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Teladorsagia Trifurcata
''Teladorsagia circumcincta'' is a nematode that is one of the most important parasites of sheep and goats. It was previously known as ''Ostertagia circumcincta'' and is colloquially known as the brown stomach worm. It is common in cool, temperate areas, such as south-eastern and south-western Australia and the United Kingdom. There is considerable variation among lambs and kids in susceptibility to infection. Much of the variation is genetic and influences the immune response. The parasite induces a type I hypersensitivity response which is responsible for the relative protein deficiency which is characteristic of severely infected animals. There are mechanistic mathematical models which can predict the course of infection. There are a variety of ways to control the infection and a combination of control measures is likely to provide the most effective and sustainable control. Taxonomy ''Teladorsagia'' is a member of the subfamily Ostertagiiniae in the family Trichostrongylid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Texel Sheep
The Texel is a breed of domestic sheep originally from the island of Texel in the Netherlands. A heavily muscled sheep, it produces a lean meat carcass and will pass on this quality to crossbred progeny. The wool is around 32 micrometres and is mostly used for hosiery yarns and knitting wools. It is presently a popular lean meat sheep across Europe, as well as Australia, New Zealand and the United States. History The Texel sheep originated on the island of Texel, the largest of the Wadden Islands off the north coast of the Netherlands. The exact origin of the breed is unknown although it is thought to be a cross of the original Texel sheep with multiple English breeds. It was slowly bred into a meat breed of outstanding carcass quality. It is now one of the most common meat breeds in the Netherlands, making up seventy percent of the national flock. United Kingdom In the early 1970s, the superior quality of the Dutch Texel caught the attention of some English breeders who were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scottish Blackface
The Blackface or Scottish Blackface is a British breed of sheep. It is the most common sheep breed of the United Kingdom. Despite the name, it did not originate in Scotland, but south of the border. History The origins of the breed are uncertain. It originated south of the Anglo-Scottish border, and did not arrive in the Highlands of Scotland until the second half of the eighteenth century. It replaced the earlier Scottish Dun-face or Old Scottish Shortwool, a Northern European short-tailed sheep type probably similar to the modern Shetland. There are several types of Blackface in the United Kingdom, including the Perth variety, which is large-framed and coarse-woollen, and mainly found in north-east Scotland, Devon, Cornwall and Northern Ireland; the medium-framed Lanark type, with shorter wool, found in much of Scotland and in parts of Ireland; and the Northumberland Blackface, which is large with relatively soft wool. Characteristics The Blackface is always horne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haemonchus Contortus
''Haemonchus contortus'', also known as the barber's pole worm, is a very common parasite and one of the most pathogenic nematodes of ruminants. Adult worms attach to abomasal mucosa and feed on the blood. This parasite is responsible for anemia, oedema, and death of infected sheep and goats, mainly during summer in warm, humid climates. Females may lay over 10,000 eggs a day, which pass from the host animal in the faeces. After hatching from their eggs, ''H. contortus'' larvae molt several times, resulting in an L3 form that is infectious for the animals. The host ingests these larvae when grazing. The L4 larvae, formed after another molt, and adult worms suck blood in the abomasum of the animal, potentially giving rise to anaemia and oedema, which eventually can lead to death. The infection, called haemonchosis, causes large economic losses for farmers around the world, especially for those living in warmer climates. Anthelminthics are used to prevent and treat these, and othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disease Resistance
Disease resistance is the ability to prevent or reduce the presence of diseases in otherwise susceptible hosts. It can arise from genetic or environmental factors, such as incomplete penetrance. Disease tolerance is different as it is the ability of a host to limit the impact of disease on host health. In crops this includes plant disease resistance and can follow a gene-for-gene relationship. See also * Disease resistance in fruit and vegetables There are a number of lines of defence against pests (that, those animals that cause damage to the plants we grow) and diseases in the orchard, principal among these being the practice of good husbandry, creating healthy soil and ensuring high s ... * Disease resistance breeding References {{Reflist Diseases and disorders ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Response To Selection
