Shoaling and schooling
In biology, any group of fish that stay together for social reasons are shoaling, if the group is swimming in the same direction in a coordinated manner, they are schooling. In common usage, the terms are sometimes used rather loosely. About one quarter of fish species shoal all their lives, about one half shoal for part of their lives. Fish derive many benefits from shoaling behaviour including defence against predators, enhanced foraging success, higher success in finding a mate, it is likely that fish benefit from shoal membership through increased hydrodynamic efficiency. Fish use many traits to choose shoalmates, they prefer larger shoals, shoalmates of their own species, shoalmates similar in size and appearance to themselves, healthy fish, kin. The "oddity effect" posits that any shoal member that stands out in appearance will be preferentially targeted by predators; this may explain. The oddity effect thus tends to homogenize shoals. An aggregation of fish is the general term for any collection of fish that have gathered together in some locality.
Fish aggregations can be unstructured. An unstructured aggregation might be a group of mixed species and sizes that have gathered randomly near some local resource, such as food or nesting sites. If, in addition, the aggregation comes together in an interactive, social way, they may be said to be shoaling. Although shoaling fish can relate to each other in a loose way, with each fish swimming and foraging somewhat independently, they are nonetheless aware of the other members of the group as shown by the way they adjust behaviour such as swimming, so as to remain close to the other fish in the group. Shoaling groups can include mixed-species subgroups. If the shoal becomes more organised, with the fish synchronising their swimming so they all move at the same speed and in the same direction the fish may be said to be schooling. Schooling fish are of the same species and the same age/size. Fish schools move with the individual members spaced from each other; the schools undertake complicated manoeuvres.
The intricacies of schooling are far from understood the swimming and feeding energetics. Many hypotheses to explain the function of schooling have been suggested, such as better orientation, synchronized hunting, predator confusion and reduced risk of being found. Schooling has disadvantages, such as excretion buildup in the breathing media and oxygen and food depletion; the way the fish array in the school gives energy saving advantages, though this is controversial. Fish can be facultative shoalers. Obligate shoalers, such as tunas and anchovy, spend all of their time shoaling or schooling, become agitated if separated from the group. Facultative shoalers, such as Atlantic cod and some carangids, shoal only some of the time for reproductive purposes. Shoaling fish can shift into a disciplined and coordinated school shift back to an amorphous shoal within seconds; such shifts are triggered by changes of activity from feeding, travelling or avoiding predators. When schooling fish stop to feed, they become shoals.
Shoals are more vulnerable to predator attack. The shape a shoal or school takes what the fish are doing. Schools that are travelling can form squares or ovals or amoeboid shapes. Fast moving schools form a wedge shape, while shoals that are feeding tend to become circular. Forage fish are small fish. Predators include other larger fish and marine mammals. Typical ocean forage fish are small, filter-feeding fish such as herring and menhaden. Forage fish compensate for their small size by forming schools; some swim in synchronised grids with their mouths open so they can efficiently filter feed on plankton. These schools can become huge, migrating across open oceans; the shoals are concentrated food resources for the great marine predators. These sometimes immense gatherings fuel the ocean food web. Most forage fish are pelagic fish, which means they form their schools in open water, not on or near the bottom. Forage fish are short-lived, go unnoticed by humans; the predators are keenly focused on the shoals, acutely aware of their numbers and whereabouts, make migrations themselves in schools of their own, that can span thousands of miles to connect with, or stay connected with them.
