eChapters

(Colorimetric Method of Barker and Summerson, 1941)
I. Method for Blood / Plasma
Principle

In this method, glucose and other interfering material of the protein free blood filtrate is removed by the Van Slyke-Salkowski method of treatment with copper sulphate and calcium hydroxide. A part of the resulting solution is heated with concentrated sulphuric acid to convert lactic acid to acetaldehyde, which is then determined by reaction with p-hydroxydiphenyl in the presence of copper ions.

Preparation of Samples

Before withdrawing portions for analytical determinations, bring the sample to a temperature of 26 to 28ºC and mix throughly by pouring gently into a clean dry receptacle and back, until a homogenous mixture is assured. If lumps of cream do not completely disappear, warm the sample to about 40ºC, mix throughly, then cool to 26 to 28ºC. In case a measured volume is required in a determination, bring the temperature of the sample to about 27ºC before pipetting. All samples shall be allowed to stand for three to four minutes after mixing to allow air bubbles to rise ; the sample bottle shall then be inverted three or four times immediately prior to taking the milk for analysis. If a sample is curdled, excessively churned or decomposed, the sample should not be taken up for analysis.

Adulteration in animal and human foods has become common feature in the country, therefore we should be cautious while selecting animal/human feed ingredients.

The author of this compendium has developed. “Animal Feed Testing Kit” based on novel cud liquor enzyme complex (innovation certified by ISA, International Search Authority - Patent office, Vienna), registered with WIPO (Geneva). This method is described in detail in this chapter and Patent application is field at Indian Patent Office Delhi.

Now-a-days, animal feed is being adulterated with extraneous materials viz, Saw dust, Ric hulls, sand and Silica, Castor husk, oat hulls and urea (higher than 01 percent limit on dry matter basis).

Answer the followings
    Q.1.    What is mastitis?
    Ans.    It may be defined as inflammation of mammary parenchyma and characterized by physiochemical changes in the milk and pathological changes of the glandular tissue.
    Q.2.    What are the cardinal changes of milk and udder in mastitis?
    Ans.    Changes of milk includes discoloration, presence of clot, and presence of huge leukocytes whereas, mammary gland becomes hot painful swelling and induration.
    Q.3.    What is sub clinical mastitis?
    Ans.    In subclinical mastitis, normally mammary gland is normal by physical examination; however, cellular constitution only indicates presence of mastitis (i.e. increased somatic cell count).
    Q.4.    What is the basis of diagnosis of sub clinical mastitis?
    Ans.    Diagnosis sub clinical mastitis depends largely on indirect tests which are related to leukocyte content of milk.

Answer the followings
    Q.1.    What is the relative incidence of  Streptococcus agalactiae, other Streptococci and Staphylococcus aureus
    Ans.    1:1: 2
    Q.2.    What are sources of contagious pathogen for mastitis?
    Ans.    Udder surfaces of infected quarters 
    Q.3.    What are sources of environmental pathogen for mastitis?
    Ans.    Bedding of cow’s environment
    Q.4.    When animal get infection from environmental pathogen?
    Ans.    Animal get infection at any time during the life such as milking time, between milking, during dry period and prior to first calving.
    Q.8.    What is the probable period of new infection from environmental pathogen?
    Ans.    Early part of dry period and first two months of lactation.
    Q.9.    What is the relation of growth of Corynebacterium bovis in milk and lactation?

Answer the followings
    Q.1.    What is the different stage of pathogenesis in mastitis?
    Ans.    There are three stages in pathogenesis 
These are as follows:
Invasion: here pathogens move from the exterior of teat to milk inside the teat canal.
Infection: Here pathogens multiply rapidly and invade the mammary gland.
Inflammation: In this stage clinical mastitis occurs with varying degree of clinical abnormalities of milk and udder.
    Q.2.    Of these phases, which phase is important to reduce the incidence of mastitis in control program?
    Ans.    Invasive stage is very important. The incidence of mastitis can be reduced by taking preventive measures at invasive stage by good management and good hygiene practices.
    Q.3.    What are the common abnormalities encountered in udder during mastitis?

Q.1.    What are the major clinical findings in mastitis?
    Ans.    These are abnormalities of secretions, abnormalities of udder related to size, consistency, temperature and sometimes systemic reactions.

Q.2.    How clinical forms of mastitis could be classified based of severity and duration?
    Ans.    Based on severity it is classified in four forms: Per acute mastitis, acute mastitis, subacute mastitis and subclinical mastitis. However, based on duration it is of three forms: Short term clinical or subclinical mastitis (Coliform mastitis), recurrent mastitis (Staphylococcus aureus mastitis, Streptococcal dysgalactiae mastitis) and persistent clinical or subclinical mastitis (Streptococcus agalactiae mastitis).

Q.3.    What is sub clinical mastitis?
    Ans.    In sub clinical mastitis there is evidence of inflammation which is evidenced by only raised SCC in milk without any visible abnormalities of milk and udder.

   Q.1.    How milk sample is collected for diagnosis of mastitis?
    Ans.    At first the end of teat is cleaned with a cotton swab dipped with 70% alcohol, then the dirt and wax are removed from the external sphincter by pressure. After this milk sample is collected in screw cap bottle.

    Q.2.    When milk sampling should be done in suspected cases of tubercular mastitis?
    Ans.    Last few streams of milking is crucial in cases of tubercular mastitis.

