Harvest

1
Harvest post-harvest Physiology and
Preservation
2
Forage Harvest Losses

• Fresh Forage
• Living, Breathing, Making Using Energy
• Taking up and Losing Water
• 70 90 Water (10 30 DM)
• Bacteria and Fungus Contamination

3
Forage Harvest Losses start in the field

• What happens after cutting
• Plants continue to live
• Using stored energy
• Losing water through pores and epidermis
• Miner amounts of proteins are converted to
  Non-protein N (0.5 / hour)
• lt bacteria and fungi are still around gt

4
Forage Harvest Losses start in the field

• At about 50 60 moisture
• Pores close at about 70 , water loss rate slows
  down
• Some part still alive using sugars
• (until about 3040 moisture)
• About 14 of DM is lost as non-structural
  carbohydrate, up to 16 during extended warm,
  humid condition
• lt bacteria and fungi still around, using energy,
  generating heat gt

5
Forage Harvest Losses start in the field

• Below 40 moisture(2640)
• Plant is dead (no longer respiring)
• Soluble sugars can leach from all damaged and
  dead cells
• Bacteria, fungi, yeasts etc using sugars,
  generating heat

6
Forage Harvest Losses start in the field

• Below 25 moisture
• Most bacteria are inactive
• Fungi yeasts are still active, using sugars,
  generating heat
• Below 10 moisture
• Bacteria, fungi, yeasts are inactive
• Hay is stable until moisture content increases

7
Post-Harvest Physiology

• Drying process
• Factors which influence drying and the quality
  of forage during drying
• Metabolic
• Mechanical
• Weathering

8
Post-Harvest Physiology

• Drying rate
• Methods for increasing drying rate
• Adequate periods without rainfall
• (probability of rain-free period)
• Mechanical Conditioning crush, bend
• Chemical conditioning potassium carbonate,
  Organic Acids
• Raking, Tedding

9
Preservation and Storage

• Hay and Silage storage system
• Important processes in curing or fermentation
• Preservative and additives