Module ANUT-300-500-12

Part 1: The Theory and Practice of Animal Nutrition

Aggregated document(s) for Part 1 can be downloaded from the adjacent icon(s).

On completion of Part 1 you should be able to:

• Describe the major components of diets for livestock: energy and nutrients
• Explain the importance of ‘anti-nutrients’

All living animals, and indeed the cells they are made of, have the same basic requirements for energy, protein (as amino acids), minerals, vitamins and water.  There is considerable confusion when the terms ‘energy’ and ‘protein’ are used in discussing feeds and their nutritive value. For all animals, and especially ruminants, feeds cannot provide purely ‘energy’ or ‘protein’. All sources of protein can contribute in some way to the energy metabolism of the animal. In ruminants, even sources of purified carbohydrate, containing no protein as such, provide a source of energy for rumen microbes to grow and the microbes then supply additional protein and amino acids to the host animal. We have lectures that focus on ‘energy’ and ‘protein’ and, from what has just been said, this may seem inappropriate. However, there are some feeds that do provide more energy relative to protein than other feeds. Conversely, there are feeds that provide more protein relative to energy. Such sources are referred to as ‘energy’ and ‘protein’ concentrates. It is important not to think in terms of absolutes when it comes to defining feeds as sources of energy or protein. Most protein and energy concentrates will also provide vitamins, minerals and small amounts of water.

Topic 01: What are the Major Nutrients

On completion of this topic you should be able to:

• Describe the major components of diets for livestock: energy and nutrients
• Explain the importance of ‘anti-nutrients’

Topic 02: Energy Requirements

On completion of this topic you should be able to:

• Describe the requirements for energy by livestock to support their survival and various forms of production

Topic 03: Digestible and Metabolisable Energy

On completion of this topic you should be able to:

• Describe the concept of digestible energy.
• Describe the concept of metabolisable energy.
• Discuss the nutritional factors affecting DE and ME

Topic 04: The Interactions between Energy and Protein

On completion of this topic you should be able to:

• Describe the importance of energy on protein metabolism
• Describe why the provision of energy and protein substrates effect the efficiency microbial protein production
• Describe why urea supplementation can be more effective with the provision of an energy source

Topic 05: Supplying Protein for Ruminants

On completion of this topic you should be able to:

• Describe the minimal requirements for protein and amino acids to support maintenance and production of livestock tissues.
• Describe the additional dietary requirements for protein and amino acids that are the consequence of losses of dietary protein and amino acids during digestion and metabolism

Topic 06: From Feed Components to Meat, Milk and Wool

On completion of this topic you should be able to:

• Understand how large molecules in feed ingredients are digested to smaller sub-units, absorbed and then synthesised into rather similar large molecules in cells and tissues.
• Describe how energy is released during degradation of large molecules (polymers to monomers) and reused in synthesis of large molecule

Part 2: Animal feeds – Matching feeds with needs

Aggregated document(s) for Part 2 can be downloaded from the adjacent icon(s).

On completion of Part 2 you should be able to:

• Develop an understanding of the computer-based and manual approaches to formulating diets.

• Students are encouraged to try a range of software packages, therefore an ability ‘navigate’ the software environment of nutrition and diet formulation packages is an important learning objective. The ability to adapt to and use new diet formulation software is an essential skill for any nutritionist today.

With the ingredients selected and evaluated, the next step is to put the information into a formula that will calculate the required diet. This can be done using manual calculation, spreadsheet programs or least–cost formulation computer software packages. Diet formulation is not a simple matter and is best be left to qualified nutritionists. Essentially, it is a process that matches the nutrient requirements of the animal with the nutrients present in available ingredients. It must consider not only the many individual nutritional components, such as energy, amino acids, minerals and vitamins, but also ensure that important ratios, such as energy:amino acids and calcium:phosphorus are maintained within an acceptable range. The process should provide safety margins that avoid unwanted surprises, while at the same time avoiding costly over–formulation. Finally, since the marketplace is a competitive arena, it must also consider economics at all times. Because diet formulation is quite complex when carried out properly, computers are used to reduce demands on time and avoid calculation errors, and to provide flexibility. Manual methods can still be used, but they are very limiting in scope and capability.

Topic 07: Formulating diets – introduction

On completion of this topic you should be able to:

• Develop an understanding of the computer-based and manual approaches to formulating diets.