    Q.3.    What is the effect of freezing of milk sample on bacterial count?
    Ans.    On freezing of milk, Arcanobacter pyogenis and E. coli counts are decreased, coagulase negative bacteria counts increases whereas, Streptococcus and Staphylococcus spp. counts may be unaffected or increased.

    Q.4.    Which media is suitable for initial isolation of bacteria from milk samples?
    Ans.    Blood agar. However for isolation Streptococcus agalactiae selective media is required

Answer the followings.
    Q.1.    Which factors govern the efficacy of intramammary drug in mastitis therapy?
    Ans.    The important factors are spectrum of bacteria controlled, diffusibility through mammary tissue and cost of the drug.

    Q.2.    What should be line of emergency treatment when type of infection is not known?
    Ans.    Frequent removal of milk manually or by using oxytocin, broad spectrum antimicrobials parentrally as well as via intramammary route and non steroidal anti-inflammatory drug.

    Q.3.    Why therapy of mastitis often fails to respond in lactating cows in spite of intensive veterinary service?
    Ans.    The main reasons are as follows:
    a)    Ineffective drug diffusion
    b)    Inactivation of antibiotics by milk and tissue priteins
    c)    Formation of micro-abscesses which make inaccessible of drug to pathogens
    d)    Inefficient killing of bacteria and intracellular survival of bacteria

Answer the followings
    Q.1.    What is the international organizations associated for making outline the mastitis control programme?
    Ans.    National Institute for Research on Dairying (NIRD) and National Mastitis Council (NMC).

    Q.2.    What is the important objective of dairy industry as regards to mastitis control?
    Ans.    The important objective is to achieve an excellent udder health for production of high quality of milk.

    Q.3.    What is the basic principles of mastitis control programme?
    Ans.    There three basic principles of mastitis control programme:
    a)    Elimination of existing infection
    b)    Prevention of new infection 
    c)    Monitoring of udder health status

Q1.    What is the etiology of Staphylococcus aureus mastitis?
    Ans.    Coagulase positive Staphylococcus aureus.

Q.2.    It causes contagious or environmental mastitis?
    Ans.    Contagious mastitis

Q3.    What are the important animal risk factors of S. aureus mastitis?
    Ans.
    (i)    Presence of coalgulase –ve Staphylococci and Corynebacterium bovis in the mammary gland act as protective factor for S. aureus mastitis.
    (ii)    Abrasion of teat orifice epithelium is a major risk factor of S. aureus mastitis.
    (iii)    Cows with increased parity are more prone to clinical and subclinical S. aureus mastitis.
    (iv)    Presence of different periparturient diseases like parturient peresis, retained placenta, dystocia, ketosis and ulcers in different organs are also risk    factors for S. aureus mastitis.
    (v)    Animals having very low SCC in milk are more prone to S. aureus mastitis.

Fill in the blanks

    Q1.    …………… is a contagious pathogen in bovine mastitis
    Ans.    Streptococcus agalactiae

    Q.2.    Streptococcus agalactiae causes ……… (acute/chronic) mastitis if control procedure of mastitis is not used.
    Ans.    Chronic

Answer the following
    Q.1.    Mention the strategy to reduce the prevalence of Streptococcus agalactiae mastitis at herd level.
    Ans.    Good hygienic measures, proper disinfection and efficient treatment of clinical cases.

    Q.2.    What is the relation between SCC and Streptococcus agalactiae infection?
    Ans.    The possibility of Streptococcus agalactiae infection is high with high bulk milk somatic cell count.

    Q.3.    What are the common sources of Streptococcus agalactiae infection in a dairy herd?

    Q.1.    How many species of Mycoplasma are responsible for causing mastitis?
    Ans.    At least seven species like Mycoplasma bovis, Mycoplasma Canadensis, Mycoplasma bovigenitalium, Mycoplasma alkalensis, Mycoplasma capricolium, Mycoplasma californicum, Mycoplasma disper and Ureaplasma sp. are responsible for causing mastitis

    Q.2.    Which herds are more prone to such type of mastitis?
    Ans.    The herds where milking hygiene is very poor and when the cows are imported from other farms or from public sale yards.

    Q.3.    Which organs act as common habitat of the Mycoplasma organisms?

Q.1.    Enumerate the etiological agents responsible for Coliform mastitis.
    Ans.    Different serotypes of E. coli, Klebsiella sp. and Enterobacter aerogens.

Q.2.    What is the primary reservoir of Coliform mastitis?
    Ans.    Primary reservoir of Coliform is the dairy cow’s environment as it is an environmental pathogen, however, infected mammary gland acts as reservoir of Coliform mastitis

Q.3.    What is the important factors of E. coli that affect the normal bactericidal activity of leukocytes?
    Ans.    Lipopolysaccharide-endotoxin, somatic and capsular factors. Similarly, fibronectin binding property of E. coli is also an important virulence factor which help to adhere to ductular epithelium.

    Q.1.    What are the most common isolated environmental Streptococci from mastitis cases?
    Ans.    Streptococcus uberis and Streptococcus dysgalactiae.

    Q.2.    What are the common sources of environmental Streptococcus uberis in a herd?
    Ans.    The common sources are bedding materials, lips, nostrils and abdominal skin of cows.

