Macronutrients
Before planning any diet, whether it be for people or animals, it is important to understand what is found in foods and what importance they hold for the body. Macronutrients are needed in large proportions in the diet to aid the body (Farlex, 2015). These are needed to be supplemented to the body on a regular basis in order for normal body activity. The buttons above will redirect and explain each of the macronutrients required in the body in detail.
Lipids
Lipids are organic compounds found in a variety of physical states, including fats, oils, waxes, sterols, and steroids (Fahy, 2009).
It is important for fats to be in animal diets because it is appealing in taste to animals, and can be cooked to alter the taste (through cooking processes including Smoke Point, Flash Point, and Fine Point). Fat is also lubricated, which makes it easier for animals to swallow and digest (Achitoff-Gray, 2014).
Functions
Just as lipids can vary in appearance, they also have many uses within the body. The most recognised role of lipids is to store energy. Lipids are made from the same chemical structure as carbohydrates, and can be a good source of energy when the daily intake of carbohydrates isn't achieved. Because we receive the majority of our energy from carbohydrates, lipids can store themselves as fatty compositions along the body, providing us with a layer of fat (Kannall, 2015). Although many people are known to try to avoid lipids in their diet to avoid this outcome, it is a benefit for organisms to have.
Lipids have the same chemical components as carbohydrates; carbon, hydrogen and oxygen. Because of this, they can be used to produce energy for the body; one of the main differences is that lipids are in a much more complicated atomic chain than carbohydrates, and are much more difficult to break down in the body (Pond, 2005).
Another factor that differs lipids from carbohydrates is the method used to break it down and store themselves in the body. Lipids can begin to break down within the mouth from lingual lipase enzymes found within saliva, but are more focused in digestion within the small intestine and aided by bile produced from the liver (Boundless, 2015). Here, the molecular bonds are broken down into simple lipids; fatty acids and glycerole. Glycerol is a simple sugar, that is easy to break down and be used to create Adenosine Triphosphate (commonly referred to as ATP) which is the body's natural energy source. Fatty acids are used to aid the growth and development of cell membrane structures (Fit Day, 2015).
There are two types of fatty acids; saturated and unsaturated fats. Saturated fats are solid at room temperature and are formed with single bonds between carbon atoms. These are very easy to break down in the body, and are usually stored inside the body as reserve energy and added bodily protection. Unsaturated fats are liquid at room temperature, and contain double carbon to carbon bonds within their molecular chains, making them stronger and can be increasingly difficult to break down. These assist the body in absorbing Vitamins A, D, E and K, which are all fat soluble (NHS, 2015).
Steroids are also a type of lipid, but they are rather complicated in form and extremely difficult for the body to break down, and are considered to be more of a source for hormone influence. Despite their different purposes, they are classified as a lipid due to being hydrophobic in nature (Austincc, 2015).
When enough energy is being produced within the body (or the body is exposed to enough carbohydrates in their diet for them to have no need to create ATP from fatty molecules) lipids will instead be stored in the body. This is because lipids are fat soluble, and can be stored within tissues around the body, including main organs such as the heart and the liver. This creates a layer of fat, which can aid the body through insulation, support vital organs, and can aid the body in generating heat (Peluso, 2015).
On the other hand, too much fat can cause strain on vital organs from excessive weight, as well as on the skeletal structure, and can cause many unwanted health benefits such as Atherosclerosis - where the walls of veins and arteries thicken and reduce the blood flow that can pass through the body, eventually leading to strokes and heart attacks (Woods, 2015).
Chemical Properties
It is important to understand the chemical properties of nutrients; this is so we can identify how quick it can take an enzyme to break down the molecular structure (and thus digest the food) within the body and see what foods would benefit specific animals according to their diets.
Lipids are composed of carbon, hydrogen and oxygen atoms, which is the same formula as carbohydrates. Unlike carbohydrates, there are no definite ratio of hydrogen atoms to oxygen atoms.
Dietary Sources
Lipids can be found in a variety of sources of food; unsaturated fat sources can include soybean oils, vegetable oils, olive oils, sunflower oils, nuts, and fatty oily fish (such as salmon and trout). Saturated fat sources can include red meats (such as beef and pork), dairy products (including milk and cheese), coconuts and palm oils (McNight, 2015).
