Lecture 7: Dairy 3- Reproductive health and disease

Question 1

What are the dairy cow’s objectives and tasks?

Answer 1

Objectives
-Make at least 10,000kg milk/yr with less then 200.000 SCC
-Remain healthy
-Get pregnant by 120 DIM on 1st or 2nd insemination
-Repeat until overtaken by better animals

Tasks
-Eat, drink, display estrus
-Get milked 2-3 times a day
-Lie down 11h and ruminate 8h per day

Question 2

What are problems in cattle reproduction?

Answer 2

OPEN (failure to cycle)
——-> Failure to conceive
PREGNANT (early embryonic death)
——->Abortion
CALVING (Dystocia/perinatal mortality)

Question 3

What are the problems related to the OPEN cattle reproduction?

Answer 3

Failure to cycle
-Freemartin
(Heifer is born co-twin to male, female characteristics androgenized, abnormal external and/or internal genitalia, 95% are sterile)

-True anestrus
(20-25% may not be cyclic by 60 DIM,Associated with NEB, risk factors related largely to transition period health ex ketosis treatment is supplemental progesterone to help develop a follicle)

-Cyctic ovarian condition
(Follicular cyst disruption of normal estrus cycle through failure to ovulatory events, diagnosed via rectal palpation, fluid filled structure that is > 25 mm in diameter. Clinical signs; frequent signs of estrus. Treatment often unresponsive to treatment GnRH may be effective (hormone restarts ovarian cycle causing follicle)

Question 4

What are the problems related to the failure to conceive cattle reproduction?

Answer 4

Inhospitable uterus
-Endometritis
-High levels of urea-N
-Heat stress
-Infectious disease
-Trichomonas
-Campyobacter

*NOTE: can also be failure to ducted heat on the producer so if having trouble getting pregnant first look into this then the ones listed above

Question 5

What are the problems related to the PREGNANT cattle reproduction?

Answer 5

Early embryonic loss
-10-15% of pregnancies diagnosed at 28 d gestation are lost by 60d
Causes:
-Nutritional/endocrine –> lack of progesterone which is needed in pregnancy
-Failed recognition of pregnancy
-Genetic/developmental anomalies
-Heat stress
-Infectious disease such as mastitis and BVD

Question 6

What are the problems related to the ABORTION cattle reproduction?

Answer 6

Infectious disease
-Bovine viral diarrhea virus
-Infectious bovine rhinotracheitis virus
-Leptospirosis
Toxic
Trauma
Iatrogenic (genetically wrong with calf and just happens)

Question 7

What are non-infectious abortion causes?

Answer 7

-Twins
-Heat stress
-Fetal genetic anomalies
-Maternal disease (inflammatory response may cause abortion ax mastitis)
-Latrogenic (Accidental PGF injection, inject wrong hormone)

Question 8

What are types of infectious abortion? Not stared on slide*

Answer 8

1.Sporadic abortion (expected incidence 3-5%)-Fungal through blood stream
-opportunistic bacteria from infection else where in body
-Although infectious doesn’t represent a danger to rest of herd, not highly
contagious
2. Contagious agents-Infectious Bovine Rhinotracheitis (IBR) more concerning
-Bovine Viral Diarrhea Virus
-Leptospirosis
-Neospora; no vax

VAX IS CRITICAL IN PREVENTION

Question 9

What are the reproductive manifestations of BVD?

Answer 9

Breeding—42d -Decrease in conception

42d———-125d-Persistantly infected calf (PI);born alive and shed increase levels of BVD will have to euth.

100d——–170d- Abortion or congenital anomalies; missing cerebellum unable to walk/stand, missing limbs/short limbs

170d——-280d- No fetal harm born seropositive; immune response

Question 10

what is Neospora caninum?

Answer 10

-Parasite that insects cattle, dogs and other canine (coyotes)
-Infection is life long bc no effective treatment
-Manifestation is abortion (4-7 months gestation) cattle that abort will likely do again if fetus not aborted calf very likely to be infected

Question 11

What is the life cycle of Neospora?