    Q.3.    What are the common sources of environmental Streptococcus dysgalactiae?
    Ans.    The common sources are tonsils, mouth, vagina and mammary gland of cows.

    Q.4.    Why incidence of Streptococcus uberis is highest just prior to calving?
    Ans.    The important reasons are the excessive accumulation of milk due to lack of milking, lack of keratin plugs from the streak canal and immunosuppression at periparturient period.

    Q.5.    The cattle fly sometimes involves in persistent bacterial contamination on teat of a cow. Mention the name of the cattle fly.

    Q.1.    The mastitis-metritis-agalactia (MMA) is a disease syndrome of which animal species? 
    Ans.    Swine

    Q.2.    What is MMA syndrome?
    Ans.    MMA syndrome is post parturient disease of sows and manifested as fever, anorexia, lethargy, agalactia, mastitis, swollen udder and appearance of vulvar discharge due to development of metritis.
 
    Q.3.    What is the critical time of occurrence of MMA in sows?
    Ans.    The mastitis-metritis-agalactia (MMA) syndrome occurs between 12-48 hrs of farrowing in sows.

    Q.4.    What is the probable causes for the development of MMA syndrome?
    Ans.    The probable causes of MMA syndrome are infectious mastitis, metritis, more feeding at pregnant period, nutritional deficiency, endocrine disorders and constipation.

Fill in the blanks

    Q.1.    ---------- and -------------- are the synonyms of mastitis of sheep.
    Ans.    Bluebag, garget
    Q.2.    In gangrenous mastitis, besides Staphylococcus aureus, ----------- organism may also be involved.
    Ans.    Clostridium perfringens A
Answer the followings

    Q.1.    What are the characteristic symptoms of mastitis in sheep?
    Ans.    The important symptoms include severe necrotizing inflammation of mammary gland, severe systemic reaction and reduced milk production
    Q.2.    Classify the sheep mastitis based on etiology and clinical symptoms.
    Ans.    a) Gangrenous mastitis by Staphylococcus aurcus mastitis b) Herd mastitis by Pasteurella hemolytica
    Q.3.    When the risk of mastitis in sheep is high?
    Ans.    During summer month between parturition and weaning

Fill in the blanks
    Q.1.    ………… organisms are the common isolates from clinically affected quarters.
    Ans.    Coagulase-negative staphylococci
    Q.2.    ………….is the most common cause of mastitis in goats.
    Ans.    Staphylococcus aureus
    Q.3.    Streptococcal zooepidermicus causes …………. in does.
    Ans.    Chronic suppurative mastitis.
 
Write True/ False about the statements
    Q.1.    Pseudomonas organism causes an acute mastitis characterized by extensive necrosis and fatal septicemia.
    Ans.    True.
    Q.2.    In summer mastitis, non-lactating goats develop severe mastitis whereas lactating goats suffer from moderate degree.
    Ans.    False

    Q.1.    What is the cause of mastitis in non-lactating mare?
    Ans.    Mastitis may develop in a non-lactating mare due to abnormally high estrogen levels in her system. This excess female hormone can result from a pituitary gland tumor or consumption of high estrogen containing hay. High estrogen concentrations can cause mammary gland enlargement and trigger the production and secretion of milk, even though the mare is not pregnant and has not foaled. If the non-lactating mare begins to secrete milk due to excess estrogen, she may become a candidate for mastitis.

    Q.2.    Why equine mammary glands are less prone to mastitis than bovines?
    Ans.    The possible reasons are as follows:
    a)    Mammary glands are relatively smaller in size
    b)    Concealed position of the glands
    c)    Small milk capacity of the glands
    d)    Greater resistance to infection in equine mammary glands because of differences in endocrine environment and local immunity

    Q.1.    How mastitis occurs in dogs? 
    Ans.    Mastitis in dogs initiates with the infection in the milk ducts of the dogs, where in the dog’s breast is enlarged as well as milk duct is blocked. The skin around the nipple might get cracked which might give a way to bacteria. In neglected cases it leads to cause gangrenous mastitis which is a severe form of mastitis in dogs.

    Q.2.    What are common pathogens responsible for mastitis in bitch?
    Ans.    Staphylococcus spp., Streptococcus spp. and Escherichia coli.
 
    Q.3.    What are the characteristic features of milk cytology during mastitis in bitch?
    Ans.    Milk cytology will show the presence of erythrocytes, degenerated neutrophils and bacterial agents.

    Q.4.    What characteristic physical changes of milk are seen during mastitis in bitch?
    Ans.    The viscosity of milk is increased and the colour of milk will be yellow to brown depending on the amount of blood and purulent exudates present.

    Q.1.    What are the common infectious diseases affect teat skin of mammary gland?
    Ans.    The common infectious diseases that affect teat skin of mammary gland are cowpox, buffalopox, pseudocowpox, bovine ulcerative mammillitis, black pox, foot and mouth disease, vesicular exanthema, swine vesicular diseases, contagious exanthyma, Staphylococcus sp., Pasteurella sp etc.

    Q.2.    What is thelitis?
    Ans.    Thelitis is the inflammation of tissues of teat wall caused by traumatic injury to the teat cistern. It is generally manifested with gangrenous mastitis.

    Q.3.    What is the main etiology of gangrenous mastitis?
    Ans.    Staphylococcus aureus

    Q.4.    What are the causes of coming blood in milk and mentions its treatment?

