Lecture 22

Question 1

What is the main reproductive goal in sheep and goats?

Answer 1

1.5 lambs or kids per year; 5 lambs or kids in 3 years

Question 2

What are the characteristics of small ruminant female anatomy?

Answer 2

-similar to the cow
-want good tonicity and coiling during AI
-coiled uterine horns

Question 3

What are the characteristics of the normal ovine cervix?

Answer 3

-pronounced annular folds
-difficult to pass pipette through canal with the folds aimed towards the vagina
-external os of the cervix is offset from the more linear arrangement of other species

Question 4

How does the small ruminant cervix impact AI practices?

Answer 4

laparoscopic AI is done in these species to circumvent the cervix

Question 5

What are the characteristics of the small ruminant male anatomy?

Answer 5

-have 4 accessory sex glands
-similar to the bull
-can get blockages in the sigmoid flexure if castrated/have small anatomy
-have vermiform appendage in which things can get stuck; can be removed without affecting fertility

Question 6

What is the age at puberty in small ruminants?

Answer 6

sheep: 6 to 9 months
goats: 6 to 8 months

Question 7

What are the factors that can affect timing of puberty?

Answer 7

*environmental:
-season of birth; spring-born animals have earlier puberty
-crossbreeds
-nutritional status

*nutrition:
-winter/spring does must gain 0.3 lbs/day to breed in fall
-delay breeding until 60% of mature body weight

*male presence:
-hastens onset of puberty

Question 8

What are the characteristics of sheep and goat breeding season?

Answer 8

-generally seasonal polyestrous
-short day breeders (August-December)
-black-faced sheep mostly fall breeders
-white-faced sheep breed in spring and fall

Question 9

What are the charactersitics of small ruminant breeding patterns?

Answer 9

-first and last cycles are often irregular
-out of season breeding is possible but with decreased fertility, offspring numbers, and birth weights
-isolate females from males to prevent unwanted heats/breedings

Question 10

What are the characteristics of the estrous cycle in ewes?

Answer 10

-total cycle length of 14 to 19 days
-estrus for 10 to 40 hours
-ovulation occurs near end of estrus
-breed every 12 hours until out of heat

Question 11

What are the characteristics of the estrous cycle in does?

Answer 11

-total cycle length of 21 days
-estrus for approx. 24 hours
-ovulation occurs near end of estrus

Question 12

When do small ruminants have the highest ovulation rate?

Answer 12

October and November

Question 13

What are the signs of estrus in small ruminants?

Answer 13

-increased urination, activity, and vocalization
-decreased appetite and milk yield
-swollen vulva
-rides other goats/sheep
-clear then cloudy mucus
-personality changes
-tail wagging

Question 14

How is heat detection done in ewes?

Answer 14

-introduction of an intact or epididymectomized male with chalk harness
-chalk harness color is changed every two weeks; color gets more dark/intense each change
-allow for fence line exposure

Question 15

How is heat detection done in does?

Answer 15

-create a buck jar by rubbing a rag on the buck’s head and storing it in a jar
-offer jar to does once a day; does will follow opened jar if in heat
-allow for fence line exposure

Question 16

What are the behaviors seen in teaser bucks/rams when a female is in heat?

Answer 16

-sticking nose in stream of urine from females
-flehmen reaction
-strikes with front leg
-flicking of tongue
-mounting

Question 17

What is the desired ratio of rams/bucks to ewes/does?

Answer 17

2 to 4 males per 100 females

Question 18

What are the characteristics of AI in does?

Answer 18

-allows for better genetics
-prevents STDs
-must have proper heat detection and/or estrus synchronization
-breed towards the end of the AM-PM rule
-vaginal or cervical deposition
-fresh or frozen semen

Question 19

How is pregnancy diagnosed in sheep and goats?

Answer 19

-no return to estrus
-parturition
-ballottement
-ultrasound as early as 25 days; fetal heartbeats at 27 days; typically done at day 50
-radiographs at day 70; number of kids at day 75

Question 20

What are the possible laboratory tests done for pregnancy detection in sheep and goats?

Answer 20

*progesterone:
-must collect precisely one cycle after doe was bred
-use milk or serum

*estrone sulfate:
-can test urine, plasma, or milk
-conjugated estrogen is produced by conceptus

*bioPRYN:
-measures pregnancy-specific protein B
-protein is produced by placenta
-detectable 30 days post-breeding

Question 21

What is the gestation length for ewes and does?

Answer 21

ewes: 140 to 155 days; avg. 148
does: 140 to 155 days; avg. 150

Question 22

What is the progesterone source in ewes and does?

Answer 22

ewes:
-progesterone from CL during 1st trimester
-placenta takes over after 50 days

does:
-progesterone primarily from CL

Question 23

What are the characteristics of prostaglandin-induced abortion in small ruminants?

Answer 23

-can be done in sheep from 7 to 50 days gestation
-can be done in goats from 7 days gestation until term
-drug of choice in goats; will abort 1 to 2 days after admin.
-does not work in sheep after 50 days since CL is no longer essential

Question 24

What are the characteristics of dexamethasone-induced abortion or parturition in small ruminants?

