Learning how to think about grazing
September 25, 2010
This endeavor began in the winter months, when long nights and cold days found me inside by the fire, imagining the potential for this year. It seems fitting that as the northern hemisphere begins it's slow transition toward shorter days and the next solstice, I am revisiting these ideas, and seeing how far I have progressed in these two seasons.
At first I did not realize, but there is an entire universe behind intentionally and sustainably grazing animals. When I first began investigating our options, there was an overwhelming amount of questions and data to sort through. As Walt has told me, when faced with an incredibly complex task, start with what you can do and move from there.
When beginning any project as large as this, there is always an evolving process in consideration of the appropriate path to take. Here is some documentation of my evolving thoughts on the subject.
Winter is a time for dreaming and planning
For the sake of consistency in these articles I will be focusing on sheep. There are some aspects of grazing sheep that are unique; however, most herbivores have relatively similar needs and ways of grazing. I will attempt to point out the important differences as they come up.
My visions were vague and generally idealistic, but they seem like an appropriate place to start a longer conversation about the future potential of grazing at windward.
A grazing system I'd like to see in place here would
sheep grazing in spring time by the lavender patch
- Be ecologically viable over an indefinite period of time, within the context of our particular forest, and its cycles.
- Become more productive and resilient over time. This is goes beyond "sustainability," or a steady state system, implying continual improvement of the lands potential to foster grazing.
- Require minimal amount of people-hours and calories input. I would hope about one human hour per day average of general work. To me this demands that the system simulate a self- regulating natural prairie ecosystem.
- Have a grazing season that extends as far as possible into the early spring and late fall. Ideally this means that the animals would have access to living pasture for 9 months out of the year. With us having to store only 3 months worth of forage in reserve for the winter months.
October 8: Factoring in the community needs and scale
Once I'd figured out the general goals I understood that I needed to understand the appropriate scale.
I started out by factoring in the future size of Windward. Of course, no one can say to what size any community will grow, but in general we believe that the optimal size of a rural community on our size land is about 20 (adult) people.
This number constitutes the population of people living on site at any given time, and is only an approximation. 20 people is scaled to the small village level; large enough to have the diversity needed to fulfill essential tasks and have degrees of individual specialization, but not too large that you cannot personally know everybody in the community.
the group photo displays
about half the size of the community scale
we are talking about
Ideal herd size, some preliminary questions
With the human population scaled at 20 adult people, I went back to the herd sizing. And there stood another burning question‒What do we want the sheep to do for the community? What niche(s) do the sheep fill in our grand vision of the community?
Just as Lindsay recently wrote about stewarding the forest, we necessarily interact differently with living systems depending on the desired output.
There are several niches that the ruminant creatures fill in the integrated community system. Each species of creature fills one or more primary niches, while also yielding goods and benefit on several other levels.
For example, the primary purpose of our goats is to provide nutritious milk. On a secondary level, the goats provide all of what composes their bodies; bones, sinew, meat, leather, hair, etc. Also, they can be utilized to clear unwanted vegetation. On a tertiary level, the goats can act as nutrient transporters and processors. By harvesting nutrients from the forest, and depositing them in a concentrated form that is inoculated with bacteria. And, on an interpersonal level they're also good company to have around.
The sheep have a different primary function, but provide essentially the same secondary, tertiary and social benefits. The production of woolen fiber is what sets sheep apart from any other animal we could have, and is why we have invited them into the community.
Goat kids are adorable. They make it all seem worth while
Knowing the niche we want to sheep to fill, the question arises as to how many sheep do we need in order to provide woolen goods for 20 people.
The needs of twenty people may be highly variable from year to year. Also, the amount of wool that each sheep will make is highly variable and depends upon genetics, diet, stress, environment, and the way they are handled and sheared. Also the quality of a fleece changes throughout the season, with the age of the animal, and with how they are handled and sheared. We may also shear the animals more than once per year, increasing our annual yield.
Each article of clothing can potentially use drastically different amounts of wool. To take a sweater for example, depending on the density and weave, a small loosely-woven sweater can use 3/4 lbs of yarn, whereas a large densely-woven sweater can use upwards of 2 lbs of yarn.
All of these subtleties will need accounting if a median set of numbers is to be found in order to arrive at an appropriate herd size
Walt and I engaged in this year's shearing
Building off of other peoples data
Well, I know that the Rambouillet breed of sheep (pronounced "ram-boo-lay") has a lot of potential here at windward. Rambouillets are a good general purpose and hand spinning wool breed. We want a breed that will be able to do well here with the minimal amount of help from us. Rambouillet's are very adaptable to extremes in both hot and cold (they range from Baja Mexico all the way to British Columbia).
