eChapters

Introduction

Improvement of growth rate and feed efficiency through formulating effective diets are mostly considered for its effect on gut health. Several factors need to be well thought-out such as genetic makeup of the birds, feed source and quality, environmental condition and disease incidence. Apart from these factors, maintenance a good gut ecosystem or enhancement of it is essential for the welfare, optimum performances and productivity of birds. 

Introduction

Climate change and pollution are the two major concerns that retard growth in animal sector particularly in a developing country like India. Pollution is directly contributed by human beings, while the former is also an after effect of continuous abuse of nature and natural resources. Hence these two areas are to be looked into seriously for country’s growth in general and animal production in particular.

Stress Effect

Stress is nothing but inability of an animal to cope with its environment, a phenomenon that is often ends up with a failure to achieve the full genetic potential. Stress may be from any origin and can even be a disease itself. There exists a variety of endocrine regulatory points of stress which limits the efficiency of production and reproduction. A simple transport produces an immediate constant increase in arginine, vasopressin and corticotrophinreleasing hormone secretion in animals. However, adenocorticotrophic hormone reaches a maximum in the first hour, while cortisol is highest during the second hour. Contrastingly, the hypothalamo–pituitary–adrenal response is delayed occurring only after glucose decreases below a threshold in an insulin treated animal. Negative feedback effects appear to operate mainly at the pituitary level during transport but at the hypothalamus during hypoglycaemia.

Introduction
A significant aspect of an animal’s existence is their adaptability to changing circumstances and their willingness to adapt their behaviour. An animal becomes more intelligent the more it learns. Associative and non-associative learning are the two main categories into which learning can be divided. Whereas associative learning involves classical conditioning, non-associative learning involves sensitization and habituation. When a stimulus
occurs frequently, an individual develops a gradual familiarity with it. This is known as habituation. Sensitization, on the other hand, is the increased response to the same stimulus that may or may not be related to other variables. In order to get the desired response, training is required for the behavioural responses to two independent stimuli that are kept associated during the conditioning process. In general, non-associative learning stems from an animal’s perception of its environment or circumstances, whereas conditioning is based on training-based learning.

To sustain the meat industry in profitable manner, efficient utilization of meat by-products is an important issue. In today’s competitive world the realization of old saying “Only the last cry of the animal is wasted” has become essential. The utilization of by-products not only ensures additional revenue but also reduce the cost of various mandatory disposal treatments. The live animals are becoming costlier over the dressed carcass which compels the utilization of by-products. Moreover, unused by-products is also a great threat to environment and public-health apart from loosing nutritional resources. According to FAO (2004) estimates 106.75 million livestock and more than 650 million poultry birds were slaughtered annually in India leading to production of 6.3 million MT meat and different by-products of appreciable value. Now a day’s various techniques are available for the utilization of by-products for different purposes still significant portion of the by-products are unutilized and poses huge economic losses.

Animal By-products are the portions of animal body which are not included in dressed carcass. Animal by-products can be estimated by subtracting the dressing percentage from 100. Dressing percentage is inversely proportional to the byproducts means lower the dressing percentage, higher will be the yield of by-products and vice versa. In normal cases dressing percentage usually ranges between 50-70 percent and by-products yield in between 30-50 percent. However, the actual percentage may be higher because it excludes the weight of bones in muscles which is a part of dressed carcass.

Introduction

Use of acid/base is common in laboratories for experiments like titration and proper safety in their handling laboratory is necessary. In this chapter we will briefly discuss about the safety measures necessary to be adopted while using acids/bases in laboratory for any experiment.

Handling of Strong Acid/Base

There are four major points that need to be taken care of while working with strong acids or bases that might be quite harmful if any accident happens.

1. Protect Yourself

Wear a lab-coat and acid-resistant gloves: Always use lab-coat/apron and make it sure that the sleeves properly cover your arms. More importantly, use gloves made of acid-resistant materials and also wear shoes to protect your feet while wearing long-pants/jeans. Female with long hair, must tie her hair properly (with rubber band) to avoid any disturbance caused by appearance in between.

Wear safety goggles: It is important to wear safety goggles to protect your eyes using larger and fitting goggles that cover front as well as sides of your eyes. Always use properly fitting and adjustable goggles because smaller/ loose goggles may not protect the areas around your eyes against accidental acid spills and it may fall down from your face, if it is too loose.

Locate emergency wash area: There must be an emergency washing area nearby the work place or laboratory containing lab spill management kits. All the workers in the laboratory must be aware of using the kits and emergency plans.

