Wildlife NutritionNutrients - WaterWeek 8

Nutrients

Nutrients are substances, elements or ingredients that are involved in the metabolic process of an organism. Generally, nutrients can be classified into one of five major categories:

WaterMineralsVitaminsProteinsEnergy

WaterOf all the nutrients, water is the most vital. The animal can go for prolonged periods with deficiencies of all the other nutrients, and recover, however, even periods of less than several hours without water in some form may be fatal for some species.Water constitutes the single largest component of an animal body. Water content of the body may range from as high as 80% in a young lean animal to as low as 40% in an mature fat animal

Factors Influencing Water Content of the Body

1. Species of Animal:

2. Age/Stage of Growth:Young > Mature

3. Body Conditioning:

Lean > Fat

Major Functions of Water

Primary constituent of body fluids:Cytoplasm – 95%Blood – 85%Lymphatic Fluid – 90%

Digestive Functions:Solvent for Taste Co-Factor in Digestion and Metabolism Transport Medium

Physiological FunctionsThermo RegulationGas ExchangeLubrication – Joints, vision (tears), viscous of eye Cushion -nervous system, placenta

Factors Influencing Water Requirements

1. Species: Reptiles > Avian > Mammals

2. Age/Stage of Growth: Young > Mature

3. Body Condition: Lean > Fat

4. Body Size:(SA/W): Small > Large Overall Biomass: Large > Small

5. Sex: Female > Male

6. Reproductive Condition:Gestating > non-GestatingLactating > non-Lactating

7. Activity: Active > Sedentary

8. Climatic Conditions: Hot > Cool Dry > Wet

9. Diet:

10. Metabolic Efficiency:

Sources of Water

1. Free Water (Drinking Water)Water freely consumed by the animal on an ad libitum basis.

Considerations:

Water Quantity: Most animals consume water at the rate of approximately 5-8% BW/Day. This amount will vary based on a number of conditions. When estimating amount of water needed, several additional factors should be considered:

Potential evaporation

Drinking behavior of the animal

Water Quality: The quality of the water may be as important as the quantity available. Water containing contaminants, either chemical or biological, may reduce the availability to the animal.

2. Dietary Water (Food Water)The water content of the food consumed has a great impact on the amount of free water needed by the animal.

Forages: Fresh green vegetation – 65-80% H20 Cured Vegetation - < 10% H20

Grains: Soft (green) grains - 25-40% H20 Hard (dried) grains 10-20% H20

Meat: Fresh 85% H20

Fruits: > 75% H20

3. Metabolic WaterFor many species water produced as a result of metabolic reactions within the body serve as a major source of water to meet daily water requirements.

Water Yields from Nutrient Metabolism:Carbohydrates 60 % H20

Proteins 40 % H20

Lipids/Oils 110 %H20

Sources of Water Losses

1. Urinary LossesIn normal healthy animals, a major pathway for water loss is through metabolic waste product elimination in the urine. Factors influencing urinary water loss are:

Nitrogen content of the diet.

Mineral balance – especially Na & Cl.

2. Fecal LossesReabsorption of water in the colon is not totally efficient, with fecal materials ranging from 65-80% H2O.

Factors influencing fecal water loss are:Species of animal

Health

Production demands

Diet

3. Evaporative Water LossesThe largest single water loss is through evaporation, primarily across the lungs.

Factors influencing evaporative water loss are:

Health of the animalAmbient Temperature/Relative HumidityActivity level.