PROTEINS, VITAMINS, & MINERALS

VITAMINS IN VETERINARY MEDICINE

Discovery of Vitamins

  • Initial Diet Studies: Rats were given diets composed of purified proteins, fats, carbohydrates, and inorganic salts. Findings indicated that this diet was insufficient for normal growth.

  • Addition of Milk: A small quantity of milk was added, which demonstrated that essential factors were missing from the pure diet.

  • Coining the Term 'Vitamines': The term ‘VITAMINES’ (derived from ‘VITAL AMINES’) was introduced to describe these accessory food factors. It was later shortened to 'Vitamins'.

Importance of Vitamins

  • Essential Nutrients: Vitamins are essential compounds needed in the diet or synthesized by microorganisms in the digestive tract. Absence or improper utilization can lead to deficiency diseases.

  • Role in Biochemical Processes: Unlike other nutrients that serve primarily as building blocks or energy sources, vitamins act as mediators for biochemical pathways.

Biological Roles of Vitamins

  • Co-factors: Serve as co-factors in enzymatic and biochemical reactions that regulate various bodily functions.

  • Immunity and Aging: Vitamins improve immunity, prevent illness, and may slow the aging process.

  • Dietary Enhancement: Some vitamins, like Vitamin D and E, are added at higher levels to improve the quality of animal products (e.g., eggshell strength, carcass shelf life).

Vitamins and Biochemistry

  • Provitamins and Precursors: Substances related to the active form of a vitamin but lacking activity until converted (e.g., Vitamin D synthesis).

  • Vitamin Destruction: Many vitamins are sensitive to oxidation, which can be accelerated by factors such as heat, light, and certain metals (e.g., iron).

  • Commercial Preparations: Vitamin supplements often utilize wax or gelatin coatings to protect against oxidation.

Vitamin Supplementation Guidelines

  • Characteristics of Supplements:

    • Must be free-flowing and non-dusty.

    • Should mix well with other dietary ingredients despite being present in small quantities.

  • Stabilizing Methods:

    1. Oily vitamins adhered to silica.

    2. Coating or micro-encapsulation.

    3. Antioxidants added to prevent breakdown.

    4. Use of stable vitamin derivatives.

Factors Affecting Vitamin Stability

  • Environmental Conditions: Stability may depend on temperature, humidity, acidity/alkalinity, oxygen exposure, UV light, trace minerals presence, and storage duration.

Groups of Vitamins

Fat-Soluble Vitamins

  • Definition: Vitamins that dissolve in fats and oils, including:

    • Vitamin A

    • Vitamin D2

    • Vitamin D3

    • Vitamin E

    • Vitamin K

Vitamin A

  • Sources: Accumulates in the liver; found in fish liver oils, egg yolk, milk fat, and leafy forages.

  • Functions: Important for vision (component of rhodopsin), cellular differentiation, epithelial tissue protection, and immune function.

  • Deficiency Symptoms:

    • Cattle: Roughened hair, scaly skin, eye issues.

    • Pigs: Eye disorders, reproductive issues, and growth retardation.

Vitamin D

  • Sources: Obtained from halibut and cod liver oils, egg yolk, and sun-cured hay.

  • Function: Reduces parathyroid hormone production, boosts calcium and phosphorus absorption, promotes bone formation.

  • Deficiency Symptoms: Rickets in young animals, osteomalacia in older animals, issues in poultry such as soft bones and reduced egg production.

Vitamin E

  • Sources: Found in seed germ or germ oils, green forage.

  • Functions: Acts as an antioxidant, aids immune system development, and participates in cell signaling and gene expression.

  • Deficiency Symptoms:

    • Cattle: White muscle disease.

    • Lambs: Stiff lamb disease.

    • Pigs: Myopathy, cardiac disease, and mulberry heart disease.

Vitamin K

  • Sources: Found in green leafy materials, cabbages, egg yolk, liver, and fishmeal.

  • Function: Critical for prothrombin synthesis in the liver and essential for blood clotting.

  • Deficiency Symptoms: Associated with sweet clover disease in cattle and delayed blood clotting in chicks.

Water-Soluble Vitamins - The B Complex

  • Main Water-Soluble Vitamins: B1 (Thiamine), B2 (Riboflavin), B3 (Niacin), B5 (Pantothenic acid) whose actions can be summarized by the mnemonic: "Then Roland N Peter Played Bowling For Chester".

Vitamin B Characteristics

  • Thiamine (B1): Involved in carbohydrate metabolism; sources include green forage and cereal grains.

  • Riboflavin (B2): Vital for energy production; found in green forages and milk products.

  • Niacin (B3): Important for hydrogen transfer in metabolism; synthesized from tryptophan.

  • Pantothenic Acid (B5): Essential for fatty acid oxidation and metabolism; produced by E. coli.

  • Pyridoxine (B6): Involved in amino acid metabolism; sourced from grains and yeast.

  • Biotin (B7): Functions in fatty acid synthesis and carbohydrate metabolism; sourced from liver and vegetables.

  • Folic Acid (B9): Crucial for RNA and DNA synthesis; found in green leafy materials.

  • Cyanocobalamin (B12): Important for ruminant metabolism of propionic acid; sourced from animal protein feeds.

  • Choline: Synthesized from methionine, contributing to lecithin synthesis.

  • Vitamin C: Functions in antioxidant mechanisms, collagen maintenance, and iron transport; sourced from citrus fruits and leafy vegetables.