It is necessary to understand the dietary requirements for the given animal in order to supplement it with the correct feed. Due to animals having different roles within modern life can vary the animal's diet overall. For example, a working dog would have a much high energy content in their diet than a standard companion dog, because it has more work to do and will be burning off more energy than a pet that may only sustain a couple walks a day.
As such it is also important to consider the animal in its wild state, and consider what it would naturally eat. A cat for example, is a carnivore and would not naturally sustain itself upon a product such as wheat, and therefore shouldn't be considered a suitable feed.
The lifestyle of the animal can also have a major effect on what to feed them. A meat production cow wouldn't be as large nor as muscular as they were if they were fed on a maintenance diet - where there is enough nutrition consumed to sustain the body without exceeding minimum requirements (Sanderson, 2013). To grow at the rate it needed to to produce as much meat as possible, it would instead be on a high protein diet. Whilst there are many sources of protein in foods, you'd have to consider what the animal would naturally eat. Instead of going for a blood meal of a bone meal (consisting of dead animal remains), you'd be more likely to feed them a sunflower (oil) meal, as they are natural herbivores (Perry, 2004).
Figure 1. Brands of oils, a common source of lipids (AllBiz, 2010).
Physical Properties
Lipids can be found in different forms and shapes due to it's chemical properties. Lipids are considered to be hydrophobic, and thus are insoluble in water (Britannica, 2015). Physically they should be able to soften considerably through heating. In texture, lipids are considered to be a natural lubricant.
When lipids oxidise (react to oxygen), it becomes rancid in taste and unnapealing for animals to eat, so it is recommended to be stored before serving. When the fatty acids within the source liberate from glycerol through enzymes (a process known as hydrolysis), it has the same effect as oxidisation; making the food taste bitter and foul for animals, thus creating aldehydes and ketones, which are carbohydrate chains (as seen in Figure 2. Biotopics, 2015).
Figure 2. The process of Hydrolysis in Lipids (Biotopics, 2015).
Depending on the fatty acid chain, the chemical bond varies. If the fatty acid is an unsaturated, there will be a double bond within the chain. If there are only singular ester links, then the fatty acid is a saturated fat (Edinformatics, 1999).
Lipids are a combination of bonded (this chemical bond is called an ester) of fatty acids and glycerol - the estered component is known as a glyceride. If a single fatty acid chain is estered to a single glyceride chain, it becomes a monoglyceride (see figure 3). When the three glycerols (known as trihydric alcohol glycerol) are estered to a fatty acid chain, they create a triacylglyceride (McDonald, 2002).
There are no set formula for triacylglycerides as they differ depending on the sources of lipids and fats presented, but the process will always contain an ester link between a carbon atom and two oxygen atoms within the chain (Indiana University, 2015).
Figure 3. Examples of a Monoglyceride, Diglyceride, and Triglyceride (antranik, 2015).
Carbohydrates
Figure 4. Food sources of Carbohydrates (Duncan, 2014).
Carbohydrates are another organic compound digested to receive energy for the body (Oxford, 2015). Carbohydrates are digested by an amylase enzyme found in saliva, and continues to be further digested in the stomach and small intestine. (Kellems, 2002)
Physical Properties
Carbohydrates are made of different lengths of chains of saccharides. Saccharide is a term for sugar, literally translating as "sweet sand" in Latin (Hunt, 2015). Monosaccharides are the simplest form of sugar, commonly referred to as a simple sugar. They are known to be commonly sweet, found mostly in the form of fruit and other natural sugars (Agriculture and Consumer Protection, 2010).
Disaccharides are two chains of monosaccharides, like the simpler chain they are water soluble (Britannica, 2015). Oligosaccharides (a chain between two and ten monosaccharides) are also water soluble (Harrison, 2013). This means they can be stored within water, being unable to be stored in the body and thus need daily replenishment.
Polysaccharides contain ten or more monosacharide chains, and are known as a complex sugar (Department of Chemistry, 2015). They are considered to be viscous in texture, usually used as a thickener in food products, making them more difficult to digest (CFS, 2015). Polysaccharides such as cellulose and starch are fat soluble, able to be stored within fat (usually in the form of glycogen) (Linhardt, 1997).