1. California mastitis test

The California mastitis test (CMT) is conducted during milking of lactating cows. The CMT paddle is used to collect about three to four ml of fore milk from each quarter of cows after discarding few streams to which an equal volume of CMT reagent (composition mentioned below) is mixed immediately by circular motion (Fig. 1). The reaction is graded by intensity of gel formation and color changes as follows:

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Aitken, I.D. 2007. Diseases of sheep, 4^th edition, Blackwell publishing, UK.

Bennett, R. H. and Jasper, D. E. 1980. Bovine mycoplasmal mastitis from intramammary inoculations of small numbers of Mycoplasma bovis: local and systemic antibody response. Am. J. Vet. Res. 41(6):889-92.

Bennett, R.H. and Jasper, D.E. 1977. Bovine mycoplasma mastitis from intramammary inoculation of small numbers of Mycoplasma bovis. I. Microbiology and pathology. Vet. Microbiol., 2(4): 341–355.

Bergey’s Manual of determinative bacteriology. (edited by) John, G. Holt Fetd. 9th edn. (1994).

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Bertschinger, H. U., Pohlenz, J. and Hemlep, I. 1977. Studies on the mastitis-metritis-agalactia syndrome (milk fever) in sows. II. Bacteriological findings in spontaneous cases. Schweiz Arch Tierheilkd.119(6): 223-33.

Bostedt, H., Lehmann ,B. and Peip, D. 1988. The problems of mastitis in mares. Tierarztl. Prax.. 16(4):367-71.

Bradley, A. J. 2002. Bovine Mastitis: An Evolving Disease. Vet. J., 164(2): 116–128.

Buchanan, A. G. 1982. Clinical laboratory evaluation of a reverse CAMP test for presumptive identification of Clostridium perfringens. J. Clin. Microbiol. 14:761–762.

Bushnell, R. B. 1984. Mycoplasma mastitis. Vet. Clin. North Am. Large Anim. Pract., 6(2):301-12.

Chareonsirisuthigul, T., Kirpal, G., Amtsberg, G. 1979. Biochemistry, serology, pathogenicity and antibiotic resistance of an Escherichia coli strain from healthy sows and from animals with mastitismetritis-agalactia syndrome. Berl. Munch Tierarztl. Wochenschr. 92(21):409-16.

Christie, N. E., Atkins, N. E. and Munch-Petersen, E. 1944. A note on a lytic phenomenon shown by group B Streptococcus. Aust. J. Exp. Biol. Med. Sci. 22:193–195.

Claxton, P.D. and Ryan, D. 1980. Bovine mastitis bacteriology. Australian Standard Diagnostic Techniques for Animal Diseases. Pp. 1-8

Daley, M. J., Oldham, E. R., Williams, T. J. and Coyle, P. A. 1991. Quantitative and qualitative properties of host polymorphonuclear cells during experimentally induced Staphylococcus aureus mastitis in cows. Am. J. Vet. Res., 52(3): 474-9.

Darling, J. F. 1975. Standardization and evaluation of CAMP reaction for the prompt, presumptive identification of Streptococcus agalactiae (Lancefield group B) in clinical material. J. Clin. Microbiol. 1:171–174.

De, U. K. and Mukherjee, R. 2005.Status of nitric oxide production by polymorphonuclear cells during clinical mastitis in lactating cows. Indian J. Comp. Microbiol. Immunol. Infec. Dis., 26(1): 61-62.

De, U. K. and Mukherjee, R. 2008. Anti-inflammatory and respiratory burst activity of Azadirachta indica during acute bovine mastitis Indian J. Anim. Sci., 79(2): 32-34.

De, U. K. and Mukherjee, R. 2009. Expression of cytokines and respiratory burst activity of milk cells in response to Azadirachta indica during bovine mastitis. Trop. Anim. Health Prod., 41(2): 189-197.

De, U. K. and Mukherjee, R. 2009. Inhibitory response of Azadirachta indica extract on nitric oxide production by milk leukocytes during clinical mastitis. Vet. Arhiv, 79(1), 41-50.

De, U. K. and Mukherjee, R. 2009.Prevalence of mastitis in crossbred cows. Indian Vet. J., 86:858-859.

De, U. K. and Mukherjee, R. 2011. Potential of Indigenous Enzymatic Activities, Nitric Oxide and Ceruloplasmin in Bovine Milk to Diagnose Subclinical Mastitis. J Veterinar Sci Technol 2:109. doi:10.4172/2157-7579.1000109

Aquaculture is the culture of aquatic organisms per unit water area per unit time for maximum profit. The economically important finfishes and shellfishes, whose body physiology is adjustable to varied environmental conditions, are considered as aquaculture candidate species. So, an overall knowledge on the physiology of such species is required to improve the culture practices.

1.1. Finfish

A fish may be defined as a vertebrate, adapted for a purely aquatic life, propelling and balancing itself by means of fins, and obtaining oxygen  (O2) from the water for survival and life processes. As the fishes have fins, they are also known as finfishes. Fish describes a life from rather than a taxonomic group. They share certain features with other vertebrates. These are gill slits, a notochord, a dorsal hollow nerve cord and tail. In number of individuals, and may be also in number of species, fishes are presently superior to other vertebrates, including mammals. There are 20,000 different species of fishes. Fishes form largest group of vertebrates, Pisces. The various types of fishes differ so much in shape, color and size that it is difficult to believe they all belong to the same group of animals. Fish in general are cold-blooded and adjusted either to freshwater, brackishwater or marine environment.

