Fish Nutrition, Feed Formulation

and Feed preparation

Arlyn Arreglado-MandasCAPE Consultant

Department of Science and Technology(DOST)Region XII, Cotabato City

Associate ProfessorCollege of Fisheries

Mindanao State UniversityFatima, General Santos City

OutlineI. Introduction to Fish NutritionII. Digestive Physiology and Feeding Behavior of FishIII. Nutrient RequirementsIV. Feed Formulation

1. Basic Informations Required

2. Procedure for Feed FormulationV. Feed Preparation

What is Fish Nutrition?

Answer:

It is the combination of the processes of food ingestion, digestion,

absorption and egestion in fish

FEEDING HABITS AND DIGESTIVE PHYSIOLOGY

OF FISHES

How to maximize the use of feed?

Understand the following:

Feeding habits and behavior

Digestive Physiology of fishes

Important informations on:

1.rate of digestion of food – determines

•feeding rates•Feeding frequency•ration size

*Any food that is not digested and absorbed will not have any nutritional value to the fish

•2. knowledge of the digestive physiology of fish – necessary for an effective feed formulation and in choosing a proper feeding regime

Feeding habits and Behavior of fishes -

- refers to the process of and ingestion of food

- also includes the manner and the stimuli for feeding (food habit)

Classification of fishes based on their food and diet •Herbivores -feed exclusively on plant materials•Carnivores - feed exclusively on animal matter•Omnivores - derive their nutrients from both plants and animals•Planktivores - feed on plankton and bacteria•Detritivores - feed on decaying matter

Food availability -the key factor in determining what the fish will eat

Classification of feeding behavior of fishes based on the manner of feeding

•Predators -feed on macroscopic animals•Grazers - feed on bottom organisms or planktons•Strainers - filter organisms•Suckers - suck in mud or food-containing material to obtain food•Parasites - obtain nutrients by sucking body fluids of host fish

Feeding Process in Fish

•Appetite and Satiation -state that initiates arousal and feeding behavior

-Appetite is controlled by the hypothalamus and is

stimulated by the gut fullness and or other metabolic changes which affect food consumption

Factors affecting appetite

A. Biotic 1. food availability and food distribution2. Competition- no fish is 1.5 times larger than another3. presence of predators4. Physiological condition such as starvation and circadian

rhythm5. Selection of prey

5.1choice in terms of size and form is limited by the mouth gape of fish

5.2 “optimal foraging theory”-states that the natural selection favors those fish that maximize efficiency of prey capture

6. Handling – causes stress in fish

B. Abiotic

1. Dissolved oxygen-most important abiotic factor affecting feeding

2.Temperature -daily and seasonal fluctuation affect food intake

3. Light intensity – larval fish rely on vision to recognize food

4. Unionized ammonia(NH3)

Stages in feeding

•Arousal and Search- fish on a fixed feeding schedule can learn to anticipate feeding times but arousal is often due to Pavlovian coditioning(sight or sound of farm workers)

•Capture – food particle size and avoidance behavior is a factor in capture success

•Location and Identification - Vision, olfaction and gustation are all important in finding or locating food. Consider the chemical and physical characteristics of food.

•Taste Testing- not all materials taken into the mouth are swallowed, they are tested for suitability by taste receptors inside the mouth,gill arches and rakers and in the tissue surrounding the pharyngeal teeth

•Swallowing or Rejection- food which tastes good and have optimal particle size, shape and texture will be swallowed by the fish. More rejections and disintegration occur in pellets that are hard, abrasive and are much longer than their diameter.

Anatomy and Physiology of the Digestive System

Fish adapts anatomically and behaviorally resulting to anatomical differences in fish digestion

Example:a. Carnivorous fishes have a relatively

simple and short gut with thick mucosa for absorption

b. herbivorous fishes have an accesory masticatory apparatus or other physiological adaptation to help in breaking down plant cell walls before the digestion process starts, and a long thin gut

to enhance digestion and absorption.

Digestive System of Fish – includes the mouth, esophagus, stomach, intestine, liver and pancreas

It is tubular in structure and often referred to as the gut

4 Divisions of the gut

1. headgut-includes oral or buccal cavity and gills

2. foregut-begins at the posterior edge of the gills and includes the esophagus and stomach

3. midgut-consists of the intestine and the pyloric ceca if present.

4. hindgut-includes the enlarged portion of the intestines and the rectum or anus

1.HEADGUT

Mouth and various ingestion mechanisms-the mouth has a variety of adaptations for capturing , handling, and sorting of food before entry into the stomach(different mouth shapes and teeth which vary in terms of type, number and arrangement)

*generally, the more active feeders have strong jaws with sharp teeth to bite and shred the food while zooplankton feeders and most planktivores have practically no teeth.

2. FOREGUT

Esophagus- most fishes have short, wide esophagus that serves as a transitional area between the striated muscles of the mouth and the smooth muscles of the gut .

-produces mucus and there is enzyme activity

Stomach –varies greatly in their anatomical structure due to adaptations to specific foods

- generally, fish that eat relatively small, soft particles have small stomach whereas fish that eat large food particles have larger stomach.