Answer 11

-Has both horizontal and vertical transmission
-Infected cow will give birth and dog/canine will eat placenta/cyct/spores and become infected. Oocysts in poop and unaffected cow eats food infected or will fed faces somehow and become infected

Question 12

What are some neospora abortion patterns?

Answer 12

-Endemic is common to have a few cases which are vertical (cow-calf). >5% /yr. only 5-7% risk of abortion.

-Epidemic less common. Horizontal transmission (cow-canine or canine to cow). Up to 30% more abortion rates, and up to 40x grater abortion risk.

Question 13

How are cows managed if they contract N. Caninum?

Answer 13

-Cows that have been aborted due to neospora will eventually be culled
-Seropositive cows generally do not breed, could breed dairy to beef sire
-ET to seronegative recipients

Question 14

What are the problems related to CALVING cattle reproduction?

Answer 14

-Feto-pelvic disproportion
-Fetal posture
-Incorrect assisted delivery

Question 15

What are the parturition stages?

Answer 15

Stage 1- Dilation of cervix
Stage 2- Delivery of newborn
Stage 3- Shedding of the placenta or fetal membranes

Question 16

What happens in the first stage of parturition?

Answer 16

Stage 1; Dilation of cervix

-relaxation of pelvic ligaments (tail head is up)
-Relax and dilation of cervix
-Fetus changes position (superman)
-Placenta mebranes push against cervix by rhythmic contractions of the uterus
-Can take 6-8 hrs for this stage to complete

Question 17

What happens in the second stage of parturition?

Answer 17

Stage 2; Calving

-Allantois ruptures
-Amniotic sac ruptures
-Fetus is expelled from uterus by
-Abdominal contractions
-Uterine contractions
-Fetal movement
-Short time (10-70 mins) but depends on stage of animal, important to check on every 30 mins if taking longer then 70 mins intervene

Question 18

What are the 3 p’s of parturition?

Answer 18

-Presentation
-Positon
-Posture

-90% of normal calving are superman and 10% of normal are backwards superman
-Breach is when calf’s legs are together and have to pull out legs to feet facing right way but head isn’t

Question 19

What are causes of dystocia and what is the most common one?
*not stared

Answer 19

1. Failure of the cervix to dilate
2. Obstruction of vagina
3. Failure of vulva or vagina to dilate
4. Uterine torsion-uterus twists around long axis
5. Uterine inertia
6. Maternal-fetal disproportion (fetus too large)
7. Abnormal presentation, position, posture
8. Twins
9. Malformed fetus

Question 20

What are the calving 101 rules?

Answer 20

• If calf presentation is OK can leave cows for 30-1hr, heifers 1-2hr
  -Maximum force= 4 arms
  -Keep it clean (bad contam uterus)
  -Use lots of lube
  -Follow natural downward arc in delivery
  -Rotate coif during delivery (increases amount of space)

Question 21

What are consequences of dystocia?

Answer 21

1. death of fetus
2. Vaginal tears
3. Uterine tear
4. Obturator nerve paralysis (calving too tight)
5. Sciatic nerve paralysis (down too long)
6. Muscle damage due to being down

Question 22

What happens in the third stage of parturition?

Answer 22

Third stage; Shedding of placenta or fetus membrane

-Expulsion of fetal membranes (<12hr is normal) longer then 24hr called retained placenta
-Uterine involution (<28days) shrink happens relatively quick given size of calf

Question 23

What is postpartum uterine disease timeline?

Answer 23

Retained placenta (first 24hr)
Metriris (7-10d)
Endometriris (28-60d after calving)
Anestrus (40-60d)
Pyometra (45-60d)

Question 24

What are the definitions of postpartum uterine disease?

Answer 24

-Retained placenta: Failure to expel fetal membranes by 24 hrs post calving
-Metritis: Systemic signs (off feed, toxaemia) referable to uterine infection 7-10d most frequent
-Endometritis:infection/inflammation of uterus; no systemic signs 28-35d after calving
-Pyometra: Uterus distended with pus, functional CL present, cow may think its actually pregnant treat with progestone