Neutralize acid: Don’t panic even if an acid or chemical spill happens. Stay calm and act as quickly as possible. In case an acid spills, neutralize it by using sodium bicarbonate so that they can be cleaned and disposed safely. If acid comes in contact of skin, wash it off under running tap water but do not use/ apply sodium bicarbonate on skin.

Introduction

For proper and efficient experiment to be conducted, experimenters need so many chemicals to deal with. This includes different acids, base, salt, different kind of indicators and so on. Some of these chemicals are safe for health, but some of them are dangerous to health when come in close proximity to our body while some of the chemicals cause health issues on inhaling. These may cause improper functioning of some of our physiological activities. Acids and bases are very dangerous for our tissues when come in our contact. These may cause serious respiratory problem in addition to injuries on coming to our contact. Some chemicals are exploratory yet they may cause even death of the person working with them in laboratory. Therefore, mere use of the chemicals in laboratory is not only the objective of the experimenter. The person working in laboratory should also be concerned about the proper use and handing of the chemical while working with it. Thus, every researcher of an institution who has to work with chemicals in a laboratory should be made aware about the chemicals to be used in the laboratory and the consequences if any mishandling of a laboratory chemical occurs. Not only these, suitable precautionary measures should also be known to the researcher along with ensuring the availability of the required safety equipment/installations. Hence, a proper understanding of the ways of handling of chemicals in a laboratory is of prime importance for the personals like you who are working or have to work in laboratory.

Safe Handling of Chemicals in Laboratory

Safe use/handling of chemicals in laboratory include minimized exposure to chemicals, maintaining safety data sheets, proper labelling, storage, segregation, and transport of chemicals for personal hygiene.

Introduction

We come across a variety of chemicals every day in a laboratory. While some of them are relatively safer, others are extremely hazardous. Thus, it is very important to know the potential hazards that can be caused by the chemicals present in the laboratory and the safety measures needed to be followed to avoid the hazards. Additionally, we should also be aware of the steps necessary to be taken on such hazardous situations. According to IUPAC, a hazardous chemical mean the chemical which has the potential to cause damage in various ways. In a laboratory, there are chemicals that might be irritant, carcinogen, respiratory fibrogen, systemic poison, asphyxiant, flammable, etc. which have the potential to cause hazard to the workers or environment. Therefore, it is important to use appropriate procedure to reduce the risk and protect the health/safety of laboratory personnel, the public and the environment.

Types of Hazards Associated with Chemicals

Chemical hazards: The hazards caused by chemicals can be broadly classified into three categories.

1. Health hazard: This is also known as toxic effects of chemical. The risk associated with a chemical in laboratory depends on the extent of exposure and the inherent toxicity of the chemical. Many chemical reactions form the product that might be much more toxic than the reacting chemicals. For example, inadvertent mixing of formaldehyde (a common tissue fixative) and hydrogen chloride results in the generation of bis(chloromethyl) ether, a potent human carcinogen. For most of the chemicals, the route of exposure (through skin, eyes, gastrointestinal tract, or respiratory tract) is more important (Figure 17.1) that must be considered during risk assessment.

HANDLING OF ANIMALS

Objectives

• For carrying or shifting the animal
  Sexing the animal – to know the sexing of animal.
• Administration of substances
  To conduct experiments.

Materials required – Laboratory animals, apron, tattle and clean towel, weighing balance.

Principles of Incubation

Incubation is a process by which the embryo within egg develops into a fully formed chick capable of breaking free from the shell. Basically, when a hen incubates an egg, it means she is on the egg in order to keep it warm for a certain period of time, 21 days for chicken, until the chick embryo has fully formed and is ready to hatch. The incubation period in other species is given in Table 41. The following factors affect the incubation on egg

1. Temperature

Incubator temperature should be maintained between 99 and 100 oF. The acceptable range is 97 to 102 ^oF. Overheating is more critical than under heating. An incubator should be operated in a location free from drafts and direct sunlight. Temperature is probably the most important single factor influencing the development of the embryo. A higher temperature will advance the hatch and a lower temperature will delay hatch. Younger embryos are especially susceptible to high temperatures because the upper lethal limit is very close to the optimum incubating temperature. High temperature will cause the embryonic membranes to dry out too soon. Chicks that hatch may have an unsteady gait.

