eChapters

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.

The Agromet/Livestock advisories are issued on the basis of weather forecasts made at the meteorological centers. These forecasts are made by numerical methods which employ the process of solving the equations governing the motion of the air. For solving the equations, observations of various meteorological parameters such as pressure, temperature, wind direction and speed and other weather variables are required. The observations are taken at specified times called synoptic hours in all the observatories located throughout the World. The instruments used to measure the weather parameters are housed in the observatory. Instruments used for the measurement of different elements are given below:

(Method of Schram and Aines, 1959)

All the legume seeds and their byproducts are very rich in urease activity which may be responsible for an appreciable loss of urea nitrogen on long duration storage. Therefore it is necessary to estimate urease activity in legume seeds and their byproducts.

Reagents

    1.    Dimethyleaminobenzaldehyde solution (DMAB). Dissolve 16 g DMAB in 1 litre 95% ethyl alcohol and add 100 ml concentrated hydrochloric acid (Stable one month).
    2.    Pyrophosphate buffer. Dissolve 233 g Na4P2O7. 10H2O in approximately 980 ml distilled water. Add 3 ml of conc. Hcl and then dropwise further Hcl until the pH of the buffer is 7.7 to 7.8. Dilute to one litre.
    3.    Buffered urea solution. Dissolve 0.4 g urea in one litre pyrophosphate buffer (Stable one week).

Different basic as well as advanced laboratory equipment need to be used in a laboratory while conducting experiments. Many of them like pH meter, laminar air-flow hood, viscometer, thermometer, magnetic stirrer, microwave ovens, incubators, sand-bath, water-bath, oil-bath, etc. are the basic and simple equipment which require to be used routinely while conducting experiments in a laboratory. However, basic knowledge of their operation, handling procedure, when to be used, how to be used, and more importantly what not to be done with it, etc. are essential for keeping them in serviceable condition as well as for the accuracy/precision in their operation. In this chapter, we will discuss about some of the routinely used laboratory equipment along, while some other sophisticated equipment will be discussed in other chapters.

pH Meter

A pH meter measures exactly the H+ concentration of a solution; thus indicates acidity or alkalinity of a solution with greater precision. Actually, it measures the difference in electrical potential between a pH electrode and a reference electrode, and display the results converted into the corresponding pH value. Electrode is the key part (rod-like structure, usually made of glass) of a pH meter, having a bulb at the bottom containing a sensor. The pH meters range from simple and inexpensive pen-like devices (portable/pocket pH meter) to complex and expensive laboratory instruments with computer interface (Figure 5.1).

Frequent calibration of a pH meter using the solutions of known pH (standard solution of pH 4.01, 7.00, 10.01, Figure 5.2), generally before each use, ensures the accuracy of the instrument. For very precise work the pH meter should be calibrated before each measurement. For normal use calibration should be performed at the beginning of each day. This is necessary because the glass electrode does not give a reproducible measurement over a longer period of time.

Introduction

To accomplish experimentations in laboratories, sometimes we need microscope to test/validate our ideas/findings. A microscope is needed to examine objects which are very small which cannot be visualised by naked eyes. However, microscopic study requires some expertise in operating the microscope, particularly the sophisticated microscopes, as well as to prepare (peeling, sections, cutting, fixation, staining, dehydration, mounting, etc.) the sample, so that it can be appropriately examined for the anticipated details.

According to the scientific requirements different types of microscopes are used in the laboratories for research purpose. In this chapter, our aim is to acquaint you with the basics of using and handling of microscopes, particularly a compound microscope that is commonly used by the graduate and post graduate students for basic research.

Microscopy is often designated as the scientific investigation that is employed to review and analyse minute structures and objects using a microscope. The term “microscope” has been derived from ancient Greek words “micros” meaning “small” and “skopeîn” meaning “to look at or see,”.

Microscope

A microscope is a laboratory instrument used to examine objects (biological specimens) which are too small to be seen by the naked eye. The microscope must accomplish three tasks:

• Magnification- to provide a magnified image of the specimen.

