Unit 1 Animal Nutrition

Unit 1

Fundamentals of Animal Nutrition, Classification of fodder and Anti-Nutritional Factors

1. Introduction of Animal Nutrition
2. Nutritional Terms and Their Definitions
3. Nutritional Aspect of Carbohydrates, Proteins, and Fats
4. Classification of Feed and fodder
5. Anti-Nutritional Factors in Feeds  

1. Introduction of Animal Nutrition

1.1 History

• Antoine Laurent de Lavoisier: Introduced the balance and thermometer into nutrition studies. He is also founder of the science of nutrition, Father of Nutrition, Father of Modern chemistry.
• Laplace: Designed animal calorimeter for detecting body heat.
• G.J. Mulder: gave the name ‘Protein’ to nitrogenous food. The term protein means ‘to take first place’.
• Starch equivalent system of energy given by Kellner.
• Armsby: Constructed respiration calorimeter also developed Net energy system of evaluating feed.
• F.B. Morrison: write ‘Feed and Feeding’ Book.
• Max kleiber: Developed the use of weight to the 0.75 power
• Van Soest: Developed the fibre estimation method.
• Vitamin A discovered by McCollum and Davis
• Vitamin K discovered by Henrik Dam
• Rumen Bacteria discovered by R.E. Hungate
• Protozoa discovered by Gruby and Delafond
• Fungi discovered by C.G. Orpin

1.2 Importance of Nutrients in Animal Production and Health

Nutrients are essential for growth, reproduction, maintenance, and overall well-being of animals. nutrients are two type-

 Macronutrients

• Carbohydrates: Primary energy source. Found in grains, cereals, and forages.
• Proteins: For growth, repair, and maintenance of body tissues. Sources are soybean meal, fish meal, and legumes.
• Fats: Concentrated energy source; essential for cell membrane integrity. Common sources are oilseeds and animal fats.
• Water: Vital for digestion, nutrient transport, waste excretion, and temperature regulation.

 Micronutrients

• Vitamins: Essential for various biochemical functions.
  • Vitamin A: Important for vision, reproduction, and immune function.
  • Vitamin D: Necessary for calcium absorption and bone health.
  • Vitamin E: Antioxidant that protects cell membranes.
  • Vitamin K: For blood clotting.
• Minerals: Required for structural and regulatory functions.
  • Macrominerals: Calcium, phosphorus, potassium, sodium, and magnesium.
  • Microminerals: Iron, zinc, copper, selenium, and iodine.

1.3 Composition of Animal Body and Plants

• Water, protein & ash content of a fat-free animal body are in the ratio of 19:5:1
• (74-76% water, 20-22% protein & 3% ash).
• Total body water of an animal body is 60-70% of total body weight.
• The total blood content of the animal body is 8% of total body weight.
• The total mineral content of the animal body is 3% of total body weight. (Ca-1.33%, P-0.74%, K-0.19, Na-0.16, S-0.15, Cl-0.11, Mg-0.04).
• In animal body composition the major variables are- water and fat.

2. Nutritional Terms and Their Definitions

• Dry Matter (DM): The portion of feed remaining after removing water content.
• Crude Protein (CP): Measure of protein content in feed, calculated from nitrogen content.
• Crude Fibre (CF): Indigestible cellulose, lignin, and hemicellulose. 
• Ether Extract (EE): Portion of feed soluble in ether, representing fat content. 
• Nitrogen-Free Extract (NFE): Readily digestible carbohydrates such as sugars and starches. 
• Ash: Inorganic residue after burning feed, representing total mineral content.
• Acid Detergent Fibre (ADF): Measures cellulose and lignin, indicating the less digestible portion of the feed. Higher ADF = Lower digestibility.
• Neutral Detergent Fibre (NDF): Measures hemicellulose, cellulose, and lignin, indicating the total fibre content. Higher NDF = Lower feed intake potential, but necessary for rumen health.
• NDF-ADF=Hemicellulose
• Total Digestible Nutrients (TDN): Sum of digestible fibre, protein, lipid, and carbohydrate components of feed.
• Proximate principles (6): Moisture, Crude Protein (CP), Crude Fiber (CF), Ether Extract (EE), Total Ash, Nitrogen-Free Extract (NFE) (calculated)

