eChapters

Physicochemical parameters of meat
1. Moisture, ash and fat content
• Meat samples are dried at 105 °C for 24 h for determining the moisture content and for ash content analysis, samples are burned at 525 °C
• Fat determination is done by acidic hydrolysis of the sample
• Sample is boiled initially and then cooled and later, it is filtered, washed and dried
• Thereafter, petroleum ether is used to extract the fat
• Ether is evaporated and the remnant is dried and weighed
2. Protein content
• Often, protein in meat sample is estimated using Kjeldahl method
• The protein content is determined by multiplying the nitrogen content in the meat sample by an appropriate conversion factor
• Strong acid is used to digest the meat sample and the released nitrogen is measured by proper titration technique
• Then, the protein quantity of the sample is determined from the nitrogen concentration of the meat
• Kjeldahl method does not determine the protein content in straightway manner; a conversion factor (F) is required to convert the nitrogen content to protein content
• Usually, a conversion factor of 6.25 (corresponding to 0.16 g nitrogen/g of protein) is used for several food samples

Coconut, cocoa (cacao), coffee, cashew, cardamom, black pepper, tea, rubber, oil palm and areca nut are the major plantation crops that are perennially grown along the coastal belt in southern States of the Country and to some extent in high rainfall zones of the northeastern States of India. These crops are also known as perennial crops. The life span of these crops varies from fifteen to sixty years or more depending upon the crop and its management. Coconut and cashew are also popularly known as the coastal trees. Cardamom and black pepper are also known as the spice crops. Once these plantation crops are well established, they mature for fruiting in three to eight years depending upon the nature of plantation crops and the crop management. The reproductive phase is seen round-the-year in case of coconut and cocoa. Cashew is one of the plantation crops with seasonality in fruiting from September to June. Cocoa is mostly grown as an intercrop in coconut gardens and in some pockets as a pure crop. Black pepper is trained to coconut and areca nut in many locations and seen as mono crop as well. All these crops are grown in laterite, sandy and alike in well drained soils. The hill slopes with terrace cultivation are also suitable for all the plantation crops. Tea, coffee and cardamom are seen on hillocks extending up to the base. Some of the plantation crops are seen in multitier cropping system as well as mixed/intercrops/homestead gardens. They are grown mostly under the rain fed and summer irrigation is beneficial for better harvest. The plantation crop distribution, production and productivity are influenced by air temperature, rainfall and the other meteorological variables viz. sunshine, cloud cover, solar radiation, vapour pressure, evapotranspiration, humidity and wind. Interestingly, coffee spread in Wayanad District while cardamom in Idukki District. Coffee experiences unimodel rainfall while bimodal in the case of cardamom.

Introduction
• The main objective of food preservation is to avoid food spoilage • So, the underlying principle behind all the meat preservation technique is providing adverse conditions for the growth and survival of the harmful microbials and such adverse conditions may be provided in the from of heat, cold, high level of salt, increasing acidity or removal of water/ oxygen
• Meat can be preserved by many techniques such as drying, heating, low temperature, curing, addition of chemicals or by application of irradiation and high pressure
• Addition of chemical i.e. chemical preservation which is accomplished by smoking is generally done after salting and pickling of meat
Physical changes in stored raw meat
1. Shrinkage
2. Sweating
3. Bloom loss

Introduction
Storage of fresh meat without microbiological degeneration at temperature more than freezing point of meat is known as ‘conditioning’ or ‘ageing’ and it is said to enhance tenderness and flavor of the meat Conditioning is also known as ageing or proteolysis of meat
• In the initial 24–36 h after the slaughter, glycolysis is the prevailing reaction going on during post-mortem
• The organization of the contractile proteins can only be conserved by the constant supply of ATP (energy source)
• But ATP supply becomes scarce with the passage of time after death and denaturation of the proteins starts
• Denaturation is a physical or intramolecular reorganization without involving hydrolysis of the bonds occurring between the various amino acids of the polypeptide proteins chains
• Denaturation is characterized by heightened reactivity of different chemical groups, a modification in molecules shape or size, reduced solubility and lost biological reactivity in cases of enzymes or hormones
• In the course of post-mortem conditioning, proteins are prone for denaturation due to lower pH than in-vivo, temperatures more than 25 °C or less than 0 °C, dehydration and higher non- hysiological salt levels
• Connective tissue proteins such as collagen and elastin do not undergo denaturation during conditioning

