Lecture 5

Question 1

What are the goals for naturally bred beef cattle?

Answer 1

-12 month calving interval
-90% weaned calf crop
-60 day breeding and calving seasons
-less than 2% pre-weaning death loss
-have at least 60-65% of cows pregnant at any time

Question 2

Why is a 60 day breeding season utilized in cattle?

Answer 2

with an estrous cycle length of 21 days, this provided around 3 chances per cow to conceive

Question 3

What are the goals for dairy cattle breeding?

Answer 3

-12 to 13 month calving interval
-85 or fewer days open
-50% pregnant after first service conception
-15% or fewer cows open on pregnancy check
-88% of cows requiring 3 or fewer services/conception

Question 4

What are the current averages for dairy cattle breeding?

Answer 4

-14.5 month calving interval (can be okay if producing lots of milk)
-145 days open
-35% pregnant after first service conception

Question 5

What is the estimated cost per day for a cow to be open beyond 100 days?

Answer 5

$2-5 a day

Question 6

What should be included in a history on breeding cattle?

Answer 6

-retrospective nature of problem
-parturitions
-estrous cycles
-breedings
-abnormal reproductive occurrences
-previous diagnoses/therapies/vaccinations

Question 7

What should be assessed via transrectal palpation?

Answer 7

-cervix
-uterus
-ovaries
-uterine tubes
-non-reproductive organs

Question 8

What are the characteristics of the cow’s cervix?

Answer 8

-1 to 5 cm wide
-7 to 10 cm long in a normal, non-pregnant cow
-can be more abdominal in some breeds
-abnormalities include bigger or smaller size, abscessed, or asymmetrical

Question 9

What are the characteristics of the cow’s uterus?

Answer 9

-1 to 5 cm in diameter
-smaller in heifers; can be enlarged in cows with hx of multiple pregnancies
-abnormalities include segmental aplasia, asymmetry, and uterine tumors

Question 10

What are the characteristics of the cow’s ovaries?

Answer 10

-1x1x2 cm if inactive
-2x2x4 cm if active
-lots of variability
-small ovaries can indicate hypoplasia
-large ovaries can indicate cystic ovarian disease or tumor

Question 11

What are the characteristics of the cow’s uterine tubes?

Answer 11

-difficult to palpate or image
-abnormalities include missing tubes, enlarged tubes, or inflamed tubes; may palpate if large

Question 12

What is the main goal of pregnancy diagnosis?

Answer 12

identifying non-pregnant cows so they can be re-bred

Question 13

What are the methods of pregnancy diagnosis?

Answer 13

-waiting to see which cows calve (most common, not cost effective)
-failure to return to estrus
-rectal palpation after 30-34 days
-chemical assays
-ultrasound after 28 days

Question 14

What are potential indications (but not for sure signs) of pregnancy in cows?

Answer 14

-asymmetry of the uterine horns
-fremitus/enlargement of middle uterine artery

Question 15

What are the positive/cardinal signs of pregnancy?

Answer 15

-amniotic vesicle
-membrane slip
-fetus
-placentomes

Question 16

What are the characteristics of the amniotic vesicle?

Answer 16

-present around and after 30 days gestation
-may need to palpate entire uterus to discover
-diameter correlates to stage of pregnancy
-over-aggressive palpation could result in intestinal atresia (not proven) or fetal death

Question 17

What are the characteristics of chorio-allantois palpation/membrane slip?

Answer 17

-present around and after 35 days gestation on the ipsilateral side
-present around and after 48 days bilaterally
-cannot be felt after about 90 days
-not associated with birth defects or pregnancy wastage

Question 18

What are the characteristics of fetus palpation?

Answer 18

-can be done around and after 65 days gestation
-relative size can correlate with length of gestation
-from 3.5/4 months to 7 months fetus is more so in abdomen and hard to palpate

Question 19

What are the characteristics of placentome palpation?

Answer 19

-palpable around and after 75 days gestation
-continue growing in size until 150 days
-want to palpate right in front of the cervix; can be larger if felt elsewhere
-usually palpable from 4 to 7 months gestation
-can potentially still be felt post-partum

Question 20

What are the characteristics of pregnancy-associated glycoproteins?

Answer 20

-measurement of Pregnancy Specific Protein B
-reliable indicator of pregnancy after 26 to 30 days
-cows must be 3 months or greater post-partum; otherwise false-positives can occur due to long half-life

Question 21

What are the characteristics of real-time B mode ultrasound?

Answer 21

-allows for accurate identification of ovarian structures
-can assess uterine size and contents
-used for early pregnancy diagnosis and fetal sexing

Question 22

What are the general characteristics of anestrous?

Answer 22

-absence of overt signs of estrus
-does not necessarily correlate with inactive ovaries
-most common fertility-associated complaint
-most frequent source of wasted therapy

Question 23

Why is functional anestrous considered a myth?

Answer 23

-persistent or retained CLs do not exist in the absence of uterine pathology
-problem in cows with functional anestrous is poor heat detection

Question 24

What are the characteristics of cavitated CLs?

Answer 24

-young CL waiting to become fully filled in
-occur after ~ 1/3 of all ovulations in the cow
-typically young CLs; but not all young CLs are cavitated
-fluid filled cavity within the CL
-due to incomplete luteinization of antrum of follicle
-structures are normal and cycle length is unaltered

Question 25

What is the most frequent cause of anestrous in nature?

Answer 25

pregnancy

Question 26

What are the characteristics of organic anestrous?

Answer 26

-exists in cows having inactive ovaries -accounts for ~ 10% of anestrous cows -can be due to malnutrition (most common), post-partum, debility, age, immaturity, or senility -therapy is based on time and increased plane of nutrition -can also see disorders of sexual development

Question 27

What are the characteristics of cystic ovarian disease?

Answer 27

-anovulatory follicular structures -10% of post-partum dairy cows -occurs 15 to 45 days post-calving -50% spontaneously resolve

Question 28

What are the two cyst types in COD?

Answer 28

-follicular cysts: thin walled, often multiple -luteal cysts: some luteinization present

Question 29

What is the definition of ovarian cysts?

Answer 29

large, anovulatory, follicular structures > 25 mm that persist beyond the normal period of a dominant follicle (10 days)

Question 30

What are the outcomes for ovarian cysts?

Answer 30

-regress and replaced by another cyst -regress and replaced by normal ovulation -may exist in conjunction with CL

Question 31

What are the possible etiologies of cystic ovarian disease?

Answer 31

-malnutrition/inadequate energy (most common) -disorder of GnRH release -disorder in response of pituitary to GnRH -improperly timed LH surge -missing/fewer receptors for LH/FSH

Question 32

What are the clinical signs of COD?

Answer 32

-nymphomania/hypersexual activity; 20% in literature, more rare in real life -anestrous; 80% in literature, almost all cows in real life

Question 33

How is COD diagnosed?

Answer 33

-history -rectal palpation -ultrasound

Question 34

How is COD treated?

Answer 34

-wait a minimum of 40 days post-partum before treating -can use PGF, GnRH, or a protocol of GnRH + CIDR followed by PGF -do NOT try to pop; can cause scarring

Question 35

What are the characteristics of freemartinism?

Answer 35

-chromosomal disorder -can try red top tube test/inserting into vagina -blood chimera; XX and XY chromosomes -occurs when a female was an in-utero twin to a bull -anti-mullerian hormone from male affects development of female and causes her to carry Y chromosome DNA