production animal reproduction

proestrus

• phase where CL regresses

• progesterone decreases maturation of dominant follicle

• estrogen increases

estrus

• female is receptive to mounting

• standing heat

• ovulation DOES NOT occur

metestrus

ovulation and early development of CL

diestrus

• CL is functional

• progesterone high

day 0

• end of proestrus beginning of estrus

• “standing heat”

• dominant follicle- producing estrogen

standing heat length

• avg 15-18 hours

• ranges from 8-30 hours

dominant follicle

cells lining the follicle have been producing estrogen

functions of estrogen

• uterine sensitivity, improves transport of semen

• signs of heat

• initiates LH surge- causes ovulation

primary heat signs

• allows others to mount her without moving away

secondary heat signs

• mounting others

• mucus discharge

• swollen red vulva

• vocalization

• base of tail hair is rubbed

• dirt flanks

• decreased feed intake

• decreased milk production

day 1

• LH causes ovulation (estrogen decreases)

• luteal cells grow in replacement of follicle

  • form CL and prepare uterus for pregnancy, produce progesterone

functions of progesterone

• uterine milk- substance that nourishes embryo

• forms thick plug in cervix

• prevents release of FSH so no dominant follicle will form

day 16-21

• uterus looks for embryo

  • pregnancy occurs if embryo secretes substance prevents release of PGF2

day 16-21 no pregnancy

• if no embryo uterus produce prostaglandins

  • destroys CL and decreases progesterone levels

  • increases FSH, follicle development, increased estrogen

day 19-21

• proestrus

• estrogen getting very high, soon signs of standing heat

day 0 summary

• estrus

• standing heat

• estrogen increased

day 1-5 summary

• metestrus

• ovulation

• early CL development

• progesterone increased

day 5-19 summary

• diestrus

• long CL activity

• progesterone increased

• maternal recognition

day 19-21 summary

• proestrus

• FSH and estrogen increased

if bred

• 4-5 days fertilized ova moves towards uterus

• 30 days attach to uterus

cotyledon

fetal placental side of attachment

caruncles

uterine side of attachment

pregancy dx

• failure to return to heat

• rectal palpation

• rectal ultrasound

• transabdominal ultrasound (small ruminants)

early signs of onset of parturition

• segregation from the herd

• udder edema

• elevated tail head

• uneasy and restless

• vulva enlarges

relaxation of sacro-sciatic ligament occurs

24-48 hours prepartum, concaving of gluteal

stage 1 parturition length cattle

2-3 hours

stage 1 parturition length goat

2-12 hours

stage 1 parturition length pig

2-12 hours

stage 1 parturition

• contractions occur at 10-15 min intervals

• animal continues to eat and drink

• cervix in process of dilation

• fetus extended

termination of stage 1

• colic signs

• back may be arched

• anorexia

• may lie down and get up frequently

• cervix ¾ dilated

• placenta and fetus enter cervix and birth canal

stage 2 parturition

• animal is more oblivious

• lies down on side to strain

• breaking of allantoic 1 chorionic membranes

• amniotic sac with fetus forced into cervix

• uterine contractions increase, last longer

• fetal head and feet pass into birth canal

• oxytocin released

• feet appear in vulva, visible through amnion

• nose,head,body appear

• fetus is expulled

• pelvis and hind legs may remain in birth canal

allantoic 1 chorionic membranes

blueish vascular semitransparent sac

oxytocin

increases smooth muscle contactions

amnion

• translucent grayish white

• fluid is viscous, provides lubrication

when calf lays behind mother after parturition

• blood is transfused into calf as it lies behind dam through umbilical cord

• cord breaks when dam rises

• if dam rises too early and/or cord breaks calf may be anemic

stage 2 total time cattle

• older cows: 3/4-1 hour

• 1st calf heifers: 1-2 hours

stage 2 total time goats

1-3 hours

stage 2 total time sheep

1-2 hours

stage 2 total time pigs

• 1-5 hours

• <15 min in between piglets

post partum cow

• dam rises and licks calf in 2-3 min

• calf gets up in 10-15 min

• calf nurses within 1 hour

post partum meconium

passed within 1st 24 hours

stage 3 parturition

• immediately post birth visible straining ceases

• after short lull contractions resume

  • prevents hemorrhage

• separation of maternal and fetal placenta

• placental expulsion

  • nursing aids in

• blood vessels of fetal placenta collapse

• chorionic villi become smaller

placental expulsion cows

1-6 hours post birth

placental expulsion goats

1-12 hours post birth

placental expulsion pigs

1-3 hours post birth