Classes of Nutrients
Classes of Nutrients
General Overview
This study guide covers major classes of nutrients, their definitions, implications in animal sciences, and specific factors affecting nutrition in animals.
Learning Objectives
Define the various aspects that encompass the term “nutrition”.
Understand the concept of “feed efficiency”.
List and describe the major properties of the main classes of nutrients.
Understand some key differences among various species of animals.
Definition of Nutrition
Nutrition: A series of processes by which an organism takes in and assimilates food for promoting growth, replacing tissue (maintenance), and production (e.g., milk, eggs, wool).
Definition of a Nutrient
Nutrient: Any chemical compound in the diet that supports the physiological functions necessary for growth, reproduction, work, lactation, or maintenance of life processes.
Essential Nutrient
Essential Nutrient: A nutrient that is required for specific physiological functions and must be supplied in the diet as the body cannot synthesize sufficient amounts.
Criteria for an Essential Nutrient:
Eliminate deficiency: Remove the nutrient from the diet.
Reintroduce the nutrient: Add it back.
Observe results: If reintroduction leads to the correction of an abnormality or condition, it confirms essentiality.
Examples of Essential Nutrients
Calcium: This nutrient is crucial for various bodily functions. Deficiency can lead to conditions such as:
Milk Fever: A complication occurring in dairy cows due to low calcium levels.
Vitamin D: Aids calcium and phosphorus absorption; deficiencies can lead to conditions like:
Rickets: A disease linked to insufficient vitamin D, leading to improper bone formation.
Definitions in the Context of Nutrition
Food: Edible material providing nutrients, commonly used in companion animal applications and refers to animal feed, especially for domesticated farm animals.
Feed: The food used for animals; encompasses any material made into or used as food to supply nutrients.
Feedstuff: A component in the diet, could refer to a diet overall or a specific mix supplying nutrients.
Nutrition as a Science
Nutrition is a discipline focused on:
The needs of the animal body for specific essential factors such as:
Water
Energy
Lipids (fats)
Proteins (amino acids)
Minerals
Vitamins
Notably, carbohydrates are not considered essential.
Analysis of various foods and diets.
Effects of nutrient deficiencies.
The impact of non-nutrients (e.g., antibiotics, enzymes).
Effects of physical properties (e.g., density, particle size).
Importance of Forage Particle Size
Crucial for cattle as it helps control intake and is important for rumination.
Rumen particle size: Approximately 2-4 inches long is considered ideal for optimal digestion and nutrient absorption.
Factors Affecting Nutrition
Stage of Lifecycle: Different phases of life require varying nutrient levels.
Environment: Conditions such as temperature and habitat impact nutritional needs.
Genetics: Different breeds have unique nutritional requirements.
Physical Activity: Varies among animal species; active animals need more energy.
Health Status: Sick animals typically have decreased appetites affecting nutrient intake.
Specific Lifecycle Considerations
Gestation/Lactation: Higher energy and protein are necessary.
Adult Animals: Basic maintenance energy requirements.
Young, Rapidly Growing Animals: Require higher energy for growth versus maintenance.
Environmental Influences on Nutrition
Effects of drought on forage quality and production requires animals to consume more to meet energy needs.
Heat Stress: Decreases appetite, leading to reduced production of milk, eggs, or meat.
Cold Stress: Increases energy requirements to maintain body temperature.
Genetic Influences
High yielding dairy cows demand more energy and nutrient intake compared to others. Different breeds and genetic lines influence nutritional requirements significantly.
Water - The Most Crucial Nutrient
Animals require 2 to 5 times more water than dry food intake.
Water comprises 45-85% of an animal's body:
Muscle Tissue: About 70% water.
Fat Tissue: Around 5% water.
Cellular Composition of Water
Intracellular Fluid: Comprises about 70% of body water.
Various cell components include:
Nucleus, Ribosomes, Golgi apparatus, Mitochondria, etc.
Sources of Water
Drinking, through food, and metabolic water produced from biochemical reactions (e.g., glucose metabolism).
Water Loss
Routes of water loss include:
Urine: 20-60%.
Skin and Lungs: 10-30%.
Feces: Varies depending on animal health status.
Carbohydrates
Carbohydrates serve as the cheapest source of metabolic energy and consist of repeating units of CH2O derived from photosynthesis.
Two types:
Structural Carbohydrates: Such as cellulose and hemicellulose found in plant cell walls.
Nonstructural Carbohydrates: Include sugars and starches that are quick and easy to digest.
Specific Energy Needs
Example:
Top milk-producing cow in 2017: 77,480 lbs of milk in a year, averaging 212 lbs of milk daily equivalent to roughly 50,000 calories/day.
