalories [kcal] ME per kg) (Prawirokusumo, 1988; Gunaratne et al., 1993 and 1994). The amount of protein and ME in the SFRB was determined by analysis of the crop content. In Sri Lanka, the annual SFRB available to each family was calculated to contain 23 kg of Crude Protein (CP) and 1959 MJ of ME (468 mega [M] cal of ME) (Gunaratne et al., 1993).

In a case study conducted in Sri Lanka, collections of daily waste from 34 households were made on 14 occasions (Gunaratne et al., 1993). The collections were weighed, examined and analysed for approximate composition, calcium and phosphorus. Fifteen scavenging hens were collected late in the morning and slaughtered and their crop and gizzard contents examined and weighed.

The results indicated that the fresh weight of food product/household waste per household averaged 460 ± 210 g per day and consisted of:

• 26 percent cooked rice;

• 30 percent coconut residue;

• 8 percent broken rice; and

• 36 percent other (vegetable trimmings, egg shells, bread, dried fish and scraps).

The crop contents are shown below after Table 3.1.

Table 3.1 Calculated values of SFRB for family flocks in different countries of Southeast Asia

Source: Gunaratne et al., 1993.

The crop contents comprised:

• 72 percent household waste;

• 13 percent grass;

• 8 percent animal matter (earthworms, snails, ants and flies); and

• 7 percent paddy rice.

For composition details of crop contents and food/products household waste, see Table 3.2 below.

Each family flock had access to the food product/household waste from two households, so that on average the amount available to the household flock was 550 g of Dry Matter per day. Daily egg production ranged from 11 to 57 percent, with an average of 30 percent. This did not vary significantly over the 12 months of the study. Chicken body weight at 20 days ranged from 41 to 100 g, and at 70 days from 142 to 492 g. Mortality up to 70 days was 65 percent. Losses were attributed to predators, particularly dogs, cats, mongooses, crows and other birds of prey. More than 90 percent of the hen’s day was spent scavenging over a radius of 110 to 175 m. Cattle and goat pens were favourite scavenging areas.

Table 3.2 Average composition of major feed components and crop content of scavenging hens in Sri Lanka

Source: Gunaratne et al., 1993 and 1994

Factors affecting the SFRB

Among the factors determining the size of the SFRB are: climate; number of households; number and type of livestock owned; crops grown; and the religion of the household. This was clearly illustrated in a Sri Lankan study (Gunaratne et al., 1994), where results showed that the total biomass of the scavenging population was proportional to the SFRB. If the available SFRB is exceeded, then production falls (birds die and hens lay fewer eggs). If there is a surplus SFRB (such as a good harvest or fewer birds due to disease or stock sale), then production increases (more chicks and growers survive and more eggs are laid). Hence the SFRB available in a community determines the production potential of the poultry. If the SFRB is known, other factors affecting production can be identified and the benefits of providing additional inputs assessed.

Table 3.3 Amount of household waste, calculated SFRB and average flock biomass

Source: Gunaratne et al., 1994

The maximum productive size of the village flock depends on the SFRB. To keep the flock size in balance with the available SFRB, it is necessary to set fewer eggs for incubation, cull unproductive birds and sell stock as soon as they are saleable. Production capacity should also be adjusted to match the seasonal variations in the SFRB. For example, during harvest time, when the SFRB is increased, extra chicks and growers may be reared, but at the end of the dry season birds may need to be culled, sold or consumed. Supplementing the available SFRB with other feed resources can improve the overall quality of the nutrition of the flock and reduce chick mortality. This may then result in more and larger growers, and the expanded flock could then exceed the SFRB. If this happens, then production will fall again until the balance is restored. Feed supplements are only beneficial if they result in increased off-take rather than increased flock size.

FEED INGREDIENTS

The on-line and CD-ROM versions of the FAO searchable database Feeds and Feeding provide a full resource on this topic for all types of livestock, including poultry. The following descriptions may supplement the above source.

Cereals and cereal by-products

Examples of grains for supplementing scavenging poultry include millet, sorghum, maize, and rice in the form of whole and broken grains.

Amounts supplied are inadequate when using the surveyed estimate of 35 g supplement grain/bird.day (Obi and Sonaiya, 1995). This and the tannin content of sorghum have led to a search for alternative grains and the evaluation of agro-industrial by-products.

Dehulled rice grain

This can be used with vegetable and animal protein supplements for all types of poultry. Rough or paddy rice, off-coloured rice and broken rice have been used up to 20 to 30 percent in poultry rations. Rice bran has a moderate quality protein of 10 to 14 percent, approximately 10.4 MJ of ME/kg (2500 kcal of ME/kg), and about 11 percent Crude Fibre (CF). It is rich in phosphorus and B vitamins. Because of its high oil content (14 to 18 percent) it easily goes rancid. For this reason it should make up no more than 25 percent of the ration. This also applies to rice polishings. Rice bran usually includes rice polishings, but is often adulterated with rice hulls/husks, which are very high in fibre and silicon, and have a low nutritive value. Nevertheless, rice bran is still an important feed resource.