Rambouillet's originally came from the Spanish Merino, and possess quality fine-medium textured wool, and are generally heavy wool producers. The better lines of the breed also have a distinct curl to the wool, making it preferable for hand spinning.
The Merino line was crossed with a French line of sheep, and later brought to America where they were more intensively bred to be good range mothers, lactaters, and posses a stronger "flocking" instinct. Rambouillet is also a very common breed in America, so in the future it may prove easier to find pure bred rams keep the lines straight.
Because we've had good experience with Rambouillet's, and we will likely continue with their breeding in the future, I will build off the body of fleece info that exists for the Rambouillet breed as the base line for calculating the ideal herd size for providing about 20 people with woolen fibers.
Dolly, our best mama and Senior Ewe, a primarily Rambouillet sheep
The Arithmetic of Sweaters
The Bradford Count is an old English test/measure for the fineness of wool that was developed before modern technology. The measure is based on how many 560 foot lengths (called "hanks") of yarn can be spun from one pound of wool. The length is a function of how fine the wool is, because the finer and more curly the wool the better it is for spinning into a small diameter yarn. The smaller the diameter yarn, the more hanks it can make. The measure is usually done by looking at the number, size and girth of each curl of wool.
The statistics of the Rambouillet sheep place it in the "fine-wool" category with a Bradford Count exceeding 60. To put this into perspective, this means that one pound of premium Rambouillet yarn could make 33,600 ft or 6.3 miles of thinly spun yarn. WOW!
I don't think that our breeding lines as they stand now are even remotely as fine as the premium wool standards of national and international breeding associations. But we can assume that we are somewhere in that ballpark of having medium-fine wool and fiber size between 25 and 30 microns wide. This is fine enough to do good hand spinning for clothing, and is suited well to tightly woven under clothing.
fine spinning grade wool
from a past Windward herd
Side note: In the future, when we have little to no access to finely woven cotton fabrics, synthetic fibers, and plastic, we will again return to an age of using natural fibers for clothing. Rambouillet, and other fine to medium-fine breed have been honed to produce a certain caliber of wool. But, there are draw backs. Fine wool can't readily stand up to the harsh conditions one would impose upon socks, or outer layers of clothing.
In order for sheep to provide us with the fiber we need, we'll necessarily be running a herd with two or more kinds of wool breeds. As was stated before, Rambouillet and other fine wool breeds are preferred for the soft cloth you would be wearing close to your body.
"Long" or "course" wool breeds have a tougher fiber, and are desirable for a variety of reasons. Long wool breeds are generally not as curly, giving the appearance of being longer. The wool is more resilient to weathering and can resist the kind of wear and tear we would be placing on an external layer or blanket.
There are some drawbacks, in that most long wools were developed in cold damp climates, and are less tolerant of the kind of heat we have here in the summer time. They yield a thick coat that would most likely need to be sheared twice a year.
wool on tables for purchase
at the annual Black Sheep Gathering
in Eugene Oregon
"Course wool" heritage breeds such as Karakul, Dine (Navajo) and Spanish Churro are wild tempered with "unrefined" wool. The coarseness makes it exceptionally rugged, and is used in carpets, rugs, blankets, and even shoes. These sheep can be very hard to handle, and both have horns. But, with wildness comes benefits. These breeds have been rigorously selected for independent motherhood, fiercely protecting their young from predators, and being disease resistant. They are also well suited to survive in our conditions; they can take care of themselves pretty well, and are adapted to deal with incredibly low quality forage. Windward once had a Karakul sheep line going.
Being from Arizona, I am a little biased, but I'd love to see the Dine blood in the herd. The high altitude plateau environment of Northern Arizona that this breed was developed in is very similar to Windward in terms of climate, precipitation, and vegetation; mostly scrub lands, Ponderosa pine and oak forests, with cold snowy winters, and hot dry summers.
a karakul ewe and lamb from Windward's past
Back to the Numbers
According to the American Rambouillet Sheep Breeders Association a mature Ewe will produce an 8-18 lbs fleece before washing, with a 33-55% "scouring yield" (the percent yield of washed and filtered wool). The range of possibilities all depends on the environment the animal lives in, and how it is tended to. The more the animal sweats and the dustier the environment, the more crap will be washed out of it, so the heavier its unwashed weight.
