Lec. 14 - Milk Synthesis and Lactation Flashcards
What is the purpose of lactation?
To provide immune protection and nutrition to the young.
What is colostrum?
Shows up about 5 weeks before parturition, transitions to milk within 2-3 days after parturition. Rich in protein, fat, vitamin A, source of immunoglobulins and hydration and heat.
What is milk?
A fluid secreted by the mammary glands of females for the nourishment of their young.
Composition of milk?
Water - 87.7%
Lactose - 4.9%
Fat - 3 to 4%
Protein - 3.5%
Minerals - 0.7%
What is milk on the shelf?
Pasteurized, homogenized, Vit. D fortified, and Grade A
What is essential for milk production?
Pregnancy and appropriate management (nutrition, comfort, health)
What is milk production dependent on?
Genetic potential and environmental factors.
What is the alveoli?
Made up of epithelial cells, which synthesize and secrete milk into lumen of alveoli. Also made up of myoepithelial cells, which cover the surface of alveoli and small ducts down within a lobule, and they contract for milk ejection.
What are the 5 stages of mammary development?
Fetal, prepubertal, postpubertal, pregnancy, and lactation.
What does prolactin do?
Stimulates milk secretion by epithelial cells, secretion is stimulated by estrogen late in pregnancy and milking/suckling after parturition.
What does thyroxine do?
Increases appetite, heart rate, blood flow, to mammary gland, and rate of milk secretion.
What is galactopoiesis?
The filtration of milk components from the blood and the synthesis of components by cellular metabolism in the alveoli.
