AGR 301 :: Lecture 21 :: PRESERVATION OF FODDER - HAY & SILAGE MAKING
Hay making
“Hay -refers to cereals, grasses or legumes that are harvested at appropriate stage, dried and stored”
- High quality hay is light grey color
- Leafy, pliable & free from mustiness
- Easy method of storing seasonal excess
- Only way for farm by-products
- Principle is to reduce water content
- Legume, non-legume & mixed gay are the major three types
Field method
- In field there are two methods
- Windrows – occupies 1/3rd land area
- Swath – Entire field
- Drying in ‘Windrows’ faster than swath
- For this, harvest few hrs after dew drying
- Allowed to cure in the field itself
- Turned after every 4-5 hrs
- By the evening moisture reduced (75% to 40%)
- Next day requires 1 or 2 turnings
- Moisture content in the 2nd day comes to 25%
- Now ready for storage as bales or in tripod stand
- End of curing moisture to be reduced to 20%
- Normally 70-75 sunshine hrs require
- Not suitable for rainy season
Mechanical method
- Fence method – wire fencing with angle iron posts are used
- More suitable for berseem, Lucerne, groundnut haulms and legume fodders
- Protein loss is minimized (2-3%)
- Forced air batch – developed at IGFRI
- Capacity 1 t /day
- Cost Rs.60/t
Chemical changes in hay making
- Conversion of soluble sugars to CO2 & H2O
- Loss of digestibility
- Increase in cellulose and lignin content
- Reduce in nutritive and keeping quality
Loss in fodder value
- Nutrient loss in late cutting
- Shattering of leaves & finer parts (in legumes)
- Fermentation loss leads to dry mass loss by 6%
- Oxidation by sun bleaching leads to
- Loss of chlorophyll and carotene
- Carotene decreases from 150-200 to 5-10ppm
- Carotene is to give aroma
- Animals are color blind
- Leaching leads to loss of
- Protein, nitrogen free extract (NFE), minerals, and vitamins
- Consequently crude fibre increases & digestibility deceases
- In Berseem crude protein loss is from 22% to 16-18%
Ensilage / Silage making
‘Silage’ may be defined as the green succulent roughage preserved under controlled anaerobic fermentation in the absence of oxygen by compacting green chops in air and watertight receptacles
- Silage leads to fermentation of water soluble carbohydrates to organic acids which increases acidity of the materials (pH – 4)
- Such anaerobic acid (lactic acid) arrests the
- growth of bacteria
- Moulds
- Inactivates putrefying organisms (act as preservative)
- Consequently reduces nutrient losses and
- Change in nutritive value
- Best method than hay
Crops suitable for silage
- Crops suitable are based
- Dry matter of 30-45%
- Soluble sugar 8-10%
- Ratio between water soluble CHOs and buffer capacity
- Ratio of sugars to crude protein
- All these decide production of lactic acid
- Crops suitable for cut at 50% flowering and at milking
- Crops like sorghum, maize
Points for consideration while ensiling
- Dry matter content for the materials should be 30-45%
- More succulent materials may be taken after field drying only
- Polythene layering on all sides improves the quality
- Filling should be done on a clear day as quickly as possible
- Filling should be in layers of 20-30cm at a time and uniformly
- Compaction must be perfect
- Trampling is useful to remove air pockets
- Top must be convex / dome
- Silage pit size
- 20 x 20 x 20 c. ft for 50-55 t
- 5 x 5 x 6 c. ft for 22.5 t
- 10 x 5 x 6 c. ft for 45.0 t
Characteristics of good silage
- No mould growth
- Golden / greenish yellow
- Pleasant fruity odour or acceptable aroma
- Free flowering and non-sticky texture
- 3-4% increased palatability
- Increased nutritive value
- pH around 4.0 – 4.5
- Lactic acid proportionally more than other acids
- Decrease in nitrate-N and increase in ammoniacal-N
- Ammoniacal N should not exceed more than 15% of the total N
Haylage
- It is low moisture silage (40-45%)
- Made from grass / legume that is wilted to reduce moisture content
- But for moisture it is almost silage
Fortification of Fodder
‘Fortification or enriching is the direct addition of feed supplements to the poor quality roughage to improve its fodder value’
- Mixing green legume with fodder
- Mixing liquid ammonia (2.5 to 3.0%)
- Mixing Urea molasses
- 2-3% for concentrates
- 1% of dry matter
- After mixing similar to silage
Fortifying materials and usage
- Molasses for rice, wheat
- Mineral mixture and salt for low grade grass hay
- Urea for sorghum & maize green fodder
- Tapioca powder/ maize powder for leguminous fodder
- Bacteria and / fungi for dried ground nut haulms
Advantages of Fortification
- Improves palatability
- Reduces wastage
- Improves rumen environment
- Increases crude protein
- Cleavage of cell wall for increased digestibility
- Neutralize or reduce the concentration of toxic principles
- Increases digestibility
- Milk protein and fat increase
Multiple choice questions
- Green succulent roughage preserved under controlled anaerobic fermentation
a. Forage b. Hay c. Silage - Cool-season grass is ________
a. Rye b. Bermuda c. Corn - Warm-season grass is __________
a. Rye b. Blue grass c. Bermuda - Enriching is the addition of feed supplements to the poor quality roughage _____
a. Silage b. Haylage c. Fortification - Moisture content in silage is ________
a. 40-45% b. 20 - 25% c. 25 - 35%
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