Both disaccharides and polysaccharides can be crystallised in a natural form (Atkins, 2004). If a carbohydrate isn't naturally crystalline, they're more likely to be in the form of amorphous solids, gasses, and syrups (Davidson, 1998).
Carbohydrates are generally moist in texture, due to containing a substantial amount of water, and is considered to be very difficult to dry completely (McClements, 2009).
Chemical Properties
Carbohydrates are atomically made from carbon, hydrogen, and oxygen; specifically one carbon atom (C) for every two hydrogen atoms (H2) to every one oxygen atom (O) (see figure 5). This shows that carbohydrates contain a lot of water (H2O) (Eewi, 2012).
Function
Carbohydrates are the most important nutrients needed within the body, if not including water. This is due to the roles it plays within the body. Carbohydrates are the body's main supply of energy; without it the body would be unable to sustain itself and would waste away. The energy is needed for all parts of the body to work, including suplying energy for cells (IOWA State University, 2015).
Carbohydrates also have the ability to be stored within the body; as we can't be eating constantly, and there isn't always a supply of food available, it is natural for the body to be able to absorb fat soluble carbohydrates (in the form of glycogen) within the body; usually in the liver and other fatty areas (Berg, 2002).
Having enough energy in the body also allows carbohydrates to maintain blood glucose levels, needed to regulate blood sugar to prevent diabetes (Agar, 2001).
Carbohydrates also play a role within reproduction. Female mammals need to produce milk when they have young, and milk comes from lactose; which is a disaccharide (Perkins, 2015). The body needs to be able to produce lactose to allow mothers to lactate. This is also important for production animals who are used for milk production, such as cattle and goats (Cerbulis & Farrell, 1975).
Dietary Sources
Sources of simple sugars can vary depending on the type of saccharide needed within the diet. Fructose can be found within all fruits and various grasses (Renee, 2014). Lactose is present mostly in milk, and can be found in other dairy products (however these are not naturally found within an animal's diet) (Pennington & Spungen, 2009). Sucrose is found in sugary plants such as sugar beets and ripe dates, and glucose is found in the simplest of sugars (French, 2015).
Sources of complex sugars also vary depending on the saccharide; chitin can be found within starch (which is found in content such as potatoes, cassavas, wheats and cereals), cellulose (found within body cells), and insect shells (Younes & Rinaudo, 2014). Pectin and arabinoxylas can be found in generic green plants and citrus fruits (Andrew, 2015). Pulses (including beans, peas and legumes), whole grain and vegetables are also good sources of polysaccharides (Whole Food Catalogue, 2015).
Sources of fibrous saccharides (poylsaccharides that are too long to digest efficiently, without the aid of a rumenant stomach) include beet pulp, brans (such as corn and wheat), wheat midlings, and grasses (Palmer, 2008). It is important that fibre doesn't take up much of a diet that does not need it; whilst a cow is dependent on fibre within their diet, a working dog would be opposite. High energy required animals such as dogs and young puppies would need to avoid fibrous content, as they need simpler sugars that can provide them with suitable energy for their activities. If they were unable to digest the energy they were eating, they would become ill and exhaust quickly (ASPCA, 2015).
Proteins
Figure 7. Sources of Protein (Farr, 2014).
Carbohydrate atoms are connected through covalent bonding; this is one of the strongest atom bonds and are difficult for the body to break down (Kenneth, 2015). These are more present in polysaccharides, which is why they are more difficult to digest. Simple sugars have smaller chains than complex sugars, which make their molecular structure much simpler to break down. This makes digestion quick and creates a “sugar rush” (lots of energy released into the body in a short span). Because polysaccharides take longer to digest, they release energy slower, and provide the body energy for longer periods of time (Calkins, 2012).
All digested saccharides are broken down into their simplest form; Glucose. This is because glucose is one of the main components that create ATP (the body’s energy source) (Lodish et al, 2000).
Monosaccharides, being a simple sugar, are found in sugary content, and are categorised in regards to the food they are found in. Examples include Glucose (found in any sources of sugar), Fructose (found in fruits) and Galactose (found in milk products) (Riordan Clinic, 2013).
Despite Glucose and Fructose coming from different sources, they both have the same components within their molecular structure, and would be identical if not for the molecules being in a varied order. These are called Isomers (Bleam et al, 2008).
