Gestation in Sheep How Long is Pregnancy in Sheep
Gestation periods in sheep, like many others, comes in stages. And that’s why today, we are going to have a detailed discussion on the gestation period of sheep, and how it can be controlled by their owners.
The usual gestation period for a ewe often takes about 147 days, spanning from 144 to 152 days. However, the medium-wool and meat-type breeds of ewe, often have a quite shorter gestation period than the fine-wool ewes. Also, a very high temperature, coupled with perhaps a high dose of nutrition levels may also reduce a ewe’s gestation period by two or three days.
Sheep(Ewe) Reproduction Cycle
Typically, female sheep(Ewes) do reach their puberty between 5 to 12 months after birth, depending on the nutrition they are given, date of birth, and breed.
And in regards to their conception, when a Ewe is in her Anestrous period (a period when they can’t reproductive) she won’t show any signs of heat(estrus) for mating. And Anestrous in ewes is often as a result of how long a day is, the effect from sucking stimulus of lambs, and postpartum.
Length Between Ewe’s Heat Periods
The usual cycle for ewes is approximately 17 days between heat periods. However, sometimes, it can range between 14 to 19 days. It also has what is known as the mirror estrus period, which usually lasts for 30 to 35 hours under a range of 20 to 42 hours. A ewe’s ovulation takes place late in this period.
Sheep Ewe’s Gestation Period
The usual gestation for sheep is for a period for a ewe often takes about 147 days, spanning from 144 to 152 days. However, some of the Breeds Slightly Differ, the medium-wool and meat-type breeds of ewe, often have a quite shorter gestation period than the fine-wool ewes.
Also, if you add a very high temperature, coupled with perhaps a high dose of nutrition levels may also reduce a ewe’s gestation period by two or three days. Which speeds up the time frame
And ewes raised to white-faced, wool-breed rams, are more likely to have a little longer gestation period than those raised to black-faced, meat-type rams.
How to Raise Ewe Lambs
Here are some facts you need to know in order to properly raise a ewe’s lamb.
- Yearling ewes that give birth to lambs while they are a year old, often have a greater lifetime production than ewes give that birth to their first lamb while they are 2-year-olds.
- Also, given that a ewe’s puberty depends greatly on their body weight, you need to feed the lambs with adequate levels of nutrition, so that they could at least have a two-third of a mature ewe’s body weight before they start breeding.
- It has been observed that lambs given birth to during the winter or early spring season, are more often likely to display estrus(heat) during their first year, compared to those born during the summer.
- Always separate ewes that give birth to lambs in their first year, from other mature ewes. Plus, also endeavor that you place the yearling ewes, under proper nutrition so they could grow to their biggest size.
Another reason why you should separate yearling ewes that have just given birth from the older ones is that yearling ewe and their lambs are naturally shy breeders. Sometimes, you can successfully separate them by making use of a smaller breed of rams on young ewes, to lessen the chances of experiencing any lambing difficulties.
Controlling Reproduction Cycle in The Ewe Sheep
Progesterone Therapies in Sheep
The most common way of inducing estrus in non-cycling ewes is through progesterone-based therapies. And in case you never knew, progesterone stops a ewe from returning to estrus and ovulating. It is produced by the corpus luteum (CL) of the ovary following ovulation and sustains pregnancy.
And how it works is that whenever progesterone is injected in a ewe’s body, it fools her into thinking that she is pregnant, thus causing her not to ovulate or get into heat. However, as soon as the progesterone source is completely taken off the ewe, she will eventually realize that there was no pregnancy and would ovulate immediately.
Progestogens can be given to a ewe by feeding her Melengesterol acetate (MGA), or through implants under the skin (Synchro-Mate B®), or through the use of sponges (or pessaries) inserted right into the ewe’s vagina, or can be done by plastic delivery devices inserted straight into the vagina, in a process known as CIDR (controlled internal drug release).
As soon a single shot of prostaglandin is induced into a flock of cycling ewes, about 60 to 70 percent of such ewes, will automatically display a synchronized heat period that will commence 30 to 48 hours after taking in the prostaglandin.
For non-cycling ewes, melatonin treatments can be used to induce heat periods after a minimum of at least 35 days of treatment.
Controlled lighting can be used to initiate estrus in short-day breeding cattle like ewes, by making sure that light is constantly by shone in the area where the ewes are kept. This will trick them into estrus.
Sheep Artificial insemination (AI)
There are 4 main AI ways of controlling a ewe’s reproductive cycle.
Sheep Vaginal Artificial Insemination AI
This is the simplest form of insemination, as it just entails depositing fresh semen into the ewe’s anterior vagina.
Sheep Cervical Artificial Insemination AI
Cervical AI is another easy way of insemination because it just entails depositing fresh semen into the first fold of the ewe’s cervix.
Sheep Trans-cervical Artificial Insemination AI
In this approach, you have to grasp the cervix and retract it into the ewe’s vagina, through a pair of forceps, that will allow the insemination into the ewe’s cervical canal.
Sheep Laparoscopic Artificial Insemination AI
This process involves the deposition of semen straight into the ewe’s uterine horns, through the use of an endoscope, a unique telescope with a fiberoptic light, that allows the vet or technician to have a clearer view of the ewe’s reproductive tract.
Embryo Transfer(EF) in Sheep
This approach involves harvesting embryos from a ewe’s reproductive tract, right before they get attached to her uterus. This method works best if you want a ewe to produce multiple lambs.
In a nutshell, just like all other animals like mammals and the rest, ewe has a gestation period, which can also be controlled through the use of external techniques.