Maize starch residue (MSR)

This is a by-product of the extraction of starch from fermented, wet-milled maize, which is used as a breakfast cereal in West Africa. It usually has more than 16 percent Crude Protein, although the amount varies according to the maize variety and processing method.

By-products from local breweries and other local industries

Brewer’s grain and yeast have become common ingredients for poultry rations, but the process of drying the wet by-product can be very expensive.

Legumes and legume by-products

Non-traditional legumes, such as boiled jack bean (Canavalia ensiformis) and sword bean (Canavalia gladiata), have been shown to be acceptable to laying hens, although they should not form more than ten percent of the ration because the sword bean is of low nutritive value (Udedibie, 1991). Winged bean (Phosphocarpus tetragonolobus) contains approximately 40 percent Crude Protein and 14 percent oil, and its overall nutritive value is very similar to that of soybean and groundnut cake for broiler meat chicken (Smith et al., 1984). Winged bean leaf foliage is also acceptable to laying hens. Unless the plant is grown with stake supports, the yield is very low, which makes its cultivation on a large scale less economical. However it is suitable as a feed and fodder crop for smallholder poultry.

Soybean (Glycine max)

This crop is being grown increasingly for human consumption. If the cotyledons (fleshy beans) are used for human food, the testa (bean-seed coat) is given to poultry. Raw soybeans heat-treated by boiling for 30 minutes and then fed to scavenging birds in amounts of up to 35 percent of the ration resulted in satisfactory performance in broilers and laying hens. In pullets and layers fed raw soybeans with no heat treatment as 12 percent of the ration, there was a significant reduction in body weight at 20 weeks, as well as a delay of four days in the onset of sexual maturity (as measured by age at the 50 percent egg production). The heat treatment destroys a trypsin (a digestive enzyme present in the intestine of poultry) inhibitor, which, if left intact, prevents digestion of raw soybean.

Cowpea (Vigna unguiculata)

This legume crop is grown solely for human consumption in Africa. Its by-products, especially the testa (seed coat), are used as a feed for small ruminants and have also been fed to poultry (Sonaiya, 1995). The testa represents about six percent of the weight of the whole cowpea, but is usually discarded (in West Africa) when the cotyledons are made into a puree for a locally popular fried cake. With its crude protein content of 17 percent, its apparent metabolizable energy (AME) value of 4.2 MJ of AME/kg (1005 kcal AME/kg) and its mineral profile (44 g ash/kg; 9.0 mg Ca/g; 0.9 mg P/g), cowpea testa should be a good feed resource, but the presence of tannin (53 mg/g) and trypsin inhibitor (12.4 units/mg) limits its utilization. Cowpea testa should not make up more than ten percent of the total feed of a poultry ration.

Roots and tubers

Cassava (Manihot esculenta)

This is grown in large quantities in Africa, Asia and Latin America, both for human consumption and as a livestock feed. Cassava and its by-products (in the form of leaves, small tubers, pulp, peels, chaff, gari [fermented grated tubers], gari sievings, whole fermented roots and ensiled cassava meal) are used. The dried chips are high in energy and fibre but low in protein. In regions where cassava is used for human food, the peels are the most useful part of the cassava plant for feeding livestock. Amounts of 20 to 45 percent cassava peel meal (CPM) have been fed to chickens, but its use is limited because of the high content of the poison hydrogen cyanide (HCN), as well as high Crude Fibre, low protein content and dust. There is a considerable range of HCN levels in cassava, according to variety. When cassava completely replaces grains in a ration, there is a consequent reduction in egg weight and a change in egg yolk colour. Whether or not there are negative effects on egg fertility and hatchability is not known. Cassava meal gives good growth in meat chickens, although protein and other nutrients must be carefully balanced. Molasses or sugar may be added to sweeten the bitterness of the cyanide and thus improve palatability. Oilseeds such as full fat soybean can compensate for the high fibre and low protein content and for the dustiness. To remove the cyanide, detoxification methods include ensiling, sun-drying, air-drying, roasting, boiling and soaking. For smallholders, the most practical method is sun-drying (Sonaiya and Omole, 1977). Palm oil can also moderate the effects of cyanide on poultry. Some “sweet” varieties of cassava (which do not contain cyanide) are used in human food preparation, and these are often fed to poultry, particularly ducks.

Sweet potato (Ipomoea batatas)

Dried sweet potato forming up to 35 percent of the ration has been fed successfully to broilers and layers. The tubers are boiled before use, which overcomes any problems with dust or fungal growth from storage.

