Feed Formulation, Rations and Formulation Principles for SS 1

Feed Formulation and Ration

Performance Objectives

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

1. explain the meaning of feed formulation and ration;
2. itemize types of rations;
3. discuss the principles of feed formulation;
4. calculate feed mixtures or rations;
5. discuss feed mill operations.

Meaning of Feed Formulation and Ration

Feed formulation is the process of combining different feed ingredients in specific proportions to provide livestock with the precise nutrients required for optimum growth, health and productivity.

This process requires a deep understanding of the nutritional requirements of different classes of farm animals and the nutrient composition of available feedstuffs. The goal is to create a balanced diet that meets these requirements at the lowest possible cost.

A ration is the total amount of feed allowed or provided to an animal during a twenty-four-hour period.

A ration may be given to an animal in a single feeding or divided into multiple portions throughout the day. The quantity and quality of a ration depend on the animal’s age, weight, physiological state and production level.

Types of Rations

Rations are classified based on the primary purpose they serve in the body of the animal. The main types of rations are:

1. Maintenance Ration

A maintenance ration is the type of feed given to an animal to keep its body weight constant, maintain its body temperature and support vital life processes without any gain or loss of weight, or production of milk, eggs or meat.

This ration is designed for mature, non-producing and non-pregnant animals. It provides just enough energy and nutrients to keep the animal alive and healthy. The vital life processes supported by a maintenance ration include:

1. Heartbeat and blood circulation.
2. Respiration and breathing.
3. Body temperature regulation.
4. Tissue repair and cell maintenance.
5. Basic movement and digestion.

2. Production Ration

A production ration is the additional feed given to an animal over and above its maintenance requirement to support productive purposes such as growth, reproduction, lactation, egg-laying or work.

Production rations are highly nutritious and are formulated to meet specific production goals. Examples of production rations include:

1. Lactation Ration: Given to milking cows, ewes or sows to stimulate and sustain high milk production.
2. Fattening (Broiler/Beef) Ration: High-energy feed given to meat-producing animals to promote rapid muscle and fat deposition.
3. Egg-Production (Layers) Ration: Formulated with high calcium and protein levels to support continuous egg-laying in poultry.
4. Gestation (Pregnancy) Ration: Given to pregnant animals to support the growth of the developing foetus, especially during the last trimester.
5. Growth Starter Ration: High-protein feed given to young animals, such as chicks or piglets, to support rapid bone and muscle development.

3. Balanced Ration

A balanced ration is a feed mixture that contains all the essential nutrients in the correct proportions and quantities required to meet the daily nutritional needs of a specific class of livestock.

A balanced ration ensures that no nutrient is deficient or in excess, which prevents nutritional diseases and maximises the feed conversion efficiency of the animal.

Principles of Feed Formulation

To formulate a successful feed, certain scientific and economic guidelines must be followed. The main principles of feed formulation include:

1. Knowledge of the Nutrient Requirements of the Animal: The formulator must know the exact nutrient requirements of the specific animal species, age, weight and production stage. For example, broiler starters require more protein than broiler finishers.
2. Nutrient Composition of Available Ingredients: The chemical composition of the feed ingredients must be known. This includes the percentages of crude protein, crude fibre, ether extract (fats), minerals, vitamins and metabolisable energy.
3. Availability of Feed Ingredients: Only ingredients that are readily available and consistent in supply should be selected. Formulating a feed with scarce ingredients leads to frequent formulation changes, which can stress the animals.
4. Cost of Ingredients (Least-Cost Formulation): Feed accounts for up to seventy percent of the total cost of livestock production. Formulators must select ingredients that meet nutritional standards at the lowest possible cost.
5. Palatability and Digestibility: The formulated feed must taste good to the animals so they consume enough of it. It must also be highly digestible so the animal can absorb and utilise the nutrients.
6. Presence of Anti-Nutritional Factors and Toxins: Some feed ingredients contain harmful substances, such as trypsin inhibitors in raw soyabeans or gossypol in cottonseed cake. These ingredients must be processed properly or limited in the formulation.
7. Physical Form of the Feed: The feed must be presented in a physical form suitable for the animal, such as mash, pellets or crumbles.

Calculation of Feed Mixtures or Rations

Feed formulation calculations are used to determine the exact proportions of different ingredients needed to achieve a target nutrient level. The most common and simple method used for calculating two-ingredient mixtures is the Pearson Square Method.

The Pearson Square Method

This method is used to blend two feed ingredients—one high in a specific nutrient and one low in that nutrient—to obtain a mixture with a target nutrient concentration. It is most commonly used to calculate crude protein (CP) levels.

