eChapters

Estimation of silage quality parameters: Process of making silage is called ensiling. The green fodder harvested at a proper stage is stored, packed and compressed in silo and it is then tightly covered to prevent the contact with air. Thus, the forage is preserved by controlled microbial anaerobic fermentation in a silo with minimum loss of nutrients for use as a succulent fodder during scarcity (lean) period. This form of preserved fodder is known as silage. Silage is prepared by obtaining enough acid content in ensiled feed which inhibit the microbial fermentation thereby preserving the green fodder. Following are
points to ponder:
1. Maize, sorghum, bajra crops having thick solid stems and rich in soluble carbohydrates, are best for silage preparation. Silage can also be prepared from oats, berseem etcetera, after wilting to 35 – 40 % dry matter.
2. Dry matter content in fodder crop for ensiling should be between 30 – 40 % (average 35 %) and should have sufficient soluble sugars for acid production during fermentation.
3. The crop is harvested in bloom stage, which is best for silage preparation.
4. If the crop is deficient in soluble carbohydrates, (for example, legumes), then a sugar industry by – product is added.
5. Silage having acidic flavour and pH 3.5 to 4.2 is considered to be excellent.
6. The crop should be properly trampled / pressed to remove the air out of silo.
7. The crop is chopped into small pieces for better microbial action due to increased surface are and sufficient acid production.

Familiarization with various fertilizers, manure and Agri – implements: Manure: * Nutrients are added to soil for healthy growth of plants. * Continuous growing of crops makes the soil poor in nutrients. * Manures are organic substances obtained from decomposition of plants animal wastes. * Manuring is done to replenish soil with nutrients.
Advantages of manuring: * Improves water retaining capacity of the soil. * Makes the soil porous and exchange of gases becomes easy. * Increases the number of friendly microbes. * Improves the texture of the soil. * Replenishes the soil with necessary nutrients.
Fertilizers: * These are chemical substances rich in nutrients. * These are produced in factories.
Advantages of fertilizers: * Help farmers to get better yield of crops.
Disadvantages of fertilizers: * Sources of water pollution. * Make the soil less fertile. * Artificial fertilizers often cause diseases.

Qualitative detection of undesirable constituents, adulterants in Feeds: The nutritive value of feed ingredients from the same origin may exhibit variation. The factors which are responsible for the variation are natural variation are natural variation, processing, adulteration and damage, deterioration. These days, due to shortage and high prices of feed ingredients, adulteration is one of the main problems. Feed quality can be examined by different techniques:
(a) Feed microscopy: Stereo or compound microscopy may be used for: (i) Screening method; (ii) Floatation technique.
(b) Chemical tests: For heavy metals, nitrates, phosphates, sulfates, free sulfur, salts: carbonate, chloride, salt, sugar, urea, blood, hoof or horn, leather meal, uric acid.

Estimation of calcium and phosphorus in feeds: Calcium is precipitated as calcium oxalate by adding ammonium oxalate to acid soluble extract prepared after running a sample for ash. Precipitates of calcium oxalate are dissolved in sulfuric acid and titrated with potassium permanganate to know the content of calcium.
Using N1V1 ≡ N2V2, 1.0 ml of 0.1 KMnO4 = 2.004 mg Calcium.
Calcium, g % = Burette reading difference X 2.004 X dilution factor X 100 / weight of the sample used for preparation of acid soluble mineral extract X 1000.
[dilution factor, (for example) = 250 / 25 (ml aliquot taken) = 10]
Phosphorous present in the sample is precipitated with ammonium molybdate and the precipitates are dissolved in NaOH solution. Excess sodium hydroxide is titrated with nitric acid to calculate the actual volume of NaOH used up which is direct proportion to the Phosphorous content.
1 ml of 0.1 N NaOH = 0.1347 mg Phosphorus
Phosphorus % = Actual volume of 0.1N NaOH solution used to dissolve precipitate X 0.1347 X dilution factor X100 / weight of sample used for acid soluble extract X 1000
[Here, dilution factor is 250 / 50 (aliquot taken) = 5]

Proximate analysis: Weende’s system is followed. Weende was a small village in Germany, near the University of Goettingen at that time (1860), when this system was developed by Hanneburg and Stohmann. Although it is neither true nor approximate, but somewhere in the middle, that is, proximate analysis of the various parameters for assessment purpose; it gives information about the quality of feeding stuff and still followed.