• Resolution- to separate the details in the image.

• Contrast- to render the details clearly visible to the eyes.

Although we will tnroduce to you the different types of microscopes used for different speciments, our main focus is to discuss about compound microscope, which is commonly used in the laboratories. Compound microscope was developed around the beginning of 17th century.

A variety of glassware like burettes, pipettes, measuring cylinders, flasks, separating funnel etc. are used for experimental purposes in a laboratory. All of these need to be used and handled correctly, otherwise the chances of experimental error and damage to the glassware increase significantly. Being made of glass, they need special care while washing and using in experiments because even a minor mistake in handling of glassware may result in breakage of the apparatus. With this precautionary note, let us discuss about some of the specific glassware used in the laboratories.

Burette

Burette is a long graduated glass tube with a stopcock at one end for delivering a known/desired volume of a liquid, especially in titration experiments. It contains a stopcock at the lower end and a tapered capillary tube as the stopcock’s outlet. The flow rate of liquid from the tub stopcock’s outlet can be controlled with the help of stopcock valve. Burette is used for measuring the volume of a solution/chemical added in a quantitative (titrimetric) estimation experiment.

Procedure of using a Burette

The burette reading must be noted before and after delivering the chemical/ solution from the burette. The difference in these two readings is the volume of the chemical/solution released out of the burette. The solution should be released slowly/drop-by-drop to avoid any experimental error/mistake. If the solution/chemical is allowed to pour out too fast, the wall of the burette will not drain properly and some liquid may remain sticking to the surface of the walls. Moreover, excessive amount of chemical may be released/dropped during the experiment, particularly during the titration experiment wherein we need to know the exact amount of acid/base needed to get neutralization point. Thus, any minor mistake may lead to get a faulty reading. The measuring capacity of a burette usually used in a laboratory is 50 mL.

Since mouth pipetting of liquid reagents in a laboratory is not advisable, different tools are needed for safe, easier, and precise dispensing of liquid reagents. This chapter is devoted to make you aware of the tools like vacupette and micropipette which can be used for the handling of liquid reagents in a safe and precise way.

Vacupette

Glass pipettes have been traditionally used by sucking liquid solvent/solution directly using mouth. For safety reasons, mouth pipetting is no longer permitted in a laboratory. Hence, to fill a pipette vacupette is used by placing it on the top of glass or plastic pipette. It acts as a device to create vacuum for filling reagent in the pipette as well as for releasing the reagent with mechanical regulation on the flow out of the liquid. Vacupette can be of different types.

1. Rubber Bulb Vacupette

Rubber bulb vacupette is often used to transfer (pump up and discharge) liquid using a pipette when a larger quantity of chemicals is to be transferred. Small/tiny rubber bulb is attached to glass/plastic pipette for drawing little amount of reagents. Small vacupette is used to precisely discharge smaller volume/ drops.

Handling of Vacupette

• Insert the top of a pipette in the bottom of the rubber bulb vacupette (Figure 6.1).

• Remove air from the pipette by squeezing valve “A” at the top of the vacupette while simultaneously squeezing the rubber bulb. The amount of air released depends on the size of the rubber bulb.

Introduction

Coccidiosis is the most economically harmful disease encountered in commercial poultry production. It is caused by single celled protozoan parasites of the genus Eimeria which are commonly referred to as coccidia. Williams (1998) reported that the annual worldwide loss is about $ 800 million. The total loss due to coccidiosis is found to be Rs. 1.14 billion in India. The important finding is that almost 70 percent of the estimated cost is due to subclinical coccidiosis, by impact on weight gain and feed conversion rate. One of the reasons for these remarkable finding is probably the difficult diagnosis of subclinical coccidiosis.