To use the Pearson Square method, the following steps are taken:

1. Draw a square.
2. Write the target nutrient percentage in the centre of the square.
3. Write the two ingredients and their nutrient percentages at the two left-hand corners (top-left and bottom-left).
4. Subtract diagonally across the square (subtracting the smaller number from the larger number) and write the results at the opposite right-hand corners.
5. The number at the top-right corner represents the parts of the ingredient listed on the top-left.
6. The number at the bottom-right corner represents the parts of the ingredient listed on the bottom-left.
7. Add the two parts together to get the total parts.
8. Calculate the percentage of each ingredient in the final mixture.

Worked Example

A farmer wants to formulate 100 kg of a poultry feed mixture containing 20% Crude Protein (CP). The available ingredients are Maize (containing 8% CP) and Groundnut Cake (containing 45% CP). Calculate the quantity of Maize and Groundnut Cake required for this mixture.

The calculation steps are as follows:

1. Target CP in the centre = 20%
2. Maize CP on the top-left = 8%
3. Groundnut Cake (GNC) CP on the bottom-left = 45%
4. Diagonal subtraction for Maize parts (bottom-left to top-right): 45 – 20 = 25 parts of Maize.
5. Diagonal subtraction for GNC parts (top-left to bottom-right): |8 – 20| = 12 parts of GNC.
6. Total parts = 25 (Maize) + 12 (GNC) = 37 parts.

The diagram below illustrates this calculation method clearly.

To find the percentage and actual weight of each ingredient for a 100 kg batch:

For Maize:

$$\text{Percentage of Maize} = \left( \frac{25 \text{ parts}}{37 \text{ total parts}} \right) \times 100 = 67.57\%$$

$$\text{Weight of Maize} = 67.57\% \times 100 \text{ kg} = 67.57 \text{ kg}$$

For Groundnut Cake (GNC):

$$\text{Percentage of GNC} = \left( \frac{12 \text{ parts}}{37 \text{ total parts}} \right) \times 100 = 32.43\%$$

$$\text{Weight of GNC} = 32.43\% \times 100 \text{ kg} = 32.43 \text{ kg}$$

Therefore, to make 100 kg of the feed, the farmer must mix 67.57 kg of Maize with 32.43 kg of Groundnut Cake.

Feed Mill Operations

A feed mill is a physical facility or processing plant where raw agricultural ingredients are processed, blended and packaged into commercial livestock feeds.

Feed mill operations involve a series of mechanical and technical processes designed to convert raw feedstuffs into safe, uniform and highly nutritious animal feeds. The main operations in a commercial feed mill include:

1. Receiving and Storage of Raw Materials: Raw ingredients such as maize, soyabean meal, wheat offal and bone meal are received at the mill. Grains are stored in large silos, while bagged ingredients are kept in dry, well-ventilated warehouses to prevent spoilage and pest infestation.
2. Cleaning and Sorting: Raw materials are passed through screens, magnets and separators to remove impurities such as stones, dust, metal fragments and straw. This protects the milling machinery and ensures feed safety.
3. Weighing and Proportioning: Ingredients are weighed precisely using industrial scales according to the specific feed formula. Accuracy at this stage is critical to ensure the feed meets the calculated nutrient specifications.
4. Grinding (Milling): Solid ingredients, especially cereal grains, are passed through a hammer mill or roller mill. Grinding reduces the particle size, which increases the surface area of the feed, making it easier for animals to digest.
5. Mixing: The ground ingredients, along with micro-ingredients such as vitamins, minerals, amino acids and feed additives, are loaded into a feed mixer. The mixer blends the ingredients thoroughly to ensure a uniform distribution of nutrients throughout the feed batch.
6. Pelleting (Optional): The mixed feed (mash) may be treated with steam and compressed through a metal die to form small, hard cylinders called pellets. Pelleting prevents animals from selectively eating certain ingredients and reduces feed wastage.
7. Cooling and Drying: If the feed was pelleted, it must be cooled and dried to reduce moisture content. This prevents mould growth during storage.
8. Packaging and Bagging: The finished feed is weighed into standard bags (usually 25 kg or 50 kg in Nigeria), stitched or sealed, and labelled with the feed type, nutritional analysis and manufacturing date.
9. Quality Control: Throughout the entire process, samples of raw materials and finished feeds are tested in a laboratory to verify their nutrient content and ensure they are free from toxins like aflatoxins.

The diagram below shows the sequential flow of these operations in a standard feed mill.

Cleaning -> Weighing -> Grinding -> Mixing -> Pelleting -> Cooling -> Packaging.
alt: A flowchart illustrating the step-by-step operations in a commercial feed mill.
caption: Figure 2: Flowchart of standard feed mill operations.
aspect_ratio: 4:3
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Summary

Feed formulation and ration preparation are essential practices in livestock farming that directly influence animal productivity and farm profitability. By understanding the nutritional needs of different animals, applying the principles of formulation, performing accurate calculations and maintaining efficient feed mill operations, farmers can produce high-quality feeds that support sustainable livestock production.