Preparation and processing of samples for chemical analysis: The preparation of samples depends upon the purpose of analysis and the nature of the constituents that are to be determined. The preparation of samples for analysis is as important as the analytical procedure and hence, it should be done with utmost care. (A) Smpling of wet material: (1) Plant material; (2) Silage; (3) Cattle faeces; (4) Sheep / goat faeces; (5) Poultry excreta; (B) Sampling of air – dry material: (I) Hay or straw; (II) Concentrates.
Small quantities of feed samples are collected from several locations, all sides, in the middle and are mixed well after chaffing. Such mixture is subjected to quarter sampling, by spreading on levelled ground in circular form. This circle is now divided into 4 equal quarters. Any 2 diagonally opposite quarters are selected and other 2 are rejected. Selected portions are mixed properly and again spread on levelled ground in circular form. This mixture is again divided into 4 equal quarters and any 2 diagonally opposite quarters are selected, while remaining 2 are rejected. This procedure is repeated till required quantity of sample is obtained. This representative sample is brought to laboratory as early for drying in a hot air oven. Dried samples are ground to pass through 2 mm sieve in a Willey mill (large samples may be ground through hammer mill), as described in chapter 10. Sample is collected in an airtight plastic bag and stored in desiccator.

Identification / familiarization of various feed ingredients: As per National Research Council (N. R. C.), there are 8 main groups of feedstuffs. (1) Dry forages and roughages; All forage and roughage cut and cured are included in this category. These are bulky feeds with low digestibility. Crude fibre is more than 18 % and Total digestible is less than 60 % because of high cell wall contents. For example: dry grass (hay), wheat straw, paddy straw, oat straw, stovers (aerial part without ears), husk (maize) or aerial part without heads (sorghum), hulls and shells. (2) Pasture range plants, tree leaves and forages; Roughage either harvested or without harvesting (fresh) are included in this group. For example: pasture grass, range plants, tree leaves, green forages (legume and non – legume). (3) Silage; only ensiled forages are included. For example: legume non – legume silages. (4) Energy or basal feeds; Feeds are of low protein content, having crude protein less than 20 %, crude fibre less than 18 % and Total digestible nutrients more than 60 %. For example: cereal grains, milk by – products, fruits, nuts, roots etcetera; (5) Protein supplements; Feeds are of high protein , more than 20 %, crude fibre less than 18 % and Total digestible nutrients more than 60 %. For example: animal, marine, avian, and plant products. Meat meal, fish meal, oil seeds, and their cakes etcetera; (6) Mineral supplements; These are natural or pure elements. For example: composite mineral mixture or specific mineral supplements; (7) Vitaminsupplements; These are natural or pu e forms. For example: composite vitamin  pre–mix or specific vitamin supplements; (8) Feed additives; these are for improving efficiency of utilization of feeds. Number of examples have been cited elsewhere in this book [theoretical part above].

Orientation and general precautions in laboratory: Laboratory safety glasses or goggles should be worn in any area where chemicals are used or stored. They should also be worn any time there is chance of splashes or particulates to enter the eye. Closed – toe shoes must be worn at all times in the laboratory. Perforated shoes or sandals are not appropriate. Lab coat, gloves, eye protection, and appropriate attire (impermeable gowns, plastic aprons, masks, face shields) should be worn at all times in the lab. Long pants and shoes completely covering the top of the foot should be worn at all times when
working in the lab. Do not eat or drink in the lab at any time. Do not expose electric sparks, open flames and heating elements to organic solvent vapours.
Do not leave your assigned laboratory station without permission of the in charge. Learn the location of the fire extinguisher, eye wash station and first aid kit [A first aid manual, different sized sterile gauge pads, adhesive tape, band aids in several sizes, elastic bandage, antiseptic wipes, antibiotic ointment antiseptic solution like hydrogen peroxide]. Fire blanket, exits from the room, fire escape route. Basic life support (BLS) is important for clinical point of view. Lab safety is important because it can prevent injury, keep us from making mistakes and save lives. Following lab safety rules is part of being a good citizen. We should follow the lab safety protocols to stay safe and healthy. We cannot tell if a chemical is hazardous (radioactive !!) just by looking at it. Friedrich Esmarch, the founder of “Modern first – aid”. Emergency kit includes - * Flashlight with extra batteries, * Whistle, * Dust mask, * Local maps, * Manual can opener, * Battery powered or hand cranked radio, * Books, games, puzzles or other activities for children.

