Slide 1 Silage- Preserved Grass for Winter Feed

Factors That Affect Silage Quality  Use of additives  Compaction  Speed of filling & sealing the pit  Wetness when cut  Time of year ensiled

Silage Data Harvest Date 15 May29 May 13 June 27 June Silage Yield Silage Digestibility Silage Intake Carcass Gain 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

Making Silage  Preserved grass by acids.  Lactic Acid from sugars in grass  Complete absence of air.  Adequate supply of sugars.

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

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

Grass Species used for Silage  Perennial Ryegrass  Italian Ryegrass (biennial)  White clover  Red clover

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

Additive  Improve Silage Preservation  Increased Silage Intake  Improved digestibility & animal performance

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

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

Silage Cutting  Mower- chops the grass up small to increase the surface area for bacteria to act on  Precision chop mower

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

To Make silage 1. Close the field in time. 2. Fertilize adequately 3. Cut at the correct stage of growth- precision chopper 4. Allow to wilt for 1-2 days 5. Pick up the grass 6. Transport to pit/bale 7. Fill pit quickly 8. Use an additive 9. Spread grass and compact evenly 10. Cover & seal the pit

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

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