• Students are encouraged to try a range of software packages, therefore an ability ‘navigate’ the software environment of nutrition and diet formulation packages is an important learning objective. The ability to adapt to and use new diet formulation software is an essential skill for any nutritionist today.

Topic 08: Assessing the Nutritive Value of Feeds – Physical Characteristics

On completion of this topic you should be able to:

• Explain the importance of feed analysis for designing feeding programs
• Describe various techniques for assessing feed quality.
• Describe the components of a proximate analysis.

Topic 09: Assessing the Nutritive Value of Feeds – Bioassy

On completion of this topic you should be able to:

• Describe the meaning of true digestibility and how it is measured.
• Describe the strengths and weaknesses of an in sacco digestibility analysis.
• Describe the importance of digestibility as a measure of feed quality and the difference between apparent digestibility and true digestibility

Topic 10: Predicting Nutrient Digestibilities

On completion of this topic you should be able to:

• Describe the importance in invitro analysis methods for experimentation and commercial feed analyses.
• Identify the potential weaknesses of in vitro methods of analysis.
• Describe why there is the potential for inaccuracies in NIRS analyses, yet why it is the most widely used analysis method.

Topic 11: Nutritive Values of Individual Ingredients

On completion of this topic you should be able to:

• Describe the importance in invitro analysis methods for experimentation and commercial feed analyses.
• Identify the potential weaknesses of in vitro methods of analysis.
• Describe why there is the potential for inaccuracies in NIRS analyses, yet why it is the most widely used analysis method.

Topic 12: Understanding Nutrient Requirements and Diet Formulation

On completion of this topic you should be able to:

• Explain the importance of understanding nutrient requirements for diet formulation.
• Source information on animal nutritional requirements and use this information toward developing diets.
• Have an awareness of some decision support software for the development of animal diets and prediction of animal performance.

Topic 13: Practical Considerations when Manufacturing and Selecting Feeds

On completion of this topic you should be able to:

• Apply some important practical considerations when designing animal diets.
• Explain the importance of feed analysis based on variation in quality between and within feedstuff types.

Part 3: Grain Feeding

Aggregated document(s) for Part 3 can be downloaded from the adjacent icon(s).

On completion of Part 3 you should be able to:

• Discuss the animal factors influencing starch digestion in ruminants.
• Discuss the dietary factors influencing starch digestion in ruminants.
• Describe the biochemical processes of starch digestion and the importance of volatile fatty acid production to this process.

Ruminant animals have evolved with the unique capacity to digest cellulose. The digestive tract of ruminants has developed in a way that allows them to survive and produce on roughage-based diets. In recent years, there has been an increasing incentive to feed concentrate diets based on cereal grains. The feeding of grain-based diets can improve animal production and produce a meat product that is more desirable to the consumer.

As ruminants have evolved to consume roughage-based diets, the provision of grain-based diets can cause digestive problems that may lead to morbidity and mortality. Therefore, careful management of grain-based feeding to ruminants is required. With careful management, significant improvements in the quality and quantity of production (milk, wool, meat and reproduction) can be achieved.

This module will provide you with an understanding of the metabolic implications associated with introducing grain-based diets to ruminant production systems and therefore an understanding of the management strategies available for commercial production.

Topic 14: Digestion of Grain

On completion of this topic you should be able to:

• Discuss the animal factors influencing starch digestion in ruminants.
• Discuss the dietary factors influencing starch digestion in ruminants.
• Describe the biochemical processes of starch digestion and the importance of volatile fatty acid production to this process.

Topic 15: Characteristics of Grain that Influence Starch Digestion

On completion of this topic you should be able to:

• Describe the dietary factors influencing starch digestion in ruminant and monogastric animals.
• Explain the importance of non-starch polysaccharides on the digestibility of grains for monogastric animals.
• Describe the processes of starch digestion in ruminant animals.

Topic 16: Methods of Processing Grain

On completion of this topic you should be able to:

• Discuss the various types of grain processing available.
• Explain how grain processing can impact on the digestion of grains.
• Discuss the impact of grain type on the selection of processing method.

Topic 17: Grain Storage, Exogenous Enzymes and Germination

On completion of this topic you should be able to:

• Define non-starch polysaccharides and their importance to the nutritive value of feeds.
• Explain the implications of oil/fat content of feedstuffs for storage.
• Discuss the impact of the duration of feed storage on feed quality and if this is variable according to feedstuff.