Chickens are susceptible to at least seven species of Eimeria. The most common species are Eimeria tenella, which causes the caecal coccidiosis, E. necatrix &E. maxima, which causes mid intestinal coccidiosis, E. acervulina which causes anterior intestinal coccidiosis and E. brunetti which causes posterior intestinal or rectal coccidiosis. E. mitis and E. praecox are generally mildly pathogenic and commonly occurring as co-infection/mixed infection in with other species. Coccidiosis is particularly difficult to combat because several different species of Eimeria exist in the field. Poultry may become infected with different species because the immunity that develops after infection is specific only to one species. Eimeria has direct and complex life cycle that involves many developmental stages within the host cells. Each Eimeria species has characteristic intestinal lesions and type of diarrhoea (with or without blood).

Introduction

• Objective of animal diet formulations to provide a palatable ration at minimumcost to meet nutritional and energyrequirements of the animal.

• To achieve this objective, it is important to have knowledge about the requirementsof specific nutrient ingredients and the nutrient composition of feeds, which are used to formulate the animal diet.

• Diet formulation is an important aspect to meet production and financial goals in the most economical way.

• A dietis called balanced if it providesenergyto meet lactation, production and specific level of health requirement.

• Economic as well as nutritional aspects should be considered while optimisingnutrient ingredients.

• These three factors are so intimately related to each other that cannot be separated during the process of feed formulation.

Preliminary Stages

• The first step in diet formulation is to define the objective of diet formulation. Depending on the objective of diet formulation (such as reproduction, lactation, live-stocketc.), requirementsfor nutrient ingredients are established

• This step includes individual units and overall requirement for diet ingredients. After defining the objective of study and diet formulation, requirements of nutrient intake are defined to achieve that objective

• While definingtherequirement, socialenvironment, internal, external and economical conditions should be taken into consideration.Nutrient requirements can be established by the empirical method and factorial method.

• The empiricalmethodisbasedonexperimental studies whereas the factorial method identifies the various functions within the animal that defines the needs of nutrient ingredients.

India has a primarily agrarian economy. A significant portion of the country’s land is utilized for agriculture, and many of its agro-ecological regions cultivate a broad spectrum of crops. With a production of 93.9 million tons (Mt) of wheat, 104.6 Mt of rice, 21.6 Mt of maize, 20.7 Mt of millets, 357.7 Mt of sugarcane, 8.1 Mt of fibre crops, 17.2 Mt of pulses and 30.0 Mt of oilseeds crops, in the year 2011-12, it is usual that a massive amount of crop residues are produced both on-farm and off-farm. The country produces approximately 500-550 Mt of crop residues per year in the country. Therefore, landholders are facing difficulties in managing crop residues in the country. The human population has grown four times in the last century. With a projected 9.7 billion people in the world by 2050, worldwide food consumption and the demand for meat and milk are likely to increase by as much as 73% and 58%, respectively. Improved agricultural and industrial practices have contributed to the population boom, which continues to put pressure on food supply to feed a growing population. Huge quantities of food resources will be needed, but again, the crop residues produced at these levels of global production pose major challenges.

Availability of Crop Residues

India produces more than 500 million tons (Mt) of agricultural residue on an annual basis. The quantity of residue produced has grown significantly due to the cultivation of wheat and rice. Crop residue output varies greatly, and the use of these residue is influenced by the crops cultivated, the intensity of cropping, and the productivity across different Indian regions. About 70% of the total crop residues (352 Mt) are contributed by cereal crops (rice, wheat, maize, millets), with rice contributing 34% and wheat 22%. The excess agricultural residues—that is, the residues left over after subtracting the amount used for other purposes—are often burned on the farm. The amount of surplus crop residues available in India is estimated between 84 and 141 Mt per year where cereals crops contribute 58. As an estimate, about 70 MTs of surplus crop residue are burned annually.

Introduction

With the perception that antibiotics should no longer be used as animal growth promoters, there has been widespread interest in natural methods of inhibiting detrimental bacteria. Their removal from the poultry diets is therefore brings with it consequences. This has lead to somewhat of a renaissance in research activity on the discovery and application of non antibiotic chemical compounds capable of either killing microorganisms outright or at the very least retarding growth sufficiently to limit their dissemination. Organic acids have a long history of being utilized as food additives and preservatives for preventing food deterioration and extending the shelf life of perishable food ingredients. In recent past organic acids have been used to control microbial contamination and replace antibiotic growth promoters in poultry (Ricke, 2003; Hassan et al.,2010; Adil et al., 2011).