Post-mortem glycolysis (anaerobic glycolysis)
• Post-mortem glycolysis is the basic function of muscle
• Irreversible anaerobic glycolysis starts after the animal has died and oxygen supply to the muscles is cut
• The various biochemical steps that occur in living animals for the conversion of glycogen into lactic acid when the oxygen supply is insufficient, are basically similar in slaughtered animal also
• After slaughter, during anaerobic glycolysis in normal animals (not in the animals that are exhausted, excited or excessively exercised just prior to slaughter), the glycogen reserve of the muscle decreases appreciably resulting in the lactic acid production which will proceed to a pH level at which the enzymes involved in glycolysis become inactivated
• In classic mammalian muscles this pH will be near to 5.4–5.5 (called Ultimate pH)
• Muscle having almost 600 mg glycogen/100 g muscle at the time of slaughter will reach this pH
• A protein called glycogenin is responsible for starting the glycogenesis (glycogen synthesis) in muscle and it binds with eight glucose molecules to produce a glycosyl-protein (Fig. 12.1)
• Glycosyl-protein is used as primer by the enzyme proglycogen synthase and thus, proglycogen is formed
• This proglycogen is converted into bigger macromolecule by the macroglycogen synthase and its branching enzyme

Introduction
The genetic code and protein synthesis are fundamental processes that underlie the
expression of genetic information within all living organisms. These processes are integral
to understanding how DNA, the hereditary material, dictates the production of proteins,
which are essential molecules that carry out various functions in the body, from structural
support to catalyzing biochemical reactions.
Genetic Code
The genetic code consists of rules that guide the translation of information stored in
DNA or RNA sequences into proteins within living cells. It is nearly universal across
all organisms, underscoring the shared evolutionary origins of life. The genetic code is
composed of codons, which are sequences of three nucleotides in mRNA (messenger
RNA) that correspond to specific amino acids or stop signals during protein synthesis.
Each of the 20 amino acids used in protein synthesis is encoded by one or more codons.
For instance, the codon AUG not only codes for the amino acid methionine but also serves
as the start signal for translation, marking the beginning of a protein-coding sequence. The
redundancy of the genetic code, where multiple codons can specify the same amino acid,
provides a protective mechanism against mutations, as some changes in the nucleotide
sequence do not alter the resulting protein.
Protein Synthesis
Protein synthesis is the process by which cells construct proteins based on the instructions
encoded in mRNA. This process takes place in two primary stages: transcription and
translation.
Transcription: Transcription is the first step of gene expression, where a particular segment
of DNA is copied into RNA by the enzyme RNA polymerase. During transcription, one
of the two DNA strands serves as a template for the formation of a complementary RNA
strand, This newly synthesized RNA strand, known as pre-mRNA, undergoes further
processing, including splicing, capping, and addition of a poly-A tail, to become mature
mRNA, which is then exported from the nucleus to the cytoplasm in eukaryotic cells. In
contrast, in prokaryotes, both transcription and translation occur within the cytoplasm.

