The document discusses factors that affect silage quality for winter feed. Key factors include the use of additives, compaction when filling silos, speed of filling, moisture levels when cutting grass, and time of year. Later harvest dates result in lower yields, digestibility, and carcass gain in animals. Proper silage making requires a complete absence of air, an adequate sugar supply in grass, and lactic acid bacteria to produce lactic acid which preserves the grass.

1. Slide Silage- Preserved Grass for Winter Feed Copyright © Veronica Walsh Coláiste Treasa , Kanturk F or non-commercial purposes only….. Enjoy! Comments/suggestions please to the SLSS Agricultural Science website forum @ http://agscience.slss.ie/forum

2. Factors That Affect Silage Quality Use of additives Compaction Speed of filling & sealing the pit Wetness when cut Time of year ensiled Veronica Walsh, Coláiste Treasa

3. Silage Data Increase in yield= longer growing period, increase photosynthesis & day length, Variation in digestibility= grass develops flower, high % cellulose, reduction in starch Decrease in carcass = lower intake, less digestible food, decreased protein content Veronica Walsh, Coláiste Treasa Harvest Date 15 May 29 May 13 June 27 June Silage Yield 4.0 5.2 6.6 7.8 Silage Digestibility 75 70 65 60 Silage Intake 9.0 8.3 7.6 7.0 Carcass Gain 0.51 0.39 0.27 0.15

4. Making Silage Preserved grass by acids. Lactic Acid from sugars in grass Complete absence of air. Adequate supply of sugars. Veronica Walsh, Coláiste Treasa

5. Complete Absence of Air Air must be excluded to enable Lactic Acid Bacteria to feed & prevents rotting. Lactobacilli Streptococci These bacteria feed & multiply to produce LACTIC ACID-Preserve Anaerobic bacteria The Faster air is excluded the quicker the bacteria can start to work on sugars to produce acid to lower pH. Fast filling the pit & sealing is vital pH 4 as fast as possible Veronica Walsh, Coláiste Treasa

6. Adequate Supply of Sugars Anaerobic bacteria feed sugars Acids Sugar content 10 –15% Different grass species Grass acts as a substrate for the bacteria & converts the sugars to acids Veronica Walsh, Coláiste Treasa

7. Grass Species used for Silage Perennial Ryegrass Italian Ryegrass (biennial) White clover Red clover Veronica Walsh, Coláiste Treasa

8. Factors forming Lactic Acid Silage Air free Fill silo quickly Short cut grass Good compaction Wilted grass Lactobacillus Streptococcus Good Acidification Low pH Effective Additive Good Sealing of silo High sugar Grass STAGE of Growth = High Palatability, High Digestibility Veronica Walsh, Coláiste Treasa

9. Additive Improve Silage Preservation Increased Silage Intake Improved digestibility & animal performance Veronica Walsh, Coláiste Treasa

10. Molasses Sugar Based Added to supplement sugars already present in grass. The sugars are converted to acids by microbes. 9-18 litres/ton of grass Added either by harvester or at the pit Young leafy grass, wet weather have reduced sugar content Veronica Walsh, Coláiste Treasa

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12. Sulphuric/Formic Acid These reduce the pH of grass from 6 to 4.8 Creates an environment which favours lactic acid production 2-3 litres/ton The lower the sugar level in grass, the leafier the grass & the wetter the grass the higher rate of acid is used Veronica Walsh, Coláiste Treasa

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14. Silage Cutting Mower- chops the grass up small to increase the surface area for bacteria to act on Precision chop mower Veronica Walsh, Coláiste Treasa

15. Wilting This is to cut the grass & leave it on the ground for 24 –48 hours before gathering up & ensiling it To remove some water from the crop Increases conc. Of sugars Reduces level of effluent Raises DM content Reduces the activity of undesirable bacteria Reduces the size of clamp required Saves on additives Veronica Walsh, Coláiste Treasa

16. To Make silage Close the field in time. Fertilize adequately Cut at the correct stage of growth- precision chopper Allow to wilt for 1-2 days Pick up the grass Transport to pit/bale Fill pit quickly Use an additive Spread grass and compact evenly Cover & seal the pit Veronica Walsh, Coláiste Treasa

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18. Experiments % Sugar in silage sample Compare silage samples-colour, smell, pH, water content. % DMD To conserve grass as silage in the lab Veronica Walsh, Coláiste Treasa

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29. To get high levels of carbohydrates Cut the grass at the young leafy stage Cut in dry conditions(water dilutes) Allow to wilt Cut using a precision chop mower Use a carbohydrate rich additive Mow in afternoon Veronica Walsh, Coláiste Treasa