Hands On

Of all of the grazing livestock (cattle, sheep, and goats, primarily), sheep seem to take the most management - and many of the things we do to manage sheep (shear them, vaccinate them, trim their feet, help them lamb) must be done by hand. As these interventions occur throughout the sheep year, they create, as my friend Dr. Rosie Busch says, "windows of opportunity," when we can take stock of other things like body condition, general health and thriftiness, and behavior. Last weekend was one of those windows in our operation.

As much as possible, we try to match our production calendar to our local ecology. We time our lambing to match the phenology of our rangeland plants - in other words, we try to lamb when we have the most high quality forage available on our annual rangelands. Our ewes have their highest nutritional demand in the last 5-6 weeks of gestation and the first 6 weeks of lactation (just before and just after lambing). Our rangeland forage (which is far cheaper to grow than the grass we have to irrigate all summer) reaches its nutritional peak (in both quality and quantity) in late winter and into springtime. And so we time our breeding so that the ewes start lambing in the third week of February - just when the grass is really starting to take off (or so we hope).

That anchor point - lambing - determines the rest of our production calendar. To make sure the ewes pass some immunity to clostridial diseases and tetanus on to their lambs through their colostrum, we vaccinate 6 weeks before the onset of lambing. To get lambs in late February, we turn our rams in in late September. To be sure the ewes are ready to breed in late September, we put them on better feed in early September. To get adequate response to this improved nutrition, we graze the ewes on lower quality dry forage after we wean their lambs in late June. And since ewes that have just recently lambed don't shear well, we wait to shear them until April (when the youngest lambs are about six weeks old).

Last weekend - about 6 weeks before the first lambs are due to arrive - was one of our windows of opportunity. We vaccinated all of the ewes during our annual Sheep Husbandry Field Day (offered through UC Cooperative Extension). Since they were in the corrals, we also checked their feet for signs of footrot or other foot health problems. We checked their general health status, and we did a 5-point check on each ewe to check her for internal parasites. The 5-point check includes a (1) FAMACHA evaluation (which looks at the color of the third eyelid as a way to determine anemia - reflective of barberpole worm infection), (2) a body condition score (which estimates nutritional status), (3) a "dag" score (which evaluates the degree of manure staining on the hind legs), (4) an evaluation of nasal discharge (indicating nose bots, which are more common in the fall), and (5) a determination of whether the ewe has bottle jaw (swelling under her chin, caused by internal parasites).

First, I want to brag (just a bit) about our ewes' feet! Like all sheep producers in California, I suspect, we've had our share of footrot. At the height of the last drought, we were diligent about treating footrot - we used the FootVax vaccine, we trimmed feet religiously, and we used a zinc oxide footbath regularly. We also culled the ewes who had chronic problems. While I like to think much of our success was due to my foot trimming, footbaths, and vaccine program, I suspect that mostly we improved by getting rid of the sheep that were most susceptible. Last Saturday, I think I trimmed less than 1% of the feet I looked at! Granted, Dr. Busch has introduced us to new management measures that discourage excessive foot trimming, but I was incredibly pleased with our foot health - especially after such extraordinarily wet conditions.

Health-wise, I was also pleased. We did have a number of ewes with nasal discharge, but I only treated one of them with antibiotics. The ewe I treated was wheezing (and had been since early December, when I also treated her). The others all seemed very health - and so I didn't treat them. Limiting our use of antibiotics to the conditions that truly require them is an important way to reduce antibiotic resistance.

Finally, I think I only treated one bred ewe for internal parasites (as the result of a subpar 5-point score). I did treat 3 open ewe lambs for parasites, which is not uncommon - they are still growing, and so they are demanding more of their nutritional system. As with antibiotics, targeted treatment for parasites helps reduce resistance to our treatments. While it may seem counterintuitive, we actually want parasites who have never been exposed to our dewormers!

These windows of opportunity, these times when we have to put our hands on all of our sheep, are important. For me, they're much like a report card - they are a time to check and see how much I've learned. And hopefully, how much I've improved my management. Since I see the sheep nearly every day, I sometimes fail to notice problems, as well as progress. I find that having someone who knows my sheep but who sees them only periodically (like a veterinarian) can be extremely helpful. Perhaps the best thing about last Saturday was the text I got from Dr. Busch after we worked the sheep: "Your sheep look incredible this year!" Thankfully, I agree!

Now we wait for lambing, our next hands-on window of opportunity!