Herring are among the more spectacular schooling fish. They aggregate together in huge numbers; the largest schools are formed during migrations by merging with smaller schools. "Chains" of schools one hundred kilometres long have been observed of mullet migrating in the Caspian Sea. Radakov estimated herring schools in the North Atlantic can occupy up to 4.8 cubic kilometres with fish densities between 0.5 and 1.0 fish/cubic metre, totalling about three billion fish in a single school. These schools move along traverse the open oceans. Herring schools in general have precise arrangements which allow the school to maintain constant cruising speeds. Herrings have excellent hearing, their schools react rapidly to a predator; the herrings keep a certain distance from a moving scuba diver or a cruising predator like a killer whale, forming a vacuole which looks like a doughnut from a spotter plane. Many species of large predatory fish also
Trifolium repens, the white clover, is a herbaceous perennial plant in the bean family Fabaceae. It is native to Europe, including the British Isles, central Asia and is one of the most cultivated types of clover, it has been introduced worldwide as a forage crop, is now common in most grassy areas of North America and New Zealand. The species includes varieties classed as small and large, according to height, which reflects petiole length; the term “white clover” is applied to the species in general, “Dutch clover” is applied to intermediate varieties, “ladino clover” is applied to large varieties. The genus name, derives from the Latin tres, "three", folium, "leaf", so called from the characteristic form of the leaf, which but not always has three leaflets; the species name, repens, is Latin for "creeping". It is a perennial plant, it is low growing, with heads of whitish flowers with a tinge of pink or cream that may come on with the aging of the plant. The heads are 1.5–2 centimetres wide, are at the end of 7-cm peduncles or inflorescence stalks.
The flowers are visited by bumblebees and by honey bees. The leaves are trifoliolate, elliptic to egg-shaped and long-petioled and with light or dark markings; the stems function as stolons, so white clover forms mats, with the stems creeping as much as 18 cm a year, rooting at the nodes. The leaves form the symbol known as shamrock. Always, a white clover will be trifoliolate. However, one can, but only possess four leaflets. Trifolium repens subsp. Macrorrhizum Ponert Trifolium repens var. nevadense C. Vicioso Trifolium repens var. ochranthum K. Maly Trifolium repens var. orbelicum Fritsch Trifolium repens var. orphanideum Boiss. Trifolium repens subsp. Prostratum Nyman It is native in Europe and Central Asia, ubiquitous throughout the British Isles, introduced in North America, New Zealand and elsewhere, globally cultivated as a forage crop. Trifolium repens is a tetraploid with two diploid ancestors. In order to increase genetic diversity for breeding, research is focused on finding these ancestors.
Proposed ancestors of Trifolium repens include Trifolium nigrescens, Trifolium occidentale, Trifolium pallescens, Trifolium uniflorum. Additionally, it is possible that one of the diploid ancestors has yet to be analyzed, either because it has not been discovered or is extinct. White clover has been described as the most important forage legume of the temperate zones. Symbiotic nitrogen fixation in root nodules of white clover obviates synthetic nitrogen fertilizer use for maintaining productivity on much temperate zone pasture land. White clover is grown in mixtures with forage grasses, e.g. perennial ryegrass. Such mixtures can not only optimize livestock production, but can reduce the bloat risk to livestock that can be associated with excessive white clover in pastures; such species mixtures tend to avoid issues that could otherwise be associated with cyanogenic glycoside intake on pure or nearly pure stands of some white clover varieties. However, problems do not arise with grazing on monocultures of white clover, superior ruminant production is sometimes achieved on white clover monocultures managed to optimize sward height.
Formononetin and biochanin A play a role in arbuscular mycorrhiza formation on white clover roots, foliar disease can stimulate production of estrogenic coumestans in white clover. However, while there have been a few reports of phytoestrogenic effects of white clover on grazing ruminants, these have been far less common than such reports regarding some varieties of subterranean and red clover. Among forage plants, some white clover varieties tend to be favored by rather close grazing, because of their stoloniferous habit, which can contribute to competitive advantage. White clover grows well as a companion plant among lawns, grain crops, pasture grasses, vegetable rows, it is added to lawn seed mixes, as it is able to grow and provide green cover in poorer soils where turfgrasses do not perform well. White clover can tolerate close mowing and grazing, it can grow on many different types and pHs of soil; as a leguminous and hardy plant, it is considered to be a beneficial component of natural or organic pasture management and lawn care due to its ability to fix nitrogen and out-compete weeds.