2.1 Proximate composition: By Henneberg and Friedrich Stohmann at Weende (Germany) in 1865.

2.2 Detergent method of forage analysis: By Van Soest in 1960

 2.3 Role and Requirement of Water, Metabolic Water

• Vital for digestion, nutrient transport, waste excretion, and temperature regulation.
• Metabolic water is produced internally during the metabolism of nutrients, particularly carbohydrates, proteins, and fats.
• Energy Metabolism: For every gram of carbohydrate, protein, and fat metabolised, approximately 0.6, 0.4, and 1.1 grams of water are produced, respectively.

3. Nutritional Aspect of Carbohydrates, Proteins, and Fats

Primary Energy Source: essential for maintaining bodily functions, growth, and reproduction.

3.1 Classification of Carbohydrates

1. Monosaccharides-

• Trioses, Tetroses, Pentoses (e.g. Ribose, Xylose, Arabinose), Hexoses (Glucose, Galactose, Fructose)

2. Disaccharides-

•  Lactose (Galactose and Glucose by beta 1-4 linkage)/ Milk sugar
• Maltose (Glucose and Glucose by alfa 1-4 linkage)/ Malt sugar
• Sucrose (Glucose and Fructose by alfa 1-4 linkage)/ Table sugar/ Non reducing sugar
• Cellobiose (Glucose and Glucose by beta 1-4 linkage)

3. Trisaccharide-

• Raffinose (Galactose, Glucose and Fructose)

4. Polysaccharide-

• Glycogen (alfa 1-4 & alfa 1-6 glucose), Starch, Cellulose (beta 1-4 glucose), Dextrin, Inulin
• Mix Polysaccharide- Hemicellulose (beta 1-4 xylose), chitin, Pectin, Mucilage
• Complex polysaccharide- Glycolipids, Glycoproteins 

3.2 Classification of Amino acid

1. Aliphatic amino acid

Monoamine- Monocarboxylic (Neutral): Glycine, Alanine. Serine, Valine, Leucine, Isoleucine

•  Monoamine-Dicarboxylic(acidic): Aspartic acid, Glutamic acid
•  Diamino-Monocarboxylic (Basic): Lysine, Arginine,
•  Sulphur containing: Methionine, Cystine, Cysteine

2. Aromatic Amino acid: Phenylalanine, Tyrosine

3. Heterocyclic: Proline, Histidine, Tryptophan

•  Ketogenic amino acid: Leucine, Lysine
•  Glucogenic & Ketogenic amino acid: Isoleucine, Phenylalanine, Tyrosine, Tryptophan
•  Glucogenic amino acid: Rest all other

Essential amino acid: (By W.C. rose)- Can not synthesised in body

• Pig: Lysine
• Poultry: Glycine
• Sheep: Methionine
• Cat: Taurine

Critical amino acid: Low in practical diet e.g.- Lysine, Methionine

3.3 Classification of Fatty acid

• Saturated Fatty acid- butyric acid, caproic acid, lauric acid, Palmitic acid
• Unsaturated Fatty acid- Palmitoleic acid, Oleic, linoleic, Linolenic, Arachidonic acid
• Essential fatty acid in cat- Arachidonic acid and in pig & Poultry- linoleic acid

4. Classification of Feed and fodder

4.1 Why Classify?

• Grouping of similar feedstuffs
• Facilitates ration formulation
• Allows for substitution based on price/availability

4.2 Base for Classification:

1. Physical characteristics (Bulkiness)- Roughages & Concentrates
2. Chemical characteristics-

4. 3 Crampton and Harris Classification (NRC):

1. Dry forage, roughages and Hay
2. Green/succulent forage and pasture
3. Silage
4. Energy feeds
5. Protein supplements
6. Mineral supplements
7. Vitamin supplements
8. Additives

1. Dry forage, roughages and Hay

Classification of Roughages

They are classified on the basis of:

A. By Moisture Content

1. Dry Roughages: Contain less than 15% moisture.

• Examples: Hay, straw, and chaff dry fodder.

2. Green/Succulent Roughages: Contain 80-85% moisture.

• Examples: Fresh pasture grasses, tree leaves, silages, roots, and tubers.

