The functioning of the avian pituitary is comprehensively reviewed encompassing the structure and... more The functioning of the avian pituitary is comprehensively reviewed encompassing the structure and functioning of the pituitary gland and neuroendocrine hypothalamus. The avian pituitary gland and neuroendocrine hypothalamus includes the pars distalis or anterior pituitary gland, the pars nervosa or posterior pituitary gland, the infundibular stalk and median eminence. Detailed consideration is given to each of the traditionally accepted hormones of the anterior pituitary gland or pars distalis, namely including the gonadotropins—luteinizing hormone and follicle stimulating hormone, thyrotropin, prolactin, growth hormone, and adenocorticotropic hormone together with its precursor, pro-opiomelanocortin. The chemistry, expression, physiology, receptors, and control of each of the hormones are covered. Consideration is given to other and novel neuropeptides/hormones produced in the anterior pituitary gland. Recent progress is elucidating both the microanatomy and the functioning of the pars tuberalis is discussed. The chemistry and roles of the posterior pituitary hormones or neuropeptides, arginine vasotocin and mesotocin, are discussed.
Summary All animals influence the environment to varying extents. The production of livestock and... more Summary All animals influence the environment to varying extents. The production of livestock and poultry has marked impacts on the environment influencing water, air, and soil. Manure or animal waste is the predominant source of concern particularly with intensive animal agriculture. At the time of writing, in the USA, livestock and poultry produce 120 million metric tons of manure in dry weight. Some researchers put the impact of animal agriculture at 27% of total human water usage globally for the production of livestock (including water used to grow the feed grains). When there are problems in management, livestock and poultry can reduce water quality. There is contamination of water from livestock and poultry facilities including phosphate and nitrate, pathogens (viruses, bacteria, and protozoa), antibiotics, and androgenic agents. Nitrates and phosphate contamination of waterways and estuaries is leading to algal blooms, eutrophication, and hypoxic areas. Antibiotics are used extensively in pig and poultry production while anabolic agents are used for cattle. Agriculture contributes 11% to global greenhouse gas emissions with ruminants adding methane. Among the gases from livestock and poultry that are potential problems are the following: carbon dioxide, ammonia, total reduced sulfur including hydrogen sulfide, and water vapor together with odors. The latter can be offensive to neighbors of farms and have the potential to impact human health. Moreover, viruses can be transmitted from animal facilities to humans via aerosol particles. Livestock contribute markedly to soil degradation with effects including erosion, salinization (due to freshwater removal), soil loss following erosion after deforestation or overgrazing, “compaction and crusting (of soils) can be caused by cattle trampling,” and waterlogging with water-impaired movement. Soil degradation related to livestock directly and indirectly is made up of overgrazing of rangeland (679 million ha globally) and deforestation (579 million ha globally).
Summary Humans have a detrimental impact on natural habitat due to various activities including d... more Summary Humans have a detrimental impact on natural habitat due to various activities including deforestation, urbanization, roads, the energy sector (renewable and coal), mining, and climate change. The most important form of habitat destruction is deforestation either to develop land for agriculture (70%) or to harvest lumber intensively. There is ongoing economic pressure to convert the forests of the Amazon to pasture and arable land, for example, for corn and soybean production for the growing pig and poultry sectors. In Malaysia, Indonesia, and sub-Saharan Africa, there is growing production of palm oil with native forests being converted to oil palm plantations. The number and proportion of people living in urban areas is increasing rapidly with 5.8 million ha urbanized between 1970 and 2000 globally. Roads are influencing habitats particularly with the destruction of wetlands and habitat fragmentation. It is estimated that by 2050, there will be an additional 15.5 million miles (25 million km) of roads. The energy sector (e.g., coal mining and wind turbines) is also responsible for habitat loss. Environmental contamination associated with the extractive industries poses risks to wildlife and is viewed as potential habitat degradation. Even the vaulted wind turbines degrade habitat with substantial fatalities for birds (>200,000 in the USA) and bats (>800,000 in the USA). Mining also degrades and/or destroys habitats; for instance, unregulated gold mining can cause considerable damage including release of toxicants including cyanide, arsenic, boron, copper, fluoride, mercury, and zinc. Anthropomorphic (human-induced) climate change is degrading habitats, such as the polar region and the oceans due to acidification.
Abstract With a continually expanding market for poultry meat products, increased production dema... more Abstract With a continually expanding market for poultry meat products, increased production demands of as much as 50% by the Year 2000 have been predicted. Indications already exist that this magnitude of expansion is not likely to be met by increased ...