Constituents of meat
i. Water- 75%
ii. Protein- 19%
iii. Soluble and non-protein substances- 3.5%
iv. Fat- 2.5%
• The muscle fibre is important unit of muscular tissue consisting of
a) Myofibrils- formed protein structures embedded in sarcoplasmic fluid
b) Sarcoplasmic reticulum- a fine system of tubules
c) Sarcolemma- a very thin membrane surrounding the myofibrils and around the exterior side of this membrane, the connective tissue is found
• 19% of protein in the muscle is muscle fibre (Table 11.1)
• α-alanine, glycine, glutamic acid and histidine are the major free amino acids present in the fresh muscle

Introduction
Experimental physiology is a fundamental aspect of medical, veterinary and biological sciences that seeks to understand how living systems function through controlled experiments. It plays a crucial role in exploring the mechanisms behind normal and abnormal physiological processes. With roots in ancient medicine, experimental physiology was notably advanced by Claude Bernard in the 19th century, who introduced key concepts
like homeostasis and experimental methods that are still in use today. The interdisciplinary nature of this field connects it with disciplines such as biochemistry, pharmacology, and bioengineering, promoting a more comprehensive understanding of biological processes.
Investigating Physiological Processes
Experimental physiology aims to explore how organisms function at the cellular, molecular, organ, and systemic levels. This field investigates both normal physiology and the mechanisms behind diseases, offering insights into how organs and systems interact. Laboratory-based experiments are central to this learning process, allowing students and researchers to apply theoretical knowledge to practical scenarios. By observing how
tissues, organs, and entire systems respond to stimuli, experimental physiology enables the exploration of the relationship between structure and function in biological organisms. The practical experience gained in the lab is critical for medical and veterinary education, as theoretical knowledge alone is insufficient. In fields like physics and chemistry, materials can often be stored for future use. However, in biology, especially physiology, fresh
live tissue is often needed for fundamental experiments. For example, muscle and nerve tissues require careful handling and immediate use after isolation to study their responses to electrical stimuli. In in vivo experiments, live organisms are studied in their natural context, while in vitro studies use isolated cells, tissues, or organs to understand their behavior in a controlled environment.

Muscle structure
• All muscles are composed of muscle fibres which are the structural unit of muscles
• In turn, every single muscle fibre is made up of numerous smaller components called myofibrils
• Functional unit of myofibril is sarcomere
Connective tissues associated with muscle
• Whole muscle is surrounded by a sheath of connective tissue called epimysium
• Whole muscle is divided into muscle bundles by perimysium formed out of connective tissue septa originating from the interior surface of the epimysium separating the muscle fibres
• The perimysium contains the blood vessels and nerves

Fat
• Utmost significant slaughterhouse byproduct is fat obtained from intestines, kidneys, channel and other offals
• Edible ox fat is rendered and the obtained product is called premier jus (higher grade fat) which is differentiated into oleo oil and oleo stearin
• If all edible ox fat is rendered, it is called dripping and it used for human consumption
• Inedible fat is used for soap manufacturing
• The highest value fat from pig is recovered from peritoneal lining (leaf fat), and the subsequent highest value recovered from back fat, mesentery and omentum
• Sheep fat is separated into oleo oil and oleo stearin because of its strong flavour
• Mutton fat is harder and its stearin content is more than ox or pig and therefore, it is applied on the top of meat paste glass jar as a protective layer
Rendering of edible fat
Three principal procedure of rendering of edible fat are:
i. Wet rendering
ii. Dry rendering
iii. Continuous low-temperature rendering

