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Pure Natural Sheep
Chemical Free St. Croix Sheep
The Right Breed for TN

Pure Natural Sheep™

St. Croix Sheep For Sale

No Dewormers, No Vaccinations, No Chemicals

Established 2009

1857 Brindley Hollow Rd. Buffalo Valley, TN
(931) 858-6892

Pure
Natural
Sheep™

Pure Natural Sheep
Pure Natural St. Croix Sheep
Never Needs Deworming

St. Croix Sheep For Sale

No Dewormers, No Vaccinations, No Chemicals

Established 2009

1857 Brindley Hollow Rd. Buffalo Valley, TN
(931) 858-6892

Pure Natural Sheep™

St. Croix Sheep For Sale

No Dewormers, No Vaccinations, No Chemicals

Established 2009

1857 Brindley Hollow Rd. Buffalo Valley, TN

Click Here to Call Us:
(931) 858-6892

 

The Natural Breeding Cycle of St. Croix Sheep

What happens when the natural breeding cycle of the St Croix Sheep is "uncontrolled" by man, and St. Croix Ewes and Rams are left together year-round?

Do St. Croix ewes naturally come into estrus or "heat" and breed year round, or only at a certain time of year?

Are there any advantages to letting Nature determine the St. Croix breeding cycle?

 

 

Why Do Humans Try to Control the Breeding Cycle?

 
 

Some sheep farmers keep the male rams and female ewes separate, and introduce the rams to the ewes only at certain times of the year. This will force the ewes to lamb at a specific time of year.

From the time that sheep mate until the time they lamb is called the "gestation period" which is 5 months long.

If a sheep farmer wants his ewes to produce lambs on April 1st, he will introduce the rams to the ewes 5 months prior, on November 1st.

The purpose of this technique is to produce lambs when the weather may be more favorable, or around ethnic/religious holidays when the demand for lamb is higher.

 


St. Croix Ram

Sheep naturally know the best time of year to breed, as they have been breeding without Man's help for thousands of years.

 

 

Why Do Humans Try to Control the Estrous Cycle?

 
 

Estrus is when a female sheep (ewe) becomes fertile for reproduction. Commercial sheep farmers will control the estrous cycle to force the ewe to breed out of season to produce more lambs.

One method is place a progesterone vaginal insert in every ewe to stop the ewe's natural estrous cycle. To start the breeding cycle, the farmer will give the ewe PMSG, which is a pregnant mare hormone called "Equine chorionic gonadotropin". This unnaturally forces the ewe to produce lambs according to the schedule set by the farmer.

I cannot imagine abusing an animal like this for profit. Or eating one of these impure animals produced by hormones.

Another "more sane" method to control the estrous cycle is to separate a very young lamb from its mother (called weaning) in an attempt to bring the mother ewe back into estrus or "heat", so that she can quickly produce a second lamb crop.

The purpose of controlling the estrous cycle is to force the ewe to bear 3 lamb crops in 2 years or less, which is very hard on the ewe, and turns an animal into a machine.

Many times, trying to accelerate the lambing process and force the ewe to bear twice in a single year will produce only a single weaker lamb per pregnancy, which is more inefficient than naturally having twins once a year.

 


Hormonal Vaginal Inserts with Progesterone to Control the Ewe's Estrous Cycle.

Yes, you need gloves to use this product.

 


St. Croix Ewes bear 2.1 lambs in a single pregnancy each year without our help.

Perhaps the ewes would produce healthier lambs if we just left them alone.

 
 

But if you think you can make a profit doing this, then Big Ag will sell you the chemicals. And the hormones. And the vaginal insert gloves. How disgusting.

Treating the ewe with dignity by leaving it alone and letting it have a "natural" single pregnancy once a year is more likely to produce twins, and the lambs will be healthier raised on their mother's milk.

It is hard to improve on Nature. And letting sheep breed naturally makes it impossible for Big Ag / big Pharma to make money off you

 

 

What Happens If Sheep Breed Without Human Interference?

Scientific Research on Natural Lambing and "Photoperiods."

 
 

 

In 1988, research was done in Monnaie, France using Ile-de-France sheep on the effects that photoperiod (which is the length of day) has on the breeding cycle of sheep.

The research found that sheep naturally breed in the late summer as the days begin to grow shorter.