The term animal waste comprises, the fresh excrement, including both solid and liquid excreta and urine. * It also includes the bedding material, animal washings, feed waste and straw which are having considerable manorial value. * The characteristics of the livestock wastes depend on fractions of the digestibility, composition of feed ration and species of animals and their physiology. * The waste ruminants have different composition than obtained from swine and poultry, which is having high nutritive value.
For fodder production, the animal waste can be utilized in many ways, that is, as pesticide and that is, as non – conventional source of source energy as pesticides bio – fertilizer to improve soil fertility for sustainable agriculture. This livestock waste can be recycled in following ways: Organic mulch, As pesticides, In organic farming, Biogas production, Composting, Vermicomposting, Profitable manure management by livestock fish integration.

The topic deals with methods to increase the amount of water stored in the soil profile by trapping or holding rain water where it falls, or where there is some small movement as surface run – off. Principles: Choice of method. There is no simple way of classifying methods of water conservation. One suggestion is to do it by comparing rainfall with crop requirements, giving 3 conditions: (a) Where precipitation is less than crop requirements; here the strategy includes land treatments to increase run – off onto cropped areas, following for water conservation, and the use of drought – tolerant crops with suitable management practices. (b) Where precipitation is to crop requirements, here the strategy is local conservation of precipitation maximizing storage within the soil profile, and storage of excess run – off for subsequent use. (c) Where precipitation is in excess of crop requirements; in this case the strategies are to reduce rainfall erosion, to drain surplus run – off and store it for subsequent use.
Some design principles: The effect of scale, methods for crop land: Broad bed and furrow system (BBF), Ridging and tied ridging, Conservation bench terraces (CBT; also known as Zingg terrace, and flat channel terrace); Contour furrows (also known as contour bunds and desert strip farming); Water spreading (the use of run–off areas): Natural run – off; Collected and diverted run – off; Inundation methods, Flood diversion; Surface drainage; Other sources of water: Snow, dew, mist . [Figure 4].

For animal rearing it is pertinent to know the technique of keeping and preserving the feed required for the livestock. Apart from the rich pasturage, one may have the longevity of their feeds is immense concern for many. Animal feeds are an amalgam of diverse ingredients, including vegetable oil, sunflower oil. There are also animal fats, like – lard, tallow etcetera, which are included in the fodder. These elements give fodder the targeted input to animal husbandry. The prime factor that occurs and becomes a challenge for many livestock rearing, the cost for their feeds, which would provide quality and quantity in their output. Once the feed is rightly chosen for the animal, that one is rearing, the next challenge arises. Here is somehow animal feeds can be preserved safely, thereby increasing the longevity of the feeds - * Stay safe from the Sun; * Metal cans; * Storage bunkers; * Sliding metal roof bunkers;
* Commodity sheds; * Plastic containers or drums; * Re – usable freezer; * Wood bins.
Important dots
• All feed and ingredients have to be stored in a cool place [ideally below 77 0 F or (77 0F –32) X 5/9 = 25 0C), although this is not possible at outside locations under summer situations].
• Feed has to be kept dry to prevent fungal or bacterial growth.
• Prevention of entry for rodents or insects is essential.
• Stable form of vitamins is important to use.
• Anti – oxidants are important for preserving fats, oils in ingredients and feed.
• Expiry dates are important on the containers, for all feed materials for their shelf – life (for ground grains = 1 month after milling)
• For fats and oils: Opened container: 1 month; un – opened or stabilized: 1 - year post mixing.