Natural nitrogen fixing reduces leaching from the soil and by maintaining soil health can reduce the incidence of some lawn diseases that are enhanced by the availability of synthetic fertilizer. For these reasons, it is used as a green manure and cover crop. Besides making an excellent forage crop for livestock, its leaves and flowers are a valuable survival food: they are high in proteins, are widespread and abundant; the fresh plants have been used for centuries as additives to salads and other meals consisting of leafy vegetables. They are not easy for humans to digest raw, but this is fixed by boiling the harvested plants for 5–10 minutes. Dried white clover flowers may be smoked as an herbal alternative to tobacco. In India, T. repens is considered a folk medicine against intestinal helminthic worms, an experimental in-vivo study validated that the aerial shoots of T. repens bear significant
Timothy-grass is an abundant perennial grass native to most of Europe except for the Mediterranean region. It is known as timothy, meadow cat's-tail or common cat's tail, it is a member of the genus Phleum, consisting of about 15 species of perennial grasses. It is named after Timothy Hanson, an American farmer and agriculturalist said to have introduced it from New England to the southern states in the early 18th century. Upon his recommendation it became a major source of hay and cattle fodder to British farmers in the mid-18th century. Timothy-grass can be confused with purple-stem cat's - tail, it grows to 48 -- 150 cm 1.3 centimetres broad. The leaves are hairless, rolled rather than folded, the lower sheaths turn dark brown, it has no stolons or rhizomes, no auricles. The flowerhead is 70–152 mm long and 6.4–12.7 mm broad, with densely packed spikelets. It flowers from June until September; the stamen are pink. The ligule is blunt, it grows well in heavy soil, is noted for its resistance to cold and drought, thus ability to grow in dry upland or poor sandy soils.
In pasture it tends to be overwhelmed by more competitive grasses. After cutting it grows slowly. There are two subspecies: Phleum pratense subsp. Pratense. Larger, to 59 inches tall. Widespread. Phleum pratense subsp. Bertolonii. Smaller, to 27 1⁄2 inches tall. Calcareous grassland. Timothy-grass was unintentionally introduced to North America by early settlers, was first described in 1711 by John Hurd from plants growing in New Hampshire. Hurd named the grass "hurd grass" but a farmer named Timothy Hanson began to promote cultivation of it as a hay about 1720, the grass has been known by its present name since then. Timothy has now become naturalized throughout most of the Canada, it is grown for cattle feed and, in particular, as hay for horses. It is high in fibre when cut late, it is considered a coarse grass little relished by livestock if cut earlier. It provides quality nutrition for horses. Timothy hay is a staple food for domestic pet rabbits, guinea pigs and degus making up the bulk of their diet.
Timothy hay is rich in long fibre and its abrasive texture helps to grind down the teeth, keeping both the teeth and jaw in good order. The caterpillars of some Lepidoptera use it as a food plant, e.g. the Essex skipper and the marbled white. It grows in roadsides and abandoned fields but requires nutrient-rich soils, its pollen is a common allergen. Plants persist through the winter. Dead, straw-colored flowering stems may persist, but only for a short time, are recognized by the distinctive spike-like inflorescence, it is confused with meadow foxtail. Timothy flowers from June until August, whereas meadow foxtail flowers from April until June; the spikelets of timothy are twin hornlike projections arranged in cylindrical panicles, whereas foxtail has a soft, single awn. Purple-stem cat's - tail grows on chalk downland. Mountain timothy grows above 6,000 feet. A "wild Timothy" was found to grow in Yosemite at the time of its discovery but may have been a foxtail. Timothy canary grass, another species with a similar cylindrical panicle, is toxic to livestock.
Flora Europaea: Phleum pratense Timothy - US Department of Agriculture
Livestock is defined as domesticated animals raised in an agricultural setting to produce labor and commodities such as meat, milk, fur and wool. The term is sometimes used to refer to those that are bred for consumption, while other times it refers only to farmed ruminants, such as cattle and goats. Horses are considered livestock in the United States; the USDA uses livestock to some uses of the term “red meat”, in which it refers to all the mammal animals kept in this setting to be used as commodities. The USDA mentions pork, veal and lamb are all classified as livestock and all livestock is considered to be red meats. Poultry and fish are not included in the category; the breeding and slaughter of livestock, known as animal husbandry, is a component of modern agriculture, practiced in many cultures since humanity's transition to farming from hunter-gatherer lifestyles. Animal husbandry practices have varied across cultures and time periods. Livestock were not confined by fences or enclosures, but these practices have shifted to intensive animal farming, sometimes referred to as "factory farming".
