How you can turn that farm waste into wealth

Farmers can earn more from maize residues (stovers). Photos/Dr Jolly Kabirizi 

What you need to know:

  • Despite the potential use of banana peels in livestock feed, handling this by-product has complicated its use by farmers because of the high moisture content.

By Jolly Kabirizi 

Due to the increase in human population in Uganda and most of it moving to cities, there is increased demand for food, and this has resulted in the production of large amounts of agricultural wastes, both at farmer, municipality and city levels. 
The bulk of the agricultural food in Uganda is transported to cities such as Kampala in its raw form, thus compounding the net effect on large deposits of waste in urban markets, around homes and in slums as well as in various dumping grounds. 
 
The collection, transportation and disposal of garbage in Kampala is the responsibility of Kampala City Council Authority (KCCA). 
The city generates about 1,500 tonnes of garbage on a daily basis and KCCA collects about 500 tonnes of garbage on a daily basis leaving more than 60 percent of the garbage uncollected.  

The uncollected garbage results into indiscriminate disposal of garbage by the public as they have nowhere to put it. 
KCCA is overwhelmed by the waste output due to its lack of capacity to collect and dump it at its landfills in Kitezi, Wakiso District.
More than 40 percent of the garbage collected from urban markets are agricultural wastes. Three quarters of the garbage rots uncollected on pavements, streets, sewerage outlets and water channels. 
This unfortunate tragedy is witnessed especially in markets, blurring the city’s image and posing a serious health danger.

Agricultural wastes as livestock feed
Most of these agricultural wastes have high nutrient levels of nitrogen, potassium, and phosphorus. Such wastes can be processed and converted into high quality livestock (cattle, goats, rabbits and pig) feeds. This alternate method of utilisation of agricultural wastes by livestock farmers can reduce the rate of accumulation, with subsequent reduction on environmental pollution thus improving environmental health, livestock productivity and household income. 

Banana peels
Banana peels constitute about 30 percent of the total weight of the banana fruit. In addition to the use of banana peels as a potential low-cost feedstuff for livestock, one of the most important aspects of its use is associated with the reduction of the environmental impact caused by the disposal of this residue in nature.
Banana peels contain between six and nine percent protein in the dry matter; variable quantities of starch and soluble sugars, phosphorus, iron, calcium, magnesium, sodium, zinc, copper and potassium. Green banana peels contain about 40 percent starch that is transformed into sugars after ripening. 

A lactating dairy cow needs a good supply of glucose due to the demands of milk synthesis for glucose. It is practical to produce animal ensiled feedstuff by utilising banana peels which have been discarded in urban food markets which can advantage the small-scale urban dairy cattle farmers.  
Despite the potential use of banana peels in livestock feed, handling this by-product has complicated its use by farmers because of the high moisture content (about 80 percent). 
Therefore, it is necessary to support the processing of this material to reduce the moisture content, allowing nutrient concentration and inhibition of the proliferation of deteriorating microorganisms, longer storage time and reduction of transportation costs.

For small-scale urban dairy cattle farmers, the high-grade conventional feed resources such as Napier grass is quite expensive to get and also less available.  It is therefore necessary to increase the availability of alternative feed resources for cattle. 
Therefore, producing feed resources from ensiled banana peels that contain valuable nutrients such as glucose is important as alternative feed resources, especially for resolving scarcity of feed resources.
Ensiling banana peels with sweet potato vines or maize stover and agro-industrial wastes such as molasses has an appreciable level of nutrient and can be adopted in urban dairy cattle or pig feeding systems. 

Sweet potato residues
Sweet potato residues (vines, non-commercial roots and peels) provide a good source of energy (roots) and protein (vines). 
Sweet potato residues are highly perishable. In case of urban areas, sweet potato residues create a disposal problem as they are dumped within the markets after sale of the roots. 
Conserving sweet potato residues as silage has potential to mitigate seasonal feed shortages and help cope with seasonal feed prices fluctuations that many smallholder pig and dairy cattle farmers experience. 
It also provides opportunity to reduce waste in urban market and at household level as well as can open up business opportunities for youth and women.

A farmer chops maize stover to make animal feed.