The knowledge of food, feeding habit, anatomical adaptations and the physiology of digestion of the candidate aquaculture species is highly essential to develop cost-effective artificial feed for successful culture practices. The digestion of poikilothermic aquatic fishes and shellfishes is influenced by many factors, and is different from the digestion of terrestrial animals.

2.1.    Anatomy and Physiology of Fish Digestive System
2.1.1.  Feeding Behavior of Fishes

Based on the feeding habit, the fishes are generally classified as herbivores, omnivores, carnivores and detritivores. Within these categories, the fishes further categorized as euryphagous, having a mixed diet, stenophagous, consuming a limited combination of food types and monophagous, accepting only one type of food. A majority of fishes are euryphagous carnivores, and their feeding mode and food types are associated with the body form and digestive system. Fish generally change their feeding habits depending upon the availability of food. Fishes may be classified as predators, grazers, strainers etc. Plankton is a collective term for variety of marine and freshwater plant or organisms that drift on or near the surface of the water. Most fishes eat the material that is smaller than them. The smallest fishes eat these planktons, which act as their main food and all smaller fishes are the food of the bigger fishes. Largest shark feed on plankton by straining these tiny marine plants and animals from the water. The zoo-planktons, comprise protozoa, small crustaceans, jelly fish, and mollusks, together with the eggs and larvae of many species of marine and fresh water.

Embryologically, the circulatory system is the first organ system to develop in the living animals. The form and function of this system vary considerably among the animals and are shaped by a variety of environmental factors i.e. phenotypic plasticity. Oxygen (O₂) acquisition and carbon dioxide (CO2) elimination occur simultaneously at the gill site of fish and shrimp. The gases are transported around the body by the circulation of the blood.

3.1. Circulatory System of Fishes

In fishes, heart is simply a muscular enlargement and modification of a part of the main blood vessels, lying between the hepatic capillaries and the gills. Fishes have a closed circulatory system with a heart that pumps blood in a single loop throughout the body. From the heart, blood goes to the gill capillary bed. Then via the systemic capillaries it returns back to the heart. Usually the gills account for approximately 30% of the total resistance to blood flow, the rest being in the visceral and somatic vasculature. Tuna requires more O₂ and the gill area is large with gill resistance up to 57%.

Various activities of the body in different external environmental conditions are co-ordinated by the appropriate message from the neurons due to the stimuli from the environment. These messages pass in the form of impulses through the co-ordinated links between a number of neurons or nerve cells. The constant passage of messages require a very little energy but high level of O₂ .There is interaction between the nervous and endocrine system with the areas of interchange among the two systems. Some neurons show the action of both the systems and thus termed as neurosecretory or neuro-endocrine. Fishes have a well-developed nervous system. Broadly the nervous system can be divided into central nervous system (CNS) and peripheral nervous system (PNS).The brain and spinal cord are the parts of the CNS. The motor and sensory nerves link the receptor and effector organs. All nerve tissues other than brain and spinal cord are grouped under PNS. Peripheral nervous system consists of nerves, ganglia and receptors. The nerves carry sensory information from special receptor organs like eyes, internal ear etc. to the integrating centers of the brain and spinal cord. The PNS also carries information via different nerve cells from the integrating centers of the brain and spinal cord. This coded information is carried to the various organs and body systems, such as the skeletal muscle system for appropriate action in response to the original external and internal stimulus. The PNS can be divided into somatic and visceral. The term visceral is sometimes used in referring to the autonomic or involuntary nervous system (ANS), controlling visceral functions. The ANS helps to co-ordinate the activities of many glands and organs, and it is closely connected to the integrating centers of the brain.

The respiration of animals includes the exchange of gases either at the surface of the body or through the internal processes involving circulatory system. The gases that are exchanged are oxygen (O₂), carbon dioxide (CO₂) and the inert gas like nitrogen. When the organism respires, the O₂ that is taken up from the external environment is transported by the vascular system to individual cells within the tissues. At the same time this system picks up CO₂, an end product of cellular metabolism, and releases it to the environment. Thus respiration is a term applicable either to a whole organism or one of its cells. The mechanical process, by which respiration is achieved, is called ventilation.  This ventilation rate of aquatic organisms is controlled directly by the concentration of dissolve oxygen (DO₂) in water.

Respiration in aquatic medium is produced by a water current passing in a single direction. The area of respiratory surface is thus an important limiting factor in the movement and growth of the animal. For aquatic animals, if the water is at all deficient in O₂, the rate of breathing is naturally accelerated, and the animal appears to respire hurriedly. Other factors, which lead to an increased rate of respiration, are the stresses.

