I’m finally getting around to analyzing my lamb yield from last spring, driven by my need to plan vaccine purchases for 2017 lambing, which is driven by my need to analyze what went wrong from last season!

As all who live in this area will recall, the summer and fall of 2015 we had a terrible drought. It basically stopped raining after June and didn’t start again until November. Normally we only manage to get a few dry, good-for-camping weeks in August, but otherwise we have a healthy mix of rain and sun all summer and fall. So 2015 was very abnormal to have such a long, dry summer. This was not great for pasture growth nor hay production.

What does this have to do with my 2016 crop? Everything. Normally I can graze my ewe group through fall, maybe all the way through breeding in November, and maybe even until Thanksgiving. Not in 2015! I started feeding the ewes hay on the 4th of July; preserving what little grass we had for the butcher lambs. All my growing ewelambs, therefor, were stuck with local grass hay rather than our much richer fresh grass, during all of their growth period, rather than just some of it.

On top of this, I didn’t flush the ewes with grain leading into breeding, which helps bump up conception rates, especially in ewelambs. I’d spent so much extra on hay, I just couldn’t justify buying several tons of grain, too. I did feed some grain once breeding started, just because it makes it easy for me to view all the ewes each day to check for breeding marks. So, ewes bred later in the cycle may have had some advantage there; though I didn’t think I saw birth rates rise with later deliveries. I knew I’d be taking a financial hit on the following year’s crop, but it is what it is: pay now, or pay later. I somewhat regret this, and maybe had I laid down another grand in feed for those ewelambs and fed them separately on alfalfa, I may have yielded more than a grand in lambs out of them, getting some payback there. But maintaining a separate feeding group all winter is extra labor, and I don’t have a good space for that many ewelambs. So, I took the hit.

Below is a table of my lambing percentages. I am one who tries to fish around in afterbirth to look for tiny perished fetuses, because I want that data. So, counted in here are *any* observed conceptions, even if they were only an inch tall when they perished. I want to both give the ewe credit for the conception, but then also penalize her for the loss.

Dam Age

#Ewes here

# Ewes lambed

# Conceptions

Lambing % of those that lambed

Total lambing % of all ewes

1

24

10

11

110%

46%

2

18

17

31

182%

172%

3

15*

15*

29

193%

193%

4

7

7

15

214%

214%

5

8

8

18

225%

225%

6

2

2

5

250%

250%

7

1

1

2

200%

200%

13

1

1

2

200%

200%

75

59

113

192%

151%

 

*I had one ewe abort a fetus about a month early, the day after a vaccination protocol. The vaccination may have been the trigger; either a reaction the vacc itself, or some rough handling issue, maybe the ewe slipped and fell, or was overly squished by a gate when being pushed by the dogs. Anyway, I was not able to figure out which ewe aborted; it had rained, and any telltale blood had washed away. I had two mature ewes fail to lamb, a two-year-old and a three-year-old; along with the 14 open ewelambs. In the above table, I’ve guessed that it was the three-year-old that lost the lamb and included the count there.

Overall, given the circumstances, I’m happy with the percentages. The mature ewes (three and over) delivered on an over-200% crop, which is what we’re after with Katahdins. The two-year-olds were respectable at 182%. And, the ewelambs, well, I cheered for the ten of them that did manage to lamb, they are my fertility superstars. Especially the lone ewelamb that twinned! The rest are pardoned due to management decisions on curtailing their feed quality.

Now, on to losses! Of these conceptions, eighteen lambs were lost. That’s at least $3600 worth of lambs, 15% of all conceptions. That number may seem high, but it’s partly because I’m counting those tiny fetuses I find, and I’m also counting late losses, some long after weaning. Some producers only count post-birth and/or pre-weaning losses; but for me, it doesn’t really matter when they die, they are all opportunity cost. So I want to try to track and reduce the common causes as much as I can. Below is a Pareto Chart showing the numbers of each (estimated) cause.

image

Stillborns are still the most vexing problem: full-term lambs that look perfectly healthy and well-formed, but were born dead. For all but one of these I wasn’t present when they were delivered; but they all looked dead-on-arrival for one reason or another. Things like still being half-enveloped in the sack, this indicates that the lamb never really kicked its legs or reared its head to breathe, thus breaking the sack wide open. Other times, the ewe may have cleaned it off thoroughly, but rolled it around in the dirt a lot, trying to nudge it into action; leaving the lamb very dirty. If the lamb’s hooves are clean and pointy,  showing no wear, that means it never tried to stand.