4 General configurations or shapes of fish stomachs

1. a straight stomach with enlarged portion

2. a U or J-shaped stomach3. a stomach shaped like Y on its side

where the stem faces the caudal portion4. stomachless fish, such as in carps and

other cyprinids

3. MIDGUT and HINDGUT-the digestion process actively continues into the intestines after preliminary digestion in the stomach

Absorption –takes place in the intestine among finfishes

Nutrient Requirements

The nutritional value of different artificial feeds

depends on the palatability, digestibility

and nutrient composition

*The nutrient composition of the feeds should be tailored to the requirement of the fish to be fed

What then are the nutrients required by the fish?Answer:

1. Protein2. Carbohydrates3. Lipids4. Vitamins5. Minerals

1. Protein is the most important component of the diet of fish because protein intake generally determines growth

•Protein is required in the diet to provide indispensable amino acids and nitrogen for synthesis of non-indispensable amino acids.•It also provides energy

 

Amino acids Salmonid Catfish Carp Tilapia Milkfish Sea Bream Sea Bass

Arg 4.2 4.3 4.4 4.1 5.6    

His 1.6 1.5 2.4 1.7 2.0    

Ile 2.0 2.6 3.0 3.1 4.0    

Leu 3.6 3.5 4.7 3.4 5.1    

Lys 4.8 5.0 6.0 4.6 4.0 5.0 4.8

Thr 2.0 2.1 4.2 3.8 4.9    

Trp 0.6 0.5 0.8 1.0 0.6 0.6  

Val 2.2 3.0 4.1 2.8 3.0    

Met+Cys 2.4 2.3 3.5 3.2 4.8 4.0 4.4

Phe+Tyr 5.3 4.8 8.2 5.6 5.2    

Table 1. Indispensable amino acid requirements of different species of teleost (g / 100 g protein)

  CP Met

(+Cys) Lys Trp Thr Ile His Val Leu Arg

Phe

(+Tyr)

Requirement  1.7

(2.4) 4.8 0.6 2.0 2.0 1.6 2.2 3.6 4.2

2.7

(5.3)

Fish meal 68 3.1 7.9 1.1 4.0 4.2 8.8 7.9 7.1 8.3 3.6

Soybean meal 48 1.6 6.7 1.3 4.2 5.5 2.7 5.7 8.0 8.0 5.7

Corn gluten meal 60 3.2 1.7 0.5 3.3 3.8 2.0 4.5 15.7 3.2 6.3

Blood meal 85 1.2 6.3 1.2 4.5 0.9 3.6 6.1 12.2 2.8 6.0

Meat and bone meal 50 1.2 4.9 0.4 4.0 3.8 3.3 5.3 5.7 6.0 4.0

Poultry by-product meal 65 1.7 5.9 0.9 4.0 2.9 2.2 4.8 5.7 7.5 2.5

Feather meal 85 0.7 1.2 0.5 3.3 3.1 0.3 5.4 9.2 4.6 3.1

Table 2. Amino acid composition of common protein sources (g/ 100 g protein)

 

Amino acids Milkfish

Fish meal

Arg 5.2 8.3

His 2.0 8.8

Ile 4.0 4.2

Leu 5.1 7.1

Lys 4.07.9

Thr 4.54.0

Trp 0.6 1.1

Val 2.8 7.9

Met+Cys 3.2 3.1

Phe+Tyr 5.2 3.6

2. Carbohydrates – provides energy and contributes significantly to the water stability of pellets

3. Lipids - have many roles: energy supply, structure, precursors to many reactive substances, etc.

- composed of fatty acids

4. Vitamins – needed in trace amounts for normal growth and development

5. Minerals – important both in structure (bone formation) and osmoregulation - are required in trace amounts and are present in sufficient quantity in the surrounding water for the fish to absorb through their gills

Locally available materials which can be utilized as supplemental feed or feed ingredients

Feed Formulation

What is Feed Formulation?

It is a process in which feed ingredients and various vitamin and mineral supplements are blended to produce a diet with the required quantities of essential nutrients

Why do we formulate?

Answer:Because there is no single ingredient that contains all the nutrients required by the fish

The primary objective of feed formulation is to produce a mixture that (is) :

1.Nutritionally balanced2.Economical3.Palatable

4. Water stable 5. Minimizes waste output & effect on water quality6. Produces desirable final product (attractive & safe)

Practical considerations :

1. Ingredients price and availability2. Anti-nutritional factors3. Pelletability of mixture4. Storage and handling requirements

Basic information required for feed formulation 1.Nutrient requirement of the species2.Feeding behavior and digestive capacity of the species3.Available feed ingredient sources4.Type of ration desired (larval, starter, grower, finisher)

5. Expected feed consumption6. Feed additives required7. Type of feed processing to be used

Methods of Feed Formulation

1.Pearson Square Method2.Algebraic Method3.Trial and Error Method4.Linear programming

Pearson Square Method

Fish meal 60%

Rice bran 13%

34%

26

21

____ 47

2147

26 47

X 100 = 44.68%

X 100 = 55.32%

FORMULA 001

Ingredients Amount_______________________________________________________

(g/100g diet) 1kg 10kg 20 50 100

Fish meal 44.68 446.8 4.47 8.94 22.35 44.7

Rice bran 55.32 553.2 5.53 11.06 27.65 55.3

Feed conversion ratio (FCR) is the wet weight (kg) of feed required to grow one kg of fish, depending upon the feed quality, moisture, cultured species, culture system and so on.

FEED PREPARATION

Steps

1. Grinding2. Sieving3. Weighing4. Mixing5. Steaming6. Pelleting7. Drying8. Packing