Disaccharides examples include Maltose (made of two glucose chains and found in cereals and grains), Sucrose (made of glucose and fructose and found in sugar cane and sugar beet), and Lactose (made of glucose and galactose and found in dairy) (Kimball, 2011).
Polysaccharide examples include Starch (found in various foods, including potatoes and grains), Glycogen (stored glucose found within the body, including livers), and Cellulose (found in plant cells including wheats and oats) (RSC, 2015).
Figure 5. The atomic Structure of Carbohydrates (Theodore, 2008).
Just like we prepare our foods with cooking and treatments before eating, we are expected to prepare the foods for our animals too. Digestion of complex sugars is difficult on all animals, so having alternatives to break down the chains before beginning digestion is very beneficial for the animal intending to receive energy from their meal (Foodsafety.gov, 2007). Preparation can include events such as crushing food, breaking them down, cooking/burning, and adding fluids to soften the meal (Palmer, 2012).
Preparation is especially important in monogastric stomached animals (animals with one stomach chamber - see figure 6). These digestive systems hold a caecum, which is used to digest fibre, however they are not efficient and fibre is usually left undigested and passes through the system relatively untouched (Husvéth, 2011).
Ruminant stomachs, on the other hand, are very effective at digesting polysaccharides; these have several stomach chambers (usually four) that each participate in spending periods of time digesting food (see figure 6) (Boundless, 2015). A lot of ruminant stomached animals, such as cattle, participate in additonal digesting by regurgitating their food back into their mouths to predigest once more and further assist in digestion, making them very efficient at eating fiborous content. For this reason, their digestive tract needs to be constantly in motion, and they should be on very high fibred diets (McCarthy, 2015).
Figure 6. Examples of Ruminant and Monogastric digestive systems (Fears, 2011).
Water
Macronutrients are all organic compounds, being derived from natural components such as living organisms. Protein is no exception to this, being found in all body cells (as it is used as the basic structure for every living cell) (NCS Pearson, 2015). The body is unable to synthesis protein, and because of this it is very important for the body to receive protein through consumption; without it our bodies would be unable to sustain themselves.
Proteins are scientifically referred to as Polypeptide, which translates as ‘many amino acids’ (Biology-Online, 2015). This is because protein is a long chain of several amino acids, and created entirely by amino acids (Talaga, 2015).
When digested, protein is digested into the stomach, broken down into smaller amino acids and short polypeptide chains. When they convert into free (singular) amino acids they are small enough to pass into the blood stream, where they are then transported to the liver (Feinle-Bisset, 2005). The liver is a very complex organ, taking care of many different tasks simultaneously; one of these include synthesising protein for the body. The amino acids of other organisms digested into the system are then converted to become the body’s own supply of cell specific proteins. This synthesis is a continuous process and the body’s protein is constantly being reconverted for other tasks within the body (Stanford Medicine, 2015).
Physical Properties
The physical properties of foods can alter the appeal for animals to eat. Because of this, macronutrients are naturally textured and tasted in order to attract and influence the chances of an organism eating its requirements.
Protein is water soluble, meaning it is passable through the body through water; it uses this to pass through the blood to meet all the locations of the body it may need to be used for (Pace, 2004). It is difficult to melt, needing a high temperature around 200 degrees Celsius average (Rees, 2001). Despite its changes in physical state through heat, it can also change taste on the degree of cooking, as well as the type of amino acids being heated. Sweet tastes can be found in Glycine, Alanine, and Valine (AJINOMOTO CO, 2015). Protein can be tasteless when in the form of Leucine, and can be found to be bitter in Arginine and Isoleucine (Shallenberger,1993). Salty tastes can also be found in Sodium Glutamate (Taylor, 2010).
Identifying what amino acids can taste like can help assist helping find a suitable feed for the required animal. Animals have preferences in tastes in order to identify possible toxic foods, so if a necessary amino acid is unappetising to eat (such as Isoleucine, an essential amino acid that can taste particularly bitter), it may be required to find a guise an unwanted taste with a tastier substance (Bachmanov, 2009). If unable to convince an animal to eat a necessary nutrient, supplements may need to be applied.