Introduction
The renal system is primarily responsible for the filtration of waste products from blood plasma through urine production. The kidneys, along with the ureters, bladder, and urethra, are part of the urinary system responsible for removing waste products from blood and eliminating them in urine. They filter around 120 ml of blood plasma per minute and perform homeostatic roles such as regulating blood volume and pressure, pH and electrolyte
composition, stimulating erythropoiesis, and supporting vitamin D biosynthesis. Nephrons, with around 1-1.3 million per adult kidney, are primarily cortical, with 80-85% of them located in the renal cortex. The remaining 15-20% are called juxtamedullary nephrons. The kidneys remove nitrogenous compounds like urea, uric acid, and creatinine, as well as metabolic waste products, toxins, excess hormones, water, and electrolytes. Urine formation involves three main stages: glomerular filtration, tubular reabsorption, and secretion. The kidneys produce renal filtrate, which contains blood components that can be filtered out, and the body recovers 99% of the water and electrolytes from the filtrate. The renal corpuscle, comprising the Bowman’s capsule and glomerular capillaries, is responsible for filtration of blood plasma and producing renal filtrate. Its structural elements allow
for efficient filtration, with glomerular capillaries having a 100-fold greater permeability to water, small ions, and solutes. The glomerular capillaries also have increased pressure due to the smaller diameter of the efferent arteriole. The filtration membrane consists of endothelium, basement membrane, and podocytes. The proximal convoluted tubule in the kidneys plays a crucial role in reabsorption of water and electrolytes, including sodium,
chloride, potassium, calcium, and bicarbonate. It reabsorbs approximately 80% of filtered bicarbonate, with further reabsorption from the loop of Henle and distal convoluted tubule. This reabsorption regulates the body’s acid-base balance, contributing to the acidic nature of urine. The proximal convoluted tubule is the only region able to reabsorb glucose. The loop of Henle is a crucial region in the kidney, responsible for concentrating urine and facilitating water and electrolyte reabsorption. It regulates fluid volume, blood pressure, and acid-base balance through bicarbonate reabsorption. The loop consists of two main regions: the descending limb and the ascending limb.

Introduction
• Slaughtering of meat animals in way so as to effect minimum pain and suffering to animals is referred as humane slaughter
• Slaughtering method followed should inflict least stress and suffering to the animals
• There are acceptable and the unacceptable slaughtering methods and there is no ‘nice’ method to slaughter the food animals
• In advanced countries, common slaughtering method consists of two steps, stunning and bleeding
• Stunning is done to make animal unconscious and not to feel the pain during actual bleeding process which is followed next
• Exception of stunning-- Jewish and Muslim methods of slaughter
Stunning
Humane slaughter consists of stunning followed by sticking (bleeding). Stunning is the process of making the animal unconscious till it is slaughtered so that the pain suffered during actual act of slaughtering can be alleviated

Introduction
The skin, also known as the integumentary system, is the largest organ of the human body and protects animals from external factors. It consists of different tissues (epidermis, dermis, hypodermis, glands, hair and nails) and plays an important role in maintaining homeostasis, especially in regulating body temperature, protecting the body from damage and sensing the outside world. The skin consists of three main layers: epidermis, dermis and subcutaneous tissue; each has its own specific function. The epidermis is the outermost layer of keratinocytes that produce keratin as a protective layer. The dermis, beneath the epidermis, is rich in collagen and elastin, which give the skin strength and elasticity. The subcutaneous tissue beneath the dermis consists of fatty tissue and acts as an insulator for the body. Dermal fibroblasts are the primary cells that synthesize and maintain the skin’s extracellular matrix, contributing to its structural integrity and function. The integumentary system also plays an important role in regulating temperature, providing sensation, synthesizing biochemicals, absorbing nutrients, and protecting the body from various types of damage. In general, the integumentary system plays an important role in the body’s overall health and function by regulating body temperature, providing a sense of well-being, producing important biochemicals, absorbing nutrients, and protecting the body from external factors.

Post-mortem (PM) examination
The core objective of post-mortem examination is to identify and eradicate defects and contaminations and thus, confirming that only meat suitable for ingestion are allowed to be passed
Facilities for post-mortem inspection
• Normal infrastructure amenities which delivers comfortable working environment and assist in presenting the carcases and its offals for PM examination
• Every inspection place on the dressing over-head line must have lights of -- 540 lux (50 foot-candle) intensity light which does not alter the normal colours
• Adequate facility for sanitising the hands, equipments and aprons should be provided
• To sterilise the knives, cleavers and saws–a water bath operating at 82 ºC
• Head, viscera and carcase are the three major inspection parts
• On moving rails, viscera from a particular animal should move little ahead of its carcase so that any abnormality in viscera could be conveyed to the carcase examiner well in time
• For precise recognition of carcases and its correlated viscera from an animal, the lines conveying the carcases and viscera should move in synchronized way
• When a carcase is declared unfit for human consumption, all its the related parts such as head, viscera, blood and hide must be collected and disposed off
• Every inspection point must have a easily accessible overhead rail line stop button

