Lactation Flashcards
3 purposes to lactation
Nourishment, immunity, quick energy
3 locations for mammary glands
Pectoral region: human + elephants
Inguinal region: btw hind legs
Abdominal region: litters
What do myoepithelial cells do?
Eject milk
What do epithelial cells do?
Synthesize milk
What does the lactation path look like for animals without cisterns?
Alveoli-> ducts -> nipple
How many mammary glands does a cow have?
4
How many mammary glands does a ewe have?
2
What is unique about a nannies mammary glands?
2 and funnel shaped
Describe a mares mammary structure?
2 glands
2 lobes per gland
2 streak canals per teat
Broad and flat
Describe mammary structure for sow?
10-14 glands
Several lobes per gland
2 streak canals per teat
2 teat cisterns per teat
Define multiparous
Many births
Describe a dog mammary structure?
10 glands
8-22 streak canals
Describe a cat mammary structure?
8 glands
4-8 streak canals
Development of mammary gland prior to birth
Mammary streak with primary buds + sprouts
Teats
Development of mammary gland from birth to puberty?
Streak canal and teat
Development of mammary gland from puberty to first pregnancy?
Major ducts get larger (foundation)
Development of mammary gland during early pregnancy?
Large and small ducts
Development of mammary gland during late pregnancy?
Alveoli and lobes forming
Development of mammary gland during lactation?
Alveoli begin functioning
# declines after peak
Define involution
Secretory and ductile tissue regress
Alveoli and lobes regress
“Dry up”
Same term for uterus
Pattern for subsequent lactations
Alveoli begin functioning
Alveoli decline
Involution
(Duct system remains)
2 reasons for decline in lactation curve
Baby begins on water
Mother becomes pregnant again
What does somatotropin do for lactation?
Mammary growth prior to puberty
Isometric
What does estrogen do for lactation?
Duct and cistern growth at puberty onset
Allometric
What does progesterone do for lactation?
Alveoli, secretory tissue, and lobes development
What does prolactin do for lactation and birds?
Milk formation and secretion
Maintain lactation
Broodiness in birds
What do glucocorticoids, somatotropin, and adrenalcorticotropin do for lactation?
Initiation and maintenance of lactation
What does thyroxin do for lactation?
Increase metabolic rate for mammary gland tissues
What does Parathyroid Hormone (PTH) do for lactation?
Regulate blood calcium levels by moving blood from bone to bloodstream
What does oxytocin do for lactation?
Causes myoepithelial cells to contract
Force milk ejection
Same for uterine contractions
What does adrenal do for lactation?
When mother frightened
Vasoconstriction
Reduces oxytocin flow
What are names, cause, symptoms, and treatment for Hypocalcemia
Parturient Paresis or Milk Fever
Caused from immobilized calcium from lacking PTH
Symptoms: sheep cannot stand b/c no muscle contractions
Treatment: dextrose + calcium
What is the importance of gestation termination and lactation initiation?
TIMING: so colostrum is not early or late for babies birth
Theory for gestation termination and lactation initiation
High progesterone decreases Prolactin amount and effect
How are different nutrients of milk syntehsized?
Water- filtration
Minerals + vitamins- selective absorption
Casein + lactose + milk fat - cell metabolism
What solid component is closest to milk yield and why?
Lactose because it takes the water with it when secreted into lumen
Monogastric vs. ruminants glucose metabolism
Mono- carbohydrates from diet into glucose in bloodstream
Rumin- propionic acid into glucose in liver (gluconeogenesis)
Define lactose synthetase
Only found in lactating tissue
Derived from a protein
How are proteins synthesized?
In mammary gland from amino acids
Casein’s: Kappa, Beta
Whey proteins: albumins, globulins
Monogastric vs. ruminants milk fat synthesis
Mono- blood lipids + glucose
Rumin- blood lipids + acetic acid
Monogastric vs. Rumin with vitamin absorption
Mono- need all vitamins in diet
Rumin- need vitamins A + E
Define milk secretion
Movement of milk into lumen of the alveolus
3 cycle of events of milk secretion
Synthesis
Secretion
Rest
Rate of milk secretion
High pressure = slow rate b/c epithelial cells get flattened
Compare how milk fat, casein, and lactose are secreted.
Milk fat- takes phospholipid membrane with it
Casein + lactose- leave phospholipids in epithelial cell membrane
Lactose- takes water with it
Define neural hormone process
Nerve impulse triggers hormone release
List process of milk- let down w/ oxytocin
Stimuli: suckling or sound
Nerves tells hypothalamus to tell posterior pituitary gland to release oxytocin
Oxytocin travels through bloodstream to udder
What interferes with oxytocin effectiveness?
Epinephrine/ Adrenalin
Energy balance and weight throughout lactation
Beginning- negative, weight lose
Middle- zero, no weight change
End- positive, weight gain
What are 2 goals for the metabolic profile during lactation
Minimize negative energy balance in the beginning
Prevent obesity at the end of
Define persistence
How well an animal maintains her milk production level throughout her lactation
Compare older and younger animal persistence
Older= higher peak
Young= greater persistence
Older= more milk
Mastitis: cause, symptom, effect
Bacteria, algae, yeast
Inflammation/ infection/ swelling of mammary gland
Lower milk production = most costly disease in dairy industry
Define udder edema
Natural accumulation of fluid in udder before parturition