B. By Type

1. Legume Roughages: High in protein and often used for production purposes.

• Examples: Berseem, Lucerne (Alfalfa), Cowpea.

2. Non-Legume Roughages: Lower in protein compared to legumes.

• Examples: Maize, Bajra (Pearl Millet), Sorghum, Oat.

C. By Nutritional Value

1. Non-Maintenance Type: Contain less than 3% Digestible Crude Protein (DCP). Examples: Straw, stover.
2. Maintenance Type: Contain 3-5% DCP. Examples: Non-leguminous cereal fodder.
3. Production Type: Contain more than 5% DCP. Examples: Legume fodders.

D. By Season

1. Rabi Season Roughages: Grown during the winter season.

• Examples-Oats, lucerne (alfalfa, known as the “queen” of forages), berseem (known as the “king” of forages).

2. Kharif Season Roughages: Grown during the summer season.

• Examples: Maize, Cowpea, Bajra, Sorghum.

• Annual Forages:Examples-Maize, sorghum, berseem, cowpea.
• Perennial Forages:Examples-Hybrid napier, para grass, desmanthes.

Examples & Common Terms Related to Dry Feeds

• Forages: Plant materials that are fresh or preserved and used for feeding animals.Examples: Hay, straw, silage, and pasture.
• Roughages: Feedstuffs with higher fibre content.Examples: Husk, shells.
• Hay: Dried product of thin-stemmed crops.Examples: Alfalfa hay, Timothy hay.
• Straw: Byproduct of cereals/legumes left after the removal of grains/pulses.Examples: Wheat straw (0% DCP), gram straw.
• Fodder: Aerial parts including ears/heads.Examples: Corn fodder.
• Stover: Aerial parts without ears/heads.Examples: Corn stover (Kadbi).
• Bagasse: Leftover of sugarcane after the extraction of juice.Examples: Sugarcane bagasse.
• Hull: Outer covering of beans/peas.Examples: Cottonseed hull, soybean hull.
• Husk: Outer covering of grains and legumes.Examples: Rice husk, gram husk.
• Shell: Hard covering of nuts.Examples: Groundnut shell.

Advantages of Dry Roughages

• Hunger Satiety: Helps in satisfying the hunger of animals.
• Moisture Control: Maintains dry matter intake (DMI).
• Cost-Effective: Cheaper source of dry matter.

Disadvantages of Dry Roughages

• Poor Digestibility: High lignin content leads to low intake.
• Low Nutritional Value: Except for hay, most dry roughages have low crude protein (CP) and digestible crude protein (DCP).CP: 3%
• Hay: Higher nutritional value with 15-17% CP.

2.  Green/Succulent Forage and Pasture: They have high moisture content(80-85%).

Types of Green/Succulent Forages

1. Pasture: Plants that are either natural or cultivated and used for grazing Examples: Various grasses and legumes that are grown in fields and consumed directly by grazing animals.

2.  Fodder:Crops harvested and used for stall feeding. Examples: Maize, sorghum, and other cereal crops that are cut and brought to the animals.

3. Top Feeds:Tree leaves, top cuttings of plants, and agricultural crops. 

Energy Feed

1. Characteristics of Energy Feeds:

• Crude Protein (CP): <20%
• Crude Fibre (CF): <18%
• Total Digestible Nutrients (TDN): 75-80%

2.  Main Types of Energy Feeds:

a) Cereal Grains:

• Main component: Starch (60-65%)
• CP: 8-12%
• Fat: 2-5% (mostly unsaturated fatty acids)
• Deficient in essential amino acids (lysine and methionine)
• Calcium deficient, phosphorus rich (but in phytate form)
• Deficient in vitamins D and A (except maize)
• Risk of causing Subacute Ruminal Acidosis (SARA)

Key Cereals:

• Maize: High in metabolizable energy, contains cryptoxanthin (vitamin A precursor)
• Barley: Higher fiber, lower oil content, preferred in summer
• Oats: High crude fiber (10-18%), lower TDN, preferred in summer
• Wheat: Easily digestible starch, higher risk of SARA
• Millets (e.g. Sorghum, Bajra): Small grains, higher fiber, preferred in winter

b) Molasses:

• Instant energy source (sugar)
• Rich in minerals
• CP: up to 5-6%
• Used with urea in ruminant diets
• Can be included up to 10% in concentrate mixture
• Higher levels may cause digestive disturbances

c) Fat:

• Highest energy yield (2.25 times that of carbohydrates)
• Limitations in ruminants:Not more than 6% of dry matter intake
• May be given in bypass form for high-yielding animals
• No major digestive issues in monogastric animals 

Protein supplements

Characteristics of Protein Supplements

• Crude Protein (CP): Greater than 20%
• Crude Fiber (CF): Less than 18%
• Protein Types: Can be true protein or Non-Protein Nitrogen (NPN)

A. Plant Origin Protein Supplements

1. Cottonseed Cake (CSC) CP
2. Groundnut Cake (GNC) CP
3. Soybean Meal (SBM) CP
4. Mustard Cake CP
5. Guar Meal CP
6. Sesame/Til Cake CP
7. Gram CP
8. Guar CP

B. Animal Origin Protein Supplements

1. Fishmeal CP
2. Meat and Bone Meal (MBM) CP
3. Blood Meal (BM) CP
4. Feather Meal CP
5. Hatchery Byproducts CP

C. Single Cell Protein (SCP)

• Bacteria: Methanomonas methanica.
• Yeast: Spirulina.
• Algae: Torulopsis utilis.

 Note: SCP is a sustainable protein source but can be expensive to produce.

Important Notes on Specific Supplements

• Sesame/Til Cake: Very rich in calcium, making it a valuable supplement for balancing mineral content.
• Soybean Meal (SBM): Low in methionine, often requiring supplementation with synthetic amino acids.
• Meat and Bone Meal (MBM): Banned in some regions due to the risk of BSE (mad cow disease) caused by prions.
• Mustard Cake: Contains erucic acid, limiting its inclusion to 10-12% of the concentrate mix.
• Blood Meal: Poor digestibility, palatability, and low in calcium and phosphorus.

Methods of Making Vegetable Protein Supplements

1. Hydraulic/Ghani Method: Produces cake with about 8% fat.
2. Expeller Method: Produces cake with about 6% fat, with some bypass protein.
3. Solvent Extraction: Uses ether or benzene to produce meals with less than 1% fat.

Note: Cake has higher oil content and lower protein, while meals have lower oil and higher protein content.

D. Non-Protein Nitrogen (NPN) Sources

• Definition: Nitrogen in forms other than true protein and peptide.
• Examples: Urea (46% N), Biuret (35% N).
• Function: Increases microbial growth in the rumen.

Issues with Urea Supplementation

• Rapid Hydrolysis: which can lead to toxicity.
• Source of Nitrogen Only: Requires energy (e.g., starch) for effective utilization.
• Optimal Ratio: Starch to urea ratio should be 10:1 (1 kg starch per 100 g urea).
• N:S Ratio: For optimal rumen microbial function, the nitrogen to sulfur ratio should be 10:1.

Urea/NPN Supplementation Guidelines

• Concentrate Mix: Up to 3% of the mix.
• Total Dry Matter Intake (DMI): Up to 1%.
• Total Nitrogen/Protein Need: Up to 33% (one-third).
• Salt: 0.5% of the mix.
• Straw Treatment: 4% for treating straw.
• Not Beneficial: If Total Mixed Ration (TMR) CP is greater than 13%.
• Maximum Permissible Level (MPL): 27 g/100 kg body weight or 100 g/day for an adult cow, and not more than 10 g/day for goats.
• Toxicity Treatment: Administer 45 liters of cold water followed by 2-6 liters of 5% acetic acid (vinegar).

Urea Products

• Examples: Uromol, Urea-Molasses Mineral Block (UMMB), Urea-Molasses Liquid Feed.