Introduction
• Meat inspection involves proper veterinary examination of live food animals prior to slaughter (called ante-mortem examination), inspection of carcases and offals and pathological examinations where deemed fit
• Full ante-mortem inspection represents 50% of meat inspection
• Ante-mortem inspection is particularly useful for detecting scheduled or infectious diseases which are communicable to man e.g. anthrax, rabies and glanders
• Diseases where animals show nervous symptoms like tetanus, tuberculous meningitis, sturdy in sheep, lysteriosis, rabies, cysticosis etc. and where skin lesions are manifested such as food and mouth disease, swine fever etc. are easily detected during ante-mortem inspection which are difficult to be detected in post-mortem inspection
• Animals must undergo veterinary ante-mortem inspection on the day of their arrival at the slaughterhouse or before the beginning of daily slaughtering
The inspection must determine
1. Whether the animals are suffering from a disease which is communicableto man and to animals or whether they show symptoms
2. Whether they show symptoms of disease or of a disorder of their general condition which is likely to make their meat unfit for human consumption-- any medicine/substances
3. Whether they are tired, agitated or injured
4. Whether they are sufficiently clean to enter the normal slaughter protocol
• For public health purposes, the veterinarian must separate normal animals from those which may be suffering from a potentially zoonotic disease or present a hygiene risk to the slaughter hall environment owing to the soiled condition of their hide/fleece

Introduction
Respiratory diseases are a common clinical issue in dogs, particularly in those housed in environments like pet shops, shelters, breeding and boarding kennels. Puppies and senior dogs are at a higher risk of developing respiratory infections compared to adult dogs. The respiratory system is one of the body’s four major systems, comprising the upper airways (pharynx, larynx, and trachea and the lower airways (bronchi, bronchioles, and
alveoli). The pharynx, which serves as a common passageway for both the respiratory and gastrointestinal systems, explains the relatively high incidence of aspiration pneumonia. The luminal diameter of the pharynx is the widest, followed by the larynx and trachea.
The ratio of tracheal diameter to thoracic inlet height (TD:TI) remains relatively constant, regardless of the animal’s size or respiratory phase. The respiratory tract is typically protected from harmful pathogens by physical, chemical, and immunologicbarriers, including mucus, mucociliary clearance, innate antimicrobial factors, alveolar macrophages, and the pulmonary immune response. The entire respiratory tree is lined with ciliated epithelial cells, except for the bronchioles, which are lined by non-ciliated granular secretory cells known as club cells. The respiratory system’s primary function is achieved through four major processes: pulmonary ventilation; diffusion of oxygen and carbon dioxide between the alveoli and the blood; transport of these gases in the blood and body fluids to and from the body’s tissue cells; and regulation of ventilation and other respiratory factors. The pulmonary alveoli, the main sites for gas exchange between air and blood, are highly vulnerable to injury if the body’s defense mechanisms are compromised, underscoring the importance of prompt emergency treatment for respiratory diseases

Introduction: Relation between transportation and meat quality
One of the fundamental aims of animal production system is to ensure better quality meat. Apart from various animal husbandry practices that affect the meat quality, the transportation of meat animals from farm to slaughterhouse and their handling at lairage, affect the meat quality greatly. For better meat quality, the pH of the meat should fall from normal pH 7.0 - 7.2 in live animal to pH 5.5 (ultimate pH) after slaughter at the onset of rigor-mortis. The low muscle pH is required to inhibit the microbial growth and meat tenderization (cathepsins system is activated at low pH). The ultimate muscle pH is achieved through the accumulation of lactic acid which is produced as a result of anaerobic glycolysis of glycogen. After slaughter, as the oxygen supply to muscle ceases, ATP is generated through anaerobic glycolysis of glycogen and in this process lactic acid is produced. ATP is required to keep the muscle in relaxed stage. This anaerobic glycolysis carries on till the glycogen reserve is exhausted. So, higher the glycogen reserve at the time of slaughter, longer the length of time duration of anaerobic glycolysis and higher the quantity of lactic acid production and greater the reduction of muscle pH. Hence, livestock should be transported and handled before slaughter carefully because stress during transit and in lairage could severely deplete the glycogen reserve of livestock.
The following facts should be especially taken care by the farmers raising livestocks for meat
1. Housing arrangement and design
• Any flaws/deficiencies in design, layout, cubicle size and its design, drainage, water bowls, slats, air circulation, etc. should be rectified