Excretion is the process of elimination of metabolic wastes that include toxic nitrogenous end products of the protein metabolism and the gas such as carbon dioxide (CO₂). These nitrogenous wastes are excreted through urine. Fecal matter is not included in the excretory products as it is simply the undigested food materials, and are not metabolic end products. The membranes of aquatic animals, that is permeable to gases, pass water and solutes between environment and body. Most aquatic animals maintain in their bodies a reasonably constant proportion of water and solutes. When it is different from the surrounding water, it requires some mechanism for regulation, which is known as osmoregulation. Most invertebrates in the sea have nearly the same salt concentration (isosmotic or isotonic) as the environment. Sharks and rays (elasmobranches) tend to have a slightly higher concentration of salts and urea (excretory end products) than seawater but the body fluids of most teleosts (bony fishes) have much lower salt concentration than seawater. Freshwater fishes, which live in a medium of lower salt concentration (hyposmotic or hypotonic), have the threat of hydration, so they have special mechanisms to get rid of excess body water. Marine fishes that live in an environment of high salt concentration (hyperosmotic or hypertonic) have the regulatory mechanisms by which excessive loss of water from the body is prevented and body osmolarity (proper osmotic concentration) is maintained by retaining less toxic nitrogenous excretory products. Marine fishes, which lose water osmotically across the gills and must get rid of salt, tend to drink large volume of seawater and produce very small quantities of urine (Fig-6.1).

Most of the aquatic organisms spend much of their lives and energies for reproduction. The young ones mature, develop sperms or eggs, spawn, and then recover to repeat the breeding cycle that continues till their death. In a majority of fish species males and females are separate individuals, fertilization is external and large number of eggs are produced (on an annual basis, its fecundity) which develop, hatch and mostly grow without parental care. The sperm and eggs are usually produced in such quantities that they represent a large expenditure of energy. The spawning process may be preceded by migrations or nest building, and followed by care of the young. Thus the success of any fish is ultimately determined by the ability of its members to reproduce successfully in a fluctuating environment and thereby to maintain viable populations.  As each fish species occurs under an unique set of ecological conditions, it has an unique reproductive strategy with varied anatomical, physiological, behavioral and bioenergetics adaptations. Unlike the finfishes, in shellfishes sexes are separate. The shellfishes use various signals to attract the opposite sex.

The highly specialized organs that receive physical and chemical stimuli from the environment and various body parts, and transform them into stimuli are called sense organs or sensory receptors. These organs are closely associated with nervous system. The physical stimuli such as change of heat, light intensity and quality, acoustical stimuli and chemical stimuli like hear, taste, smell, touch, lateral line etc are received by the sense organs such as ear, eye, nose and others. These are more prominent sense organs. Less obvious ones in fishes are sensory crypts and papillae, ampullae of Lorenzini and Savi.

The crustaceans have various sense organs whose action are mediated through the nervous system. Crustacean antennae are important sites for the reception of environmental information, mainly chemical, and aesthetases, the olfactory hairs on the first pair, are usually well developed. The aesthetases help not only in locating food but also in recognizing other individuals and their sexual state.  The frequent grooming of the antennae by many decapods prevents fouling of the receptor sites (Bauer, 1971).

Introduction

The cereal cyst nematode, (Heterodera avenae Woll.) a causal organism of ‘molya’ disease in wheat and barley, since after its first report (by Wollenweber, 1924, Vasudeva, 1958 and Prasad et al., 1959), it has been timely reviewed about its spread and losses caused in the various parts of wheat and barley growing areas of the world. It has been reported to occur in Australia, Canada, Israel, South Africa, Japan, in most of the European countries, North America, India, Morocco, Tunisia, Pakistan, Libya, Turkey and Australia (Prasad et al., 1959, Smiley et al., 1994, Rumpen horst et al.,1996, Krall et al., 1999, Nicol, 2002 and Rao et al., 2002). Its economic importance has been assessed by mapping the yield losses caused in cereals i.e. ranged from 15-20% in Pakistan, 40-92% in Sauthi Arabia, 23-50% in Australia (Nicol, 2002) and 40-50% in India (Mathur 1969, Mathur et al., 1980, Handa et al., 1985, Mathur, et al., 1987).

Preamble

In India, agriculture plays an important role as it accounts for about 18% of the GDP and supports nearly 58% of the total working population for employment. Food grain production increased significantly from a low level of 50 million Tons during 1950-51 to a record of 230.7 million Tons in 2007-08. The demand for food is growing rapidly due to increasing population and rising income levels, hence we need to produce about 320 million Tons of foodgrains by the year 2025. It implies more pressure on our exhisting land, soil and water resources which are already in short supply, degraded, fragile and this similar situation is being faced by mainly developing countries today. Plant parasitic nematodes are of great economic significance. Since most of them live in the soil hence represent one of the most difficult pest problems in terms of identification, demonstration and management.

Introduction

India has the distinction of being the largest producer of pulses in the world. Among the important pulse crops cultivated in the country are: chickpea, pigeonpea, lentil, mungbean, urdbean, fieldpea, rajmash and lathyrus. The pulse crops occupied an area of 22.85 million ha with a total production of 13.07 million tones and average productivity of 572 kg/ha. Being a high protein grain, pulses have special status in the diet, particularly for vegetarian population. Apart from being a good source of protein, they are also good source of energy, essential amino acids and vitamins in the daily diets of the people, especially of low-income group. Pulses have importance in sustainable agriculture by way of fixing atmospheric nitrogen in the soil.But with intensification of agriculture and introduction of irrigation and other facilities the area and production under pulses is declining so much so that per caput availability of pulses has declined from 69 g day-1 to about  36 g day^-1.