Maize stover
Maize stover consists of stalks, leaves, and husks of maize plants left in the field following the harvest from farmers’ fields or in food markets after selling fresh or roasted maize cobs. 
Two youth vendors in USAFI and Owino markets in Kampala City have been trained to process fresh maize residues into maize stover. They collect maize leaves and stems from women and men who sell fresh maize cobs, dry them under sunshine and pack them in bags. They sell the maize stover at Shs1,500 per 50 kilogramme bag.
Farmers in urban areas overlook this economical source of feed for their dairy cows. Those who attempt to use it fail to extract maximum energy from maize stover. 
Yet this is a strategy that can be adopted to lower the cost of feeding without necessarily lowering the physical growth process and productivity. 

Maize stover is a highly fibrous feed of limited digestibility and palatability that requires treatment to enhance its nutritional value. 
The feeding value of maize stover can be improved by ensiling it with banana peels and sweet potato vines.
Livestock feed
The accumulation of agro-industrial by-products is a major environmental threat, and their use in livestock feeding would help in solving the problem. Most of the agro-industrial wastes are untreated and underutilised. 
Agro-industrial by-products such as molasses, brewery yeast solution and maize bran and others, can be utilised to improve the nutritional value of poor quality feeds such as maize stover.

Molasses 
Molasses is a by-product from a sugarcane factory. It is the heavy, dark viscous liquid remaining after the final stage of sugar crystallisation.
Molasses is in dry or liquid form and is a source of dietary sugars for dairy cows. Molasses is used as a blend for unpalatable but beneficial dry feeds such as grass hay and maize stover. 

Feeding molasses to a dairy cow helps the rumen function and ultimately the digestibility of other feeds the cow is eating. Molasses provide a source of energy for dairy cows and contribute to improving milk yield.
Brewery spent yeast solution
Brewery spent yeast solution is a by-product of the brewing industry, created when the yeast used in fermentations is no longer useful and must be disposed of. 
A small amount of brewery spent yeast solution is used to start the next batch of fermentation; however, the majority of the spent yeast solutions discarded. 
This discarded yeast is high in nutrients, in particular proteins (45–60 percent protein), vitamins and minerals, and is generally regarded as safe. Brewer’s spent yeast solution can be obtained from Uganda Breweries Limited, Luzira and Nile Breweries Limited, Jinja.

Maize bran
Maize bran (commonly known as “kyachu” is a product of the flour-mills and is the coarse portion that is separated on sieving of the crushed maize grain, to yield fine flour.  
Bran is composed largely of seed coat. Maize bran is one of the most valuable feed ingredients in many livestock feed rations.
Good maize bran contains minerals such as calcium, phosphorus, magnesium, potassium, zinc and iron.  
The benefits of these minerals cannot be overstated. The bran also contains crude proteins, crude fat and crude fibres. 
It also has lignin and starch as well as insoluble ash and fatty acids. Maize bran, when mixed with other feed ingredients and supplementary feed components, produces best results in quality of meat and increased milk production in dairy cattle.


How to process 
• Wilt clean (without polythene material) banana peels.
• Chop maize stover into pieces of about 3 cm length. Maize stover (dry leaves and stems) can be bought from farmers’ fields. 
• Chop sweet potato vines into pieces of about 3 cm length and wilt them under sunshine for about 3 hours. 
• Mix banana peels with maize stover and sweet potato vines in a ratio of 1 bag (about 50 kilogrammes) of banana peels, 3 bags (about 180 kilogrammes) of maize stover and 2 bags (about 120 kilogrammes) of sweet potato vines. 
• Mix molasses with brewery spent yeast solution using a ratio of one jerrican molasses with three jerricans of brewery spent yeast. Some of the molasses sold to farmers is a bit diluted. This means that you will use more molasses to produce quality silage.

• Spread the solution over a mixture of maize stover, banana peels and sweet potato vines and mix thoroughly until the material is completely wet. Molasses provide the animals with sugar (energy) while brewer’s spent yeast provides protein, minerals and vitamins. Molasses improves palatability of the feed and aid fermentation during silage making. 
• Store the mixture in airtight plastic drums or polythene tube silos (for urban farmers) for 30 days.