LACTATION PHYSIOLOGY IN DAIRY COWS

Sakina Rubab2nd semester

Introduction

Modified sweat gland Mamma and teat Develops after puberty Suckling ceased Production ceased gland regresses

Prenatal mammogenesis

Mammary ridge Mammary buds Mammary gland Epidermal sprout Duct system

Udder anatomy

External anatomy(7 attachments,teats,quarter ratio rear:front,60:40

Internal anatomy

Streak canalTeat cisternGland cisternLactiferous ductsSecretory cells: alveoliBlood and nerve supplyMyoepithelial cells

Blood supply

Arteries External pudendal artery Internal thoracic artery Lateral thoracic artery Intercostal artery Veins Cranial superficial epigastric vein Internal thoracic vein Caudal superficial epigastric vein External pudendal vein Pudendal nerve Superficial inguinal lymph node

Udder development

Estrogen Duct growth ,blood supply Progesterone Duct and alveolar growth

Phases

Mammogenesis Preparation Lactogenesis, Synthesis and secretion Galactokinesis, ejection Galactopoiesis, maintenance

Stage1 Enzymatic activity Stage2 Copious secretion of milk components

Hormones

Second stage Prolactin Adrenocorticotropic hormone Estrogen Progestrone(minute amount) Thyroid stimulating hormone Oxytocin

Other hormones

Glucocorticoid Estardiol Growth hormone Prostaglandins

Hormonal interactions

Prolactin Induces gene expression for casein

synthesis with gulococorticoid

Progesterone Prevents formation of prolactin binding

sites Wiithdrawal is prerequisite

Prostaglandin Increase just before parturition Regresses corpus luteum Declines progestrone

Estrogen Enhances production of prolactin

Growth hormone Directs nutrients to mammary gland for

milk synthesis

Histology

Lobes

Lobules

Alveoli(150-220) in lobule Milk secretion

Myoepithelial cells

Oxytocin

References

en.wikivet.net/Mammary_Gland_-_Anatomy_%26_Physiology

http://www.webpages.uidaho.edu/avs172/images/Gross%20Anatomy%20MG%20Notes.pdf

http://www.tankonyvtar.hu/en/tartalom/tamop425/0010_1A_Book_angol_05_termeleselettan/ch14s02.html

http://unaab.edu.ng/attachments/460_LECTURE%20NOTES%20ON%20ANP%20501.pdf

Thank you