Oilseeds

Oilseeds in full-oil or partly oil-extracted form are a source of both energy and protein for extensive and intensive poultry systems.

Cotton (Gossypium spp.)

Glanded cotton seed cake (CSC) is a high-demand supplement fed to ruminants, but if available it can be fed in amounts up to 25 percent in the diets of layers and broilers without adversely affecting egg production and growth (Branckaert, 1968). Poultry are tolerant of the gossypol found in CSC, but it can cause an olive discolouration of egg yolks, which consumers do not like. Addition of 0.25 percent ferrous sulphate should be added routinely to laying hen rations containing up to ten percent CSC.

Sesame (Sesamum indicum)

The feed consumption and conversion rates for birds fed various forms of raw unhulled sesame seeds were better than those for birds fed dehulled but whole sesame seeds, confirming the practice of smallholders who use whole sesame seeds as a supplement for scavenging poultry. Sesame seeds should used in amounts between 20 and 35 percent of the ration.

Groundnuts (Arachis hypogaea)

Groundnuts may be used in the oil-extracted cake form to make up 8 to 24 percent of the ration. Mouldy groundnuts may contain toxic substances, the most dangerous of which is aflatoxin.

Coconut (Cocos nucifera)

Coconut meal can be used to form 50 percent of the ration, especially when combined with a high-energy source such as cassava meal. It is low in lysine, isoleucine, leucine and methionine.

Sunflower (Helianthus Annuus)

Sunflower seeds can be fed whole, or the decorticated meal can be used to replace groundnut cake and soybean meal and up to two-thirds of fishmeal. It has the highest sulphur amino acid content of all the major oilseeds.

Oil Palm (Elaeis guineensis)

Most oil palms are processed locally. The by-products are kernels and an aqueous solution of oil, fibre and solids. This solution can be filtered to remove the fibre (which is used as fuel). This leaves an aqueous mixture called palm oil sludge (POS), which supplies feed energy and fatty acids. Sludge processed using chemical solvents should not be used, as the chemical residue may be toxic to the birds. It can be fermented and used in smallholder poultry systems or dried to form up to 40 percent of commercial compound feeds (Hutagalang, 1981). Palm kernels are processed locally into palm kernel oil by heat or cold-water extraction. The residue from heat extraction is similar to ash and of no use in poultry feed, but the residue from water extraction is very nutritious and palatable to birds, and can be used in the same way as groundnut cake. The meal can provide up to 30 percent of the ration. However, the product is low in the sulphur amino acids.

Soybean - see under Legumes and legume by-products

Other oilseeds

Other oilseeds that have been fed to poultry under research conditions include rubber, amaranth, Niger seed (Nueg), breadfruit (Artocarpus altilis), locust bean (Ceratonia siliqua), African oil bean, melon, mango and castor oil. Okra seed (Hibiscus esculentus) has not yet been evaluated as a protein source for poultry, and although it is lower in protein, it compares favourably with soybean in all other nutrient components. Since okra is widely grown by smallholders and the seeds are kept for planting, it may be a potential source of protein for smallholder poultry.

Bambara groundnut (Voandzeia subterranea)

This is a good source of protein with a high lysine content. As the nut is not widely eaten, the plant is grown mainly as a mulch crop and the foliage is scavenged by poultry.

Trees, shrubs and fruits

Neem leaves

A pilot study was undertaken to test the response of three groups of layers to neem leaves. One group was fed a ration containing ten per cent fresh neem leaves, the second a ration of ten per cent dried neem leaves, and the third none. The group receiving the fresh neem leaves had increased feed intake, daily egg production and egg weight compared with the other two. There appears to be a fat component of fresh neem leaves (Azadirachta indica) that enhances egg production and egg weight (Siddiqui et al., 1986).

Coffee pulp

This is high in fibre, but as the essential amino acid content is similar to that of soybean, it can only be used in limited amounts.

Citrus pulp

No more than two percent citrus pulp should be included in the ration to avoid reduction in growth rate and off-colour egg yolks.

Over-ripe bananas and plantains

These are of greater palatability for poultry than green bananas, which contain free or active tannins.

Derinded sugarcane pith and molasses

Sugarcane juice can make up to 25 percent of the poultry ration and molasses up to 30 percent, but it should be noted that over ten percent molasses results in watery faeces. Raw sugar however can be fed at up to 50 percent of the ration without watery faeces. Combining one part molasses with three parts sugar gives good production without the digestive problems. Molasses is often added to rations at low levels of inclusion to make it more palatable, although there may be problems with evenly mixing the liquid, and with fungal toxins in the stored feed, encouraged by the sugar levels.

