Agriculture Reference
In-Depth Information
the lambing season tend to come into estrus sooner because of reaching puberty sooner than
twin-born lambs, lambs that are not fed for fast growth, or younger lambs.
When to breed
Before you breed your ewes, they should be in the best health condition possible. A sick ewe
will have difficulty carrying a pregnancy to term, may give birth to sickly lambs, or may not
be able to properly care for her lambs. Vaccinations should be finished before breeding to en-
sure the mother can fight diseases and pass on some of her immunity to her lambs. The herd
should be treated with a dewormer and have their hooves trimmed as a matter of routine
maintenance. Intestinal worms are highly contagious; so all sheep in the herd should be
treated at the same time to lessen the chance of having an infected sheep in the herd. Any
sheep with abscesses, those in poor body condition, those with poor teeth, or sheep with any
chronic health condition should be treated aggressively or culled.
The sheep's estrous cycle averages around 16 days. Standing estrous — when the sheep will
show interest in the ram and stand to be mounted by the ram — is influenced by the presence
of the ram and lasts for around 30 hours. Most sheep show estrous when the days are shortest.
The daylight enters the eye and stimulates the brain, which in turn regulates the release of hor-
mones that stimulate estrous. In the Northern Hemisphere, the most natural time to breed
sheep is October through November. This seasonal estrous (polyestrous) is normal for most
sheep although some sheep breeds will mate all year. An ewe in estrous will be hard to detect
unless a ram is present. Then she will show the ram attention (such as nuzzling him) and
standing still for him to mount her. One ram can service 30 females.
Lambing
The average length of gestation is 148 days. Around ten days before lambing (giving birth),
the ewe's udder and vulva will swell. The teats become firm and fill with colostrum, which is
the vital first milk the lamb needs to develop its immune system. An ewe close to lambing
should be moved to a lambing pen or “jug.” This is typically a 5-foot by 5-foot pen that is
isolated from the rest of the flock. It should be kept scrupulously clean and deeply bedded
with clean, dry straw.
As lambing approaches, a thick white mucus will discharge from the vulva. Uterine contrac-
tions will cause the ewe to become uneasy and swish her tail. She might bleat and get up and
down. The ewe might start to strain as the cervix continues to dilate in preparation for the