Now, over 99% of livestock are raised on factory farms. These practices increase yield of the various commercial outputs, but have led to negative impacts on animal welfare and the environment. Livestock production continues to play a major economic and cultural role in numerous rural communities. Livestock as a word was first used between 1650 and 1660, as a merger between the words "live" and "stock". In some periods, "cattle" and "livestock" have been used interchangeably. Today, the modern meaning of cattle is domesticated bovines. United States federal legislation defines the term to make specified agricultural commodities eligible or ineligible for a program or activity. For example, the Livestock Mandatory Reporting Act of 1999 defines livestock only as cattle and sheep, while the 1988 disaster assistance legislation defined the term as "cattle, goats, poultry, equine animals used for food or in the production of food, fish used for food, other animals designated by the Secretary."Deadstock is defined in contradistinction to livestock as "animals that have died before slaughter, sometimes from illness".
It is illegal in many countries, such as Canada, to sell or process meat from dead animals for human consumption. Animal-rearing originated during the cultural transition to settled farming communities from hunter-gatherer lifestyles. Animals are domesticated when their living conditions are controlled by humans. Over time, the collective behaviour and physiology of livestock have changed radically. Many modern farm animals are unsuited to life in the wild; the dog was domesticated early. Goats and sheep were domesticated in multiple events sometime between 11,000 and 5,000 years ago in Southwest Asia. Pigs were domesticated by 8,500 BC in the Near 6,000 BC in China. Domestication of the horse dates to around 4000 BC. Cattle have been domesticated since 10,500 years ago. Chickens and other poultry may have been domesticated around 7000 BC; the term "livestock" is may be defined narrowly or broadly. Broadly, livestock refers to any breed or population of animal kept by humans for a useful, commercial purpose.
This can mean semidomestic animals, or captive wild animals. Semidomesticated refers to animals which are only domesticated or of disputed status; these populations may be in the process of domestication. Traditionally, animal husbandry was part of the subsistence farmer's way of life, producing not only the food needed by the family but the fuel, clothing and draught power. Killing the animal for food was a secondary consideration, wherever possible its products, such as wool, eggs and blood were harvested while the animal was still alive. In the traditional system of transhumance and livestock moved seasonally between fixed summer and winter pastures. Animals can be kept intensively. Extensive systems involve animals roaming at will, or under the supervision of a herdsman for their protection from predators. Ranching in the Western United States involves large herds of cattle grazing over public and private lands. Similar cattle stations are found in South America and other places with large areas of land and low rainfall.
Ranching systems have been used for sheep, ostrich, emu and alpaca. In the uplands of the United Kingdom, sheep are turned out on the fells in spring and graze the abundant mountain grasses untended, being brought to lower altitudes late in the year, with supplementary feeding being provided in winter. In rural locations and poultry can obtain much of their nutrition from scavenging, in African communities, hens may live for months without being fed, still produce one or two eggs a week. At the other extreme, in the more developed parts of the world, animals are intensively managed. In between these two extremes are semi-intensive family run farms where livestock graze outside for much of the year, silage or hay is made to cove
Fodder, a type of animal feed, is any agricultural foodstuff used to feed domesticated livestock, such as cattle, sheep, horses and pigs. "Fodder" refers to food given to the animals, rather than that which they forage for themselves. Fodder is called provender and includes hay, silage and pelleted feeds and mixed rations, sprouted grains and legumes. Most animal feed is from plants, but some manufacturers add ingredients to processed feeds that are of animal origin; the worldwide animal feed industry produced 873 million tons of feed in 2011, fast approaching 1 billion tonnes according to the International Feed Industry Federation, with an annual growth rate of about 2%. The use of agricultural land to grow feed rather than human food can be controversial. In many cases the production of grass for cattle fodder is a valuable intercrop between crops for human consumption, because it builds the organic matter in the soil; some agricultural byproducts fed to animals may be considered unsavory by human consumers.
Alfalfa Barley Birdsfoot trefoil Brassica spp. Kale Rapeseed Rutabaga Turnip Clover Alsike clover Red clover Subterranean clover White clover Grass Bermuda grass Brome False oat grass Fescue Heath grass Meadow grasses Orchard grass Ryegrass Timothy-grass Corn Millet Oats Sorghum Soybeans Trees Wheat Conserved forage plants: hay and silage Compound feed and premixes called pellets, nuts or cake Crop residues: stover, straw, sugar beet waste Fish meal Freshly cut grass and other forage plants Meat and bone meal Molasses Oligosaccharides Seaweed Seeds and grains, either whole or prepared by crushing, etc. Sprouted grains and legumes Yeast extract Native green grass Bran Concentrate mix Oilseed press cake Green maize Green sorghum Horse gram Leaves from certain species of trees Grass/lawn clipping waste In the past, bovine spongiform encephalopathy spread through the inclusion of ruminant meat and bone meal in cattle feed due to prion contamination; this practice is now banned in most countries.
