An economy consists of the realized economic system of a country or other area, the labor, capital and land resources, and the economic agents that socially participate in the production, exchange, distribution, and consumption of goods and services of that area. A given economy is the end result of a process that involves its technological evolution, history and social organization, as well as its geography, natural resource endowment, and ecology, as main factors. These factors give context, content, and set the conditions and parameters in which an economy functions.


In most birds, reptiles, insects, and fish, an egg (Latin, ovum) is the zygote, resulting from fertilization of the ovum. To enable incubation the egg is usually kept within a favourable temperature range as it nourishes and protects the growing embryo. When the embryo is adequately developed it breaks out of the egg in the process of hatching. Some embryos have a temporary egg tooth with which to crack, pip, or break the eggshell or covering.

Oviparous animals are animals that lay eggs, with little or no other development within the mother. The study or collecting of eggs, particularly bird eggs, is called oology.

Reptile eggs, bird eggs, and monotreme eggs, which are laid out of water, are surrounded by a protective shell, either flexible or inflexible. The special membranes that support these eggs are traits of all amniotes, including mammals.

The 1.5 kg ostrich egg is the largest egg currently known. The Bee Hummingbird produces the smallest known bird egg, which weighs half of a gram.


Fertilizers are soil amendments applied to promote plant growth; the main nutrients present in fertilizer are nitrogen, phosphorus, and potassium (the ‘macronutrients’) and other nutrients (‘micronutrients’) are added in smaller amounts. Fertilizers are usually directly applied to soil, and also sprayed on leaves (‘foliar feeding’).

Fertilizers are roughly broken up between organic and inorganic fertilizer, with the main difference between the two being sourcing, and not necessarily differences in nutrient content.

Organic fertilizers and some mined inorganic fertilizers have been used for centuries, whereas chemically-synthesized inorganic fertilizers were only widely developed during the industrial revolution. Increased understanding and use of fertilizers were important parts of the pre-industrial British Agricultural Revolution and the industrial green revolution of the 20th century.


The domestic goat (Capra aegagrus hircus) is a subspecies of goat domesticated from the wild goat of southwest Asia and Eastern Europe. The goat is a member of the Bovidae family and is closely related to the sheep: both are in the goat-antelope subfamily Caprinae. There are over three hundred distinct breeds of goat.

Goats are one of the oldest domesticated species. Goats have been used for their milk, meat, hair, and skins over much of the world. In the twentieth century they also gained in popularity as pets.

Female goats are referred to as does or nannies, intact males as bucks or billies; their offspring are kids. Note that many goat breeders prefer the terms “buck” and “doe” to “billy” and “nanny”. Castrated males are wethers. Goat meat from younger animals is called kid or cabrito, and from older animals is sometimes called chevon, or in some areas “mutton”.


The horse (Equus ferus caballus) is a hooved (ungulate) mammal, a subspecies of the family Equidae. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature into the large, single-toed animal of today. Humans began to domesticate horses around 4000 BCE, and their domestication is believed to have been widespread by 3000 BCE. Although most horses today are domesticated, there are still endangered populations of the Przewalski’s Horse, the only remaining true wild horse, as well as more common populations of feral horses which live in the wild but are descended from domesticated ancestors. There is an extensive, specialized vocabulary used to describe equine-related concepts, covering everything from anatomy to life stages, size, colors, markings, breeds, locomotion, and behavior.

Horses’ anatomy enables them to make use of speed to escape predators and they have a well-developed sense of balance and a strong fight-or-flight instinct. Related to this need to flee from predators in the wild is an unusual trait: horses are able to sleep both standing up and lying down. Female horses, called mares, carry their young for approximately 11 months, and a young horse, called a foal, can stand and run shortly following birth. Most domesticated horses begin training under saddle or in harness between the ages of two and four. They reach full adult development by age five, and have an average lifespan of between 25 and 30 years.

Horse breeds are loosely divided into three categories based on general temperament: spirited “hot bloods” with speed and endurance; “cold bloods”, such as draft horses and some ponies, suitable for slow, heavy work; and “warmbloods”, developed from crosses between hot bloods and cold bloods, often focusing on creating breeds for specific riding purposes, particularly in Europe. There are over 300 breeds of horses in the world today, developed for many different uses.

Horses and humans interact in a wide variety of sport competitions and non-competitive recreational pursuits, as well as in working activities such as police work, agriculture, entertainment, and therapy. Horses were historically used in warfare, from which a wide variety of riding and driving techniques developed, using many different styles of equipment and methods of control. Many products are derived from horses, including meat, milk, hide, hair, bone, and pharmaceuticals extracted from the urine of pregnant mares. Humans provide domesticated horses with food, water and shelter, as well as attention from specialists such as veterinarians and farriers.


Husk (or hull) in botany is the outer shell or coating of a seed. It usually refers to the leafy outer covering of an ear of maize (corn) as it grows on the plant. Literally, a husk or hull includes the protective outer covering of a seed, fruit or vegetable. It can also refer to the exuvia of bugs or small animals left behind after moulting.


Iodine is a chemical element that has the symbol I and the atomic number 53.

Chemically, iodine is the second least reactive of the halogens, and the second most electropositive halogen, trailing behind astatine in both of these categories. However, the element does not occur in the free state in nature. As with all other halogens (members of Group 17 in the periodic table), when freed from its compounds iodine forms diatomic molecules (I2).


A mare is an adult female horse or other equine.

Most of the time, a mare is a female horse over the age of three, and a filly is a female horse age three and younger. However, in Thoroughbred horse racing, a mare is defined as a female horse more than four years old; in harness racing a mare is a female horse more than three years old. The word can also be used for other female equine animals, particularly mules and zebras, though a female donkey is usually called a “jenny.” A broodmare is a mare used for breeding. A horse’s female parent is known as its dam.

An adult male horse is called a stallion, or, if castrated, a gelding. Occasionally the term “horse” is used in a restrictive sense to designate only a male horse.