When green forages are dried to approximately 85% dry matter, they retain a significant portion of their nutrients, including carotene, and are referred to as hay. Compared to straw, hay is both more nutritious and more palatable. High-quality hay should exhibit a leafy structure, be pliable, possess a green colour and be devoid of mold, weeds and dust, while also emitting a pleasant fragrance. It is essential that the moisture content does not exceed 15% (ideally between 12-14%) to ensure safe storage without the risk of fermentation or combustion.
Objectives of hay production
The primary goal of hay production is to lower the moisture content of green fodder to a level that effectively inhibits the activity of both plant and microbial enzymes.
Benefits of hay production
• Hay serves as a nutritious feed source for livestock during periods of scarcity.
• High-quality legume hay can substitute for concentrates, thereby lowering production costs.
• Fodder can be harvested at optimal times to maximize nutrient accumulation in the plants.
Crops suitable for hay production: Fodder crops with soft and flexible stems are ideal for hay production. Green oats are considered the best option for this purpose. Other suitable crops include green berseem, lucerne, cowpea, stylo, and various natural grasses, provided that leaf shattering is minimized. Both annual and perennial grasses, such as anjan, doob, rhodes, and sudan grasses, are also appropriate for hay making. However, cultivated cereal fodders like maize, sorghum and bajra are better suited for silage production than for hay. If using thick-stemmed crops for hay, it is necessary to chop or crush them into smaller pieces.

Feeding of green and succulent fodder is of utmost importance to farm animals. Grazing fresh forage year round at the optimal stage of maturity would supply the highest quality and most palatable form of feed in any livestock operation. In most part of the world, green fodder is limited to a particular season only. Because of fluctuations in seasonal growth and plant maturity, excessive biomass in the spring, it is necessary to harvest and store forages to maximize both quality and productivity. One of the important form of conservation practiced on a wide scale is hay making. Hay making is an art in which the fodder is kept for future use in lean period. Since it contains large quantity of moisture it is to be dried properly to increase its keeping quality without reducing its nutritive value. The objective of hay making is to achieve a rapid moisture loss after cutting so that the forage can be romoved from the field with minimum losses from weathering and microbial degradation (Bareebam, 1992).

Storage of hay at higher moisture contents may lead to some heating due to the activity of aerobic micro-organisms and possibly some plant respiration. The warm, moist conditions in hay will provide the ideal environment for growth of spoilage bacteria, e.g. Bacilli and yeasts, moulds and fungi. These organisms utilize the energy and protein of the hay and can lead to a substantial increase in their respective populations. Their action leads to the following reaction:- 

Hay (plant sugars) + oxygen ® Carbon dioxide + water + heat
 
The resultant heating causes a reaction between the carbohydrates and proteins rendering both less digestible as temperatures continue to increase. The best opportunity to reduce hay-harvesting losses is by shortening curing time. A combination of mechanical conditioning, chemical conditioning and high-moisture baling help accomplish this goal (Collins, 1988; Mahanna, 1994).

Hay quality really means feed value. The ultimate test of hay quality is animal performance. Quality can be considered satisfactory when animals consuming the hay give the desired performance.
 
Characteristics of Good Quality Hay

    1.    Hay should be nutritious therefore prepared form plants cut at an appropriate stage of maturity when it has the maximum nutrients.
 
    2.    Good hay should be leafy. The leaves are generally richer in proteins, minerals and vitamins then other parts of the plant.

    3.    Hay should be green in colour. The green colour indicates the amount of carotene which is precursor of vitamin A. The green colour should be preserved by minimizing the bleaching, leaching arid fermentation losses.

Haylage or baleage or round bale silage, is a somewhat newer method of preserving forage. Haylage is simply forage that is baled at higher moisture content than dry hay and then stored in a sealed plastic wrap. Because of the high moisture level and air-tight environment, the forage ferments and is preserved by acid production during fermentation. The higher pH values associated with baleage are related to a slower fermentation process. During the respiration stage of the ensiling process the oxygen that is trapped in storage is rapidly consumed by aerobic bacteria. Anaerobic bacteria, which survive in the absence of oxygen, begin to grow and multiply in the fermentation stage and convert the plant sugars into organic acids- mainly lactic acid and acetic acid. With production of acids, the pH of the silage is reduced from an original level of 7.0 to a final ideal pH of 4–5. Typical large bale haylage has a pH of 4.5–5.5. Fermentation ceases when bacteria growth is stopped by the accumulation of acids. The haylage will then remain at a stable pH with no bacterial growth and can be preserved for a long time, providing there is no exposure to air. Harvesting forages with a long fiber usually results in a slow release of the plant nutrients necessary for the growth of acid producing bacteria. This generally results in less fermentation in the baleage than in chopped silage.

