There are many different kinds of animals in the world
There are many different kinds of animals in the world. About 95% of them are invertebrate, that is to say they do not have internal skeletons with backbones. Many invertebrates have shells, others have external skeletons. So these invertebrates are soft inside and hard outside. Invertebrates include insects, which make 80 per cent of all the animals in the world. We know of about one million different kinds of insects, and scientists think there may be the same number still waiting to be discovered. About 5 per cent of the world's animals are vertebrates. Vertebrates are soft outside and hard inside. They have internal skeletons with backbones. The main groups of vertebrates are fish, amphibians, reptiles, birds and mammals. Fish, which live in water, are the largest group. Examples of two kinds of fish are trout and sharks. But not all vertebrates that live in water are fish. Whales, for instance, are mammals, although they look very like fish. Amphibians live between land and water. A frog is a typical amphibian. Reptiles, for example snake, are cold-blooded animals, which live on land. For a hundred and sixty million years large reptiles, dinosaurs, were the most animals on the earth. Birds are like reptiles in many ways but they are warmblooded. They are the only vertebrates, which can fly, except for bats. Although they look rather like birds, bats are actually mammals. There are big differences between different kinds of birds. Compare an eagle with a duck, for example. Mammals are warm-blooded like birds, but unlike birds, mammals do not lay eggs; they grow their babies inside them, and when the babies are born, their mothers feed them on milk.
ANIMAL MAGIC
A kind of treatment designed to stimulate people who are withdrawn or uncommunicative has recently been given a new name: pet therapy. It has given difficult children, lonely old people and even anti- social prisoners a completely new outlook on life.
Even though pet therapy is only now being widely used, it is not a new idea. In the 18th century an English doctor William Tuke filled the ground of a hospital for mentally disturbed people with chickens, rabbits and goats. Tuke’s idea was that patients could learn self- control by caring for creatures weaker than themselves.
Later on, in New York, horses, cows, cats and dogs were recruited to heal soldiers who had been wounded during World War II. These animals comforted the traumatized helped them to avoid becoming obsessed with their injuries.
During the 1970’s, scientific interest was rekindled by a study that had originally set out to examine the connection between social conditions and heart disease. Quite by chance, researchers discovered that the survival rate of people who owned a pet was significantly greater than those who didn’t. At last, they cawe to the conclusion that people with pets really were living longer.
It was discovered that stroking a cat or dog lowers a human being’s blood pressure and reduces anxiety. Just having an animal around you can lower your heart rate. Cats and dogs aren’t the only pets that can help you to relax either. A dental schools in America has discovered that gazing at fish in a tank helps patients relax before undergoing dental treatment.
But what aspect dental of the animal- human relationship is the cause of such benefits? One recent study revealed that there were significantly fewer minor illnesses such as colds, backaches and stomach problems among adults after they had acquired a pet. There is no real explanation, however, for way animals can change people in various ways.
Animal ecology
The word ecology originates from the Greek language and means "the study of the place to live". In general, ecology as a branch of biology deals with the relationships between living organisms and their environment. Animal ecology began to develop rapidly as an applied area of ecology only in the middle of the 20th century. Animal ecology concerns the study of population dynamics, distribution, behavior, and the interrelations of animals and their environment. In the beginning, animal ecology developed separately from plant physiology. However, animals depend upon plants for food and shelter, so it is impossible to understand animal ecology without plant ecology. This is particularly true in such applied areas of ecology as farm animal ecology as well as ecology of wildlife. Modern ecology considers interrelationship of both plant and animal communities as a whole biotic unit.
Ecology is mainly based on the ecosystem concept which is applied to units of various sizes such as a pond, a field, a pasture, a forest or a large ecoregion. When an ecologist is going to analyze any ecosystem, he will study the living organisms which inhabit this specific area, the physical environment, and all interrelations in this particular unit of space. The term "environment" includes both physical surroundings and biotic communities. The former means a large variety of local abiotic (nonliving) factors like temperature, sunlight, minerals, soil, and water. Different plants and other organisms that share the organism habitat are, known as biotic communities. In farm animal ecology, the emphasis is
Nevertheless, livestock and poultry farmers claim that if the animals are under any stressful conditions, they will show sharp decreases in productivity, but milk yields and egg production are maintained at high levels on commercial farms. Since the 1970s, the behavioral adaptation of animals to their surroundings and the effects of environmental stress on the immune status of livestock and poultry have been studied thoroughly by ecologists.
