How to store your silage for dry days

Sorghum silage at Philemon Kibusia's farm at Chemogoch village in Mogotio. December 15, 2019. PHOTO BY MERCY KAHENDA

Vaishali Malde, the marketing director at Packaging Industries Limited explain the science behind silage storage and rules that must never be broken.

Patrick Kariuki 

1. Climate change is the greatest threat to food security. As a manufacturer of packaging bags, what does Packaging Industries Limited bring to the table to help Kenyan farmers cope in the fight against climate change?

PIL has been educating farmers on preservation methods to build climate resilience within their farms. We have introduced the Mama Silage bag, designed to preserve fodder for longer durations without losing their nutritional value. We also offer farmers hermetic bags for grain storage. These tools enable farmers to better manage their food and fodder needs and cope with uncertain climatic conditions.

2. Plastic waste is a major challenge for retailers and farmers alike and yet plastic is widely used on the farm, for example in greenhouses and irrigation pipes. How can farmers use plastic in an environmentally sustainable manner?

Government policies are allowing manufacturers and producers to provide information to users on the correct disposal of packaging materials after use. The consumers are creating a drive for recyclable packaging allowing for the reduction of plastic waste. As a manufacturer, we actively promote reusing plastic packaging materials used in things such as plastic sheets, dam liners, mulching films, silage bags, grain storage hermetic bags and more. PIL also wants to actively down-gauge the thickness of the films while maintaining their physical and mechanical properties by using super quality resins to further reduce plastic waste.

3. What methods of fodder storage are now being used by Kenyan Farmers?

Heap or stack silos: The shredded fodder is simply placed on a convenient patch of ground, usually covered with dry hay, with continuous compaction up to a height of about 2m and sealed in a day, or a maximum of three days. The heap is then covered with thick black polythene sheeting and soil and heavyweights such as stones and tyres placed on the top. The area around the heap is usually drained. Heap silos are cheap to construct and for this reason, they are popular with many large-scale Kenyan farmers. However, silage along the sides usually gets spoilt (moulds) due to improper compaction and large air pockets between the particles.

Trench or pit silos: These are constructed by excavating soil to form a trench or a furrow on a slightly sloppy ground and material is ensiled below the ground surface. It is common for the large-scale farmers who find it easy to compact the material by driving trucks over the material for easy compaction. The farmers prepare the silo by covering the ground with hay and filling it with chopped forage, ensuring it does not touch the soil. Some farmers add diluted molasses and sprinkle over the layers of forage while compacting it, until the pit gets full. After the final filling and compacting, they wrap the polythene sheet around the silage and cover the top of the heap with soil or heavy tyres to avoid the cover flying off and prevent damage of the polythene by rain, birds and rodents. With good sheeting and enough soil on it, the silage can be kept for six months (nutritional value not too certain). It takes about 30 to 40 days for the silage to mature and be ready for feeding.

Polytube or bag silos: The polytube used is a seamless 1,000 gauge open-ended bag ranging between 2-2.5m long. It is tied on one end, filled with the material being ensiled and then tied at the top for fermentation to take place. The material is compressed manually by farmers stomping onto the content. A single bag silo can hold between 200kg to 250kg of silage and is suitable for small-scale farmers. The main limitation of this type of silo is limited compaction due to the bag strength, destruction by rodents and short life of the silage compacted.

Bunker or walled-surface silos: Bunker silos are used in flat areas unsuitable for trench silos. Above-ground walls are constructed using concrete or timber braced with poles. Timber walls are also used but covered with polythene sheets to prevent moisture and acid penetration. Concrete floors are usually needed for easier loading and to minimise feed waste, however, most practices in Kenya only layer dry hay on the ground before adding the fodder. They are suited for medium and large-scale farmers.

