Friday, January 13, 2012

Progress - Part 2

Last year during lambing we discovered the hard way that our sheep were deficient in selenium.  At the beginning our lambing season, we had a number of apparently healthy lambs die after two or three days.  Unable to discern the cause on our own, we took a dead lamb to the California Animal Health and Food Safety Laboratory at UC Davis.  The postmortem indicated that our lambs were selenium deficient.  The soils in our part of California are low in selenium (and as a result, so is our grass).  To counteract this, we had been giving the ewes and lambs a selenium drench, and we'd been providing a commercially available loose salt mix that has a small amount of selenium in it.  Our system obviously wasn't working! At that point we started giving every newborn lamb a selenium/vitamin E injection.  We didn't lose any more newborn lambs.

This summer, we again lost a few seemingly healthy lambs while they were on pasture.  After another trip to the lab in Davis, we learned that we were contending with internal parasites - a condition made worse by an underlying selenium deficiency.  In addition to causing weak lambs, uterine prolapses and other reproductive problems, selenium deficiency is also related to parasite and disease resistance.

We considered giving another injection to the lambs, but fortunately I called Dr. Nancy East first.  Dr. East is a veterinarian and fellow sheep producer (she happens to be the president of the California Wool Growers Association at the moment).  For many years, she worked with the School of Veterinary Medicine at UC Davis.  She explained the complicated relationship between selenium and healthy sheep.  She also explained that the mineral mix we'd been using didn't have enough selenium in it, partly because an adequate level of selenium would make the product taste bad to the sheep.  Fortunately, she knew of a solution!  Western Feed Supplements - a company in Silver Springs, Nevada (about a 45 minute drive southeast of Reno) - makes a mineral block that has adequate selenium AND is formulated to taste good to sheep.  She suggested we try providing these blocks to our sheep before giving further injections.  She also suggested that we blood test 10 of our ewes prior to giving our pre-lambing vaccinations this winter to determine if their selenium levels were adequate going into lambing.

In early September, we purchased 2.5 tons of 50 pound mineral blocks from Western Feed Supplement (unloading 100 mineral blocks by hand and stacking them in the barn made me long for a forklift!).  We started offering blocks to all of the sheep, and they seemed to find them extremely palatable.

Last Friday, my wife Samia (who happens to be a large animal veterinarian herself) took blood samples from 10 of our ewes and sent the samples to the Davis lab.  Late yesterday, we received the results - every ewe we tested had adequate selenium levels in her blood!  Thanks to the new regime suggested by Dr. East, we won't have to go to the added expense of an injection (and we'll avoid stressing the ewes with another shot as well).  We'll still give the newborn lambs an injection (adequate selenium levels in the ewes do not necessarily ensure adequate levels in the lambs), but it feels as if we've made another step towards raising healthy happy sheep.

Samia and I have raised sheep for about 20 years, and we've been doing this commercially now for 7 years - long enough to realize that there is always more to learn.  One of the things I like most about farming in general (and sheep in particular) is this continuous learning process.  As we accumulate (and apply) more knowledge and skill, we make progress in our business.  Our improvement shows up as healthier ewes, more lambs and greater productivity - and ultimately greater profitability.  While raising sheep is a way of life for us, it's also the way we try to make our living.  Each lesson learned is another step along the path that will make (and keep) our business viable.

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