Here is the link to the document on Research Gate, which you can download as a PDF document:

Seasonality of Reproduction in Sheep and its Control by Photoperiod

Click to Enlarge

 

 

This Research on Natural "Length of Day" Breeding Produced An Interesting Chart:

 
 

 

The research showed that both the males rams and female ewes follow a definite cycle based on the length of daylight and the time of year.

This provides a scientific reason why farmers who try to control the sheep breeding cycle will find it difficult for their ewes to be impregnated during the period of February to June of each year.


Click to Enlarge

 

 

The Female Sheep Reproduction Cycle

 
 

The letters at the bottom of the chart represent the months of the year.

The chart shows that the majority of ewes do not have an estrous cycle from February 1st (as the short days grow longer) until the end of July (when the long days grow shorter.)

Ovulation is reduced during this period, with the exception of a hidden ovulation spike in May that affects only 60% of the ewes.

This hidden ovulation spike exists without the signs of estrus, which would reduce the chances of attracting a male for mating.


Click to Enlarge

 

 

The Male Sheep Reproduction Cycle

 
 

This chart shows that the male sperm count and testicle size starts to drop in February, and then begins to spike upward in June, a month before the ewes start their estrous cycles.

This lack of male performance as the days grow longer explains why it may be difficult to breed sheep from February to June.

And the chart may explain why it may be easier to breed sheep in October for lambing in March, than it is to breed sheep in May to lamb in October.

The research paper states that every sheep breed has a different level of breeding sensitivity to the photoperiod or length of day, so it can depend on the sheep breed.


Click to Enlarge

 
 

From my experience with raising natural sheep outside a barn, the St. Croix sheep breed are tied to the photoperiod and naturally breed in late summer when the daylight hours decrease.

 

 

The Yearly Natural Breeding Cycle of St. Croix Sheep

 
 

 

To help me understand the St. Croix yearly natural breeding cycle, I created a circular Calendar of the months and seasons, with time rotating clockwise.

At the top of the chart is December 21st or Winter Solstice, when the days are the shortest in the Northern Hemisphere.

At the bottom is the Summer Solstice of June 21st when the days are the longest.

On each side of the chart are the Fall and Spring Equinox, when the days and nights are of equal length.


Click to Enlarge

 

 

The Length of Day Decreases in the Summer and Fall.

 
 

 

From June 21st until December 21st, the length of day or "photoperiod" decreases as the days become shorter and the nights become longer.

Sheep have a gestation period of 5 months. In Nature, sheep mate in the fall to birth lambs in late winter to early spring, as this gives the lambs the best chance for survival.

The photoperiod of amount of light received by the sheep's retina influences the amount of melatonin released from the pineal gland. This causes an increase in the neuropeptide GnRh (gonadotropin releasing hormone) in the hypothalamus.


Click to Enlarge

 
 

GnRh activates the anterior pituitary gland to release luteinizing hormone (LH) and follicle stimulating hormone (FSH), which triggers ovulation and the creation of ovarian follicles in females, and stimulates the production of testosterone and spermatogenesis in males.

Melatonin is orally active, and can be fed to sheep to make them cycle during anestrous (to come into estrus when they otherwise would not.)

 

 

Dec 15th to Jan 15th
The Natural Lambing Time for St. Croix Sheep.

 
 

 

I have noticed that when my St. Croix sheep breed and lamb naturally without interference, the majority of the adult St. Croix ewes will bear lambs from December 15th to January 15th.

In Tennessee, the winters are mild, with an average high in January of 47 degrees Fahrenheit, and an average low of 28 degrees.

Winter is not a bad time to lamb. I have seen my St. Croix ewes drop their lambs right on the snow and survive with no problems. I do have a PVC pipe shelter covered with a tarp that they can go into when it rains or snows.


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It all depends on the wind chill, which is anytime the lambs wet while a strong wind is blowing. Without shelter from the wind, you can lose lambs to hypothermia born outside, even when the weather is mild.

When there is a winter storm, I will lock the sheep up, and the lambs will be born nice and dry on the hay inside the shelter with no problems.

It is much less work to occasionally put the sheep in the barn during a winter storm than it is to force a spring lambing by keeping the rams and ewes separate for several months with separate fencing, grass, water, and guardian dogs.

And there are other reasons to lamb in winter.

We will discuss later why Nature believes it is much better to lamb in the winter than other times of the year.

 

 

July 15th - Aug 15th
The Natural Breeding Time For St. Croix Sheep.

