During dry seasons, many farmers experience shortage of fodder to feed their animals. This is because they do not conserve pasture, which is abundant during rainy seasons, for use in the dry periods. The conservation can be in form of hay or silage. The two differ in terms of how they are stored and their moisture content.
Some farmers are familiar with hay or silage made from grasses. International Livestock Research Institute (ILRI) in partnership with International Potato Centre have an innovation of making silage from sweet potato vines.
Danilo Pezo, project leader, Smallholder Pig Value Chains Development in Uganda, says the innovation was prompted by a research carried out in Mukono, Masaka and Kamuli districts. It was among pig farmers, which showed that most of the farmers feed their pigs on sweet potato vines.
“However, all the farmers we interacted with complained that they only had the sweet potato vines during harvest periods. So, we had to come up with a way to ensure they have the vine feeds throughout the year,” Pezo explains.
“This is by making silage. Sweet potato vines contain 16 per cent protein, which is quite good since pigs require between 12-18 per cent protein for proper growth,”
It is not easy to make hay from sweet potato vines; they are not easy to dry because they contain a lot of water. Hay is prepared by partially drying fresh fodder, which is then preserved for use later.
Every farmer can make silage from sweet potatoes vines because sweet potatoes are widely grown in Uganda. This silage can be fed to sheep, pigs, goats, cattle and rabbits.
Pezo says they are training farmers how to make silage from vines so that they can cut costs of production.
This and other technologies are some of the many things that will be covered in the Seeds of Gold farm clinic on May 30.
How to make the silage
First, harvest the vines, then sort them to remove the bad ones and remain with the good ones. Then, chop the vines into smaller pieces.
After chopping, sun-dry the vines to reduce the moisture content. However, avoid over-drying.
Squeeze a handful of the vines to check for excess water. The vines are ready if they go back to their shape after being squeezed.
A farmer can mix the vines with sliced potato tubers at 70-80 per cent vines with 20-30 per cent tubers. Poultry litter and salt (0.5 per cent) can also be added to the chopped vines to raise the protein level in the silo. Salt acts as a preservative.
After this, pack the mixture into a pit, plastic or nylon air-tight bag. The silage should be compacted to remove the air that can interfere with fermentation. However, the silage should be compacted in layers to be done effectively.
The silage can be ready for use after 40-45 days. However, the silage can be stored for years, if it is well-prepared and sealed.
The major advantage of silage made from sweet potato vines is that it is high-quality feed rich in proteins, carbohydrates and vitamins. Also, this silage is highly digestible by the animals.
As vines are a residue, a farmer loses nothing in terms of money when he/she uses them to make silage. This is unlike when a farmer harvests young maize plants and makes silage out of them. In this case, a farmer loses maize.
It is important to note that this type of silage reduces the cost of feeding animals. While a farmer may lose all the feed, this calls for extra care during preparation to avoid losses.