Answer 24

-drug of choice in sheep; lamb within 42 hours
-less predictable in goats; kid in 2 to 10 days
-most effective after day 140 of gestation

Question 25

What are the characteristics of enzootic abortion of ewes?

Answer 25

-caused by Chlamydophila abortus -causes late term abortions, stillbirths, and weak lambs -zoonosis rare -can cause abortions in pregnant women

Question 26

What are the characteristics of Campylobacteriosis?

Answer 26

-caused by Campylobacter fetus var. fetus or C. jejuni -causes late pregnancy abortions, stillbirths, and autolysis -C. jejuni causes zoonotic enteritis

Question 27

What are the characteristics of toxoplasmosis?

Answer 27

-caused by Toxoplasma gondii -ingestion of oocytes early in gestation leads to resorption or mummification -ingestion of oocytes late in gestation leads to abortions or perinatal deaths -zoonotic

Question 28

What are the signs of impending birth in small ruminants?

Answer 28

-udder engorgement -pelvic ligament relaxation -isolation -restlessness -vulvar edema -cervical mucus

Question 29

What are the characteristics of stage 1 of parturition?

Answer 29

-uterine contractions -cervical dilation -typically lasts 3 to 6 hours

Question 30

What are the characteristics of stage 2 of parturition?

Answer 30

-active abdominal straining -"water" breaks -lasts 1 to 3 hours -typically 1 hour before first fetus is born -always check for additional lambs/kids if dystocia occurs

Question 31

What are the characteristics of stage 3 of parturition?

Answer 31

-placental expulsion -usually within 2 hours of last fetus -lasting longer than 12 hours is considered retained fetal membranes

Question 32

What can cause dystocia?

Answer 32

-large single fetus -ringwomb -malpresentation -more than one fetus presenting simultaneously

Question 33

What are the treatment options for dystocia?

Answer 33

-forced extraction -fetotomy -c-section

Question 34

What are the characteristics of ringwomb?

Answer 34

-failure of cervix to dilate -can be failure of endocrine control or failure of tissue to respond to hormones -want to attempt manual dilation -oxytocin is given and repeated in attempt to cause dilation -c-section if dilation not successful

Question 35

What is the treatment for retained fetal membranes?

Answer 35

-oxytocin if within the first 24 hours -systemic antimicrobials if greater than 24 hours

Question 36

What are the characteristics of pregnancy toxemia?

Answer 36

-metabolic disorder of ewes and does -characterized by hypoglycemia and hyperketonemia

Question 37

What are the characteristics of pseudopregnancy?

Answer 37

-seen in dairy goats -occurs with previous heat +/- breeding -can have failure of CL to regress, early embryonic death, or fetal mortality -more common in unmated animals during non-breeding season or those experiencing out-of-season breeding -can have spontaneous resolution or treat with prostaglandin

Question 38

When is the most deadly period for lambs?

Answer 38

first 3 days of life; 10 to 45% of lambs may die

Question 39

What are the general causes of neonatal deaths in small ruminants?

Answer 39

-dystocia -low birth weight -breeding for growth and muscle -retaining mothers that have had previous problems -deficiency or infection -starvation-mismothering exposure

Question 40

What are the steps for handling difficult lambing?

Answer 40

-ewe is stuck in second stage of labor for more than 1.5 hours -want to record ID number for culling -clean the rear end -use plastic sleeves and lots of lubricant -elevate rear end -check for dilation of cervix -check fetal presentation for proper birth position -steady but gentle pulling

Question 41

What are the characteristics of starvation-mismothering exposure?

Answer 41

*starvation: -poor colostrum/milk production -single lamb dystocia -ingestion issues *mismothering: -failure to establish ewe-lamb bond -maternal behavior affected by estrogens, cervico-vaginal stimulation, lamb odor, and/or experience *exposure: -hypothermia

Question 42

Why is it important for the lamb to get up and eat quickly after birth?

Answer 42

-small energy stores -difficulty regulating body temp. -determine ewe maternal capabilities

Question 43

What are the treatment steps for SME lambs?

Answer 43

-give 20 cc/lb of warm sheep colostrum -give 5 cc per pound of 50% glucose IV -use hair dryer to warm lambs to > 100 degrees as needed -take rectal temps every 15 minutes while heating to avoid overheating -confine with mother for several days

Question 44

How can neonatal deaths be prevented?

Answer 44

-prevent difficult births -assure adequate but not excessive birth weight -maintain body temp -assure adequate colostrum intake -shear rear end of ewes prior to lambing

Question 45

How can difficult births be prevented?

Answer 45

-buy rams for low incidence of dystocia -cull ewes with difficult births -provide regular exercise in late pregnancy -observe frequently for dystocia -no more than 5% assisted births in herd

Question 46

What BCS in the ewe is desirable for ensuring good birth weight?

Answer 46

BCS 2.5 to 3.5 in November

Question 47

How can a lamb's body heat be maintained?

Answer 47

-provide shelter and supplemental heat -be prepared to give warm colostrum +/- dextrose -tube feed as needed -cull ewes that fail to raise their lambs

Question 48

How is a sanitary birth environment maintained?

Answer 48

-shear rear of ewe before lambing -clean and rotate lambing areas