 
 

 

All sheep have a gestation period of 5 months, which means that the St. Croix lambs born from December 15th to January 15th have been bred 5 months earlier starting July 15th to August 15th.

And it does not take a very large change in the photoperiod to initiate breeding.

June 21st is the longest day of the year, and the length of day in Tennessee is 14 hours, 37 minutes.

July 15th is when the light-sensitive St. Croix sheep start breeding, and the length of day in Tennessee is 14 hours, 22 minutes.

That is only 15 minutes difference.


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What is amazing is that the St. Croix sheep breeding cycle is initiated on July 15th by a decrease in daylight of just 15 minutes from June 21st.

It may be possible that this photoperiod breeding cycle could be "unnaturally" delayed with artificial light inside a barn.

But for those who are raising "natural sheep" outside a barn, knowing the timing of when this yearly natural breeding event is helpful.

This information tells us to keep the breeding rams and ewes together starting July 15th, and not to sell or separate our sheep during this period.

 

 

May 15th - June 15th
The Natural Weaning of Lambs

 
 

 

As the daylight lengthens in the spring, the ewes naturally wean their lambs at 4-5 months.

Nature will tell the ewes to kick their lambs off the teats by the middle of June to allow the ewes time put on weight before they go back into the breeding cycle in July when the days begin to shorten.

Natural weaning according to when the ewe decides to wean the lamb (and not Man) creates stronger and healthier lambs, and it reduces stress on both the lambs and ewes.

Natural weaning eliminates Mastitis in the ewe, as Nature will have time to dry up the ewe's milk during the natural weaning process.


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And the lambs will have plenty of grass in June when they come off their mother's milk. The timing is perfect.

 

 

June 22nd - June 30th
The Time to Remove Unfit Ewes Before Breeding Begins.

 
 

The end of June (after natural weaning and before natural breeding) is the time when any ewes unfit for reproduction can be removed.

With the abundance of pasture at the beginning of Summer and with the ewes no longer producing milk, any ewe that appears skinny or undersized in June should be removed.

Natural Selection is about how Nature culls the inferior animals, including the old, the lame, and the sick.

We should cull every ewe that is old, that does not produce lambs or only one lamb, that does not shed its winter coat, that has scurs or small horns, that has dark spots on its coat, or has any kind of health issue.


Click to Enlarge

 

 

Jan 15th - Mar 15th
Yearling Ewes Lambing Season.

 
 

 

Ewe lambs that are born in January will take at least 7 months or longer before they come into estrus for the first time, which can be as late as October 15th.

When these young ewes are bred by the rams as late as October 15th, this means they will give birth 5 months later between January 15th to March 15th. So expect the yearling ewes to bear later than the older ewes.

There is a good reason to let these yearling ewes breed. The first time a ewe is bred, she always produces a single lamb. After this, she can produce twins.

So by breeding the young ewes early, we increase production the following year.


Click to Enlarge

 
 

Older ewes may give birth during this period, if their earlier ovulation cycle was missed by the rams.

But with plenty of rams, if an older ewe does not give birth by March 15th, it should be culled.

A young ewe that doesn't produce by March 15th should be kept as it may have been too early to breed. Nature knows what is best.

It is a mistake to hold back the yearling ewes from breeding until they are a year to 18 months old, as this limits the flock's reproduction rate.

I have never seen a young yearling ewe bear a permanently undersized lamb. Nature knows the correct time for yearling ewes to breed. If Nature says they are ready, we need to accept it.

 

 

Oct 15th - June 30th
Time to Sell/Remove Rams Not Needed for Reproduction.

 
 

  When sheep are born, Nature provides an equal number of ewes and rams to provide genetic diversity.

Limiting reproduction to a single ram ensures that all of the flock's offspring will be half siblings, which leads to inbreeding on your farm or for those that buy from you.

For sufficient genetic diversity to lower inbreeding, we want the maximum number of rams with the ewes, and we want to get rid of any older rams that have bred the flock in prior years.

St. Croix rams reach puberty at 3 months and can breed early. A small flock with only two ewes has a 50% chance the young rams from will breed their own mothers (a 25% Coefficient of Inbreeding), and the young rams need to be removed before breeding season starts on July 15th.


Click to Enlarge

 
 

But if you have 10 or more ewes, there is only a 10% chance of the young rams will in-breed with their mothers. This is better than having a single ram breeding all 10 ewes, as all offspring in your flock will be half siblings that may ultimately breed each other (which is a 12.5% Coefficient of Inbreeding).