There are two groups of amino acids; Essentials and Non-Essentials.
Essential Amino Acids are unable to be synthesised within the body (Nave, 2015). Because of this, they are required to be supplemented through consumption, and without the body would struggle to sustain itself (Wax, 2015). Some of the essentials differ in regards to the species of animals; an example of an essential amino acid in cats is Taurine. Taurine can be lost when food is heated, and needs to be supplied as uncooked as possible before serving to felines (D’Mello, 2003). Taurine is used within the heart wall muscles, the brain, and in eye retinas; important parts of the body that need to be protected. The lack of amino acid can result in tooth decay and blindness, as well as other health defects, and need to be supplemented daily for cats (Pet MD, 2015). Figure 8 shows a list of all Amino Acids.
Non-Essential Amino Acids are able to be synthesises within the body, and are not as important in regards to consuming. The body is able to regulate these amino acids, making it rare for deficiency (Busch, 2015).
Being found in almost every living organism, proteins are understandably very different in appearances and sources. This also has an impact on their quality; some sources have higher quality of protein than others. Proteins are valued into two categories; High Biological Value, and Low Biological Value.
High Biological Value is a good quality grade of protein. These contain all of the essential amino acids required for bodily functions. Poultry, beef and fish are considered to be candidates of High Biological Value because they contain all of the essential amino acids (ASPCA, 2015).
Low Biological Value is a low quality grade of protein. Whilst it is still a source of protein, it is missing at least one or more of the essential amino acids previously listed. It is needed to note what sources of food contain what amino acids, in order to find supplements or alternative sources to apply to their animals in order to keep their body functioning to a healthy standard. These would include foods such as vegetables and soy products (EUFIC, 2015).
Chemical Properties
Just like carbohydrates an lipids, protein contains carbon, hydrogen and oxygen. What differentiates protein from the previous mentioned is the added element of nitrogen. Nitrogen is the key element to building tissue (Jackson, 2015). Unlike both lipids and carbohydrates, the chemical arrangement of protein is set out in a three dimensional structure (Adam, 2015).
Proteins are made out of many amino acid chains; the chain bond is known as a peptide bond, made to form polypeptides (Kimball, 2011).
There are twenty amino acids total that can be used within the body. Nine of them are essential amino acids (found listed above), and the other remaining eleven are non-essential (Karadaghi, 2015).
Amino acids are further categorised into acids (a cation - contains a positive charge, can be rather acidic), bases (an anion – contains a negative charge, can be rather alkali), polar (charged at physiological pH level or can participate in hydrogen bonding), and non-polar (hydrocarbons, uncharged at physiological pH level) (Mystkowska, 2015).
There are four bonding processed for protein, and they form in the following order; Primary Protein Structure, Secondary Protein Structure, Tertiary Protein Structure, and Quaternary Protein Structure. On the right shows a video showing the visual chain that occurs in Primary, Secondary, Tertiary and Quaternary protein structures (Proneural, 2007).
The next process is known as a Tertiary Protein Structure; this is where amino acids are far apart within their chain, and are able to fold their shape into a globular three dimensional structure (Corey, 1951). This rounded structure creates cells such as enzymes and antibodies (Furness, 1983).
Quaternary Protein Structure is where complex polypeptides bond to other polypeptides and begin to structure a much more complex three dimensional structure than previous; these are used to form insulin and haemoglobins (Ophardt, 2003). Being the most complex form of protein; Quaternary structures are the most difficult protein to break down (St. Rosemary Educational Institution, 2015).
Although the structure or proteins can differentiate depending on the polypeptide formation, they will all contain an Amino Group, a Carboxylic Acid Group, a Hydrogen atom, an Alpha Carbon (which can also be known as a Central Carbon), and a Side Chain (University of Arizona, 2002). The only part of the structure that will change is the Side Chain; this is the area that will define which specific amino acid is which (NCBI, 2015). Figure 9 will show an example of the simple structre of an amino acid.
Dietary Sources
Sources of protein of High Biological Value (containing all of the essential Amino Acids) usually involve anything of animal origin. This is because protein is found in all organisms, and can be extracted from the DNA of animal cells. Examples include red meats, poultry, fish, eggs and dairy products (Weingarten, 2014).
