Hay and Silage: An Alternative source of quality fodder for dairy stakeholders during lean periods
Authors: ¹Abul K. Azad, ²Sujeet K. Jha, ¹Chandan K. Rai and ¹Priojoy kar
¹ Ph.D. Scholars, ² Principal Scientist
Dairy Extension Division, ICAR-NDRI, Karnal-132001
Email:abulazad45@gmail.com

Fodder has a great role in livestock farming, it is the major source of amino acids, starch, proteins, vitamins and minerals with consideration of some anti-nutritional quality factor in sorghum (Nitrate and HCN toxicity), Lathyrus (BOAA) etc. Feed and fodder enhance the overall development of animals, production of milk, meat and primary source for sustainability. At present, India bearing 512.05 million livestock population and to meet feed and fodder requirement is a questionable issue (19^th Livestock Census-2012). The present availability of green fodder from cultivated areas and pastures is 462.05 million tonnes and in case of dry fodder is 393.88 million tonnes. By 2020, the demand of green fodder and dry fodder will be 1134 million tonne and 630 million tonne and the supply will be 405.9 million tonne green fodder and 473 million tonne dry fodder respectively (IGFRI-2012).

As India has a very unique climatic condition and major problems relating to feeding have been found during lean period in which there is a scanty fodder availability. But due to the advancement of science and technology, now we can able to mitigate the fodder requirement during lean period (Nov-Jan and may-june).

The hay and silage are the alternative source to meet the fodder requirement. The brief discussion of hay and silage making are as below-

Hay

The dry storage of forage crops is term as hay, containing less than 15 percent water. Drying can be done naturally (exposure to the sun on the ground aerating the forage regularly by turning it over) or artificially by active circulation of air. Sun-drying requires 2 or 3 days without rain. The hay must then be kept in appropriate conditions (covered area). But if the grass has matured and has already dried standing, it is not hay, it is termed as straw. Suitable crops and stages of harvesting are-

Forage crops	Growth stage	Dry matter (%)
Maize	Milk to dough	30-35
Sorghum	50-100% Flowering	40-50
Bajra	50-100% Flowering	40-50
Oat	Milk to dough	20-25
BN Hybrid	About 1.5 meter height	20-30
Guinea grass	About 1.5 meter height	20-30

Source: IGFRI-2012

Process of hay making

Timing

One of the most critical factors in hay making. Time coincide with the right stage of plant growth and weather conditions. The old timers used to talk about cutting hay around the fourth of July because maximum growth of the plant and peak yields occur around that time, the nutrient value is greatest earlier in the season, when plants put most of their energy into vegetative growth and contain high concentrations of starches, proteins and minerals.

Mowing

Mowing involves cutting shoots 2-4 inch above the soil surface. A good strategy is to mow just before or right after a rain, because of the likelihood of good weather for the next few days.

Tedding

Tedding is done to promote curing. In this steps disperse of crops are done so that air and sunlight contact the under-surfaces to promote drying . Hay mowed early in the morning could be tedded that afternoon is highly recommended. Too much tedding of alfalfa or clover can shatter leaves which leads to lowering the quality of the hay.

Raking

Raking turns the hay one more time to dry the bottom and forms it into a windrow ready to be baled. Raking is done at ideal moisture of 35-40%, DM losses usually under 4%. The windrows shouldn’t be rolled too tightly, as this creates a roping effect that prevents the hay from drying properly and causes it to clog as it enters the baler.As a rule of thumb, wait to rake hay until after the dew has dried and the sun nears its peak, or around 11:00 am.

Stacking

It is a practices of assembling or collection of bales from the field and followed by transportation of bales to the store house.

Storage

Storage of hay should be done in well-conditioned to meet the future requirement of fodder especially for the lean period. The store room should be well disinfected with 2% formaldehyde, rodenticide and make sure that no harmful agents are there to loss the hay quality and quantity.

Factors affecting the quality of hay

Plant species: plant species differ in their chemical composition, legumes have rich crude protein and digestible dry matter than cereals.

Stage of harvest : harvesting at appropriately time is highly recommended for maintaining the quality of hay. Winter forages has more of the digestible protein than rainy forages

Leaf: stem ratio: presence of large portion of leaf in the hay is good index of palatibility

Chemical composition: quality of hay depends on the protein contains of crops.

Physical form: the voluntary intake and digestibility of pelleted hay is greater than chopped and unchopped hay.

Deterioration during storage : during storage, it should not contaminated with weeds, dust or other unwanted things. Otherwise the quality of hay will affect and leading to less intake by livestock.

Silage

Silage is a method of moist forage preservation that is based on natural fermentation whereby lactic acid bacteria convert water soluble carbohydrates to organic acids, mainly lactic acid under anaerobic conditions. The process of silage making is referred as ensiling.

The product of fermentation of plant tissue produced by microbial activity under anaerobic conditions.

Plant Sugars --(Fermentation)--> Organic Acids ("Pickled" plant materiel, low ph) Importance of silage

• Silage can be prepared throughout the year
• Source of nutrients, minerals
• Less space is required for silage preparation
• It is easily digestible
• It is prepared under controlled condition, so less chance of quality deterioration and harvest loss.

The suitable crops for silage making are maize, jowar, bajra, guinea grass, para grass & napier grass but leguminous fodder are not suitable for silage making as they contain high moisture & high crude protein and low soluble carbohydrate at the comparable growth stage.

Harvesting time for silage making

Crops	Time of harvesting
Maize	Silk to milk stage (50-60 days)
Sorghum	Boot to milk stage (75-90 days)
Bajra	Boot stage (45-55 days)
Guinea grass	Flowering stage (60-75 days)
Napier grass	Up to 1 meter height (60-75 days)
Oats	Flowering to milk stage (90-115 days)

Silage making process

Harvesting of crops: The harvesting of crop should be done at proper stage and it should contain 30-35% Dry Matter.