Fodders and grasses can be preserved either as hay (dried fodder) or as silage (wet fodder), depending on weather conditions and available resources. These are fed in some (high input) farms to bridge seasonal scarcity periods.
Hay making: * The crop is harvested for hay making at its pre – flowering stage, when its growth is levelling off and its feeding value is still high; * Hay is best made during the rain free days; * Crops with thick and juicy stems should be dried after chaffing and conditioning, which will speed up the drying process and slow down the loss of nutrients; * Hay should be raked only a few times during the drying process in order to avoid the shattering of leaves and bleaching of the hay; * Legumes should be raked in the morning hours to avoid leaf shattering; * After drying and curing, bailing and / or stacking should be
done as early as possible. Storage under a roof is preferred; * For hay bailing, maximum permissible water concentration is 15%. Storage of hay before sufficient drying may cause fire due to spontaneous combustion; * Storage of hay with higher moisture concentration may result in mould growth, making the hay unfit for feeding.
Silage making: * Crops and plant materials rich in soluble sugars, such as – maize, sorghum, oats, sugarcane tops, hybrid Napier grass and other grasses are highly suitable for ensiling; * The dry matter concentration of the forage at the time of ensiling should be around 15 – 30 %, but higher is possibe; * Chaffing of the material for ensiling increases its compactness, thus eliminates the air space to the maximum content; * Green to semi – green forage, which may use the O2 present for respiration, results in high quality silage; * The silo should be air tight after filling; * Fermentation starts withing hours after closing the silo, and accelerates over the next 2 to 3 days. It terminates after about 3 weeks. Organic acids, primarily – lactic acid and acetic acid, ethanol and gasses such as CO2, CH4, NO2, and NH3 are produced during the fermentation process; * Due to production of acid, the pH of the biomass is reduced to a level below 4, resulting in the termination of all biological activities, after which material remains conserved under aerobic conditions.

Roughage contains > than 18 % crude fibre and < than 60% Total Digestible Nutrients (T.D.N.). Leguminous fodders contain more Digestible Crude Protein (D.C.P.). Some common dry legumes are: Pea straw, Arhar straw, Lucerne hay. And some common green legumes are: Berseem (clover), Cow pea, Lucerne (alfa alfa). Non – leguminous fodders contain less D.C.P. Some common dry non – legumes are: Wheat straw, Paddy straw, Oat hay, Grass hay. Whereas, some common green legumes are: Sorghum, Maize, Oat, Napier.

32 – 33. Agronomic practices for fodder production: Feeding green forages to animal is economic and better for animal health and production. To get green forage throughout the year, it is necessary to sow the crop at proper time and also to harvest it at a proper stage. According to season, following agronomical practices may be followed:
(a) Rabi crops: Berseem, Lucerne, Oat, Mustard, Sugarcane tops
(b) Zaid crops: Chari, Maize, Sorghum, Cow pea, Guar.
(c) Kharif crops: Maize, Sorghum, Cow pea, Sudan grass, Napier, Para grass.
Berseem and Lucerne (legumes) are best forages for milk production. Berseem is called as king and Lucerne as queen of the fodder crops. Maize, Sorghum, Oat (non – legumes) at flowering stage are good forages. Hybrid Napier, Guinea grass, Para grass and other green grasses are palatable, but poorer in nutritive value than legumes and many non – leguminous forages. Straws and
stovers are poor quality roughages. Average voluntary intake of legumes is 2.0 kg; Non legumes and other grasses have 2.25 kg; while of straws, stovers is only 1.5 kg Dry Matter / 100 kg body weight.