Common Poultry Diseases

Infectious diseases

Bacteria

Commonly known as “germs”, bacteria are very small living microorganisms. Only a few bacteria cause diseases. In birds these include Salmonella, Clostridia, Pasteurella, Vibrio, Staphylococci, Streptococci, Mycoplasma, Hemophilus, and Mycobacterium etc.

Cardiomyopathies in acts can be classified broadly as Hypertrophic cardiomyopathy and non-hypertrophic cardiomyopathies. Usually, no alarming clinical signs are detected during routine examination in the preclinical stage except cardiac murmurs in some cats with HCM. This is because, that the cats are sedentary and excellent in hiding the signs of illness from the pet parents. Hence the onset is often acute with the sudden appearance of the clinical signs linked to congestive heart failure like severe dyspnoea, cardiogenic shock, aortic thromboembolism, arrhythmias and even syncope and death

Cats with CHF will be presented with severe dyspnoea, due to fulminant pulmonary oedema and or pleural effusion. The pleural effusion associated with CHF is usually a modified transudate, some cases it may be chylous .In echocardiography ,the size of the left atrium should be determined .If the LA size is normal ,then the dyspnoea may not be of cardiac origin .The presence of B-lines in the lung area in association with LA enlargement confirms cardiogenic pulmonary oedema. Stress, anaesthesia, I/V fluids and steroids leads to decompensation and fulminant pulmonary oedema. Thoracocentesis is will be helpful if there is dyspnoea due to significant pleural effusion. At least 300ml of effusion can be usually removed. The dyspnoeic cat is very fragile and should be handled carefully. Butorphanol may be given for anxiolytic effect. Oxygen administration is beneficial. Furosemide when given intravenously has an initial venodilator effect and should be repeated as required monitoring the sleeping respiratory rate (SRR). Addition of nitro-glycerine (vasodilator) reduces preload, decreases left atrial pressure and help in reducing pulmonary oedema. If the clinical signs are suggestive of cardiogenic shock or myocardial failure, Pimobendan I/V or Dobutamine CRI should be considered.

The heart, composed primarily of specialized muscle tissue known as cardiac muscle, is responsible for maintaining the circulatory system’s function by pumping blood throughout the body. The unique characteristics of heart muscle allow it to respond dynamically to various physiological demands. Among these adaptive responses, hypertrophy, atrophy, and the process of pacemaking are fundamental to heart function and health. Understanding these processes is crucial for comprehending how the heart responds to different stressors, such as physical activity, disease, or aging, and how its electrical and mechanical functions are integrated.
Nature of cardiac muscle
Cardiac muscle is a specialized type of muscle tissue found only in the heart. It is unique because it combines features of both skeletal and smooth muscle, providing both strength and rhythm in its contractions. Cardiac muscle fibres are striated and connected by intercalated discs, which allow rapid transmission of electrical impulses between cells, ensuring synchronized contraction. Unlike skeletal muscle, cardiac muscle has a relatively high density of mitochondria, providing the energy necessary for continuous activity.

Introduction

Stress represents the reaction of body to stimuli that disturb normal physiological equilibrium or homeostasis, often with detrimental effects (Khansari et al., 1990). Domestic animals undergo various kinds of stress such as physical, nutritional, chemical, psychological and thermal stress (Marai et al., 2007; Nardone et al., 2010). Figure 1 summarises the different types of stressors and their effects on animals.

Introduction

A huge increase in the demand of animal production is expected in the next decades. Food and water security will be one of the other priorities for humankind in the 21st century. Over the same period the World will experience a change in the global climate that will cause shifts in local climate that will impact on local and global agriculture (Nardone et al. 2010). Global climate change is expected to alter temperature, precipitation, atmospheric carbon dioxide levels and water availability in ways that will affect the productivity of crop and livestock systems (Hatfield et al. 2008). For livestock systems, climate change could affect the costs and returns of production by altering the thermal environment of animals thereby affecting animal health, reproduction, and the efficiency by which livestock convert feed into retained products (especially meat and milk).

Stress is described as the cumulative detrimental effect of a variety of factors on the health and performance of living beings (Rosales, 1994). Heat stress arises when there is an imbalance between heat production within the body and its dissipation. Homeotherms can maintain their body temperature within a relatively narrow range and both physiological and behavioural responses help in thermoregulation. Stress occurs when an animal suddenly faces a change in its environment. Heat stress during summer and post summer months in tropical countries is a problem of great concern among farmers and livestock producers as it costs both production and reproduction of animals.