A ram can usually mate 3 to 4 ewes per day. In general, the recommended ratio for mature rams is 1:35 to 1:50. In large flocks, the percentage of rams to ewes is often higher.
Thus, ewes are normally sexually active (show 17 day oestrous cycles) mid-Autumn into Winter, and sexually inactive (anoestrous) from late winter through to autumn. Seasonality ensures lambs are born at an optimal time, in the spring, when grazing quality increases to support lactation.
The mating period ranges from about 6 to 8 weeks in commercial flocks. Longer mating times result in management problems with lamb marking and shearing etc.
Fertile adult rams can serve at least 5 ewes per day, so over a 34 days breeding season (2 full estrus cycles), one ram could theoretically service over 150 ewes.
Joining rate and time
Ewes cycle every 17 days and rams should generally be joined for at least two of these cycles (five weeks). If the ewes are joined outside the peak breeding season (before February) or joining paddocks are large, join for five weeks if teasers are used or six weeks if teasers are not.
My advice is to leave the ram with the ewes after the official breeding season has ended, at least up to lambing. He will graze with them and in the winter, he will eat hay with them. No need to add extra work to house a ram separately at that time.
A ram that is kept with ewes is likely to be overfed, as a ram does not require as concentrated a diet as pregnant and lactating ewes. Some rams may be too aggressive to be kept with pregnant ewes. In less developed countries, they have a created an "apron" to prevent rams from impregnating ewes during comingling.
As a general rule, healthy sound Merino and British breed rams can be used at a rate of 1 ram: 100 ewes.
It is convenient to wait at least 3 months after the last parturition (lambing) before a ewe is bred again. A ewe comes into first heat at 7 to 8 months of age. A ewe should not be bred when she comes into her first heat. Experts recommend a ewe of at leas 10 or 12 months old to be bred for the first time.
The flushing process involves increasing sheep nutrition and energy intake before breeding season starts. This elevated nutrition helps optimize ovulation, conception and embryo implantation rates, which can result in a higher lambing percentage.
The natural joining and breeding season for ewes usually lasts from about February to June. During this time, a ewe will go on heat and ovulate for a short period in regular cycles, called oestrus cycles, approximately every 16 days.
Gestation: Average gestation length or length of pregnancy for sheep varies from 144 to 151 days (about 147 days; figure 11). Individual pregnancies may vary from 138 to 159 days.
Once the ewe has lambed, grass hay needs to be supplemented with high protein commercial feeds in order to balance the ration. Commercial feeds are generally a good deal more expensive than legume hay.
While most ewes exhibit estrus over 24-36 hours, many exhibit heat for either less or more time. Ewe lambs show estrus for a shorter time than mature ewes. Of the cycles studied, 90% were between 15 and 45 hours in length.
A farm family have spoken of their surprise after a ewe gave birth to twin lambs ten days apart, writes Catherina Cunnane.
If a ewe presents with a dead or rotten lamb and a caesarean section is not appropriate then your vet may carry out an embryotomy, where the dead lamb is removed vaginally following surgical dissection.
Another good indicator of twinning potential is early fertility. If a ewe produces her first lamb or lambs when she is a yearling, she is demonstrating early fertility. Many of these will go on to produce twins as 2 or 3 year olds and older.
Sheep belong to the genus Ovis and have 54 chromosomes, while goats belong to the genus Capra and have 60 chromosomes. The offspring of a sheep–goat pairing is generally stillborn. Despite widespread shared pasturing of goats and sheep, hybrids are very rare, demonstrating the genetic distance between the two species.
Lambing Kit
Most ewes will lamb within an hour of their water breaking, therefore ewes must be checked at least once per hour.
Providing your flock with supplement before forages turn and throughout the fall and winter ensures ewes receive the nutrition they need to support breeding and reproduction. Reliance on grass as the sole nutrition source can take a toll on everything from ewe body condition to breeding and reproduction.
A good lambing percentage is largely achieved by early preparation between weaning and the next mating. Ewes need to be in good body weight and condition (CS3) for high ovulation rates at mating.
A Ram should have a companion. Sheep are flock animals, and should never be left alone. It is advisable to own more than one ram.
Sperm production in the ram takes six to seven weeks. This means that a ram mating a ewe on October 1 will have started producing that sperm in the middle of August. Anything that interferes with sperm production in the run up to mating can have disastrous effects on the ram's ability to impregnate ewes.
The gestation length of Dorper ewes was approximately 147 days, while they were reported to start cycling as soon as 52 days after parturition.
In my experience if you look at your sheep head on, their rounded sides become increasingly egg shaped, indicating they're pregnant rather than just fat! Like sheep growth, bagging up doesn't happen in sheep until the final few weeks before birth. However, ewes generally hold their teats very close to their body.