Summary Total and per capita consumption of animal products (meat, milk, eggs, and fish) are incr... more Summary Total and per capita consumption of animal products (meat, milk, eggs, and fish) are increasing globally. This shift reflects improved living standards, consumer demand, and efficient production. It should be recognized that 765 million people still suffer from chronic undernourishment/hunger. Animal products have high contents of protein and fat, particularly saturated fat. Animal products provide a source of highly digestible protein and of high quality with good balance of amino acids particularly indispensable amino acids. In the USA, people with an omnivorous diet consume 65% of their protein intake and 26% of their energy from animal products. The Recommended Dietary Allowance for protein is 56 g day−1 for men and 46 g day−1 for women. Meat, fish, eggs, and dairy products are a valuable source of minerals including calcium, zinc, and iron together with vitamins, such as vitamin B12. Animal products are predominantly low in carbohydrates except dairy products, which contain the disaccharide, lactose. The intestinal enzyme, lactase, is essential for lactose digestion. The expression of lactase decreases in most children. However, the enzyme persists in some people depending on their genetics and they can readily digest dairy products. In contrast, when lactase declines there is lactose intolerance. Animal products, such as liver and eggs are important sources of essential fatty acids (alpha-linolenic acid, linoleic acid, eicosapentaenoic acid, and docosahexaenoic acid; these being critical to the development of the brain and nervous system. Nutrient deficiencies, especially of animal product-rich nutrients, are a major problem globally. Protein malnutrition continues to be a major problem globally. Protein–energy deficiency results in stunting and insufficient weight in over 175 million children. Deficiencies in micronutrients result in 50% of deaths, directly and indirectly, to children and infants less than 5 years old globally. Iron deficiency impacts 30% of the world’s population. Vitamin B12 deficiency is widespread globally being found, for instance, in 40% of children and adults in Latin America, 70% of children in Kenya, and 80% of children in India and in the elderly and vegans in Western countries. Processed red meat and probably nonprocessed red meat have negative effects on health and mortality. Cholesterol is no longer viewed as a nutrient of concern for overconsumption. The safety and sustainability of animal products and ongoing use of animal products are discussed.
The functioning of the avian pituitary is comprehensively reviewed encompassing the structure and... more The functioning of the avian pituitary is comprehensively reviewed encompassing the structure and functioning of the pituitary gland and neuroendocrine hypothalamus. The avian pituitary gland and neuroendocrine hypothalamus includes the pars distalis or anterior pituitary gland, the pars nervosa or posterior pituitary gland, the infundibular stalk and median eminence. Detailed consideration is given to each of the traditionally accepted hormones of the anterior pituitary gland or pars distalis, namely including the gonadotropins—luteinizing hormone and follicle stimulating hormone, thyrotropin, prolactin, growth hormone, and adenocorticotropic hormone together with its precursor, pro-opiomelanocortin. The chemistry, expression, physiology, receptors, and control of each of the hormones are covered. Consideration is given to other and novel neuropeptides/hormones produced in the anterior pituitary gland. Recent progress is elucidating both the microanatomy and the functioning of the pars tuberalis is discussed. The chemistry and roles of the posterior pituitary hormones or neuropeptides, arginine vasotocin and mesotocin, are discussed.
Summary All animals influence the environment to varying extents. The production of livestock and... more Summary All animals influence the environment to varying extents. The production of livestock and poultry has marked impacts on the environment influencing water, air, and soil. Manure or animal waste is the predominant source of concern particularly with intensive animal agriculture. At the time of writing, in the USA, livestock and poultry produce 120 million metric tons of manure in dry weight. Some researchers put the impact of animal agriculture at 27% of total human water usage globally for the production of livestock (including water used to grow the feed grains). When there are problems in management, livestock and poultry can reduce water quality. There is contamination of water from livestock and poultry facilities including phosphate and nitrate, pathogens (viruses, bacteria, and protozoa), antibiotics, and androgenic agents. Nitrates and phosphate contamination of waterways and estuaries is leading to algal blooms, eutrophication, and hypoxic areas. Antibiotics are used extensively in pig and poultry production while anabolic agents are used for cattle. Agriculture contributes 11% to global greenhouse gas emissions with ruminants adding methane. Among the gases from livestock and poultry that are potential problems are the following: carbon dioxide, ammonia, total reduced sulfur including hydrogen sulfide, and water vapor together with odors. The latter can be offensive to neighbors of farms and have the potential to impact human health. Moreover, viruses can be transmitted from animal facilities to humans via aerosol particles. Livestock contribute markedly to soil degradation with effects including erosion, salinization (due to freshwater removal), soil loss following erosion after deforestation or overgrazing, “compaction and crusting (of soils) can be caused by cattle trampling,” and waterlogging with water-impaired movement. Soil degradation related to livestock directly and indirectly is made up of overgrazing of rangeland (679 million ha globally) and deforestation (579 million ha globally).