Common feeds and fodders: An edible material which is ingested, digested, absorbed, assimilated by the animals for their benefit, is known as feed. As per the National Research Council, Dry forages and roughages are cut and cured. These are bulky feeds with low digestibility. Crude fibre is > 18 % and TDN is < than 60 % because of high cell wall content. Some of the common feed stuffs are: dry grass (hay), wheat straw, paddy straw, oat straw etcetera. Stovers [aerial part without ears and husk (maize) or aerial parts without heads (sorghum). Hulls and shells too. Pasture range plants, tree leaves and forages are either harvested or without harvesting (fresh) are also very good for feeding, for example: pasture grass, range plants, tree leaves, green forages. Concentrates have < than 18 % crude fibre and > than 60 % TDN. Feeds rich in protein (plant origin) are: Cotton seeds / cakes, Mustard cake, Groundnut cake. Whereas animal origin protein sources are: Skim milk, Fish meal, Blood meal. Feeds rich in carbohydrates (energy) in grains are: Maize, Oat, Barley. Whereas grain by – products are: Wheat bran, Rice bran, Gram husk, Pulse chuni.
Points to ponder
• Animals are sometimes said “to feed” or to eat, therefore to mean = “food for animal”. The old English root is fedan = “nourish, sustain or foster”.
• Fodders are harvested and taken to animals; whereas, Forages are browsed on by animals, while still on the land.
• Feed manufacturing refers to the process of producing animal feed from raw agricultural products; whereas, Fodder produced by manufacturing is formulated to meet specific animal nutritionrequirements for (i) different species of animals, (ii) different life stages. The idea is: to transfer the seed energy and the plant’s energy to the animal.

Feed Additives
Feed additives are administered to animal to enhance the effectiveness of nutrients and exert their effects in the gut or on the gut walls. Some of the common feed additives are: Antibiotics, Probiotics, Prebiotics, Arsenicals, Buffering compounds, Anti – oxidants, Enzymes, Hormones, Adsorbents, Organic acids, Flavouring agent, Pigments.
(a) Antibiotics: Chemical compounds produced by other microbes (for example, fungi, and are also synthesized in the laboratory) that, when given in small amounts, halt the growth of bacteria. They are used at therapeutic levels to treat diseases caused by bacteria. In sub – therapeutic levels added to the feed or food to enhance the rate of growth. Modes of action: They halt the growth of bacteria by interfering with their cellular metabolism by (i) Interfere with the synthesis of bacterial cell wall and cause the cell to burst, (ii) Inhibitors of protein synthesis, (iii) Inhibitors of bacterial DNA synthesis, (iv) Ionophore antibiotics – interfere with Na – K electrolyte balance, for example: Monensin sodium.
(b) Probiotics: It’s a live microbial food supplement that beneficially affects the host animal by improving the intestinal microbial balance. Beneficial microbes produce enzymes that complement the digestive ability of the host and their presence provides a barrier against invading pathogens [Figure 2].

Anti–nutritional factors: Detoxification of undesirable components is very important, because some feeds may contain toxic substances, the excess consumption of which may cause decreased nutritive value of the feeds or may injure some vital organs or even cause death. 
Points to ponder
• Anti – nutrients present in the diet, either by themselves or their metabolic products arising in the system.
• Plants evolved these compounds as defensive mechanism against insects, parasites, bacteria and fungi.
• Feeds high in anti – nutrients: Lectins = legumes, cereal, grains, seeds, nuts, fruits, vegetables. Oxalates = spinach, swiss chard, sorrel, beat greens, beet root, rhubarb, nuts, legumes, cereal grains, sweet potatoes, potatoes. Phytate [IP6] = legumes, cereal grains, pseudo – cereals (amaranth, quinoa, millet), nuts, seeds.
• Anti – nutrient in wheat: Phytate being the most important among all, reduces the bio – availability of Iron and Zinc. There could be protease inhibitor, tannin, lectin, alkaloid, oxalate too.
• Main anti – nutrients in edible forage and fodders are: tannin, saponins, phytic acid, gossypol, lectin, amylase inhibitor, goitrogen, protease inhibitor.
• Removal of anti – nutrients: heating, boiling, soaking, spouting, fermentation. By combining different methods, many anti – nutrients can be degraded completely.

