Upload
julian-whitehead
View
224
Download
6
Embed Size (px)
Citation preview
Harvest & post-harvest Harvest & post-harvest Physiology and Physiology and
PreservationPreservation
Forage Harvest LossesForage Harvest Losses
Fresh ForageFresh Forage
Living, Breathing, Making & Living, Breathing, Making & Using EnergyUsing Energy
Taking up and Losing WaterTaking up and Losing Water
70 ~ 90% Water (10 ~ 30 % DM)70 ~ 90% Water (10 ~ 30 % DM)
Bacteria and Fungus Bacteria and Fungus ContaminationContamination
Forage Harvest Losses – start in Forage Harvest Losses – start in the fieldthe field
What happens after cuttingWhat happens after cutting Plants continue to ‘live’Plants continue to ‘live’
Using stored energyUsing stored energy Losing water through pores and Losing water through pores and epidermisepidermis
Miner amounts of proteins are Miner amounts of proteins are converted to Non-protein N converted to Non-protein N (0.5% / hour)(0.5% / hour)
< bacteria and fungi are still around >< bacteria and fungi are still around >
Forage Harvest Losses – start in Forage Harvest Losses – start in the fieldthe field
At about 50 ~ 60 % moistureAt about 50 ~ 60 % moisture
Pores close at about 70 %, water Pores close at about 70 %, water loss rate slows downloss rate slows down
Some part still ‘alive’ using sugarsSome part still ‘alive’ using sugars (until about 30~40% moisture)(until about 30~40% moisture) About 1~4% of DM is lost as non-About 1~4% of DM is lost as non-
structural carbohydrate, up to 16% structural carbohydrate, up to 16% during extended warm, humid during extended warm, humid conditioncondition
< bacteria and fungi still around, using < bacteria and fungi still around, using energy, generating heat >energy, generating heat >
Forage Harvest Losses – start in Forage Harvest Losses – start in the fieldthe field
Below 40% moisture(26~40%)Below 40% moisture(26~40%)
Plant is dead (no longer Plant is dead (no longer respiring)respiring)
Soluble sugars can leach from Soluble sugars can leach from all damaged and dead cellsall damaged and dead cells
Bacteria, fungi, yeasts etc using Bacteria, fungi, yeasts etc using sugars, generating heatsugars, generating heat
Forage Harvest Losses – start in Forage Harvest Losses – start in the fieldthe field
Below 25% moistureBelow 25% moisture Most bacteria are ‘inactive’Most bacteria are ‘inactive’ Fungi & yeasts are still active, Fungi & yeasts are still active,
using sugars, generating heatusing sugars, generating heat
Below 10% moistureBelow 10% moisture Bacteria, fungi, yeasts are Bacteria, fungi, yeasts are
inactiveinactive Hay is stable until moisture Hay is stable until moisture
content increasescontent increases
Post-Harvest PhysiologyPost-Harvest Physiology
Drying processDrying process
Factors which influence drying Factors which influence drying and the quality of forage and the quality of forage during dryingduring drying
MetabolicMetabolic MechanicalMechanical WeatheringWeathering
Post-Harvest PhysiologyPost-Harvest Physiology
Drying rateDrying rate Methods for increasing drying rateMethods for increasing drying rate
Adequate periods without rainfallAdequate periods without rainfall
(probability of rain-free period)(probability of rain-free period)
Mechanical Conditioning : crush, bendMechanical Conditioning : crush, bend Chemical conditioning : potassium carbonatChemical conditioning : potassium carbonat
e, Organic Acidse, Organic Acids Raking, TeddingRaking, Tedding
Preservation and StoragePreservation and Storage
Hay and Silage storage Hay and Silage storage systemsystem
Important processes in curing Important processes in curing or fermentationor fermentation
Preservative and additivesPreservative and additives