Topic 18: Chemical and physical treatment of roughages to improve digestibility

On completion of this topic you should be able to:

• Describe some chemical treatments that can be applied to low quality feeds to improve their nutritive value to ruminants.
• Explain why particle size can impact on the digestion of roughages.
• Describe some physical treatment options for improving the digestibility of low quality roughage sources for ruminants.
• Explain why urea is often used for improving the utilisation of low quality roughages.

Topic 19: Hormonal Growth Promotants and Nutritional Requirements

On completion of this topic you should be able to:

• Describe why hormonal growth promotants are used in the Australian beef industry.
• Discuss the banning of HGP usage in some countries.
• Describe the mechanisms by which improved growth is achieved from the use of HGP’s and production situations in which their use is not appropriate.

Topic 20: Growth Promotants for Pigs and Poultry

On completion of this topic you should be able to:

• Discuss the need for alternatives to antibiotic use in monogastric feeding systems.
• Define probiotics and prebiotics and how they can be used to improve production in monogastric production systems.
• Describe how organic acids and feed enzymes can be used in monogastric diets to achieve improved production.
• Describe why hormones are not used in commercial poultry production systems

Topic 21: Acidosis and its Control in Ruminants

On completion of this topic you should be able to:

• Describe the dietary conditions that expose ruminants to high risk of acidosis.
• Apply feeding management strategies that will minimize the risk of acidosis and maximize production outcomes.
• Discuss the mechanisms of managing acidosis by the use of antibiotics and probiotics.
• Explain how grain processing and manipulating the site of digestion can be used as strategies for managing acidosis

Part 4: Nutrition management for grazing animals

Aggregated document(s) for Part 4 can be downloaded from the adjacent icon(s).

On completion of Part 4 you should be able to:

• Discuss the importance of efficient microbial activity on the digestion of nutrients.
• Discuss the importance of the provision of carbohydrate and ammonia to rumen bacteria.
• Describe how changes in diets of ruminants can alter volatile fatty acid production and the impact of these changes on energy availability to the animal.
• Describe the ideal rumen conditions for maximising microbial protein production

Feeding ruminant animals is often described in industry as feeding two animals – feeding the livestock (sheep or cattle) and feeding the “rumen bugs”. While this concept has some merit, it is hoped that by the end of this topic you will understand that as animal managers we are in fact feeding millions of animal and plants that make up the “rumen microflora and fauna”. This is important to understand as the balance of the rumen bacteria, protozoa and fungi will change with diet composition and this can influence the effectiveness of the feeding strategy.

The rumen bacteria have a particular requirement for ammonia, which allows the production of microbial protein. This is a unique ability of ruminants, allowing the feeding of non-protein nitrogen sources (such as urea) that will enable the production of protein. In this topic you will cover the process of digestion by the rumen bacteria and the important roles that fungi and protozoa play. The mechanisms of microbial protein production and the factors influencing the efficiency of this process will also be introduced.

Topic 22: Providing Nutrients for the Rumen

On completion of this topic you should be able to:

• Discuss the importance of efficient microbial activity on the digestion of nutrients.
• Discuss the importance of the provision of carbohydrate and ammonia to rumen bacteria.
• Describe how changes in diets of ruminants can alter volatile fatty acid production and the impact of these changes on energy availability to the animal.
• Describe the ideal rumen conditions for maximising microbial protein production.

Topic 23: Factors Influencing the Voluntary Intake of Food

On completion of this topic you should be able to:

• Appreciate the importance of knowing the voluntary intake of food by ruminants in the particular circumstances of grazing, as compared with penned or feed-lot animals
• Understand the difference between the factors that are animal attributes and those that are feed attributes
• Understand the importance of distinguishing between the mature size, stage of maturity and body condition of the animal in assessing its potential intake of food
• Understand the effects of feed quality and feed availability and their interaction with selective grazing
• Understand the principles of substitution when supplements are fed to grazing animals

Topic 24: Diet Selection

On completion of this topic you should be able to:

• Define neophobia and describe its importance in feeding systems for sheep.
• Discuss the importance of post-ingestive feedback on diet selection in animals.
• Describe practical examples of social transmission of feeding behaviour and how it can be used as a management strategy for supplementation and intensive feeding production systems.
• Discuss the behavioural and pathological factors impacting on diet selection.