Forage preservation as silage is a key component of high input (zero-grazing) systems (Mannetje, 1999). It has allowed producers to intensify the productivity of the land and the productivity of the livestock. Large quantities of forage can be conserved in a short time, forage conservation is less weather dependent and thirdly, silage is well suited to mechanization. However, a major disadvantage associated with silage making is that the feeding value of the resultant forage is reduced relative to that of the original crop. Ensiling offers many advantages over haymaking.

Introduction

An ionophore is a lipid-soluble molecule usually synthesized by microorganisms, which transport ions across cell membranes of susceptible bacteria, dissipating ion gradients and uncoupling energy expenditures from growth to kill these bacteria. The term ionophore was first used in 1967 for their ability of organic molecules to bind metal cations and form lipid soluble complexes that facilitate their transport across cell membrane. The ionophore antibiotics show wide varieties of biological activity ranging from antibacterial, antifungal, antimycoplasma, antiparasitic, antimalarial, antiviral, anti-inflammatory and tumourcell cytotoxic activity (Augustine, et al., 1987; Gumila et al., 1996). Presently seven polyether antibiotics include monensin, lasalocid, salinomycin, narasin, maduramycin, laidomycin and senduramycin are used around the world in various segments of cattle and poultry industries. These ionophores are mainly used as anticoccidial drugs in poultry and growth promoters in the ruminants. Polyether antibiotics are not used in human but recently, it has been shown that some of these compounds are able to selectively kill human cancer stem cells and multidrug resistant cancer cells. Hence, they are recognized as new potential anticancer drugs.

Uterine prolapse also called casting of the “Calf Bed” in cow is a condition in which there is eversion of whole or part of uterus outside the vulva after its movement through dilated cervix and vagina. It occurs in cow after the birth of calf and mostly in dairy cows having given birth many times to a calf. It occurs due to hypocalcaemia, defective involution, inadequate exercise, excessive force applied during removal of calf etc.

Uterine torsion in cow is actually the rotation of the pregnant uterus on its longitudinal axis and usually occurs before onset or during late first stage of parturition but rarely encountered during early second stage of parturition. In cattle, uterine torsion involves both gravid and non gravid horns because of strong intercornual ligament and distension of uterine horn and body with placenta and fluid. The remarkable feature of uterine torsion is its association with advanced pregnancy and process of parturition in cow.

Definition of Utility
Utility is the ability of a good or service to satisfy human wants and needs in economics. It is an important concept as it represents the satisfaction experienced by a consumer from consuming a good or service
Utility characteristics
1. Measuring satisfaction, benefit, or happiness from a good or service is difficult.
2. Economists have devised ways to represent and measure utility in terms of economic choices that can be quantified.
3. Total Utility (TU): The aggregate sum of satisfaction or benefit gained from consuming a given amount of goods or services (e.g., drinking three glasses of water provides more satisfaction than just one).
4. Marginal Utility (MU): The additional satisfaction gained from each extra unit of consumption (e.g., the first glass of water gives maximum satisfaction compared to each additional glass).
5. Total utility usually increases as more goods are consumed.
6. Marginal utility typically decreases with each additional unit consumed, demonstrating the Law of Diminishing Marginal Utility.