Milk processing
Milk is known to be highly nutritious, versatile food that has been used by humans since the beginning of recorded time. People enjoy drinking milk in its natural form and also use it to make a wide range of food products, including cream, butter, yoghurt, cheese, and ice cream.
Humans drink the milk produced from a variety of domesticated mammals including cows, goats, sheep, camels, reindeer, buffaloes, and llama. Cow milk is the main type of milk used for commercial production and consumption throughout the world. However, the goat is believed to be an important milk produced in China, India, and other Asian countries and in Egypt. Although goat’s milk is also produced in Europe and North America but, compared to cow’s milk, goat’s milk is relatively unimportant. Dairymen know buffalo’s milk to be produced in commercial quantities in some countries, particularly India. In general, whether the milk is obtained from a cow or other species, the technology to be used for its processing will be the same.
It is interesting that the milk of all species contain the same nutrients, varying only in proportions. Although milk is a liquid composing of 80 to 90 per cent water and most often considered to be a drink, it contains between 12 and 13 per cent total solids and perhaps should be regarded as a food. The solid part of milk consists of an abundance of the major nutrients needed by the body for good health, including fats, carbohydrates, proteins, minerals, and vitamins.
Cow milk has been found to contain about 3,5 to 5 per cent fat, which is dispersed throughout the milk in globules. In addition to providing milk’s characteristic taste and texture, fat supplies vitamins A, D, E, and K, as well as certain fatty acids that the body cannot produce on its own. Scientists consider sweet taste of milk to be due to lactose, a kind of sugar found only in milk. Making up about 5 per cent of milk’s content, lactose is a carbohydrate that is broken down by the body to supply energy. The most important protein in milk is casein, accounting for 80 per cent of milk protein. Casein is known to be a complete protein, which means that it contains all the essential amino acids. Casein molecules and globules of fat deflect light rays passing through milk, giving milk its opalescent appearance. Other proteins present in milk include albumin and globulin.
Meat processing
“Meat” is the common term applied to describe the fresh and the edible portion of domestic mammals such as cattle, calves, sheep, lambs, and swine. One should know of processed or manufactured products prepared from animal tissues being also referred to meat. Forever, the term “meat” can be applied to the edible portion of poultry and wild birds and mammals and to the portions of other animals such as crustaceans and reptiles that are eaten by humans.
Meat consists of skeletal muscle, with varying amounts of fat and connective tissue, but internal organs are also used. Known as variety meat, these include the liver, kidneys, thymus gland and pancreas (also known as sweetbreads), brain, heart, and stomach.
Meat is considered to be a nutritious food. Regardless of the animal, lean muscle usually consists of approximately 21 per cent protein, 73 per cent water, 5 per cent fat, and 1 per cent ash (the mineral component of muscle). Having changed feeding or fattening systems, it is possible to influence the percentage of the main nutrients in meats. Containing quantities of essential amino acids in the form of protein, meat is valued as a complete protein food. The fat of meat, which varies widely with the species, quality, and cut, is a valuable source of energy and also influences the flavor, juiciness, and tenderness of the lean. Generally, as fat increases, the percentages of protein and water decrease. Meat also contains B group vitamins (especially niacin and riboflavin), iron, phosphorus, ash, and calcium. Such parts as liver, kidney, and heart have been found to be especially rich in vitamins and minerals, for example liver contains vitamins A and D.
Having been consumed, meat digests somewhat slowly, but 95 per cent of meat protein and 96 per cent of the fat are digested. Fats tend to retard the digestion of other foods. Thus, the higher the proportion of fat, the longer meat remains in the stomach, delaying hunger and giving “staying power”. Extractives in meat cause a flow of saliva and gastric juice, creating the desire to eat and ensuring ease of digestion.