Thursday, November 14, 2013

Pasture Lambing on a Larger Scale

One of the first sets of twins born on pasture this year.

Managing my own sheep, I've always lambed on pasture rather than in a barn (for a full description of the system we've used, see Lambing on Pasture).  As I wrote last February, pasture lambing has several advantages (at least in our system):

  1. Lower (or no) capital costs for barns and other structures.
  2. Healthier lambs and ewes - very few of the respiratory problems that often come with lambing in an enclosed area.
  3. The development of a ewe flock with tremendous mothering abilities - ewes that give birth without assistance, develop a mother-lamb bond quickly, and produce plenty of milk.
  4. Lower feed costs - little or no supplemental feed is required.

In my new job, I'm helping ranch manager Ellen Skillings develop and implement a pasture lambing system on a much larger scale.  We'll be lambing out 1700 ewes (including mine) between November 1 and the end of March (the fall lambing ewes will finish up before Christmas - we'll have month-long break before the spring lambing ewes begin).  On this operation, the motivations and benefits of pasture lambing (as opposed to barn lambing) are different, as are the techniques.  Regardless, I continue to be sold on the system compared to the barn lambing alternative!

Over the last week, I've had several conversations with two of my fellow employees at the ranch regarding this system.  Both men are hard workers, and one in particular has had a great deal of experience working with sheep.  Walter has never worked in any system BUT barn lambing, and I get the feeling that many of the herders at surrounding ranches share his skepticism about our new approach.  Thinking about these conversations has helped me clarify my own preferences for lambing on pasture.

First I should more fully describe our system.  Earlier this fall, each potentially bred ewe was ultrasounded to determine how many lambs she was carrying.  This process allowed us to sort the open ewes (those that were not bred) from the bred ewes.  It also allowed us to further sort those carrying single lambs from those that appeared to have multiple lambs (mostly twins).

Ewes that are carrying and nursing twins need more higher quality forage than those with single lambs.  We put the single bunch on dry pasture and started feeding them grass hay and alfalfa.  The two twin bunches are grazing on alfalfa.  A fourth group, which we call the primalas (because this is their first lambing), is on alfalfa close to the main barn - first-lamb ewes can have more lambing and mothering problems, so we wanted them close to barn in case they needed to come in for assistance.

Under the old system, nearly every ewe came into a barn at lambing.  These ewes were put into "jails" - small pens - until they had fully bonded with their lambs.  Then they were combined with 3-4 other "pairs" - ewes with lambs - in mixing pens before eventually going back out on pasture.  In this system, each jail and mixing pen needed fresh water and hay twice a day.  Once a pen was emptied, it needed to be cleaned and re-bedded before the next ewe arrived.  The old system required lots of harvested feed (mostly hay) and lots of labor.  Furthermore, the old system masked mothering problems.  By forcing ewes to bond with their lambs artificially, the old system failed to select for appropriate mothering instinct and ability.

Drifting the "old" pairs forward to join the "new" pairs.
In our new system, we have prepared four 1.25-acre electro-net paddocks on the alfalfa for each group (the two twin bunches and the primalas).   Our first task each morning to drift the front group in each series of paddock forward onto fresh forage.  During this drift, any new pairs or ewes that are in the process of lambing are left back - we call this our "drop bunch" because they've dropped lambs.  These new pairs are processed - we put an electronic ear tag in each lamb's left ear, we record the ewe's identification (along with information about her mothering ability and the ease with which she gave birth), and we give each lamb two shots (tetanus antitoxin and selenium/vitamin E).  Once these new pairs are processed, we push the "old pairs" - all of the ewes with lambs already on the ground - up into the paddock with the new pairs.  We then take down the back paddock, build a new paddock ahead of the front group, and move water troughs and mineral feeders.  We're finding that this system doesn't take any less labor, necessarily, but we are discovering significant benefits in terms of mothering and feed resources.  Last year, the ranch had significantly more "bummer" lambs - lambs that were rejected by their mothers for a variety of reasons.  This year, we've had a total of 4 bummers (out of more than 175 lambs born in the first 10 days of lambing).  We've also saved money because the sheep are harvesting the alfalfa (rather than the equipment).
High quality forage is critical to a pasture lambing system - as is controlled
grazing.  We use electro-nets to manage grazing on alfalfa.

There are several steps we're taking this year that will make this system work even better in years to come - and several things we'll do differently next year.  First, we are recording every ewe's performance in three criteria - lambing ease, mothering ability and lamb vigor.  A good pasture-lambing ewe should lamb without assistance, should stay with her lambs at all times (even when we're processing the lambs), and should produce enough milk for her lamb to grow rapidly.  By recording performance, we'll be able to cull the ewes that fail in any one of these categories.  We'll also be able to make better decisions about which of this year's ewe lambs to keep as replacements.  The daughter of a ewe who had problems won't stay in our flock. Secondly, the ranch has initiated an electronic identification system.  We use EID ear tags in the ewes and lambs and handheld readers to record birth information.  This information is automatically loaded onto our computer system each evening and will give us the ability to quickly evaluate a variety of performance factors in addition to the mothering data described above.

I'm finding that these ewes are not as comfortable with humans around as my ewes (who are used to seeing me everyday).  Consequently, we're finding that we can't always get close enough to a new mother to scan her EID ear tag or to read her farm tag.  Next year, we'll paint brand each ewe's ID number on her back prior to lambing (I'm actually going to try this with my ewes this spring).

One of the reasons that the staff has had trouble adjusting to this new system, I think, is that a new task seems to take longer than a job that we're used to.  It used to take all day to bring sheep in, put older pairs into mixing pairs and then back out on pasture, feed the barn-housed sheep, change bedding, etc.  Now it takes all day to move fences and feed sheep in the pastures.  Routine is comfortable; change is not - even if change is for the better, I guess.  My job, in part, is to help the guys become comfortable in this new system and to understand the bigger picture.  To me, the bigger picture is that we'll have more lambs raised by their mothers without much help from us.  We'll have healthier lambs and ewes - and ultimately more lambs to sell.

1 comment:

  1. excellent article! all livestock should be able to give birth and raise their offspring without a lot of human input. problem is most don't select for these desirable traits. we raise and kid our goats out in the brush, supplying shelter as needed, moving them every couple of weeks. we use electric nets and wouldn't raise goats without it. goats don't know what a barn is! thanks for the great information!