Making and Maintaining Silage
Now, more than ever, as the drought continues to pummel us in Zimbabwe, knowing how best to make and maintain your silage is vital to the success of your dairy herd. Last year we brought you a tip of the month on making silage, but this year we thought we would take you into some of the finer, most important details in a blog post.
First, you obviously need an excellent maize crop. We recommend a maize variety that has a high grain yield to give you high starch levels, as well as stay-green characteristics to give you a longer window for harvesting. Ensure that the maize is planted early in the season, from first October to early December. Your maize needs enough heat units to grow big enough.
When to cut?
- Test the dry matter of the maize crop. Dry matter content should be from 28% to 36%.
- Look at the colour of your maize –most leaves should still be green with maybe the bottom two turning yellow and the pips should be in the hard, doughy stage.
How big to cut?
- The drier your maize, the smaller your chop should be, but in general you should be cutting it into 1 to 2cm size pieces. If your cutter is equipped with a nut cracker or a shredder you can have a longer chop, up to 3 cm. it is vital that there are no whole pips in the end product.
What about cutting equipment?
- We use JF silage cutters from Brazil and Van Zyl tipper trailers. We find the cutters adequate for our operation but the best cutters on the market are Claas; however these only come in large self-propelled units which are not economically suitable for the average dairy/medium-scale crop farmer. The Van Zyl trailers are excellent and have other uses in the off season.
- Your silage cutting blades should be sharpened at least twice a day during cutting to ensure a clean cut.
- In the last two years we have started to use an inoculant on our silage to reduce dry matter loss when we are storing our silage. We use a Kemin inoculant, which we spray onto the silage as it exits the chute during cutting using an electric knap sack mounted on the tractor . The use of the inoculant has reduced our dry matter losses from 20 to 5%. 1g of inoculant should be added per tonne of silage.
How should I make my pit?
- 25 to 1.5 cubic metres per tonne of silage
- Firm sides and bottom can be covered with plastic to avoid dirt getting into the silage
- Ends of the pit should be sloped so that tractors with the tippers can drive into the pit and over the already dumped silage to help with compaction.
What is best practice for filling the pit?
- Ensure that every layer of silage emptied into the pit is well compacted to cut out any air and thus avoid aerobic digestion and the loss of dry matter: ensiling is an anaerobic process. We drive over the top of our silage pit with a TLB or front-end loader for maximum compaction. If you only have a tractor use one with narrow wheels and have as much weight as possible on it.
- As soon as the pit is filled, or filling is done for the day, cover and seal it immediately by first covering it with high quality silage cover plastic to prevent any oxygen and unwanted moisture creeping in. After this you must protect this plastic with strong shade-cloth or a 30cm layer of soil.
- You might want to pile something heavy, for example old tires, on top of the plastic for extra protection.
How should I feed out of and maintain my silage pit?
- When you start to use the silage in your pit, remove a section that is at least a metre wide each day. Make sure you cut a straight edge when removing the silage.
- Use the plastic cover to protect as much of the exposed area as possible once feeding out of the pit has started. You want to prevent as much secondary fermentation as possible.
- You should only cut out enough silage to feed to your cows within a maximum of 6 hours. Silage in bags is exposed to oxygen and will start to ferment which means you will be feeding fermenting or even rotting silage to your cattle.
- Always feel your silage before putting it into the feed trough – it must be cold. If you have used an inoculant, when you fill your silage in the pit it should be freezing cold.
- It is important that you avoid water getting into your silage. During the rainy season, water can rain down from above and come through the soil below, soaking your silage and leeching its nutrients. If this happens, feed the soaked silage if not rotten, to your followers. Bag wet and dry silage separately! More wet silage needs to be fed than dry silage per cow because it has a lower dry matter content.
- Ensure that your silage baggers are trained to pick up on and discard mouldy, rotten or dirty silage. Mouldy silage could make your cattle sick so it must be avoided at all costs.
What are they?
- Silage sausages are a way to store silage in almost any spot on your farm, without having to build a silage pit. They are simply a long, tube-shaped bag of thick plastic full of silage that, if maintained properly, keep your silage safe from oxygen and moisture, and thus any secondary fermentation and loss of dry matter.
- Silage sausages can be any size you want, storing up to 80 tonnes of silage each.
What do I need to make them?
- In addition to your silage cutter, you will need the silage sausage filling machine and the trailers used to funnel silage into the machine. We buy ours from Radzim who import them from Brazil.
- A protected area of flat land with no sharp sticks or stones in the ground, at least 120 square metres per 80 tonne sausage. The area should be protected from possible vandals or anything else that might slit open the sausage’s plastic. Rat control is also vital.
How do I feed out of and maintain my silage sausages?
- When feeding out of your silage sausages, cut your desired amount of silage out along a straight edge. 1m of silage is equivalent to approximately 1300 kg of silage.
- Ensure that after each cut the plastic at the end of the sausage is tied up securely again. Weigh down the ends with something heavy for extra protection.
- Don’t ever let anyone climb up or stand on the silage sausages, and avoid driving machinery close by that might cut the plastic. Keep the sausages in a safe area.
- As with the silage pits, make sure that any mouldy or rotten silage is discarded, and that the silage is freezing cold when cut out and put into the feed troughs.