Some animals have a lower tolerance for spoiled or moldy fodder than others, certain types of molds, toxins, or poisonous weeds inadvertently mixed into a feed source may cause economic losses due to sickness or death of the animals. The US Dept. of Health and Human Services regulates drugs of the Veterinary Feed Directive type that can be present within commercial livestock feed. Fodder in the form of sprouted cereal grains such as barley, legumes can be grown in small and large quantities. Hydroponic systems can grow up to tons of sprouts to each day. Sprouted grains can increase the nutritional value of the grain compared with feeding the ungerminated grain to stock. In addition, they use less water than traditional forage. Under hydroponic conditions, sprouted fodder at 150 mm tall with a 50 mm root mat is at its peak for animal feed. Although products such are barley are grain, when sprouted they are approved by the American Grassfed Association to be used as livestock feed. Cannon fodder Factory farming Feed manufacturing Forage Grain Pasture Karl Heinrich Ritthausen Die Eiweisskörper der Getreidearten, Hülsenfrüchte und Ölsamen.
Beiträge zur Physiologie der Samen der Kulturgewachese, der Nahrungs- und Futtermitel, Bonn, 1872 from Google books. Zhou, Yiqin. Compar Fresh or Ensiled Fodders on the Production of Greenhouse Gases Following Enteric Fermentation in Beef Cattle. Rouyn-Noranda, Qué.: Université du Québec en Abitibi-Témiscamingue, 2011. N. B.: Research report. UK Food Standards Agency, Animal feed legislation and guidance FAO Feed Safety guidelines Fodder Plants at Agriculture Guide An article from Agriculture Guide
Festuca pratensis, the meadow fescue, is a perennial species of grass, used as an ornamental grass in gardens, is an important forage crop. It grows in meadows, old pastures, riversides on moist, rich soils on loamy and heavy soils, it is a tufted grass similar to the tall fescue, Festuca arundinacea. Tall fescue differs by having minute hairs on the auricles, it can hybridise with Lolium multiflorum. It is a perennial bunchgrass; the panicles are green to purplish. The spikelets have 5 to 14 flowers, it has a blunt ligule compared to other grasses 1 mm high. The leaves are bright green and up to 4 mm across. Pink, A.. Gardening for the Million. Project Gutenberg Literary Archive Foundation
Themeda triandra is a perennial tussock-forming grass widespread in Africa, Australia and the Pacific. In Australia it is known as kangaroo grass and in East Africa and South Africa it is known as red grass and red oat grass or as rooigras in Afrikaans, it does not do well benefits from occasional fire. Themeda triandra is a grass which grows in dense tufts 0.5 metres wide. It flowers in summer, producing large red-brown spikelets on branched stems; the leaves are 10–30 centimetres in length and 1–8 millimetres wide but can exceed 10–50 centimetres long and 2–5 millimetres wide. Its inflorescence is compounded, fasciculated, is 10–30 centimetres long and composed of a single raceme, it pedicels are oblong and are 0.5 mm long while its lemma is 25–70 millimetres long and is both apical and geniculate. The column of lemma's awn is twisted. Themeda triandra was first formally described in 1775 by Peter Forsskål who published the description in Flora Aegyptiaco-Arabica. There are many synonyms of this species.
The specific epithet is derived from the Ancient Greek word andros meaning "man" or "male" with the prefix tri meaning "three". Themeda triandra is found across Asia, Africa and the Pacific. In Australia, it is found in all of the territories, it grows predominantly in open woodland communities. It is a significant species in temperate grasslands in Australia, a habitat considered to be endangered or threatened in various parts of the country; the young growth is palatable to stock. T. triandra seed has been used as a famine food in Africa. It serves as a food source for several avian species, including the long-tailed widowbird, it is occasionally used as an ornamental plant. Themeda triandra. PlantzAfrica