Introduction

Plant paprasitic nematodes are one of the limiting factors in the production of horticultural crops in the country. The visible symptoms of nematode attack are: Reduced individual plant growth, varying degrees of chlorosis, wilting of the foliage and sometimes death of the plants.

The roots, damaged by nematodes are not efficient in the utilization of available moisture and nutrients in soil resulting in reduced functional metabolism. Nematode infested roots are easily infected by various pathogenic fungi and bacteria and aggrevate root damage. These deleterious effects on plant growth result in reduced yield and poor quality of crops as in citrus, banana, grapevine, pineapple, papaya and vegetable crops. Decline or death of highly prised ornamentals and turf is often the result of nematode infestation.

Introduction

Maize (Zea mays Linn) is the most widely distributed crop of the world. It adapts easily to a wide range of production environments and is grown in tropical, subtropical and temperate regions of the world. It holds a unique position in world agriculture ranking third after rice and wheat in terms of area as well as production. In India too, it is the third most important cereal crop and is cultivated in 8. 17 m ha (2007-08) area. It contributes nearly 8% to the national food basket and more than Rs 100 billion to agricultural gross domestic products with an annual production of 19. 73 million tons. It is used as a source of human food (24%) animal feed (11%), poultry feed (52%), starch (11%), brewery and seed (1% each). In India it is largely grown in Northern states where it serves as an important staple food for an economically vulnerable population of submountainarean and hilly regions.

Introduction

Rice (Oryza sativa L.), one of the most important cereal crops of India, occupies 23.3 per cent of total cropped area of the country. Rice contributes 43 per cent of total food grain production and 46 per cent of total cereal production. It continues to play a vital role in the nation’s food grain supply. It is also a staple food of nearly half of the world population. Rice is primarily a high caloric food having protein content (6-17%) with high biological value and a low amount of fat (2-2.5%). B-group vitamins content in rice grains are at par with wheat, however, calcium content in rice is generally low. It ranks third after wheat and maize in terms of worldwide production. Asia accounts for 90 and 92% of the world’s rice area and production, respectively. Thus, rice production, consumption and trade are concentrated in Asia. Among the rice growing countries in the world, India has the largest areas under rice crop and ranks second in production next to China.

Introduction

Seed spices have prominent place in India’s national economy because of their very high domestic consumption and growing demand for export. This group of spices, being consisting of mostly annual crops, is grown extensively in rotation with food and cash crops and also as inter crops under rain fed as well as irrigated conditions.

There are about 20 seed spice crops grown in India. Out of which nine are important in terms of production and export. The most important ones are coriander, cumin, fennel and fenugreek (major seed spices) and ajowain, aniseed, black cumin, celery and dill (minor seed spice crops). Although these crops are grown all over India but Haryana, Rajasthan, Madhya Pradesh, Uttar Pradesh, Orissa, Tamil Nadu and Andhra Pradesh are the main seed spice growing states.

Introduction

Banana is the forth ranked agricultural crop in the world and first among fruits. A large number of pests and diseases threaten banana production. The major constraints in production are diseases and pests transmitted through the conventional planting materials. Although the average yield for bananas worldwide is over 40 t per hectare, production in India averages only 20 t per hectare. The nematode parasites are among the most important pests on commercial and subsistence banana production and their control remains difficult, as the nematodes are involved in the destruction of primary roots that disrupt the anchorage system resulting in toppling or uprooting of plants. The most widespread and important are burrowing nematode, Radopholus similes, some species of root lesion nematode, Pratylenchus coffeae and P. goodeyi, species of root knot nematode, Meloidogyne incognita and M. javanica; the spiral nematode, Helicotylenchus multicinctus, H. mucronatus and semi endo-parasitic nematode Rotytlenchus reniformis.

Introduction

Nematodes are cosmopolitan and ubiquitous in occurrence. These have been reported in all kinds of ecological niche. Accordingly, different kinds of nematode fauna had evolved with distinct morphological features and physiological variability. However, development and perception keep changing with the ambient environment. Agriculture has progressed with leap and bounce as human being has managed this to its maximum utility. The fast changes in agriculture definitely influenced the ecological niche and affected the flora and fauna. Consequently, specific and unspecific kind of relation evolved between host and parasite. With the thumb rule of ecological balance or homeostasis. In the dynamic Mother Nature, multispecies heterogeneous complex is sustained and nature do not perpetuate homogeneity.

Protected Cultivation

Protected cultivation (PC) may be defined as the “modification of the natural environment to achieve optimum plant growth” (Singh, 2005). Modifications can be made to both the aerial and root environments to increase crop yields, extend the growing season and permit plant growth during periods of the year not commonly used to grow open field crops. PC may also indicate comprehensive systems of ‘Controlled Environmental Agriculture’ in which all the aspects of natural environment are modified for maximum plant growth and economic return.

Introduction

Biological control of plant pathogens is currently accepted as a key practice in sustainable agriculture. Plant parasitic nematodes and mycorrhizal fungi are commonly found inhabiting the same soil and colonizing roots of their host plants. These two groups of microorganisms exert a characteristics, but opposite effect on plant health. The potential role of mycorrhizal fungi as biocontrol agent for the control of nematode plant diseases has recently received considerable attention. The literature on the various aspects of VAM research such as interaction of VAM- mycorrhizal fungi with nematode pathogens (Sikora, 1995, Pinochet et al. 1996), biotechnology and future of VAM commercialization (Wood and Cumming, 1992) and trends in mycorrhizal research (Sahay et al. 1998) has been reviewed. The damage due to nematodes diseases is generally decreased in mycorrhizal fungi has shown an antagonistic influence on the population of plant parasitic nematodes (Nagesh et al. 1999, Kantharaju et al.