Introduction

Enzymes are globular proteins that act as biological catalysts. They are produced by living cells to bring about specific biochemical reactions. Digestive enzymes catalyze the degradative reactions by which substrates (i.e., feedstuffs) are digested into their chemical components (e.g., simple sugars, amino acids, fatty acids) which in turn, are used for different body functions. Different enzymes are utilized for the complete digestion of complex feed. The enzymes are being used in the feeding industry from last several decades. Various digestive enzymes have been studied for use as feed additives to enhance animal performance They are commonly used to improve the nutritive value of feeds for non-ruminants (especially, poultry and swine). They are not routinely used in adult ruminant diets because the fibrolytic activity within the rumen environment is normally very high, and it is assumed that exogenous enzymes cannot survive proteolysis in the rumen (Kopency et al., 1987). Forages are the main feed component that serve as the major source of energy available to the animal in ruminant production system. However, due to slow or incomplete digestion of fibrous substrates only 10 to 35% of energy intake is available as net energy that significantly limits livestock performance and profits in production systems. To improve the ruminal fibre degradability many strategies have been developed to stimulate the digestion of the fibrous components in ruminant feeds. That includes, use of various feed additives which stimulates fiber digestion, physical and chemical processing of feeds in order to enhance the rate and extent of fiber digestion. However, the use of “natural” product to enhance production efficiency is highly recommended that can potentially play some role in replacing performance benefits vacated by antibiotics and hormones. Enzymes are proteins that are ultimately digested or excreted by the animal, leaving no residues in products, which was a major drawback in the use of antibiotics and hormones.

A. Answer the following questions:

1.    What is NPN substances?

Ans: Feedstuffs which contain nitrogen in the form other than protein or peptides aretermed as non-protein nitrogen (NPN).

2.    What is liquid diet?

Ans: Liquid molasses containing 2-3% of uniformly mixed urea fortified with minerals andvitaminsis named as ‘liquiddiet’.

3.    Name few amides.

Ans. Urea (46.6% N) and Biuret (35%N)

4.    Name few amines:

Ans. Histamine from Histidine, Tryptamine from Tryptophan, Tyramine from Tyrosine, Betaine from Sugar beet pulp.

5.    Name few alkaloids.

Air, water and land constitute our environment and these are technically known as atmosphere, hydrosphere and lithosphere respectively. All these spheres together constitute the biosphere. In the biosphere, apart from human beings, plants, animals, birds, fishes, insects and microorganisms also exist. All these living beings get affected whenever a change, physical or chemical occurs in the biosphere. This change is termed as pollution and the agents that institute these changes are called pollutants. A kind of pollution that has come in to prominence more recently is radiation, causing environmental and health problems of immense magnitude. The radiation may either be natural like cosmic radiation from outer space and sun?s radiations or produced by disintegration of naturally occurring and manmade elements. Such radiation is not visible to our eyes, but can penetrate the body and do immense harm. Man and animals have been continually exposed to different sources of radiation. But the radiation levels were well within the tolerable limits in the past. Yet, since the mid 1970?s human activities have been changing the chemistry of atmosphere in a way that reduces the amount of ozone in the stratosphere which is responsible for protecting the living things from excessive amounts of ultraviolet radiation. Further, it is only after the advent of nuclear power stations that radiations increased to reach harmful levels. Though mankind has benefitted by harnessing nuclear energy for peaceful purposes, one cannot deny the inherent dangers of radiation. Nuclear power plants no doubt help in the production of controlled electricity. However, a worldwide controversy is ragging over the existing nuclear power plants and setting up of new plants particularly since 1986 disaster of Chernobyl nuclear plant in Russia. A fire in the plant allowed massive amounts of radiation to be released into the atmosphere. This fall out drifted into the Scandinavia and Eastern Europe causing enormous damage to crop and livestock.

Cotton (Gossypium) seed meal (CSM), the by-product of cotton seed oil industry, is widely used as an animal feed. However, its utilization as an animal feed is limited due to the presence of gossypol, a polyphenolie binaphthyl aldyde, which is toxic to non-ruminants such as poultry and swine and young ruminants such as calves and lambs. The gossypol (free gossypol, FG) present primarily in the pigment glands of cotton seed, is mostly converted to bound gossypol due to condensation of aldehyde group with free amino groups of proteins to form a schiff base. Formation of schiff base though results in the detoxification of gossypol to some extent, it also lowers the nutritive value by reducing the availability of lysine, the limiting amino acid of cotton seed. Thus, bound gossypol, consequently total gossypol (TG) (free plus bound) content is an important factor of cotton seed meal.