1 / 12

Chapter 12

Chapter 12. Animal Growth. Importance of Animal Growth. Provides earnings for animal producers Producers earn their livings by: Managing animals efficiently Maximizing growth Minimizing cost. Factors in Animal Growth. Heredity Nutrition Environment. Growth Process.

fblanchard
Télécharger la présentation

Chapter 12

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 12 Animal Growth

  2. Importance of Animal Growth • Provides earnings for animal producers • Producers earn their livings by: • Managing animals efficiently • Maximizing growth • Minimizing cost

  3. Factors in Animal Growth • Heredity • Nutrition • Environment

  4. Growth Process • Size increases due to: • Hypertrophy: Cell size increase • Hyperplasia: Cell number increase • Growth occurs in two major phases • Prenatal • Postnatal

  5. Stages of Prenatal Growth • Ovum • Embryonic • Fetal

  6. Ovum Stage • Fertilized egg divides • Cells form ball-shaped morula • Cells group to form blastula (mass with hollow, fluid-filled cavity)

  7. Embryonic Stage • Blastula undergoes differentiation • Ectoderm • Mesoderm • Endoderm • Layers become organs through morphogenesis • Embryo attaches to uterus

  8. Fetal Stage • Organs fully develop • Organ cells undergo mitosis • Fetus is expelled during birth • Oxytocin forces fetus out • Contractions forces fluid from lungs • Ground contact starts organ functioning

  9. Postnatal Stage • Growth is slow as organs develop • Then rapid to sexual maturity • Muscle • Bone • Fat deposits in strategic locations • Abdominal cavity • Between muscles, under skin

  10. Growth Control System • Glands in endocrine system release hormones • Pituitary • Thyroid • Testicles or ovaries • Adrenal glands • Artificial hormones aid in growth

  11. Physiological Age • Maturity: Nutrients for fat, not growth • Aging begins • Physiologic: Bone solidification • Chronologic: Age in years • Physical characteristics change • Reproductive system slows • Nervous system disintegrates

  12. Summary • Many factors control animal growth • Agriculturists try to understand factors to produce efficiently • More efficient animals are more economical • Consumers enjoy lower-cost products

More Related