Introduction

Plantation crops are high value commercial crops which are broadly classified as estate crops consisting of crops like tea, coffee and rubber and small holders plantation crops like coconut, cashew, arecanut, cocoa etc. Spices especially black pepper, cardamom, vanilla, tree spices like clove, nutmeg, cinnamon and allspice are generally grown as mixed crops in perennial cropping systems. In India, plantation crops including spices are grown in an area of three million hectares and generate an annual income of more than Rs, 5,53,630 million. They are valued for multifarious uses to meet the human needs such as food, oil, industrial raw materials, beverages and confectionary items. Pests and diseases are the major limiting factors in increasing the productivity of these crops. Among the pests, nematodes have got a major role in devastating the pepper plantations by the involvement in slow wilt disease, nematode diseases of cardamom nurseries, root-knot nematode infestation in ginger, turmeric, clove, nutmeg, allspice, lesion nematode infestation in tea, coffee, etc.

Introduction

Pomegranate is emerging as one of the important fruit crops owing to its hardiness and ability to withstand adverse soil and climatic conditions. Today out of world production of ten Lakh tons; India contributes 40-45 percent. Currently the export of pomegranate is around 10,000 tones, which is just 5 percent of the total export. With the increase in population the domestic demand of fruits has also increased substantially. As on date out of total area of 1,25,000 ha. area, under pomegranate major area under the crop is found in the state of Maharashtra. The state has 85,000 ha. (68 % area) under the crop, of which only 51,000 ha is under production, followed by Karnataka 12,727 ha. Gujarat 3,787 ha. up to 2003 –2004.

Breeding

Pomegranate is genetically heterozygous material thus there is lot of variability existent in the nature. Therefore there is scope for crossing two selected genotypes. Raising of hybrid population and identification of superior types for following major constraints in its successful cultivation.

    1.    Cracking and splitting of fruits is a severe menace due to variation in atmosphere, humidity. 
    2.    Resistance to fruit borer and stem borer. 
    3.    To develop varieties having high sugar (16%) and less acid (1.5 %).
    4.    All varieties bear some sterile flowers. This reduces the yield appreciably. Selection of varieties bearing high percentage of fertile flowers should be achieved.

The world’s largest collection comprising 1117 entries is maintained at Turkmenistan (CIS). They exhibit great variability for fruit size and quality, skin color, resistance to abiotic and biotic stresses but most of them are temperate in nature and do not grow well in the Indian tropics. There is scope to use this material for breeding superior types.

There are several varieties adopted to both tropical and subtemperate climate. They are either evergreen on semi deciduous or deciduous types. The flowering habit, fruiting and flower physiology are altered with the habitat. The tropical climate with mild winter of south India, growth and flowering are continuous processes, while in the subtropical climate of north India the trees remain dormant during cold winter and flowers in the following spring and in temperate climate flowering occurs in summer.

Pomegranate is emerging as one of the important fruit crops for semiarid and arid areas of India with the identification of superior varieties like Ganesh, Mrudila, Arka Ruby, and Bhagwa the area under pomegranate is increasing fast. Therefore the demand for elite planting material is also increasing fast. Pomegranate is propagated vegetatively either by cutting or air layering since ages. However now a day’s orchards raised from tissue culture are also very common. Nursery as a business preposition can also be as profitable as raising a crop. 

Types of Nurseries According to Marketing
    1.    Wholesale nurseries
    2.    Garden centers
    3.    Nurseries for large-scale gardening (municipals etc.)
    4.    Regular nurseries

Soil and Climate

Commercial pomegranate orchards are confined mainly to Mediterranean, and semi-arid regions of the world. It is hardy fruit, which can be grown successfully, even in low fertile soils. Although pomegranate of high quality can be grown only where there is a cool winter and a hot dry summer, the trees grow under wide range of climatic conditions. It can be grown from the plains to an elevation of about 1829 m. The tree can withstand frost but gets injured by temperatures below 11.1^ºC.

In areas of low winter temperatures the tree is deciduous but under tropical and sub-tropical conditions, it is evergreen or partially deciduous. The tree cannot produce sweet fruits, unless the temperatures are high for sufficiently long period. The quality of fruit is adversely affected in humid climate.

Irrigation/ Drip/ Fertigation

Pomegranate is considered to be drought hardy fruit crop. Supplemental irrigation, however, is necessary for realizing higher fruit yield and better quality. Irrigation is also used to regulate cropping in pomegranate and the total water applied therefore depends on the desired bahar. In Gujarat and Maharashtra, where Ambe bahar is taken, regular irrigation is required during March to July and irrigation is stopped after the fruit harvest until January. For Mrig bahar crop irrigation is not required from July to September. However, in case of prolonged break in monsoon one or two supplementary irrigation at an interval of 10-15 days during October to December are required. In hasta bahar (September flowering) prolonged rainy season helps in reducing requirement for irrigation 3-4 irrigation at monthly interval after cessation of rainfall are must to obtain good fruit size and higher yield.