Breeding 10 rams with 10 ewes lowers inbreeding over using a single ram, and will help you keep a "closed herd" and practice bio-security.

Controlled breeding to produce a registered pedigree does prevent inbreeding, but it means you need to find a new registered and unrelated ram each year, which exposes your flock to the diseases on another farm, and your flock is no longer a "closed herd."

For a closed flock larger than 10 ewes, keeping equal numbers of rams and ewes for breeding does more to stop inbreeding than any other strategy.

Currently I have 60 ewes in a closed herd, so I keep all of the rams with the ewes from July 1 until October 15th, and I sell or process any rams no longer needed for breeding from October 15th to June 30th.

 

 

The Benefits of Letting Sheep Naturally Lamb in Winter

 
 

 

12 Reasons to Naturally Lamb in Winter


My St. Croix Lambs Born in January.
 
 

Why Does Nature Pick Winter as the Best Time for Lambs to be Born?

Here is a list:

  1. The number one threat to baby lambs is that they have not yet developed their natural resistance to intestinal parasites. In the cold of winter, parasites like the Barber's Pole Worm cannot hatch from feces or crawl up a stalk because of the cold weather. This cold winter weather keeps the winter lambs safe from parasites.

  2. There are no flying insects pests in winter. No bot flies, nose bots, or maggots can fly to attack your flock during this time. The only insects in winter are keds and lice, which don't fly and should have been eradicated from your flock long ago.

  3. There is less bacteria that will be active in winter, which means less disease transmission to the newborn lamb. If the ewe gives birth to the lamb on a pile of feces, the bacteria in winter is frozen or dormant and does not cause the problems it would during the warmer times of the year.

  4. Winter lambing means you can produce lambs in time for Passover and other religious holidays. Spring lambs are too young to be sold in the Spring.

  5. When the lambs are born in January they will be old enough to eat grass by April, which is when the grass appears. Perfect timing.

  6. The sheep can be kept in winter in a smaller well fenced area with hay bales to eat to carry them through the winter. This smaller area is easier for guardian dogs to monitor and protect both the sheep and lambs from winter predators. So it makes sense to lamb at the time the sheep are the most protected from predators.

  7. If the lambs are born in the spring, summer, or fall, the sheep flock will be grazing out in the open and not be confined to a small area with hay bales, as all of the bales will have been consumed before spring. When a ewe gives birth, it will stay with the lambs for 2 days and not follow the flock until the lambs can walk and are able to keep up with the rest of the flock. For these two days, the guardian dogs cannot patrol the herd and the separated ewe with the newborn lambs too. The ewe and newborn lambs are alone and vunerable to predators. I have lost more lambs born in the spring to predators for this reason than I have ever lost lambs born in the winter to cold weather.

  8. Sheep require additional nutrition to overcome the cold. If the sheep are to be given supplemental hay or grain in the winter, and the birthing ewes are also fed supplemental hay or grain, then it makes sense to take care of both issues at the same time, and feed all of the sheep and ewes with lambs during the winter. Without sufficient nutrition, the ewes will suffer from pregnancy toxemia. It makes sense that if you need to feed supplemental hay or grain for the sheep in winter and for raising lambs, to do both at the same time.

  9. If you only feed your sheep grain in the winter and not springtime, and you quit feeding grain before the lambs come off their mother's milk and start eating grass in the spring, then you can legitimately sell your lambs as 100% grass fed lamb, as they lambs will not have eaten only grass and not any supplemental feeds. Only the ewe will have been fed grain.

  10. Winter lambing occurs when you follow the Natural Breeding Cycle. Natural breeding means you never have to separate the rams from the ewes, so you don't need two separate areas with fencing, grass, water, and guardian dogs for both a ram flock and a ewe flock. This single flock of both rams and ewes makes rotational grazing much easier year round.

  11. During a winter storm, or if there are 2 feet of snow on the ground, the sheep need to have shelter. If the sheep are already in the barn because of winter weather, then this is also the perfect time for lambing inside the barn.

  12. Grass does slowly grow in the winter. When you lock up your flock with hay for winter lambing, it gives the larger pasture rest so it can be ready for spring.

  13. When sheep are kept in winter quarters for lambing, then all of the feces and parasites the sheep have produced for the entire winter will be dumped in one place. The winter lambing pen can be avoided in the spring when the parasites hatch. By summer after most of the worms have hatched and died, the winter lambing area can be used for rotational grazing.