Sources of protein of Low Biological Value (missing one or more of the essential Amino Acids) mostly involve vegetable protein sources. These are plant origin foods that do not need as many proteins as most animals require, and can only supplement some of what is needed for the body. These can be added onto a full meal, usually as a supplement or for a more balance within the diet. These include vegetables such as legumes, plants, grains, nuts, and seeds (Banna, 2014).
Due to plants being deficient in the essential amino acids, herbivorous animals may require supplements or alternative protein sources within their diets. If they only consumed their regular feed of vegetation, deficiencies of amino acids in the body could result in health deformities, which can be severe as proteins are needed to create their bodies. Kwashiorkor is a huge risk of developing; an ailment which has symptoms involving weight loss, loss of muscle mass, hair and skin quality decreases, diarrhoea, fatigue, and lacking the ability to effectively fight off infections. The liver also becomes damaged and enlarged, and the body begins to painfully swell (Marie, 2015).
The level of proteins needed in the diet will change on the age, species, and lifestyle of the animal. A sulcata tortoise for example is expected to be on a low protein diet, as they can grow at an astounding rate, and can receive defects in their body growth when exposed too much of the nutrient (Highfield, 2015). A production pig, however, needs lipase, an important amino acid; this is used to excel muscle growth and body mass, which is what farmers need to grow their pigs for meat production (Jenson, 1997).
Younger animals and animals lactating and/or gestating will need an increased amount of protein in their diets to assist them in growing new muscles, cells, and tissues for both the young animals and the offspring being formed (Robbins, 2015).
It is important not to overfeed animals with protein, as defects in the growth of the body occurs. Another example of this can be found in birds, who can form Angel Wings, a defect where the wings are unable to lie flat along the body when resting, and has become rigid and useless in the ability to fly (Johnson, 2011).
A Primary Protein Structure is a sequence of amino acids, usually in the beginning process of a simple chain. These are the smallest and simplest chains of amino acids, and are the easiest of proteins to break down (Street, 2009).
Secondary Protein Structure is the next sequence; these are regarded to be rather complex to break down due to their structure setting. The chain of amino acids are very compact and close, making the peptide bond more of a task for the body to digest and break apart, and can be found in two forms; Alpha Helix and Beta Pleated Sheets (Clark, 2004).
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An Alpha Helix is a three dimensional polypeptide chain in a tightly coiled in shape, consisting of rod-like structures. These are usually made to form hair on the body (Ross, 2015).
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A Beta Pleated Sheet consists of two or more straight chains of polypeptides, bonded together side by side through a hydrogen bond. This formation constitutes to the formation fibrous proteins, forming nails and other similar structures (Pauling et al, 1951).
Figure 9. An example of an Amino Acid Structure (Moniz, 2008).
Functions
Polypeptides, as mentioned previous, are the basic structure of all of the body cells, making it absolutely essential for our existence to be present (NCS Pearson, 2015). Because they are the natural building blocks of our body’s structure, they are also used to repair broken or damaged muscles and tissues (Annigan, 2015).
They’re also used to grow, replace, renew, and structure each individual cell, and provide the major functions for each cell role through DNA (Jung, 2010). Amino acids also make some of the body’s hormones, such as insulin (Bowen, 2001).
They can also be used to become a carrier, transporting substances through lipid bilayers within the body, and can act accordingly in similar mannerisms to enzymes (Alberts et al, 2002).
And in emergency situations, when the body is deficient in both lipids and carbohydrates, proteins can become a substitute for an energy source. However, this is very strenuous on the body, and usually involves the body digesting its own muscle mass, and will be used as a last resort if the body is highly malnourished (Scheinfeld, 2015).
Figure 8. A List of all 20 Amino Acids, verifying the essentials fromthe non-essentials (McKenzie, 2015).
Figure 10. A wave of water (Life Solutions, 2013).
Water is one of the most essential nutrients needed within the body. Whereas organisms can survive weeks without food, they can only last several days without water. The only acceptions to this are animals that are adapted to live in water-less environments and have adapted to conserve their fluid levels through evolution.
Despite its importance, water is constantly expelled from the body through urine, respiration, faeces, and sweat, and must be constantly replenished throughout the day.
