Repro

Question 1

Mention 3 most common causes of cyclic irregularities besides erroneous heat detection in ruminants.

Answer 1

Endometritis, intrauterine therapy, Cystic ovaries and Heat stress Other common causes are: Leptospirosis, Infectious bovine rhinotracheitis (IBR), Bovine viral diarrhea (BVD), Campylobacteriosis, Trichomoniasis, and Embryonic death after maternal recognition of pregnancy.

Smith, B. P. (2014). Large animal internal medicine. Ch 12, pg 180

Question 2

What is the average duration of estrus and length cycle in cattle?

Answer 2

18 hours average duration of estrus and 21 days duration for a normal cycle length.

Smith, B. P. (2014). Large animal internal medicine. Ch 12, pg 180

Question 3

Do mares artificially induced to ovulate using GnRH or FSH, display regular estrous cyclicity?

Answer 3

Mares that have been artificially induced to develop a follicle and ovulate during seasonal anestrus using GnRH or recombinant FSH usually do not display regular estrous cyclicity following the artificially induced ovulation till the onset of breeding season.

Smith, B. P. (2014). Large animal internal medicine. Ch 12, pg 180

Question 4

What is the difference between early embryonic death (EED), abortion, and stillbirth?

Answer 4

Early embryonic death (EED) is the death of a conceptus before organogenesis is complete (≈55 days in horses, 45 days in cattle, and 34 days in sheep).

Abortion refers to pregnancy loss after the completion of organogenesis and stillbirth refers to the delivery of a nonviable fetus at or near term.

Smith, B. P. (2014). Large animal internal medicine. Ch 12, pg 184

Question 5

Define prolonged luteal phase or pseudopregnancy in mares. - include gestational age

Answer 5

It is the embryonic loss in the presence of endometrial cups (days 35 to 150 of gestation). It may also refer to the condition in which a conceptus is lost after maternal recognition of pregnancy and before the development of endometrial cups, resulting in prolonged luteal life.

Smith, B. P. (2014). Large animal internal medicine. Ch 43, pg 1313

Question 6

What are the 3 stages in which sexual differentiation occurs?

Answer 6

All stages are dependent on one another.

• Chromosomal (genotypic or genetic) - determined at fertilization in mammals.
• Gonadal sex - regulated by the Sry (sex-determining region of the Y chromosome) gene, which produces a protein termed the HY antigen, and other sex-linked and autosomal genes downstream of Sry (X-linked Dax1 gene suppresses testis formation).
• Phenotypic - regulated by substances produced in the male testes causing regression of the female tract and formation of the male tract.

Smith, B. P. (2014). Large animal internal medicine. Ch 43, pg 1316

Question 7

What is the most commonly reported chromosomal anomaly in mares?

Answer 7

Monosomy X (Turner syndrome) - There is a lack of Y chromosome and the consequent Sry gene, but the re is presence of the Dax1 gene (present on the X chromosome) giving a female phenotype.

Smith, B. P. (2014). Large animal internal medicine. Ch 43, pg 1316

Question 8

What genetic anomaly is part of the Klinefelter syndrome and what is its phenotype?

Answer 8

With a male phenotype, the genotype for Klinefelter syndrome is XXY (XXY syndrome). The presence of a Y chromosome (and its Sry gene), phenotype is male, generally with hypoplastic genitalia and reproductive organs likely due to the presence of two copies of the Dax1 gene (on the 2 X chromosomes)

Smith, B. P. (2014). Large animal internal medicine. Ch 43, pg 1316

Question 9

What are the conditions to have a freemartin calf?

Answer 9

Happens in ruminants when an infertile female is twin to a male. Sry gene of the male twin causes the freemartin gonads to develop at least partially toward the male testis and differentiation varies with each freemartin. The zygotes fuse early in development (day 18 to 20 in cattle) and share embryonic tissue. Placentas fuse (at 30 to 50 days in bovines), and they share blood throughout gestation (sharing testosterone and anti-müllerian hormone through circulation). This occurs before gonadal differentiation at day 40 to 50.

Smith, B. P. (2014). Large animal internal medicine. Ch 43, pg 1317

Question 10

What are the possibilites of having a freemartin in a twin pregnancy?

Answer 10

92% of heifers born with a male co-twin, will be freemartins.

Smith, B. P. (2014). Large animal internal medicine. Ch 43, pg 1317

Question 11

What is the most common cause of ovarian enlargement in mares?

Answer 11

(1) tumors
(2) anovulatory follicles
(3) ovarian hematomas
(4) pregnancy

Smith, B. P. (2014). Large animal internal medicine. Ch 43, pg 1319

Question 12

What is the most common ovarian tumor in mares?

Answer 12

The granulosa-theca cell (GCT) tumor is the most common ovarian tumor in the mare, about 10% of neoplasms in horses are considered to be GCT.

Smith, B. P. (2014). Large animal internal medicine. Ch 43, pg 1319

Question 13

What type of bovine is RFM (retained fetal membrane) observed?

Answer 13

RFMs are more commonly seen in dairy than in beef breeds. In dairy cattle reported prevalence ranges from 8% to 12% after spontaneous delivery of single calves.

Smith, B. P. (2014). Large animal internal medicine. Ch 43, pg 1325

Question 14

What type of placentation do camelids have?

Answer 14

Camelid placentas resemble equine placentas (diffuse, microcotyledonary, epitheliochorial), with the exception that the left horn is almost always the pregnant horn.

Smith, B. P. (2014). Large animal internal medicine. Ch 43, pg 1326

Question 15

Which is one of the major causes of reduced fertility in broodmares?

Answer 15

Persistent endometritis is a major cause of reduced fertility in broodmares. Approximately 10% to 15% of a normal population AI with frozen semen resulted in 16% to 25% persistent
of Thoroughbred broodmares developed persistent endometritis after breeding.

Smith, B. P. (2014). Large animal internal medicine. Ch 43, pg 1326

Question 16

Mention 3 organisms that are transient residents from the reproductive tract in cows that are a common cause of uterine infections.

Answer 16

A. (Actinomyces) pyogenes, which acts with Fusobacterium necrophorum and Prevotella (formerly Bacteroides) spp. commonly cause uterine infections.

Coliforms, P. aeruginosa, hemolytic streptococci, and gram-positive and gram-negative anaerobic bacteria are also frequently isolated from animals with postpartum uterine disease.

Smith, B. P. (2014). Large animal internal medicine. Ch 43, pg 1331

Question 17

What is Infectious Pustular Vulvovaginitis (IPV)?

Answer 17

IPV is characterized by a mucopurulent vaginal discharge, inflammation of the vaginal and vulvar mucosa, and painful urination. It also develops pustules over lymphoid follicles and progresses from small (<3 mm) ulcers to coalescing erosions.

It is caused by bovine herpesvirus 1 (also cause of infectious bovine rhinotracheitis but genetically distinct)

Smith, B. P. (2014). Large animal internal medicine. Ch 43, pg 1337

Question 18

How is Infectious Pustular Vulvovaginitis (IPV) transmitted and what is the incubation period?

Answer 18

IPV is spread by coitus and mechanical means. May affect unbred heifers and the incubation period is short (1 to 3 days). It spreads rapidly through the herd, affecting 60% to 90% of the animals. IPV is not common.

Smith, B. P. (2014). Large animal internal medicine. Ch 43, pg 1337