Agribusiness in KenyaAnimal ProductionDairy Farming

Silage making for smallscale farmers

Combined silage

If more crops are available, it is highly recommendable to produce silage trough combining of more products or by products. The most economically feasible results are obtained when low quality compo- nents, (crops that cannot be silaged on their own, such as fruits and leafs of sugar beat and sunflower) are added to more qualitative components (maize, alfalfa etc.) up to 30%.

As an example, high quality silage can be produced from whole plant of maize (45%), maize cone and grain (25%) and fresh alfalfa (30%).

Leafs and fruits of sugar beat can be also used for preparation of combined silage, as they contain sufficient sugar percentage (4-6%). The best combination is sugar beat leafs and fruit, together with whole maize plants or maize straw. A main success condition is that the sugar beat does not have much earth in it.

When you combine sugar beat with whole maize plants for silage production, it is best to use maize plants in a later stage of vegetation.

The sugar beat contents depends on the dry matter of the maize plant and usually in the total mixture contributes with 25-30%.

Silage production from drought affected crops

When corn is so drought stressed that it may not resume growth, it should be ensiled. Corn in this condition usually has few ears and has leaves that have turned brown and are falling off. The net en- ergy content of drought damaged corn often is 85–100 percent of normal, and it sometimes contains slightly more crude protein. Drought stunted silage often contains high fiber digestibility, so when it is supplemented with additional grain, it can be an excellent forage and sustain high milk production.  One concern with drought-stressed corn is the potential for high nitrate levels in the silage. High nitrate levels are found where nitrogen rates were applied and when a drought-stressed crop was chopped within three days following a rain. Ensiling crops that are suspected to have high nitrate levels is pre- ferred to green chopping, because fermentation will decrease nitrate levels by about 50 percent. High temperature and drought causes accumulation of nitrogen in plants, which affects significantly the conversion of the feed. The lactic acid produced when silaging reduces the nitrogen content in plants.

Silage in bags

The ‘new’ method, whereby cut green mass is stored in large sacks made from polythene, has in fact been tested in research stations for some years. It is not, however, a complex process. Ideally, the green mass is cut into small pieces, of about 3 cm long, and these, are used to fill the bags. The mate- rial is pressed removing the air and thereby preventing decomposition once the bag has been filled and shut. The feed can be stored in this way, without losing the nutritive quality, for up to a year. This allows farmers to maintain feed levels through the dry season. 

The purpose of chopping and compacting forage for silage is:

  • To release as much plant sugar as possible for fermentation
  • To ensure that all the air is pushed out of the plant material so that when the silo is sealed, the plant material is free of air. This is when fermentation works best to pro- duce lactic

Chopping can be done by hand but this can take too much time for forage on more than 0.1 hectares, so it is preferable that a forage chopper be used.

It is important to time the cutting of the forage so that the cut forage is not sitting for more than a day waiting to be chopped and ensiled, otherwise it will become moldy or to dry.

It is important that once the forage has been chopped it is placed in the silos and compacted as much as possible to get the air out before the silo is sealed. A key feature of silage bags is that it allows con- servation of available fodder in small quantities, over a long period of time. This strongly contrasts with traditional silage making techniques, where large amounts of fodder are harvested and chopped at one time. As example a farmer family might conserve a couple of bags a day over the growing season, which would allow their milking animal to be fed over the 200 days of autumn and winter. The fodder might include all parts of the corn plant, leafy grass weeds, etc., which could be also partly air-dried before chopping and ensiling. It is also possible to progressively remove leaves from maize plants as they commence to senesce.

Advantages

  • Plastics silage bags are an economical alternative to traditional silage storage systems, such as pits and silos when related, harvest and storage losses are
  • It is an effective way for preserving feed with minimum nutrient loss. (The anaerobic environment that is created eliminates spoilage from the growth of yeasts, molds and adverse bacteria while maintaining essential proteins and nutrients).
  • Allows farmers to store silage anywhere they need it. A well graded and well drained ground surface is all that is necessary.
  • The silage is completely sealed in the bag. This means that all the acid is retained in the silage, unl ke that in pit silage when it seeps out through the bottom of the pit as effluent. This compensates for the longer pieces of forage and poorer compaction than that found with silage machinery, so that the quality of the silage is just as
  • Ensiling in a bag avoids the hard work of having to remove silage, as it has to be from a pit, when it has to be dug out every day.
  • Because the whole bag is fed out to the animal, it means the rest of the silage which is in the other bags is not exposed to air at removal and is therefore unspoiled. Much of the silage in pit s has been found to be spoiled due to poor sealing and exposure to air every day when the silage is re- moved for feeding.
  • The bag is easily stored and easily portable so that any member of the family can carry it to the feed trough for the cow.

Disadvantages

 There are a few disadvantages to using silage bags.  Among them are:

  • the importance of pest control to prevent damage on the bags,
  • containment and disposal of the plastic, once silage is removed from the bag,
  • the need to chop the green mass, as chopped material tends to make much better silage, because more air can be squeezed out of it during the packing process, and the small pieces cannot puncture the bag.

With careful planning, all of these obstacles can be overcome. Most loses of silage during the process occur due to:

  • Seepage losses when dry matter is less than 32 %.
  • Unnoticed bird/rodent damage to the bags resulting in spoilage
  • Too wet (gaseous/seepage losses) or too dry silage (spoilage).