E. Agro-Industrial By Products

They are derived from the processing of agricultural products. cheaper than primary feed ingredients, & Rich in Fiber and Minerals

• Protein Content: 12-14% Crude Protein (CP).
• Energy Value: Moderate

Examples of Agro-Industrial Byproducts

• Flour: Finely ground grains used as a feed ingredient.
• Bran: The outer covering of grains such as rice and wheat, rich in phosphorus and fibre.
• Rice Polish: A byproduct of rice milling, rich in energy and B-complex vitamins.
• De-Oiled Rice Bran (DORB): Used as a filler in feed formulations.
• Hulls: Outer coverings of beans and peas, such as soybean hulls.
• Chunni: Broken grains with husk, such as gram or dal chunni.
• Distillers Dried Grains with Solubles (DDGS): Byproduct of ethanol production, rich in protein and fibre.
• Gluten: Protein-rich byproduct from starch extraction in grains.

3. Mineral Supplements

Mineral supplements are essential for maintaining the health and productivity of livestock. They are categorised into macro-minerals and micro-minerals based on the quantities required by animals.

• Mineral Mixture (MM): Typically, 2% of the concentrate mix.
• Salt: Usually 1% of the concentrate mix. Salt acts as a condiment, encourages water intake, and helps manage heat stress.

4. Vitamin Supplements

Vitamins are organic compounds required in small quantities for various physiological functions. They are categorised based on their solubility:

Water-Soluble Vitamins

• B-Complex Vitamins: Includes B1 (Thiamine), B2 (Riboflavin), B3 (Niacin), B6 (Pyridoxine), B12 (Cobalamin), Folic acid, Pantothenic acid, Biotin, and Choline.
• Vitamin C (Ascorbic Acid): Regular supply is essential as it is not stored in the body.

Fat-Soluble Vitamins

• Vitamin A,D,E,K

Note: Vitamin B is synthesised by rumen microbes, and green fodder is a good source of vitamins.

5.  Additives

Additives are non-nutritive substances added to feed to improve body weight gain, feed efficiency, and control or prevent diseases. They include:

• Antibiotics: Used to prevent subclinical infections and promote growth.
• Antioxidants: Prevent oxidative rancidity of fats and improve feed stability.
• Buffers: Help maintain optimal pH in the rumen.
• Colors & Flavors: Enhance the palatability and attractiveness of feed.
• Enzymes: Improve the digestibility of feed components.
• Hormones: Used to enhance growth and production.
• Medicines: Added to feed to prevent or treat diseases.

5. Anti-Nutritional Factors (ANF) in Feeds  

Substances present in the diet, which by themselves or their metabolic products interfere with the feed utilization, reduce production or affect the health of animals.

• Different adulterants, produced by plants to protect themselves (tannins, lignin)

Classification of Anti-nutritive substances 

 Chemical properties Mechanism of Action (MOA)

1. Protein 1. Substances Depressing 

                                                       Digestion/Metabolism of protein

2. Glycosides 2. Substances Depressing Carbohydrate 

                                                         Metabolism

3. Phenol 3. Substances Interfering With Utilisation of  

                                                       Mineral Elements

4. Miscellaneous 4. Substances Inactivating/Increasing 

                                                          Requirements of Vitamins

5. Substances That Stimulate Immune System

1. Anti-nutritive substances according to their chemical properties:

2. Anti-nutritive substances according to their Mechanism of Action (MOA):
   1. Substances Depressing Digestion or Metabolic Utilization of Protein:

2. Substances Depressing Carbohydrate Metabolism

3. Substances Reducing Solubility or Interfering With Utilization of Mineral Elements

4. Substances Inactivating or Increasing Requirements of Certain Vitamins

5. Substances That Stimulate Immune System Antigenic proteins:

• Macromolecular proteins or glycoproteins capable of inducing a humoral response
• Polyclonal antibodies are secreted in body fluids for eliminating the antigenic protein.
• Feed antigens are exposed continuously to increase the chance that the immune system develops into an acute/chronic hypersensitivity reaction.
• Antigenic globulins of soyabean are glycinin and β – conglycinin.

Effect of Feed Antigens

• Increased protein secretion with lowered protein digestibility
• Increased maintenance requirement due to activation of the immune system

Inactivation of feed antigens:

• Chemical or enzymatic treatments
• Hydrolysis of proteins by means of acid or proteases results in products apparently free of antigenic proteins.

6. Miscellaneous

Anti-nutritional factors according to feed source