I assume that we are somewhere in the middle in terms of quality and quantity. And so, I will assume that we will be able to maintain an average a 14 pound unwashed fleece. I can attest that Dolly's fleece this year was about this weight.
The scoured fleece weighs around 5-7 lbs. We can assume that only about 70% of the scouring yield is going to be of high enough quality to be spun into yarn. The wool around the face, inner thighs, legs and "arm pits" is not good enough to be spun.
This puts the final yield of a 14 pound fleece (through several levels of approximation) at a guaranteed 4 lbs.
Dolly's unwashed fleece
hot off the sheep from this year's shearing
So, one moderately productive female sheep can reliably produce a medium fine yarn yield of about 4 lbs/ mature Ewe / year. I have purposefully taken a low ball estimate. In actuality even a lamb (less than one year old) could probably make a similar amount of useful wool. I think that 4 lbs is a reasonable amount of yarn to expect from any individual sheep.
Because this number is more or less universally applicable, it is this ratio that I built upon when factoring a mature herd size.
wool that Theresa washed and set out to dry
Weaving in Some History
The framework of the middle ages is a relatively useful one to have on hand. As the world slows down, and is forced back into pace with what can be produced with contemporary sources of energy, we will experience a similar pace of life. And a refocus on the household economy.
Cloth makers in medieval Europe were bound by the amount of time and effort needed to undergo the elaborate process of making cloth. As far as wool goes, the time needed to spin yarn was a big limiting factor in the production of clothing. A weaver can easily use yarn 10 times as fast as a spinster can create it with a spinning wheel. This does not even take into account the time needed to scour, card, comb, dye, and full the wool.
What that meant for a person of the middle ages is that only one new outfit a year could be afforded. It is now common place for people to own many (even hundreds) of outfits, and to have little or no involvement in the actual process of creating the garment, and seldom repair the ones they have.
a very labor intensive process
I am going to assume that people in the future will be returning back down to a standard similar to medieval people. With one new "outfit" or set of wool clothing and goods, per person per year.
This seems rather reasonable in terms of woolen/worsted goods, because a well made and maintained sweater, blanket or hat can last a long time. Hopefully, with good stewardship of clothing, there'll be a build up of fabric overtime. Especially as worn out clothing becomes available for felting, blankets, rugs, and other kinds of material.
machines such as this "spinning jenny"
dramatically speeded up the yarning process
Here is a list that I have derived from my own wool clothing. This list could reasonably constitute a full set of clothing. I figured the amount of wool needed by taking measure of the garments weight.
Course weave, outer layers
medieval visitors from Windward's past
notice the heft and wooliness of their outfits
Fine weave, under layer
- Heavy sweater ‒ 32 oz
- Felted pants ‒ 18 oz
- Heavy Socks, 2 pair ‒ 6 oz
- Cap ‒ 4 oz
- Scarf ‒ 4 oz
- Light sweater, vest or flannel ‒ 12 oz
- Long underwear ‒ 4 oz
- Under socks, 2 pair ‒ 4 oz
Together these items weigh 160 oz, or 10 lbs.
With an average yarn yield of 4 lbs per sheep per year, we can conclude that it should take about 2.5 sheep per person to produce this one set of woolen goods per year. That means with our herd and grazing system we should be aiming for 50 fleeces per year.
- light weave, soft under blanket - 28 oz
- heavy blanket, cloak, or tanned hide with intact wool‒ 48 oz
A permanent herd:
some dynamics of breeding
We only need to average 50 sheep producing 4 lbs fleeces per year. Our "permanent" or "breeding stock" herd can be much smaller than the expanded flock size we desire. In order to figure out these numbers, we need be able to estimate how many lambs will be birthed in a given year. The number of lambs born is known as "prolificacy".
The quantity of lambs born is limited by the amount of ova (unfertilized eggs) released by the ewe at ovulation. I know this trait as "ovulation rate"; whereas "prolificacy" (or "birth rate") is the number of lambs a mother births, and "survival rate" is the difference between the number of lambs born and how many survive early lambhood.
The maximum ovulation rate is determined by genetics. Although the actual ovulation rate in any given year is highly variable and dependent upon many non-genetic factors including; age, health, vigor, and most importantly nutrition. Birth rate and survival rate are more exclusively determined by environmental factors.
Check out the past article Flushing the Ewes for more information about how timing, location and sex separation can impact ovulation.
Philosophies for genetic selection
In a big commercial herd, shepherds have bred intensively for "market lambs" and not necessarily for wool. This is mainly because meat and wool pays better than just wool. Often it is the sale of lambs for meat that make or break a commercial herds economic viability.