Chopping of forage: Chopped the forage into desired size, so that the chopped materials fermented easily leads to faster in silage production.Additives such as urea, ammonia, bacterial inoculants, enzymes, acid etc. are also used to increase the nutritional value, improve fermentation and enhance aerobic stability.

Transportation: Transportation of chopped materials and filled into the silo

Covering and sealing: Covering and sealing with plastic sheeting of various thickness which prevent penetration of air into silo surface.

Biochemical changes: The process can be divided into distinct phase

1. Aerobic Phase or Plant Respiration

Just after ensiling, the air is still trapped between plant particles and plant biomass to continues respire and produces CO₂, water and heat by using sugars and oxygen i.e. continues metabolism of plant cells

C₆H₁₂O₆ + 6 O₂ = 6 CO ₂ + 6 H₂O + 3.8 Mcal/kg sugar

Sugar + Oxygen = Carbon dioxide + Water + Heat

During this phase, the aerobic microorganisms (both obligate and facultative) such as yeast, molds and some bacteria are still active until oxygen is depleted and PH begins to decrease. The chemical changes occurs during early stage of ensiling is proteolysis i.e. breakdown of plant proteins by the hydrolysis of peptide bond or de-amination.

1. Enterobacteria fermentation

As oxygen is removed and fermentation begins, the bacteria that become predominant are those that have the ability to live either in the presence or in the absence of air (facultative aerobic bacteria). This group includes the enterobacteria, which convert sugars into a variety of organic acids (formic acid, acetic acid, lactic acid and sometimes butyric acid), carbon dioxide (CO₂) and hydrogen (H₂).

These acids are responsible for the early decrease in pH in the silo. As fermentation proceeds, enterobacteria become less competitive because they are particularly sensitive to decreasing pH. The growth of enterobacteria is inhibited when the pH falls below 4.5, which usually occurs within a few days of ensiling.

3. Lactic Acid Fermentation

In the beginning of this phase many facultative and obligate anaerobic microorganisms such as enterobacteria, clostridia, certain bacilli and yeasts theoretically compete with the LAB flora for the nutrients (Pahlow et al., 2003).

LAB ferments soluble carbohydrates and produce lactic acid, thus resulting a drop of pH. The disappearance of enterobacteria and the development of a dominant LAB population are the major microbial change in this phase.

Proper lactic acid production depends on the following three factors:

• The number of lactic acid bacteria present at the time of ensiling
• The presence of a sufficient amount of fermentable sugars
• The absence of oxygen in the silage

1. Stable

After about 14 days of fermentation, well preserved grass silage contains 1.5 to 2% lactic acid, and pH may range from 3.5 to 4.2. In this phase highly acid tolerant yeast species can survive in an inactive stage, along with bacilli and clostridia.

1. Feedout

The silage is re-exposed to air enabling undesirable aerobic microorganisms, particularly yeasts, moulds, acetic acid bacteria to become active and spoil the silage. The presence of air allows this organism to multiply, resulting heating of silage and bringing chemical changes such as a rising of pH and loss of nutritive matters.

Categorization of silage

Types	pH	Ammonical nitrogen	Characteristics
Very Good	3.5-4.2	less than 10% of total nitrogen	It is having acidic taste and odour, traces of butyric acid
Good silage	4.2-4.5	20% of the total nitrogen.	Silage possessing acidic taste and odour, traces of butyric acid
Fair silage	4.5-4.8	20% of the total nitrogen	Ensiled material with some butyric acid, a slight proteolysis some moulds
Poor silage	4.8 and above	more than 20% of the total nitrogen	It is having bad smell due to high butyric acid & high proteolysis may be infected with moulds.

Source: ILRI, 2015

Conclusion and future aspects

From the elaborate discussion, it is found that the hay and silage are the good option for the dairy stake holders as the expansion of land for fodder cultivation is not feasible. They have to make an adjustment with the resources, land, labour, water, space as well as the quality of the feed and fodder. Hay and silage provide essential amino acids, nutrients for all round development of the animals such as growth of physical form, milk production, meat etc. As the population is growing geometrically and there will be competition for everything, so this type of enhancement will be attained significant importance in nearby future.

References:

• International Workshop on Improving the Livestock Feeding Practices and Enhancement of Feed and Fodder Availability in Odisha in collaboration with ILRI (2015)
• Annonymous (2010). "Project proposal for assistance to the farmers to take up integrated fodder production and feeding management under RKVY, Orissa" ahvs.com/ Feed fodder development/RKVY Assistance fodder.pdf
• Contrearas- Govea et al. (2006). Microbial inoculants for silage. Focus on forage. 8(4):1-4
• John C. Porter, (2009). UNH Extension Professor and Dairy Specialist Emeritus, website: ceinfo.unh.edu
• Robert F. Barnees et. al. (2003). Forages: An introduction to Grassland Agriculture
• Pahlow, G. et. al. (2009). Managing for improved aerobic stability. 15th international silage conference proceedings. July 27-29, Medison, USA
• Khanal, P. (2009). M.Sc. Thesis, The Hebrew University of Jerusalem, Israel
• Pitt R.E., et al. (1990). A model of aerobic fungal growth in silage. II Aerobic stability. Grass forage sci. 46: 301-312
• Singh, M. (2015). Fodder conservation techniques. Short Course on Good Dairy Farming Practices A Novel Initiatives and Extension Approaches During 18-27th August, 2015.




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