Abstract
Water is seldom listed among the nutritional requirements of living things, but this substance is the most basic of all needs in nutrition. There are life forms that live without air or oxygen, but none can live without water. Though water is so often taken for granted, it is the most essential nutrient and the first requirement for life. The turnover and exchange of water in the body exceeds that of any other nutrient. A 10% reduction in body content of any other nutrient usually will cause no noticeable effect, but a 10% reduction in water in the form of body fluids will cause symptoms of severe dehydration. A 20% reduction in body fluids is fatal.
Birds and other animals have three primary sources of water. First, the actual drinking of water is the main source. A number of factors may affect this source of water for cage birds. The growth of bacteria may make it unpalatable; birds frequently will refuse to drink warm water: Cool, clean water is a necessity for avian nutrition. At times, outside water sources for birds, such as a continually dripping faucet, may harbor the growth of algae. These are tiny, green, one-celled plants that are harmless to the birds and are actually an excellent nutritional addition to the diet, if eaten. Algae are nothing to be concerned about, since they grow profusely in any natural water source.
The second main water source is the bird's food itself, since food contains a considerable quantity of water. Vegetables, of course, have the highest percentage of water. Tomatoes contain about 94 % water and cucumbers are 96 % water. Carrots and onions contain 88 % ; bananas and sweet corn are relatively low in water among the fruits and vegetables, with a 76% water content. Spinach greens are about 90 % water; kale has a water content of about 87 % . Nuts and grains contain far less water. Cereal grains range from 11 % to 13 % water, with a content in millet of about 12 % . The oily seeds and nuts contain the least water of any food items, usually a maximum of about 5 % in such items as safflower seed, sunflower seed, and almonds. Walnuts, peanuts, and pecans contain even less water. You may have wondered why nuts make you thirsty, even when they're raw and unsalted: Their low water content is the reason. It also follows that nuts are your best nutritional buy, since the water content in them is so small and the other nutritional contents so high. As you
might suspect, a whole egg, even hard boiled, is an average 7 4 % water, though some will test at about 65 % water content.
The third source of water for the body is the internal metabolism. As proteins, fats, and carbohydrates are metabolized to produce energy, water is created as a byproduct. For example, about one pound of water will be formed as one pound of fat is metabolized. Obviously, in comparison to the body's needs, this is not a large amount, and this water source is minor in the life of most birds and animals. In some desert creatures, such as the kangaroo rat for example, this can be a very significant part of the body's needs for moisture. Budgerigars, the common grass parakeets so familiar as pets, can go for an incredible length of time without water. In proven tests, they have lived in perfect health for periods of 120 days - four months - without a drop of water. Their sole water sources were the small content in their feed and the by-products of their heat and energy production. Obviously, the budgerigar has a very well-developed internal system for water conservation, one perfectly adapted for desert life.
The amount of water in organism's bodies may vary considerably at different times, even within the same species. Chicks one week old may have a body water content of 85 % , while that gradually decreases to 55 % at maturity. The percent of body water is closely related to the fat content of the body. The more fat stored within the body, the less will be the percentage of water content. This is why the normal variation from 50% to 75 % water content in humans can be so large. The average water content of the human body is about 60%.
Two thirds of the body water is within the cells. Blood is 80 % water, but this is less than 8 % of the total water content of the body. The kidneys are very efficient in conserving water, and they will absorb enough water routinely to maintain blood volume at a normal level. The water content of a bird's droppings varies a great deal, even within different strains of the same species. Fifty to seventy percent seems normal for chickens, and similar proportions can be expected in cage birds. Birds with very firm droppings, such as budgerigars, probably have less than 50 % water content. Under conditions of starvation, a bird can use up almost all of its glycogen (stored carbohydrate) and fat reserves, half of its protein, and 40 % of its
total body weight and still live. However, the loss of only 20 % of the water content of the body will kill the bird.
A bird will never voluntarily consume an excessive amount of water, since the body's needs are very closely controlled by factors that are not yet completely clear. The water consumed is absorbed very rapidly, and it is lost through the kidneys and through evaporation in breathing. Water performs a very important function for the body in the regulation of body temperature, since water evaporation removes excess heat. Whenever the body begins to overheat, the bird will begin to pant. This evaporates far more moisture and results in greater cooling. Humans accomplish the same cooling effect through sweating when the body becomes overheated. The evaporation of one gram of sweat will dissipate 540 calories of heat. The panting of birds and the higher water evaporation at higher temperatures greatly increase the need for water. The difference in temperature from 70 degrees to 90 degrees Fahrenheit may increase water consumption by 100%.
Water serves several other functions in the body. In its most important function, it acts as a solvent and carrier for body nutrients, including the mo no saccharides, amino acids, phospholipids, vitamins, and minerals. These items are all vital to life. Water also carries the hormones and enzymes necessary for the proper functioning of every cell in the body. Water further serves as a lubricant, especially in the joints, and acts as the medium for many metabolic reactions.
Water carries a variety of other substances in solution that are completely invisible even under a microscope. These are dissolved minerals and compounds that the water picks up as it flows and exists in liquid form. Rain water will pick up minerals and oxygen as it falls through the air. Unfortunately, minerals absorbed in this way are often the poisonous pollutants, such as lead, or compounds, such as sulfuric acid. Ground water will absorb minerals wherever it flows, and this content is often a substantial source of minerals in the diet. Two minerals commonly found in water are chlorine from water treatment and iron from ground deposits. Both of these will destroy vitamin Eon contact. Make every effort to ex elude them from your birds' water supply.