By breeding for market lambs (that is to say high ovulation rates coupled with high birth weights and fast weight gain) shepherds can easily run up against barriers of nature's design. A mother ewe's body can only handle so many large babies. The trade off for prolificacy is difficulties giving birth; requiring substantially more human intervention. This is a trade off that commercial shepherd are willing to make.
There have been different breeding philosophies for the herds of Windward's past. Many women in the past have made the flock expansive and profitable. The quality of wool in the previous flock was literally "award winning". And it appears from previous Notes articles that the shepherds also tried to breed and manage for market lamb production.
Here is a great article about it:
Working Towards a 200% Lambing
a large flock in Chile
At that point in the flock's history, the number of animals was much larger (21 ewes, and a handful of rams), the quality of wool was extremely high, and they already had a baseline breeding flock with good mothering skills. It is sad that most of that flock left Windward, but we carry on with a small percentage of that genetic legacy.
200% lambing means 2 lambs surviving per ewe
It is the holy-grail of sheparding
That situation is very different from where we are today. The flock is a now very small (1 Ewe, 1 female lamb, 2 Gimmers and 2 rams). We have only one mother Ewe (Dolly) which has actually given birth. We have two females which will be bred for the first time this year. And we have a lamb which we will not know the mothering skills of until spring of 2012.
Almost the entire flock is directly related to one another, and the quality of wool is generally average (still good wool) but not award winning.
A glimpse of the flock in December 2001
Those are some handsome looking sheep!
At this point in time, we are not trying to compete with commercial herds. We need competent mothers from which a stable foundation for an expanded flock; mothers that can easily give birth and care for the young they have, and that will live a long time and pass knowledge to future generations.
What this boils down to is that we are not in a position to selectively breed for ovulation and lambing rates at this time. We need to establish a baseline over this next year, and maintain the quality of wool we have.
There's roughly a 60+% chance of not passing on prolific breeding traits. That means that only 1 out of 3 female lambs are likely to possess exceptional ovulation rates. Because of we are not rigorously selecting for high ovulation rates, this trait will tend to revert back to the mean. Prolificacy will tend to revert to the average display of the trait throughout the entire flock.
All of the mothers that our flock is descended from (Dolly and Pia) appear to be "twinners", meaning they have, at most, produced two healthy lambs in a given year.
Dolly (or Dolly-mama as I call her)
having babies since 2001
Princess Pia was the "herd queen" of Windward's flock for many years. One spring, Pia's lamb ruptured its umbilical cord a few hours after birth, and bled to death before anyone noticed. Pia's milk was then used to save two "bummer" lambs, an experience which raised Pia's self-esteem to the point where she took over as herd queen. She died this past winter, but her legacy lives on in her children and grandchildren.
It is likely that the average ovulation rate is 2 ova at a time under good conditions. Because of this, I will assume for the sake of numbers that each ewe will average 2 lambs per year.
Given credence for the whims of nature, we can assume that some of these children are not going to live to maturity. Exposure to wind and rain, predation, poor mothering, or freak accidents can all be guaranteed to take the lives of some lambs every year. Maybe 1 in 3 will survive, maybe 1 in 2. It's impossible to tell.
However, for the sake of consistency I will assume that we will average a 66% survival rate with 1 out of three lambs dying each spring.
Rams, Lambs, Ewes, Gimmers and Yearlings
There are many necessary members of a flock. Figuring out what they are and how to balance them is very important for good flock dynamics, as well as knowing how many animals will be over wintered.
The "Breeding Stock" consists of adults that will be bred over winter. This includes ewes that will be bred in the fall to lamb in the spring. This is the most flexible number in the flock, and will be determined after all other things are considered.
Breeding stock also includes "Sires" or rams that will be mating with the ewes. If we have two breeding lines going for different kinds of wool, we would need at least 4 rams (one main ram for each line, and a back up just in case). Ideally I would add an extra ram as an insurance policy, and to potentially carry different or mixed genes.
Lambs are all members of the flock that have not seen a winter. The number of lambs all depends on how many ewes are bred.
Also, in an ideal situation we will have ewes of various ages; from lambs to gimmers (one year old ewes) to mature adults. We have a policy of not breeding ewes until they're more than a year old. That means that within the "permanent" flock there will be individuals that are not yet breeding.
Pia provides milk to save
two abandoned lambs
Notes From Windward - Index - Vol. 70