Water is also used to balance the body's pH levels. pH stands for power of Hydrogen, and water, being H2O, contains two hydrogen atoms capable of affecting the pH balance within the body and maintaining homeostasis (Felicetti, 2012). Temperature control of the body is also regulated through water. Animals live in different environments across the world, and have to be able to adapt to the different climates of each area. Water provides them the means to regulate their temperature accordingly to the environment, and to help cool off in extreme heat through evaporation and sweating (The Water Resources, 2009).
Water is also needed to lubricate body tissues and cells, as well as joints, in order to allow the body to move and become mobile, which is essential for animals to be able to do if they wish to survive. Without movement, animals
lack the ability to hunt, forage, and escape predators, which is vital if they were to naturally survive (Agar, 2001). Water is the body's medium for carrying blood and lymph nodes. In fact, blood is made up half of plasma, which is almost completely made up of water, making it important to supply the body with suffiecient blood that the body has plenty of water to sustain blood levels (Blood, 2015).
Dietary Sources
Water evidently needs to be present in any animal's diet, and should be available ad lib regardless of the species. Water should only not be present if the animal is known to be at risk to drowning, to which may need monitoring or an alternative. Insects for example are known to be supplemented water through a daily spray of water into their environment, to avoid stranding or drowning themselves in water (Zomeren, 2015).
Although regular water can be given through a bowl or pool, water can also be provided through sprays, moss, and wet foods. Some animals don't enjoy drinking, like reptiles, and thus fruit and wet vegetables can be provided to supply water through consumption (see figure 13). Some complete foods are in a dry matter, but can be mixed in warm water if the animal is unwilling/reluctant to drink (Kleiman, 1996). It is important that all animals are provided with water; if they are reluctant to drink for a couple days, it is advised to get a diagnosis as the animal could become dehydrated (WebMD, 2005).
Although animals have different feeding requirements, it is estimated that an animal should consume enough water in mililitres equal to the number of kilocalories it recieves of energy daily (Agar, 2001).
Figure 11. The liquid composition of H2O (Tsang, 2004).
Physical Properties
Water can appear in three physical states; solid (ice), liquid (water), and gas (air). This is affected by the chemical components reacting to the exposing temperature surrounding it, altering its physical properties.
Water can freeze and solidify at the temperature 0 degrees celcius and lower, but will remain a liquid from temperatures 0-100 degrees celcius (see figure 11). Rising to and above 100 degrees celcius will convert the matter into a gas (Encyclopedia Britannica, 2015).
Chemical Properties
Water is commonly known as H2O, which shows us the chemicals that compose the nutrient. Water is made of two hydrogen atoms and one oxygen atom bonded together (NASA, 2015).
Their chemical bonding differs in regards to the temperature they are contained in which results in how the atoms bond. Atoms naturally move, and when they recieve heat, their
Figure 12. An illustration demonstrating the different bonds of H2O depending on the state it is in (Bustos, 2015).
It is important to know how the state of water changes so the animal's water can be checked regularly. Animals in hot environments such as vivariums may need a constant resupply of water, as it could evaporate over time from the overall temperature. Product animals kept outdoors will need their water being checked regularly, especially in winter, to make sure it doesn't freeze over and become undrinkable (DEFRA, 2001).
Function
Not only does water make up 60-70% of the body, but it is involved within all bodily functions. Our cells are made mostly from water, and without it we would not be able to sustain ourselves for a long period of time. Due to making up most of the body cells, water is able to transport materials through cells and body tissues, which supplies the entire body with other nutrients dissolved in the water (Science Museum, 2015).
Electrolytes are fluids in the blood that carry a positive electric charge (these have what is known as a cat ion) including potassium, sodium and magnesium (Mandal, 2014). See Minerals for more information on Electrolytes. Water is able to balance the electrolyte levels in the body, as they are commonly known to be dissolved within the water of the body. Too much electrolytes can then be expelled through urination, and in regards to sodium, through sweat (Bbraun, 2015).
movement increases until rapid enough to break a chemical bond. Therefore, the hotter the temperature gets, the looser the atomic bonds and phases of matter begin to physically alter (see figure 12 -The Concord Consortium, 2003).
Figure 13. A list of fruit and vegetables that contain high water content that animals could potentially use as a source of water (Healthy Shake Outlet, 2012).