4. What are the challenges being faced by farmers with regards to fodder storage?        

Currently, all fodder preservation methods experience oxygen transpiration through polythene sheeting. This results in the growth of fungi and mould on the exposed surfaces leading to loss of nutritional value of the fodder. There is also damage and wastage from the rodent infestation, where the aroma of the fermenting fodder attracts mice, birds, and other small animals to peck over the polythene sheet and eat into the preserved fodder.  There is a huge loss in dry matter and the fodder quality is generally deteriorated due to protein degradation. The silage retrieved is generally of poor quality. High losses are also experienced at feed out in bunkers, trench and heap silos due to the large surface exposed to air and low consumption daily. However, we have introduced a solution to these challenges called the Mama Silage bag.

5. What is a Mama Silage bag and what are the properties that differentiate it to the benefit of farmers?

This is a high-performance plastic bag comprising of multiple layers of polymers with a special oxygen barrier used for protecting and preserving fodder for a longer period. The Mama Silage bag is designed from high mechanical performance polymers that allow multiple reuses of the bags before any physical damage is experienced. When used in comparison to the existing polytubes, the bag can contain much more fodder and allows high compaction due to its excellent mechanical properties, reducing the silage packing cost to the farmer. As discussed earlier, with current fodder preservation methods, the sugar present in the fodder reacts with oxygen leading to the generation of carbon dioxide, water and heat which further leads to dry matter loss, nutrient loss, and growth of moulds and fungi. The mama silage bags have a special oxygen barrier that blocks any oxygen transpiration into the bag, preventing the growth of moulds and fungi. It also enables the creation of an anaerobic condition for controlled fermentation to occur and maintains the pH level of the fodder. The bag also creates an excellent environment to minimise nutrient degradation by conserving proteins and sugars while decreasing dry matter loss. The bag has an aroma barrier that preserves the smell of the fodder inside the bag and prevents rodent damage to the bag. The surface heating of the bag is reduced by the white reflective surface, while the inside of the bag is made black to allow preservation of the heat generated during the fermentation process.

6.  Does corn silage give animals a full meal or is there something else that should be added to balance the diet?

Corn silage can be used for feeding all dairy cattle on the farm: growing animals, dry cows, and lactating cows. It must be supplemented with protein, minerals, and sometimes energy to meet the animal’s nutrient requirements. Although corn silage is occasionally used as the only forage for dairy cattle, it is usually fed with complimentary forage such as alfalfa which is higher in crude protein but lower in energy. Corn silage feeding strategies vary depending on animal age, level of production, and physiological status as well as the other forages being fed if any. The quality factors that are important to consider when balancing corn silage rations are energy content,  digestibility, length of cut, starch content, and starch digestibility.

7.How much does a Mama Silage bag cost and where can farmers get it?

The bag retails at Sh2,000 and is available at various agrovets across the country. Because the bag is reusable the initial cost of buying the bag is divided by the number of times it is used, thereby making it extremely economical if used at least three times.

8.Why is corn silage a highly recommended feed for dairy animals and what is its ideal nutritional composition?

It is palatable forage with relatively consistent quality and higher dry matter yields with high energy than most other forages. It is also more cost effective due to its lower cost per ton of dry matter in comparison to other forage crops.

9.  How does silage from corn reduce the farmers cost of milk production and benefit them economically?

Statistics show that the largest cost item to the farmers during milk production is the cost of feeding the animal. This takes 60-70 per cent of the total costs incurred. Corn silage can be designed to provide animals with the nutrition they require and therefore reduces the need for the highly priced concentrates required for balancing the diet. This can create major savings for the farmer. When transitioning animal feeding from Napier grass to more nutritious corn silage, there is evidence of an increase in the milk yield ranging from 10-15 per cent. Using silage to feed animals during the dry season ensures constant milk production, enabling the farmer to have a stable income.

10. Smallholder dairy farmers are the largest producers of milk. How can they be helped to improve their farming practices and milk output?

We actively participate in farmer exhibitions and forums where they are educated on better practices in soil preparation, seed selection, planting distance, nurturing of plants, harvesting and till shredding and correct storage of fodder, allowing them to gather knowledge and develop skills. We also have been carrying out on-farm demonstrations and trainings for extension managers and on-field officers with various partners in the dairy chain to empower the farmers.