ANSWERS

1. Define nutrition.
   Nutrition is defined as the process of taking in nutrients and assimilating and utilising them. Proper nutrition is essential for the maintenance of optimum healthy and activity in all animals.
2. What is meant by a nutrient?
   A nutrient is a food or substance that nourishes. Nutrients are the components of food (solid or liquid) which, when ingested, supply any or all of the following:
   • Energy giving materials.
   • Materials for growth.
   • Materials for repair.
   • Materials for reproduction.
   • Substances required to initiate or regulate the processes listed above.
3. What is meant by an essential nutrient?
   An essential nutrient is one that cannot be synthesised in the body, and therefore must be provided by a dietary source.
4. What is meant by the energy content of a food?
   Energy content is the amount of each nutrient in a food providing fuel for metabolism. Carbohydrates + Fats + Protein = Energy Content.
5. Why are fats the most efficient fuel for metabolism?
   Fats supply twice as much energy per gram than carbohydrates and protein.
6. What may result if energy intake is in excess of energy expenditure over a long period of time?
   • Obesity.
   • Growth abnormalities in young animals.
7. What may result if energy intake is inadequate?
   Weight loss.
   Poor growth in young animals.
8. Define gross energy.
   Gross energy is the maximum amount of energy that can be released by a food. It is not necessarily digested and absorbed by the animal.
9. Define digestible energy.
   Digestible energy is that derived from food following absorption into the body after digestion. Gross energy - faecal losses = digestible energy.
10. Define metabolisable energy.
    Metabolisable energy is the energy ultimately utilised by the tissues of the body. Digestible energy - urinary losses = metabolisable energy.
11. What is meant by the basal metabolic rate?
    The basal metabolic rate (BMR) is an estimation of the rate of metabolism in the body required for the function of the respiratory, circulatory and urinary systems.
12. What factors may affect the basal metabolic rate (BMR)?
    • Body weight.
    • Body composition.
    • Age.
    • Hormonal status.
13. Define thermogenesis.
    Thermogenesis is an increase in metabolic rate over the basal level including the cost of digesting, absorbing and utilising nutrients. It is affected by exercise, stress and temperature.
14. List physiological states that would increase the energy requirements of a healthy adult cat or dog.
    • Activity level.
    • Gestation.
    • Lactation.
    • Cold.
    • Heat.
15. State how the energy requirements of a healthy, moderately active adult dog would be calculated.
    i) Work out the BER (Basal Energy Requirement per 24hrs) by using the following calculation: 30 x bodyweight (kg) + 70. This gives energy required in kilocalories.
    ii) Now work out the maintenance energy requirement (MER) MER = BER x 1.1
16. State how the energy requirements of a healthy, moderately active adult cat would be calculated.
    Maintenance energy requirement (MER) = 80 kcal per kilogram of body weight
17. A lactating queen or bitch requires increased energy. State how this is calculated. Energy required = MER x (1 + 0.25 x number in litter)
18. Why are nutrient requirements usually expressed in terms of the maintenance energy (ME) concentration?
    Nutrient requirements are expressed in terms of the ME concentration in order to be able to apply values to any type of diet regardless of water content, nutrient content or overall energy value.
19. Why are the estimated energy requirements of dogs calculated in a different method than those of other species?
    Dogs are unique in that there is an enormous variation in normal adult body weights. Subsequently, estimations of energy requirements are calculated from an allometric equation, which relates energy requirements to the animal's metabolic body weight.
20. What is meant by the biologic value of a food?
    The relationship between the quantity of a nutrient absorbed and the quantity utilised (retained) by the body's tissues. Biologic value = grams retained divided by grams absorbed.