Comparison: Michael Phelps (swimmer) and racehorses have high daily caloric needs (22,250 cal/day).
Lipids
Lipids: Soluble in organic solvents, providing 2.25 times more energy than carbohydrates and proteins.
Two major types:
Fats: Long-chain, saturated, solid at room temperature (e.g., tallow).
Oils: Long-chain, unsaturated, liquid at room temperature (e.g., soybean oil).
Functions of Lipids in Diet
Energy source, solvent for fat-soluble vitamins, source of essential fatty acids, increases palatability of feeds.
Proteins
Proteins are the most expensive nutrient in diets, made up of carbon, oxygen, hydrogen, and nitrogen and are essential sources of amino acids.
Vitamins
Origin of the term “vitamin” from "vital amine" indicating its essential role in metabolism; not synthesized sufficiently within the body.
Fat-soluble Vitamins: Stored in the body. Include:
Vitamin A
Vitamin D
Vitamin E
Vitamin K
Fortification vs. Enrichment
Fortification: Adding nutrients not already present.
Enrichment: Replenishing nutrients lost during processing.
Water-Soluble Vitamins
Water-soluble vitamins, including B vitamins and Vitamin C, must be provided regularly as they cannot be stored.
Minerals
Inorganic nutrients that cannot be synthesized. Essential for various physiological processes but require a proper balance—over or under feeding can cause severe health issues.
Macrominerals vs. Microminerals
Macrominerals: Required in larger amounts (>100 ppm). Examples include:
Calcium
Sodium & Chloride (Salt)
Potassium
Magnesium
Sulfur
Microminerals (Trace Minerals): Required in smaller amounts (<100 ppm). Common examples:
Selenium
Copper
Iron
Zinc
Cobalt
Feeds and Their Classifications
Forage or
Classes of Nutrients
General Overview
This study guide covers major classes of nutrients, their definitions, implications in animal sciences, and specific factors affecting nutrition in animals.
Learning Objectives
Define the various aspects that encompass the term “nutrition”.
Understand the concept of “feed efficiency”.
List and describe the major properties of the main classes of nutrients.
Understand some key differences among various species of animals.
Definition of Nutrition
Nutrition: A series of processes by which an organism takes in and assimilates food for promoting growth, replacing tissue (maintenance), and production (e.g., milk, eggs, wool).
Definition of a Nutrient
Nutrient: Any chemical compound in the diet that supports the physiological functions necessary for growth, reproduction, work, lactation, or maintenance of life processes.
Essential Nutrient
Essential Nutrient: A nutrient that is required for specific physiological functions and must be supplied in the diet as the body cannot synthesize sufficient amounts.
Criteria for an Essential Nutrient:
Eliminate deficiency: Remove the nutrient from the diet.
Reintroduce the nutrient: Add it back.
Observe results: If reintroduction leads to the correction of an abnormality or condition, it confirms essentiality.
Examples of Essential Nutrients
Calcium: This nutrient is crucial for various bodily functions. Deficiency can lead to conditions such as:
Milk Fever: A complication occurring in dairy cows due to low calcium levels.
Vitamin D: Aids calcium and phosphorus absorption; deficiencies can lead to conditions like:
Rickets: A disease linked to insufficient vitamin D, leading to improper bone formation.
Definitions in the Context of Nutrition
Food: Edible material providing nutrients, commonly used in companion animal applications and refers to animal feed, especially for domesticated farm animals.
Feed: The actual mixture of food materials provided to animals to supply their daily nutrient requirements.
Feedstuff: Any individual component or ingredient in the diet (e.g., corn, soybean meal, alfalfa hay) that provides nutrients.
Feed Efficiency
Feed Efficiency: A measure of how effectively an animal converts feed into a desired output (growth, milk, etc.).
Feed to Gain Ratio (F:G): Calculated as the amount of feed consumed divided by the weight gain (F:G = \frac{\text{Feed Intake}}{\text{Weight Gain}}). Lower values indicate higher efficiency.
Gain to Feed Ratio (G:F): The inverse calculation (G:F = \frac{\text{Weight Gain}}{\text{Feed Intake}}). Higher values indicate higher efficiency.
Nutrition as a Science
Nutrition is a discipline focused on:
The needs of the animal body for specific essential factors such as:
Water
Energy
Lipids (fats)
Proteins (amino acids)
Minerals
Vitamins
Notably, carbohydrates are not considered essential.
Analysis of various foods and diets.
Effects of nutrient deficiencies.
The impact of non-nutrients (e.g., antibiotics, enzymes).
Effects of physical properties (e.g., density, particle size).
Importance of Forage Particle Size
Crucial for cattle as it helps control intake and is important for rumination.
