Sunday, April 25, 2010

Choosing the Right Sheep

In his essay “Let the Farm Judge,” Wendell Berry proposes allowing the farm (that is, the land and its associated resources and topography) to play a role in selecting the right type of sheep (or other livestock) for the farming operation.  While he concedes that the “industry standard,” as represented by the show ring and the processor, is important, he also advocates for local adaptation:
“Intelligent livestock breeders may find that, in practice, the two questions become one: How can I produce the best meat at the lowest economic and ecological cost?  This question cannot be satisfactorily answered by the market, by the meat packing industry, by breed societies, or by show ring judges.  It cannot be answered satisfactorily by “animal science” experts or by genetic engineers.  It can only be answered satisfactorily by the farmer, and only if the farm, the place itself, is allowed to play a part in the selection.”
In our own operation, we’ve tried to balance the need to meet the demands of our customers for flavorful, tender grass-fed lamb raised without antibiotics or added hormones with the demands of our land.  Our operation exists entirely on rented ground, which means that we don’t live on the property where our sheep graze.  Our customers are mostly the end users of our lamb, which means we receive direct feedback from the people that are eating our product.
Based on our observations, we need sheep that will meet the following criteria:

·         Our sheep must be able to utilize a wide range of feed resources – from irrigated pasture to annual grasses to invasive weeds to brush.
·         Our customers want moderately sized cuts of lamb, so we need lambs that will finish at 90-110 pounds.
·         Since we finish our lambs entirely on grass, we need medium-sized sheep that do well on our feed resources.
·         We lamb in our pastures rather than in a barn.  Because we operate on rented land at some distance from our home, we cannot be with the lambing ewes around the clock.  This means that we need ewes that can lamb on their own without our assistance.  We need lambs that can get up and nurse quickly, and we need ewes that can produce sufficient milk from grass.
·         We primarily lamb in the early spring, with a smaller lamb crop coming in the fall (from the previous year’s spring-born ewe lambs).  In other words, out-of-season breeding is beneficial but not emphasized in our system.
·         The bacteria that cause foot rot and foot scald seem to be endemic in the pastures that we lease.  We’ve noticed that sheep with black feet seem to have more resistance to foot rot.
·         To optimize our profitability, we need ewes that will produce a 150 percent lamb crop with little or no external feed inputs.
·         To reduce costs, we need sheep that are resistant to internal parasites.
·         While wool is not a significant product for us, we do want sheep that produce fleeces of sufficient quality and quantity to cover the cost of shearing them.
When we started our commercial sheep operation, we purchased Dorper and Dorper-cross sheep.  Dorpers are a cross between Dorset sheep and Black-headed Persian sheep.  They are moderate-sized, produce a choice-grade carcass at 85-90 pounds, and shed their wool naturally.  The ewes that we purchased seem to have a widely varied diet, as well.  Unfortunately, their white feet also seem particularly susceptible to foot rot.  We found ourselves spending more to treat their foot problems that we were saving by not having to shear them.  While we were able to achieve a lamb crop of 130 percent with minimal external inputs, we felt that the foot problems were also impacting our lambing percentage.  While our customers were extremely happy with the product we were raising, our farm seemed to be telling us that we had not yet found the optimum genetics for our flock.
As we researched possible solutions, we discovered a 3-tier system used extensively in the United Kingdom to produce grass-fed lambs.  In this system, “hill” ewes are bred to Blue-faced Leicester (BFL) rams.  The resulting cross-bred sheep, called “mules,” have the milking ability, wool quality and length of body of the Blue-faced Leicester breed and the hardiness of the hill ewes.  The BFL breed also tends to improve twinning percentage and has black feet.  The mule ewes are then bred to a terminal sire (usually a British Suffolk or Texel), with all of the offspring marketed as lambs.  In the UK, these lambs finish at 110-120 pounds in 6 months.
            In 2008, we decided to try to produce our own “mules.”  We purchased a BFL ram from a breeder in Sonoma County and bred our Dorper and Dorper-cross ewes to him.  We also purchased a handful of North Country and Border Cheviot ewes – both Cheviot breeds are known for their hardiness.  Last spring’s lamb crop is promising – the mule lambs seem to be gaining faster and to have fewer foot problems (especially the mules out of Cheviot ewes).  We’ll breed these ewe lambs to a terminal sire next spring.
We’ve also implemented new management systems designed to help us deal with our feet problems.  We are vaccinating every ewe with FootVax every 6 months.  This is an expensive program – approximately $4.50 per head per year, but it seems to be working in about 95 percent of our sheep.  We’re also using a zinc oxide footbath on a regular basis.
To address our lambing percentage issues, we’ve started using body condition scoring to split our ewes into groups prior to breeding.  The thinner ewes are put on our higher quality feed about 6 weeks before breeding.  Next year, we intend to use teaser rams to synchronize our ewes’ heat cycles and to increase twinning percentage.  A ewe’s second estrus cycle generally will produce more eggs, which should help increase our number of twins.
            To ensure that we can pasture lamb with minimal labor, we’ve adopted another British system called Easy-Care lambing.  In this system, we record scores for every ewe in three categories: lambing ease, mothering ability and lamb vigor.  Scores are assigned as follows:
Lambing Ease
Very Minor Help
No assistance
Mothering Ability
Leaves lambs
Stands Well Back
Follows Whatever
Lamb Vigor
Has to be Sucked
Slow to suck
Up and Sucked

Anything with a total score of 1 or less is culled.
We also cull for other reasons.  A ewe with exceptionally bad feet will be culled, as will a ewe that doesn’t conceive over two consecutive breeding seasons.  We’re also trying to improve our wool quality – we’d like the ewes to produce enough wool of sufficient quality to cover the cost of shearing them.  Ewes that have natural parasite resistance are retained; ewes that are susceptible to parasites are culled.  Finally, we’re selecting ewe lambs who are twins with the hope that they will be predisposed to twin as well.
As with any system, our new approach will take time to implement.  Based on the advice of Richard Hamilton, one of the biggest and most innovative sheep producers in Northern California, we’re going to give this new genetic program 5 years to determine its success.  I’m also aware that what seems like new approach to me may have been tried by others previously.  There is a cost to being unconventional – not the least in terms of the ridicule of other producers.  We’re hoping that our innovative approach helps us make sure that our sheep fit our farm and our market.

1 comment:

  1. How do you determine parasite susceptibility in your ewes? I run fecal tests on my flock (5-6 samples/group of ewes and lambs). The ewes are usually low but the lambs are quite high. I treat based on the results, but I've considered not treating and keeping "healthy" lambs. Are you looking at your lambs for susceptibility or your ewes? By the way, I had foot rot when I had other sheep, but never in my Jacob flock!