Principles of Animal Nutrition ANIM 311

Principles of Animal Nutrition (ANIM 311)

• Course instructor: Benjamin Adjei Mensah (Ph.D.)
• Course location: Department of Animal Science, UG
• Course email: [email protected]/[email protected]
• Course title: Principles of Animal Nutrition (ANIM 311)

Concepts of Nutrition

• Lesson Objectives:
  • Introduce and discuss basic concepts of nutrition and nutritional terminology.
  • Introduce and discuss fundamental nutrients in animal diets.

The Science of Nutrition

• Nutrition: Deals with chemical reactions and physiological processes that transform food into body tissues and activities.
• Animal Nutrition: Scientific study of dietary needs, nutritional management, and animal health.
• Nutrients: Chemical elements or compounds in feed that support health, body maintenance, and productivity.
• Feed: Material ingested by animals that can be digested, absorbed, and utilized.
• Feedstuff: Material with nutritional value, used as feed.
• Ration: Total amount of feed consumed by an animal in a 24-hour period.
• Diet: Type and amount of feed an animal receives in its ration.
• Supplement: Extra feed to correct nutritional deficiencies in the basal diet.
• Concentrate: Highly concentrated source of nutrients, often diluted and mixed to form a supplement or complete feed.

Relationship between Animal and Animal Feed

• Composition of the animal body
• Composition of the animal feed

Table 1: Composition of Steers at Increasing Body Weights (%)

• Data presented in a table format showing the percentage composition (water, DM, protein, fat, ash) of steers at different body weights.

Table 2: % Composition of the Body of Different Animal Species

• Data presented in a table format showing the percentage composition (water, protein, fat, ash) of different animal species.

Composition of Some Feedstuffs (%)

• Data presented in a table format showing the percentage composition (water, protein, fat, carbohydrates, ash) of different feedstuffs (e.g., maize, maize stover, maize grain, soya beans, cassava, groundnut)

Feed Evaluation

• Classification of Feeds:
  • Traditional system (7 classes): roughages (carbonaceous and proteinaceous), succulents
  • NRC classification system (8 groups): dry forages, succulents, silages, energy feeds, protein concentrates, mineral supplements, vitamin supplements, non-nutritive feed additives.
• Assessment of feed quality:
  • Basic feed chemistry
  • Animal-based feed analysis

Handling and Storage of Samples

• Representativeness: Collected samples should represent the entire batch or load. Aim for a composite sample by taking multiple core samples from different points.
• Proper grinding, drying to preserve sample integrity.
• Avoid contamination
• Control storage temperatures to prevent spoilage or degradation.

Sampling Methods and Techniques

• Importance of combining multiple core samples and then sub-sampling
• Avoiding samples from exposed areas and considering seasonal variations
• Ensuring collected samples are truly representative to avoid poor analysis and wasted costs.

Tools and Equipment for Sampling

• List of sampling tools and equipment and their purpose

Best Practices and Recommendations

• Frequency of analysis depends on batch size, feed source variability, and cost considerations
• Regular analysis helps track consistency in feed quality.

Proximate Analysis

• Principles of proximate analysis:
  • Based on the elimination of water in feed
• The Determination of five proximate principles in the remaining dry matter:
  • Crude protein
  • Ether extract
  • Ash
  • Crude fiber
  • Nitrogen free extract

Dry Matter vs. As-Fed

• Importance of comparing feed values on a dry matter basis as all feeds contain water.

Dry Matter (DM)

• Determination of dry matter:
  • Drying test material at 105°C overnight in an oven
• Calculation of dry matter and possible errors in analysis.

Crude Protein (CP)

• Kjeldahl Method: Developed by Johan Kjeldahl in 1883, used for protein estimation.
• Protein estimation based on nitrogen content.

Kjeldahl Procedure (Steps)

• Digestion :chemical reaction with acids
• Distillation: Separation of ammonia gas
• Titration: measurement of ammonia

Ether Extract (EE)

• Procedure for extracting fat.
• Limitations of the test in estimating feed caloric value and quality of fat.

Ash

• Ash determination
• High ash values indicate feed contamination.

Crude Fiber (CF)

• Procedure for estimating crude fiber: Boiled in acid and alkali solutions.
• Calculation of crude fiber

Nitrogen-Free Extract (NFE)

• Formula for calculating NFE
• NFE is a calculated and not measured value.

Fibre Estimation

• Neutral Detergent Fiber (NDF) and Acid Detergent Fiber (ADF)
• Methods and formulas for determining NDF and ADF.

Why is Nutrition Important? (Reasons)

• Human Dependence: Livestock depend on humans for balanced diets in controlled environments.
• Human-provided nutrition aligns livestock productivity with agricultural needs.
• Economics of Production: Feed costs typically account for a significant portion of livestock production costs. Efficiently balanced diets reduce costs.
• Environmental Protection: Balanced diets can reduce methane emissions from ruminant livestock. Optimized feeding leads to better manure quality.
• Enhanced Food Production with Limited Resources: Optimized feed efficiency allowing animals to produce more meat, milk, eggs with less feed. Adaptation to local conditions allowing efficient use of available resources to reduce reliance on imported feed.
• Human Health and Enhanced Food Quality: Nutritionally enhanced animal products and reduced antibiotic residues and contamination.