How to Make High-Quality Grass Silage
Grass silage is pickled pasture, preserved through the conversion of its sugars into lactic acid by bacteria.
For quality silage, make light crops and cut early.
Quality may not be important for feeding stock on a maintenance diet. But for supplementing milking cows, or for growing young stock, quality is essential.
Lighter crops, harvested earlier, produce better silage. For best ME, cut pastures before they reach a yield of 4t DM/ha (i.e. harvest about 1.5-2.5 t DM/ha).
Paddocks cut earlier also regrow much faster and are available for grazing earlier than those that are not.
Using later-heading ryegrasses can help silage ME because these better maintain pasture quality in late spring.
Cut paddocks in the afternoon when the WSC percentage is greatest in the plant.
Leafy spring pasture has an ME of 12 or more. As soon as the yield exceeds 3500kg DM/ha, quality decreases.
Pastures that are not cut before 4t DM/ha can lose 1 ME unit every two to three weeks as stems, seed heads and dead matter increase.
Silage quality has a direct effect on dairy cow milk production as shown in the graph opposite. Quality also dramatically effects LWG in young stock.
Survey work has shown New Zealand farmers are generally good at what happens after cutting (stacking, compacting, covering etc.). The biggest reason for poor silage is making it from poor quality pasture cut too late.
Another reason is weather. If made in good conditions, pasture typically loses 0.5 ME unit through ensiling. Rain can increase this loss.
Nitrogen fertiliser
Applying nitrogen fertiliser after the paddock has been taken out of the grazing rotation for silage production can help increase growth rates, so the paddock is available for grazing again sooner.
Fertiliser application after cutting is also recommended, as large amounts of nitrogen and potassium, in particular, are removed in the silage.
• Article sourced from www.agriseeds.co.nz