Summary Humans have a detrimental impact on natural habitat due to various activities including d... more Summary Humans have a detrimental impact on natural habitat due to various activities including deforestation, urbanization, roads, the energy sector (renewable and coal), mining, and climate change. The most important form of habitat destruction is deforestation either to develop land for agriculture (70%) or to harvest lumber intensively. There is ongoing economic pressure to convert the forests of the Amazon to pasture and arable land, for example, for corn and soybean production for the growing pig and poultry sectors. In Malaysia, Indonesia, and sub-Saharan Africa, there is growing production of palm oil with native forests being converted to oil palm plantations. The number and proportion of people living in urban areas is increasing rapidly with 5.8 million ha urbanized between 1970 and 2000 globally. Roads are influencing habitats particularly with the destruction of wetlands and habitat fragmentation. It is estimated that by 2050, there will be an additional 15.5 million miles (25 million km) of roads. The energy sector (e.g., coal mining and wind turbines) is also responsible for habitat loss. Environmental contamination associated with the extractive industries poses risks to wildlife and is viewed as potential habitat degradation. Even the vaulted wind turbines degrade habitat with substantial fatalities for birds (>200,000 in the USA) and bats (>800,000 in the USA). Mining also degrades and/or destroys habitats; for instance, unregulated gold mining can cause considerable damage including release of toxicants including cyanide, arsenic, boron, copper, fluoride, mercury, and zinc. Anthropomorphic (human-induced) climate change is degrading habitats, such as the polar region and the oceans due to acidification.
Abstract With a continually expanding market for poultry meat products, increased production dema... more Abstract With a continually expanding market for poultry meat products, increased production demands of as much as 50% by the Year 2000 have been predicted. Indications already exist that this magnitude of expansion is not likely to be met by increased ...
Summary Total and per capita consumption of animal products (meat, milk, eggs, and fish) are incr... more Summary Total and per capita consumption of animal products (meat, milk, eggs, and fish) are increasing globally. This shift reflects improved living standards, consumer demand, and efficient production. It should be recognized that 765 million people still suffer from chronic undernourishment/hunger. Animal products have high contents of protein and fat, particularly saturated fat. Animal products provide a source of highly digestible protein and of high quality with good balance of amino acids particularly indispensable amino acids. In the USA, people with an omnivorous diet consume 65% of their protein intake and 26% of their energy from animal products. The Recommended Dietary Allowance for protein is 56 g day−1 for men and 46 g day−1 for women. Meat, fish, eggs, and dairy products are a valuable source of minerals including calcium, zinc, and iron together with vitamins, such as vitamin B12. Animal products are predominantly low in carbohydrates except dairy products, which contain the disaccharide, lactose. The intestinal enzyme, lactase, is essential for lactose digestion. The expression of lactase decreases in most children. However, the enzyme persists in some people depending on their genetics and they can readily digest dairy products. In contrast, when lactase declines there is lactose intolerance. Animal products, such as liver and eggs are important sources of essential fatty acids (alpha-linolenic acid, linoleic acid, eicosapentaenoic acid, and docosahexaenoic acid; these being critical to the development of the brain and nervous system. Nutrient deficiencies, especially of animal product-rich nutrients, are a major problem globally. Protein malnutrition continues to be a major problem globally. Protein–energy deficiency results in stunting and insufficient weight in over 175 million children. Deficiencies in micronutrients result in 50% of deaths, directly and indirectly, to children and infants less than 5 years old globally. Iron deficiency impacts 30% of the world’s population. Vitamin B12 deficiency is widespread globally being found, for instance, in 40% of children and adults in Latin America, 70% of children in Kenya, and 80% of children in India and in the elderly and vegans in Western countries. Processed red meat and probably nonprocessed red meat have negative effects on health and mortality. Cholesterol is no longer viewed as a nutrient of concern for overconsumption. The safety and sustainability of animal products and ongoing use of animal products are discussed.
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