Introduction
The testicle is a unique and important reproductive organ that serves two main purposes. The primary purpose is the development of mature spermatozoa that are able to fertilise the egg.The production of hormones, which plays a role in ensuring that mature spermatozoa are delivered to mature eggs where fertilisation may take place, must be considered a supplemental function to the development of germ cells. The induction of behavioristic
reactions—also referred to as sex drive or mating instincts—and the provision of a means of transportation for spermatozoa, as well as the regulation of ejaculate—either its release into the aquatic medium surrounding the egg in the case of lower vertebrates or its introduction into female passages through an organ of intromission—are the two concrete necessities involved. The animal loses its ability to reproduce as long as either the production of germ cells or the propensity to mate is impaired, even though the two processes undoubtedly work in tandem to achieve the end result.

Facilities required for buffalo, sheep and goat slaughterhouses
1. Lairage
2. Large enough slaughterhouse area-
• Separate area for pig slaughtering
• Slaughter line and area for operations such as singeing, depilation, scraping should be demarcated by a high wall of at least 3 m high or by an open space of 5 m width
3. For stomachs and intestines emptying and cleaning, there should be one dedicated room
4. Separate rooms for handling guts and tripe
5. Fat and hides, hooves and horns should be stored in separate rooms
6. Accommodation for sick or suspected animals; detained meat or seized meat
7. Chilling/refrigeration room
8. Room for veterinary services
9. Provisions for lavatories, wash basins, changing rooms, and showers
10. Facilities for veterinary inspection
11. Entry and exit of slaughterhouse should have control mechanism
12. Separation of clean and unclean area
13. Waterproof flooring of room where meat is processed
14. Provision for steam exhaustion and sufficient ventilation
15. Sufficient artificial or natural lighting
16. Adequate potable water supply
17. Adequate hot potable water supply
18. Effluent treatment plant (ETP)

Introduction
The haematological system, essential for sustaining life and comprising blood and its components, is fundamental to human and animal physiology. Blood is a unique connective tissue that performs several critical functions, including transporting oxygen, nutrients, and hormones to cells and removing metabolic wastes. It also plays a pivotal role in immune response, haemostasis, and the regulation of body temperature and pH. This
section provides an in-depth overview of the clinical physiology of the haematological system, covering the composition of blood, haematopoiesis, haemostasis, and common haematological disorders. Blood is composed of two main elements: plasma and blood cells. Plasma, the liquid component, constitutes approximately 55% of blood volume and consists predominantly of water, electrolytes, proteins, waste products, and dissolved gases. Plasma is the medium for transporting nutrients, gases, hormones, and waste products throughout the body. It contains important proteins such as albumin, which maintains osmotic pressure; globulins, which are involved in immune responses; and fibrinogen, which is crucial for blood clotting. The blood cells include erythrocytes (red blood cells), leukocytes (white blood cells), and platelets. Erythrocytes are the most abundant cells in the blood, with the primary function of transporting oxygen from the lungs to tissues and carbon dioxide from tissues back to the lungs. This is facilitated by haemoglobin, an iron-containing protein within erythrocytes that binds to oxygen. The lifespan of an erythrocyte is approximately 120 days, after which it is phagocytosed by macrophages, which are a type of myeloid phagocytic cells in the spleen and liver. Leukocytes are integral to the immune system, protecting the body against infections and foreign pathogens. They are categorized into granulocytes (neutrophils, eosinophils, and basophils) and agranulocytes (lymphocytes and monocytes).