Livestock Feeds, Feed Classes and Nutrient Sources for SS 1

Classes of Livestock Feeds

Performance Objectives

By the end of the lesson, students should be able to:

1. explain the meaning of feed and feeding;
2. classify feed ingredients based on their nutrient composition;
3. identify the characteristics of good feed.

Meaning of Feed and Feeding

Feed refers to any nutritious substance or material that is consumed by livestock to sustain life, promote growth, support reproduction and facilitate production.

Livestock feed contains essential nutrients such as carbohydrates, proteins, fats, minerals, vitamins and water. These nutrients are absorbed by the animal body to perform various physiological functions.

Feeding is the physical and physiological process of providing livestock with the appropriate quantity and quality of feed to meet their daily nutritional requirements.

Proper feeding management ensures that animals receive balanced rations. This maximizes their productivity in terms of meat, milk, egg and wool production, while maintaining their health and immune systems.

Classification of Feed Ingredients Based on Nutrient Composition

Livestock feed ingredients are grouped into different classes based on their primary nutrient content, physical form and digestibility. Understanding these classes helps farmers formulate balanced rations for different categories of farm animals.

Energy-Giving Feeds

Energy-giving feeds, also known as basal feeds or carbohydrate feeds, are feedstuffs that contain high amounts of carbohydrates and fats but are low in crude fibre and protein. They provide the energy required for daily body maintenance, movement, growth and production.

Common examples of energy-giving feeds include:

1. Maize (corn) grains
2. Cassava tubers and cassava peel meal
3. Guinea corn (sorghum) grains
4. Millet grains
5. Wheat offal and rice bran

Protein Feeds

Protein feeds are feedstuffs that contain a high concentration of crude protein, usually 20 percent or more. Proteins are essential for tissue growth, muscle development, repair of worn-out tissues, enzyme production and egg or milk formation.

Protein feeds are divided into two main sources:

1. Plant protein sources, which include groundnut cake, soybean meal, palm kernel cake and cotton seed meal.
2. Animal protein sources, which include fish meal, blood meal, meat meal and feather meal.

Mineral Feeds

Mineral feeds are feed ingredients that supply essential macro-minerals and micro-minerals required for bone and teeth development, eggshell formation, fluid balance and metabolic regulation in the animal body.

Common examples of mineral feeds include:

1. Bone meal, which supplies calcium and phosphorus.
2. Oyster shell meal, which is a rich source of calcium.
3. Salt licks and common salt (sodium chloride), which supply sodium and chlorine.
4. Dicalcium phosphate, which provides concentrated calcium and phosphorus.

Vitamin Feeds and Sources

Vitamin feeds are substances that supply organic compounds required by livestock in very small quantities to regulate body processes, boost immunity and prevent deficiency diseases.

Common sources of vitamins for livestock include:

1. Synthetic vitamin premixes, which are added directly to commercial feed formulations.
2. Fish liver oil, which is rich in vitamins A and D.
3. Green pastures and fresh fodder, which supply vitamins A, E and K.
4. Yeast, which is an excellent source of B-complex vitamins.

Roughages

Roughages are feedstuffs that contain a high concentration of crude fibre, typically exceeding 18 percent, and have relatively low digestible nutrient content. They are essential for ruminant animals, such as cattle, sheep and goats, to maintain proper rumen function and stimulate digestion.

The main types of roughages are:

1. Green fodder, which refers to fresh pasture grasses and legumes grazed directly or cut and carried to animals.
2. Hay, which is forage grass or legume cut and dried under controlled conditions to reduce moisture content to about 15 percent or less for storage.
3. Silage, which is high-moisture forage preserved through anaerobic fermentation in a silo.

Concentrates

Concentrates are feedstuffs that contain low levels of crude fibre, usually less than 18 percent, and have a high concentration of easily digestible nutrients. They can be formulated to be high in energy, high in protein, or balanced with vitamins and minerals to supplement roughages.

Common examples of concentrates include:

1. Cereal grains such as maize and sorghum.
2. Oilseed cakes such as groundnut cake and soybean meal.
3. Commercial compound feeds, such as broiler starters, grower mashes and layer layers.

Practical Skill: Classifying Livestock Feeds

Classifying feed ingredients based on their physical appearance, texture and nutrient composition is an essential skill for livestock farmers. This practical guide outlines the procedure for identifying and grouping common feed ingredients.

The required materials are:

1. Samples of maize grains, groundnut cake, bone meal, hay, silage and fish meal
2. Hand lenses
3. Sample trays or clean containers
4. Labelling stickers and markers
5. A laboratory notebook

The procedure involves the following steps:

1. Place each feed sample on a separate, clean sample tray.
2. Examine the physical appearance, colour and texture of each sample using a hand lens.
3. Smell each sample to identify characteristic odours, such as the sweet, fermented smell of silage or the fishy smell of fish meal.
4. Record the physical characteristics of each sample in the laboratory notebook.
5. Group the samples into their respective nutrient classes based on their known composition and physical properties.
6. Label each sample tray with the correct feed class, such as energy feed, protein feed, mineral feed, roughage or concentrate.

Characteristics of Good Feed

Good quality feed is essential for achieving high livestock productivity and maintaining animal health. Farmers must evaluate feed ingredients to ensure they meet quality standards before feeding them to livestock.

The main characteristics of good feed include:

1. High Palatability: The feed must have an appealing taste, smell and texture that encourages livestock to consume it readily.
2. High Digestibility: The feed must be easily broken down and absorbed within the digestive tract of the animal to ensure maximum nutrient utilization.
3. Nutrient Balance: It must contain all the essential nutrients, including carbohydrates, proteins, minerals and vitamins, in the correct proportions required by the specific class of livestock.
4. Freedom from Toxins and Contaminants: Good feed must be free from harmful substances such as moulds, mycotoxins, heavy metals, sand, stones and chemical residues.
5. Optimal Moisture Content: Dry feeds, such as grains and concentrates, must have a low moisture content, typically below 12 percent, to prevent fungal growth and spoilage during storage.
6. Freshness: The feed must be fresh and free from rancidity, stale odours or signs of insect infestation.
7. Appropriate Physical Form: The particle size of the feed must be suitable for the age and species of the animal, such as mash for chicks and pellets for adult rabbits.