Reproduction in Small Ruminants

Length of the season depends on:

Daylength

Breed

Nutrition

In ______ _______ sheep and goats breed _________ the year.

Tropical environments

Throughout

Dorset, merino, and rambouillet breeds originated

near the equator

longer breeding seasons than British breeds

First Ovulation in Ewes

6-9 months

First ovulation in Does:

5-7 months

What age does viable spermatozoa for copulation happen in sheep and goats?

6 months of age

Onset of puberty in sheep is influenced by:

Genetic factors

Environmental factors

Season of birth

The ram does not have a restricted mating season but:

Sexual activity increases in the fall

Two primary factors that influence the onset of breeding season

1. Photoperiod

   1. Temperature

Eww Estrous Cycle

17 d

Doe Estrous Cycle

21 days

Ewe Estrus Length

24-36hours

Doe Estrus Length

24-48 hours

_____ breeds have a longer duration of estrus than meat breeds.

Wool

Angora goats have a shorter duration of estrus than ______ breeds.

Dairy

T/F: Estrus in the ewe is easy to spot.

False; estrus in the ewe is inconspicuous.

Ewes and does typically display a strong ____-_________ _________.

Male-seeking behavior

The response of ewes to the ram is dependent on an _______ ________ secreted by the _____ ______ of the ram

androgenic pheromone

sebaceous glands

A period of sexual isolation is necessary to obtain the ____ _____

Ram Effect

Both the ewe and doe are ________ ovulators

Spontaneous

the ___ ovulates about 24-37 hours after the onset of estrus.

Ewe

The _____ ovulates 24-36 hours after the onset of estrus.

Doe

Two things that influence ovulation rate:

Season and Level of Nutrition

What is it called when the ovulation rates can be increased by increasing the plane of nutrition?

Flushing

Increased ovulation rate of Booroola Merino is due to what?

A single gene

Ram and Buck Ejactulate

Low Volume → High Concentration

Normal gestation length of small ruminatnts

150 days

Genotype of the fetus accounts for ______ of the variation in gestation length.

2/3

_______ lambs are carried longer than _______ lambs.

Male; Female

_____ born lambs longer than ______ born lambs

Spring; Fall

______ lambs longer than _____.

Single; Twins

Which species can the placenta take over progesterone produciton?

Sheep `

Duration of birth varies on:

Lamb size

Twins

Abnormal presentation

T/F: The critical period of attachment is long for sheep and goats so you have a while to work with the lamb in need be.

False, fresh lamb can be rejected 6-12 hours after being removed at birth

What attracts the ewe to her offspring?

Fetal fluids

Spermatogenesis length in rams and bucks

48 days

How many weeks prior should a BSE be done before turnout?

4-6 weeks

Male to Female Ratio:

1:30-40

1:20 if synchronized

3 Pregnancy Check Options

Non-return rate

Ultrasound

Blood tests