Topic 25: Principles of Supplementary Feeding in Grazing Systems

On completion of this topic you should be able to:

• Explain the differences between the processes of supplementation, substitution and complementation
• Discuss why true supplementation does not often occur under grazing conditions
• Define the factors which influence the level of substitution between pasture and supplement
• Define the grazing situations in which substitution and complementation are likely to occur
• Use this information and information about the nutrient requirements of grazing animals to devise supplementary feeding regimens for different classes of livestock

Topic 26: Supplementary Feeding for Wool Growth and Reproduction

On completion of this topic you should be able to:

• Explain the differences between the processes of supplementation, substitution and complementation
• Discuss why true supplementation does not often occur under grazing conditions
• Define the factors which influence the level of substitution between pasture and supplement
• Define the grazing situations in which substitution and complementation are likely to occur
• Use this information and information about the nutrient requirements of grazing animals to devise supplementary feeding regimens for different classes of livestock

Topic 27: Supplementation of Ruminants – Dry Pasture

On completion of this topic you should be able to:

• Develop a practical supplementation program for sheep grazing pastures of low digestibility.
• Describe the range of supplement delivery system available to producers and the benefits/drawbacks of each.
• Compare and contrast the situations when NPN and true protein supplementation are appropriate.
• Understand why supplementing sheep and cattle with urea-based supplements will increase feed utilisation and feed consumption.

Topic 28: Ketosis and Urea Poisoning

On completion of this topic you should be able to:

• Describe the management strategies available to sheep producers to minimise the risk of pregnancy toxaemia.
• Describe the mechanisms of ketosis and the production and nutrition conditions that predispose animals to risk of developing ketosis.
• Describe why urea toxicity can be fatal to ruminants and apply management strategies that minimise the risk of urea toxicity.

Topic 29: Precision Nutrition for Grazing Sheep

On completion of this topic you should:

• Understand the concepts of precision nutrition
• Be able to identify situations where precision nutrition of sheep is cost-effective
• Have a basic knowledge of trigger points and how to set these foe supplementary feeding
• Understand the principles and practical aspects of feeding for precision management systems
• Understand nutritional constraints in the context of other limiting factors

Part 5: Companion Animal Nutrition

Aggregated document(s) for Part 5 can be downloaded from the adjacent icon(s).

On completion of Part 5 you should:

• Understand the concepts of feeding companion animals based on their nutrient and energy requirements
• Understand the nutritional needs of dogs and cats in relation to their phylogeny and ancestral origins
• Be able to apply appropriate feeding strategies for dogs and cats in different life stages and physiological states
• Have a basic knowledge of the dietary factors that impact on companion animal health and some dietary strategies for disease prevention
• Understand the nutritional claims of pet foods and how these are substantiated

The first commercial dog food was produced and sold in London in 1860 by James Spratt and by the mid 1930’s there were several brands available on the supermarket shelves. By 1992 commercially prepared dog foods accounted for more than 60 percent of all food fed to dogs in Australia. This century has seen an increased awareness of the nutritional needs of dogs and cats, with an increased focus on animal health. The ready availability of nutritionally complete and balanced commercial pet foods has greatly reduced the incidence of nutritional deficiencies. Dogs and cats of today are more likely to suffer nutritional imbalances related to over-consumption and over-supplementation than deficiencies due to nutritionally inadequate diets.

Topic 30: Nutrient requirements of dogs and cats

The basic nutrient requirements of dogs and cats is similar to those of all animals; energy, protein, vitamins, minerals and water.  However, companion animals, and in particular cats, have a unique suite of requirements outside those previously discussed in this text.  Also, the objective of companion animal nutrition is to maintain a healthy pet for many years, unlike many other domestic animal species.

Water and energy requirements are discussed in this topic with specific reference to the differences between cats and dogs.

Topic 31: Feeding throughout the life cycle

With respect to companion animals this topic covers:

• Feeding management
• Pregnancy and lactation
• Growth
• Geriatric nutrition

Topic 32: Diet related health disorders in dogs and cats

With respect to companion animals this topic covers:

• Obesity Diabetes
• Mellitus Periodontal disease
• Inherited metabolic disorders
• Vitamin deficiencies and excesses

Amongst the array of health problems afflicting our canine and feline companions, there are those that can be classified as diet-related, being either directly attributable to the diet; or the condition being ameliorated by dietary intervention even where the diet is not the cause of the disease (e.g. some inherited metabolic disorders). This topic covers some of the more common diet-related health disorders in dogs and cats.