Table 3.4 Optimum levels of inclusion in poultry rations of some ingredients

Source: Hutagalung, 1981

Animal protein

Blood meal

This is recognized as a high crude protein source with an imbalanced, relatively poor amino acid profile. Handling and processing of blood is difficult in low-technology situations. For processing small amounts, one method is to absorb the blood on a vegetable carrier such as citrus meal, brewers grain, palm kernel, ground maize, cob rice or wheat bran, after which the material is spread out for drying on trays heated from below or placed in the sun (Sonaiya, 1989). At the farm level, the blood may be supplied from the slaughter of livestock. Abattoirs and slaughterhouses provide large volumes of blood for making up feeds at the commercial level.

Termites

Farina, et al., (1991) described a technique used to collect termites for scavenging poultry. Briefly, the straw of sorghum, millet and maize are chopped, placed in clay pots or calabashes and moistened. The mouth of the container is placed over a hole in a termite colony under construction. The container is covered with a jute sack to prevent drying out and a heavy stone is placed on it to secure it in position. After three to four weeks, a new colony of termites should be established inside the container. The eggs and larvae are particularly relished by chicks, guinea keets and ducklings, while adult birds also feed on the adult insects. Cattle dung can be used in place of the cereal straw.

Maggots

Alao and Sonaiya (1991) grew maggots on cowpea testa (seed coats) and monitored the chemical composition of the mixture over ten days. Cowpea testa samples were placed in a basket near a pit latrine to attract flies to lay eggs on them. Every two days, a sample was steeped in boiling water to kill the maggots. They were then sun-dried and ground before analysis. Results showed that the Crude Protein content of the mixture doubled by the second day. Soukossi (1992) produced maggots from fibrous vegetable material and poultry droppings. The method was developed for feeding fish, but can easily be adapted for smallholder poultry. A tank with a capacity of one cubic metre is filled with water to about 15 cm from the top. Dried stalks of maize, amaranth, groundnut, soya and other legumes are soaked in the water to which some poultry droppings are added. Flies and other insects are attracted to the soaked material to lay their eggs. After five to seven days, eggs are hatched and larvae are sufficiently developed to be fed to fish. Beyond this period the maggots develop into adult flies. It was observed that up to 50 percent of the eggs laid by flies died if exposed to the sun for several hours. A cover, at least for the hottest hours of the day, is therefore necessary. Similar trials have been carried out in Burkina Faso.

Earthworms

Vorster et al. (1992) produced earthworms as a source of protein for chicken feed. In an area of 25 m², one kg of fresh earthworm biomass was produced daily. This is sufficient to supplement at least 50 chickens with high-quality protein. It must be noted, however, that earthworms (and snails as well) may be important vectors for tapeworms such as Davainea and Raillietina and also contain a growth inhibitor.

Other animal products

Aquatic animal products containing mineral sources include marine shells from mangrove oysters (Ostrea tulipa), mangrove periwinkles (Tympanostomus fuscatus) and clams, and shells from land snails. Marine shells are abundantly available in coastal areas. Snails and their shells are harvested from forests, but there is also on-going development of productive snail farms. It is estimated that a box with a capacity of one cubic metre capacity on a snail farm can yield 40 snails each year. Ducks are an important biological control of the semi-aquatic golden snail in the Philippines and Bangladesh. Other marine by-products, such as prawn dust and shrimp heads, supply both minerals and protein.

CONCLUSIONS

There are feed resources available for feeding poultry at all levels of production. Smallholders using the semi-intensive system who make their own feed must base the rations on home-produced feed resources or obtain the ingredients locally. In backyard systems, available resources should be supplemented with appropriate nutrients as necessary. Food products from household waste fed to free-range birds should also be supplemented. Potential substitutes for expensive commercial feeds are cassava, sweet potato, coco yam (Colocasia esculenta), arrowroot (Marantha arundinacea), coconut residues, coconut oil, palm oil and other non-traditional energy sources. Non-conventional feedstuffs which are good substitutes for fish meal and soybean and groundnut oil meals include earthworm meal, maggot meal, winged bean, pigeon pea, jack bean, Azolla (A. pinnata, A. caroliniana, A. microphylla), leaf meals and leaf protein concentrates.

In different regions, the importance of these feed resources for family poultry depends on their availability in sufficient quantities for farm use, simple preparation and processing methods, knowledge of the potential nutritive values and (for comparison) the price and availability of conventional commercial feeds.

For the family poultry situation with a scavenger flock, free-choice supplements with three containers each containing either protein-rich, energy-rich or mineral-rich feed sources will provide a solution to the problem of balancing nutrient intake for different age-groups. Poultry have an instinctual ability to select exactly what they need in the above food nutrient groups, and will not overeat from any one container. Young growing poultry (under two months of age) should always be fed in a “creep” system, where older stock cannot get access to their feed supply.