In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the population during that process. Thirdly, it is a phenotypic trait or adaptive trait, with a functional role in each individual organism, that is maintained and has evolved through natural selection. Historically, adaptation has been described from the time of the ancient Greek philosophers such as Empedocles and Aristotle. In 18th and 19th century natural theology, adaptation was taken as evidence for the existence of a deity. Charles Darwin proposed instead that it was explained by natural selection. Adaptation is related to biological fitness, which governs the rate of evolution as measured by change in allele frequencies. Often, two or more species co-adapt and co-evolve as they develop adaptations that interlock with those of the other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenotype
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological properties, its behavior, and the products of behavior. An organism's phenotype results from two basic factors: the expression of an organism's genetic code, or its genotype, and the influence of environmental factors. Both factors may interact, further affecting phenotype. When two or more clearly different phenotypes exist in the same population of a species, the species is called polymorphic. A well-documented example of polymorphism is Labrador Retriever coloring; while the coat color depends on many genes, it is clearly seen in the environment as yellow, black, and brown. Richard Dawkins in 1978 and then again in his 1982 book ''The Extended Phenotype'' suggested that one can regard bird nests and other built structures such as cad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heritability
Heritability is a statistic used in the fields of breeding and genetics that estimates the degree of ''variation'' in a phenotypic trait in a population that is due to genetic variation between individuals in that population. The concept of heritability can be expressed in the form of the following question: "What is the proportion of the variation in a given trait within a population that is ''not'' explained by the environment or random chance?" Other causes of measured variation in a trait are characterized as environmental factors, including observational error. In human studies of heritability these are often apportioned into factors from "shared environment" and "non-shared environment" based on whether they tend to result in persons brought up in the same household being more or less similar to persons who were not. Heritability is estimated by comparing individual phenotypic variation among related individuals in a population, by examining the association between ind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastroenteritis
Gastroenteritis, also known as infectious diarrhea and gastro, is an inflammation of the gastrointestinal tract including the stomach and intestine. Symptoms may include diarrhea, vomiting, and abdominal pain. Fever, lack of energy, and dehydration may also occur. This typically lasts less than two weeks. It is not related to influenza, even though in the U.S. it is sometimes called the "stomach flu". Gastroenteritis is usually caused by viruses; however, gut bacteria, parasites, and fungi can also cause gastroenteritis. In children, rotavirus is the most common cause of severe disease. In adults, norovirus and '' Campylobacter'' are common causes. Eating improperly prepared food, drinking contaminated water or close contact with a person who is infected can spread the disease. Treatment is generally the same with or without a definitive diagnosis, so testing to confirm is usually not needed. For young children in impoverished countries, prevention includes hand washing with so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Livestock
Livestock are the domesticated animals raised in an agricultural setting to provide labor and produce diversified products for consumption such as meat, eggs, milk, fur, leather, and wool. The term is sometimes used to refer solely to animals who are raised for consumption, and sometimes used to refer solely to farmed ruminants, such as cattle, sheep, goats and pigs. Horses are considered livestock in the United States. The USDA classifies pork, veal, beef, and lamb (mutton) as livestock, and all livestock as red meat. Poultry and fish are not included in the category. The breeding, maintenance, slaughter and general subjugation of livestock, called '' animal husbandry'', is a part of modern agriculture and has been practiced in many cultures since humanity's transition to farming from hunter-gatherer lifestyles. Animal husbandry practices have varied widely across cultures and time periods. It continues to play a major economic and cultural role in numerous communities. Lives ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenotypic Variation
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological properties, its behavior, and the products of behavior. An organism's phenotype results from two basic factors: the expression of an organism's genetic code, or its genotype, and the influence of environmental factors. Both factors may interact, further affecting phenotype. When two or more clearly different phenotypes exist in the same population of a species, the species is called polymorphic. A well-documented example of polymorphism is Labrador Retriever coloring; while the coat color depends on many genes, it is clearly seen in the environment as yellow, black, and brown. Richard Dawkins in 1978 and then again in his 1982 book '' The Extended Phenotype'' suggested that one can regard bird nests and other built structures such as ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