Feed processing includes all operations necessary to achieve the maximum potential of nutritional value of a feed stuff. The process involves changing ingredients in such a manner as to maximize their natural value and the net returns from their use. Feed processing may be accompanied by Physical, Chemical, Thermal, Bacterial or other changes of a feed ingredient before it is fed. The primary reasons for processing feeds are to make changes in the moisture content, density of feed, particle size, palatability; or to make more profit, to improve nutrient availability, keeping quality (shelf – life); or to reduce storage – transportation space, cost, moulds, Salmonella and other harmful substances. Feed mill equipment: The milling industry has been concerned with “Grinding” – a process of particle size reduction. During
earlier times, the same equipment was used Food for humans to produce Food for livestock because, the process was basically ‘grinding’ of whole grains. As milling developed into the “Modern Flour Industry”, the milling process was extended to include:

Crude protein of feeds contain true protein and non – protein nitrogen. True protein is made up of amino acids and for maximum efficiency, feed must have essential acids in correct proportion, correct balance as well as non – essential amino acids should also be in sufficient amounts. About digestion in simple stomached animals, the true protein is degraded to oligopeptides (less than 10 peptides) in the stomach, subsequently to mono peptide amino acids in the small intestine. Thereafter amino acids are assimilated in the small intestine.
But in ruminants, the situation is complex in the sense that feed proteins get digested in the rumen, but even amino acids are also broken down by the microbes, and thereafter, amino and carboxylic groups are released. Secondly, synthesis of new amino acids or proteins takes place for formation of their own microbial body coat. Because of these reasons, the approach for protein evaluation or expression is different in ruminant animal. Further, non-protein portion of the feed cannot be utilized effectively by non – ruminants like swine and poultry. These animals are usually fed with oil cakes, cereals and
cereal by products, which are poor in non-protein compounds, however, young succulent fodders, clover etcetera are rich in such compounds. In the laboratory, crude protein may be estimated by kjeldahl’s method and true protein may be precipitated from non – protein nitrogen fraction by treating with cupric hydroxide or trichloro acetic acid. The precipitate is filtered off and subjected to kjeldahl’s process. For experimental evaluation of non – ruminants: albino or wistar rats, rabbits, guinea pigs or poultry birds are taken. Casein (milk protein) or albumen (egg protein) are fed to these animals for a period of 4
weeks and any of the following methods are undertaken to look for the protein quality based on response of animals.

There are 3 types of systems for expressing the energy value of feeds and many examples have been depicted in each of these systems the world over, but here, one example has been taken up in each of these categories. [a] Digestive Nutrient Type: For example, Total Digestible Nutrient (TDN) system: Digestibility coefficients of various organic nutrients like – carbohydrate, fat and protein are determined by digestibility trials, which can be involved for total digestible nutrients as a measure of nutritive value of feeds. Hence only faecal energy loss has been considered barring losses from other channels. Hence, roughages are overestimated by such calculations. Otherwise, this method is simple, economical and has some basis for animals to be fed on such standard. The TDN value is expressed in % age as following - % TDN = % digestible crude protein + % digestible crude fibre + % digestible nitrogen free extractives + [% digestible ether extract x 2.25]. where Nitrogen Free Extractives = 100 – [crude protein % + ether extract % + crude fibre % + ash %] on dry matter basis.
[b] Production value type: For example, Starch Equivalent (S.E.) system originated from Germany, hence followed in those areas of Europe and takes into account almost all the losses involved in digestion of feed. The method is based on Carbon – Nitrogen balance studies without the help of any costly equipment, but faced some criticism too. The animals were kept in big animal calorimeter, where different sources of energy losses could be determined to the best of their ability. When it was ensured that the ration on which the animals were neither gaining nor losing weight (by measuring the intake and outgo of both carbon and nitrogen), then pure starch, straw pulp, that is, cellulose, wheat gluten (protein) and oil were added to this diet and determined the carbon and nitrogen separately again. Feeds for productive purposes are measured in terms of starch values. S.E. = Weight of fat stored per unit of feed / weight of fat stored per unit of starch x 100. That is, amount of feed required to produce as much animal fat as is being produced by unit amount of starch, when fed in addition to maintenance. For example, if linseed cake has got SE of 75, which means that 100 kgs of linseed cake can produce as much fat as 75 kgs of pure starch, when fed in addition to maintenance ration.