Rumen particle size: Approximately 2-4 inches long is considered ideal for optimal digestion and nutrient absorption.
Factors Affecting Nutrition
Stage of Lifecycle: Different phases of life require varying nutrient levels.
Environment: Conditions such as temperature and habitat impact nutritional needs.
Genetics: Different breeds have unique nutritional requirements.
Physical Activity: Varies among animal species; active animals need more energy.
Health Status: Sick animals typically have decreased appetites affecting nutrient intake.
Specific Lifecycle Considerations
Gestation/Lactation: Higher energy and protein are necessary.
Adult Animals: Basic maintenance energy requirements.
Young, Rapidly Growing Animals: Require higher energy for growth versus maintenance.
Environmental Influences on Nutrition
Effects of drought on forage quality and production requires animals to consume more to meet energy needs.
Heat Stress: Decreases appetite, leading to reduced production of milk, eggs, or meat.
Cold Stress: Increases energy requirements to maintain body temperature.
Genetic Influences
High yielding dairy cows demand more energy and nutrient intake compared to others. Different breeds and genetic lines influence nutritional requirements significantly.
Water - The Most Crucial Nutrient
Animals require 2 to 5 times more water than dry food intake.
Water comprises 45-85% of an animal's body:
Muscle Tissue: About 70% water.
Fat Tissue: Around 5% water.
Cellular Composition of Water
Intracellular Fluid: Comprises about 70% of body water.
Various cell components include:
Nucleus, Ribosomes, Golgi apparatus, Mitochondria, etc.
Sources of Water
Drinking, through food, and metabolic water produced from biochemical reactions (e.g., glucose metabolism).
Water Loss
Routes of water loss include:
Urine: 20-60%.
Skin and Lungs: 10-30%.
Feces: Varies depending on animal health status.
Carbohydrates
Carbohydrates serve as the cheapest source of metabolic energy and consist of repeating units of CH2O derived from photosynthesis.
Two types:
Structural Carbohydrates: Such as cellulose and hemicellulose found in plant cell walls.
Nonstructural Carbohydrates: Include sugars and starches that are quick and easy to digest.
Specific Energy Needs
Example:
Top milk-producing cow in 2017: 77,480 lbs of milk in a year, averaging 212 lbs of milk daily equivalent to roughly 50,000 calories/day.
Comparison: Michael Phelps (swimmer) and racehorses have high daily caloric needs (22,250 cal/day).
Lipids
Lipids: Soluble in organic solvents, providing 2.25 times more energy than carbohydrates and proteins.
Two major types:
Fats: Long-chain, saturated, solid at room temperature (e.g., tallow).
Oils: Long-chain, unsaturated, liquid at room temperature (e.g., soybean oil).
Functions of Lipids in Diet
Energy source, solvent for fat-soluble vitamins, source of essential fatty acids, increases palatability of feeds.
Proteins
Proteins are the most expensive nutrient in diets, made up of carbon, oxygen, hydrogen, and nitrogen and are essential sources of amino acids.
Vitamins
Origin of the term “vitamin” from "vital amine" indicating its essential role in metabolism; not synthesized sufficiently within the body.
Fat-soluble Vitamins: Stored in the body. Include:
Vitamin A
Vitamin D
Vitamin E
Vitamin K
Fortification vs. Enrichment
Fortification: Adding nutrients not already present.
Enrichment: Replenishing nutrients lost during processing.
Water-Soluble Vitamins
Water-soluble vitamins, including B vitamins and Vitamin C, must be provided regularly as they cannot be stored.
Minerals
Inorganic nutrients that cannot be synthesized. Essential for various physiological processes but require a proper balance—over or under feeding can cause severe health issues.
Macrominerals vs. Microminerals
Macrominerals: Required in larger amounts (>100 ppm). Examples include:
Calcium
Sodium & Chloride (Salt)
Potassium
Magnesium
Sulfur
Microminerals (Trace Minerals): Required in smaller amounts (<100 ppm). Common examples:
Selenium
Copper
Iron
Zinc
Cobalt
Feeds and Their Classifications
1. Forage (Roughage)
Definition: Feedstuffs high in fiber (cell wall components like cellulose) and generally lower in energy density.
Contains more than 18% Crude Fiber (CF).
Includes pasture, hay, silage, and straw.
Significance: Vital for ruminant health because it stimulates rumination and maintains rumen pH.
2. Concentrates
Definition: Feedstuffs low in fiber and high in energy or protein density.
Contains less than 18% Crude Fiber (CF).
Includes cereal grains (corn, barley), soybean meal, and fats/oils.
Significance: Used to increase the nutrient density of the diet, especially for high-producing animals.