Animal Science Overview

Introduction

• Animal science aims to meet human needs for food and other products efficiently without harming the environment.
• The Philippines is mostly self-sufficient in pork and eggs.
• The Philippines imports an average of 4,500 tons of beef annually.
• Commercial farms in urban areas often raise hogs and chickens, using commercially mixed feeds.
• Rural farms rely on roughages and concentrates.

II. Anatomy and Physiology of Farm Animals

External Anatomy

• External structures have integral parts of the organ systems located internally.
• Functions include protection (feathers, hair, skin), digestion (mouth, beak, snout), sensation (skin, eyes, ears), and aesthetics (comb, wattles, feathers).

Internal Anatomy

• Organs function in a coordinated manner for survival.
• Location includes the thoracic cavity (lungs, heart), abdominal cavity (stomach, intestines, liver, spleen, kidneys), and pelvic cavity (reproductive organs).

Animal Physiology

• Study of the function of organ systems and living matter.
• Focuses on the functions and the working of organs.

Homeostasis

• Maintains internal conditions constant.
• Crucial for the study of modern physiology.

The Skeletal System

1. Axial Skeleton

• Includes the skull, vertebrae, and ribs.

1.2 Appendicular Skeleton

• Composed of forelimbs and hindlimbs.

Bones

• Highly specialized supportive tissue, characterized by rigidity and hardness.
• Functions include providing mechanical support, enabling locomotion, providing protection, and as a metabolic mineral reservoir.

Bone Composition

• Cells:
  • Osteogenic cells: Located in the periosteum, the fibrous membrane that covers bone surfaces.
  • Osteoblasts: Bone-producing cells, forming new bone.
  • Osteocytes: Mature bone cells that maintain bone integrity.
  • Osteoclasts: Break down and reabsorb bone.
• Osteoid: Non-mineral organic matrix of bone.
• Inorganic mineral salts: Deposited in the matrix, which hardens the bone.

Two Types of Bones

• Interosseous space: Space between adjacent trabeculae.
• Trabeculae: Spicules of bone substance.
  • Cancellous bone (spongy bone): Few trabeculae.
  • Compact bone (lamellar bone): Extensive lamellae (layers of bone).

Classification of Bone

• Long bones: E.g., forelimbs and hindlimbs – provide leverage for locomotion.
• Short bones: E.g., carpals and tarsals, which absorb shock and cushion joints.
• Flat bones: E.g., skull, ribs, scapula, pelvic bones, protect vital organs.
• Sesamoid bones: Small bones embedded in tendons (e.g., patella).
• Irregular bones: E.g., vertebral column (protection and support).
• Pneumatic bones: E.g., maxillary and frontal bones (air spaces).

The Muscular System

• Creates movement, protects organs
• Types of muscle tissue:
  • Skeletal muscles: Attached to bones, cause movement through contraction and relaxation.
  • Smooth muscles: Found in hollow organs and aid in digestion and blood flow. Involves the autonomic nervous system for involuntary regulation.
  • Cardiac muscles: Muscle of the heart that pumps blood. Involuntary, with three layers found in the heart.