Why these are occurring, I don’t know. Ideas for prevention are:
a) increased vigilance at lambing, really trying to check every four hours to catch any distressed births and revive them;
b) revisit vitamin E supplementation to ensure its adequate in late winter,
c) increase the length of time I’m serving up potassium via apple cider vinegar in the water

Both vitamin E and potassium are supposed to help the ewe’s muscles relax for lambing, and make the lambs supple and flexible so that they can actively “twirl” and position themselves correctly for birth. As much vigilance as I try to offer, it’s still a patch; so correcting the problem at the source, with nutrition, will be best, if that is indeed a contributor.

A note on birth weights: One of those DOA lambs I did witness stuck in the birth canal at my morning check, and it was a “hard pull” to extract it. It likely perished from being in the birth canal too long. So, this was one case where had I been doing midnight checks, I might have caught this one and saved it. This was also a case where I paired a ram with a high BWT value to a ewelamb, so I’ve made a mental note to watch that a bit more carefully going forward.

My goal birth weight range is  7-11 pounds. This year, I had birth weights ranging from 3.85 (!) to 13.6 lbs. The average was 8.7 lbs. right in the sweet spot where I want to be. I only had one other “hard pull” lamb, and I had one big lamb that triggered a uterine prolapse in the dam; in all cases, lamb and ewe were ok. So, I’m doing fine on birth weights in general. But I am keeping an eye on one ram which has genetics for much bigger birth weight than the rest. Behold both average “raw” weights and the BWT EBV in the four sires this spring:

image

Because I feed pretty carefully and manage ewe weights to keep them from getting too fat, I am getting by with using a ram with a very high BWT EBV (this value is in the highest 10% of the population in the country…). I actually butchered some of the ram lambs out of him with very high BWT values, even though they were great rams, because I worry about selling these to other people. Many of my buyers have small flocks that get fed luxuriously, and I know fat ewes with babies sired by a high BWT ram are gonna cause those people all sorts of problems.

Selenium Toxicity: this is new this year, and it’s a theory. Last year, I had one lamb death diagnosed as selenium deficiency. This surprised me, since there is quite a bit of Se in my mineral mix. I decided to increase it, so over winter and heading into lambing, the ewes were getting more. In addition, my vet talked me into giving a BoSE shot to each lamb at birth, 1 cc per 10 lbs. Kind of because “everybody does it.” The trouble I found is this: BoSE is a very thick liquid. It doesn’t want to suck up well into a 1cc syringe. I have a lot of shots to give. So, I was pulling it into a 5cc syringe, then trying to eyeball +/-1 cc doses out of that, based on birth weights and mental math of the right dosage. This is fairly imprecise. Selenium has a very narrow range between deficiency and excess.

My radar was alerted when one of the last-born lambs crashed at four days, died at seven, after me treating it for everything under the sun. This is unusual for me. Once I verify a lamb is up and nursing and has gotten colostrum, they’re almost always good-to-go after this. Especially single lambs, they almost can’t fail. At least, not until later-in-life things can kill them, like clostridium or parasites. So, what killed this lamb so early? A few days later, I had a seven-day-old lamb die, again crashing fast and perishing. A few days later, a lamb died at the age of eight hours; with its mother standing obsessively by it, trying to nudge it up. This is nearly unheard of for me! This last one broke my heart, to think that I might have killed a beautiful newborn outright, with a treatment intended to save it! Upon reflection, I had one lamb die earlier of what looked like starvation. This one, I had noticed frequently, it wasn’t keeping up with its mother and kept acting mentally sluggish. I kept picking it up and putting it back with her, she’d acknowledge it, and then later, I’d find it lagging again. At first I thought it was  temperamentally challenged; but now I wonder if it wasn’t also Se toxicity that caused the lamb to fail to function.

So! Four percent of my crop potentially lost due to an attempt to correct an earlier source of loss. Murphy’s Law for sure! This is still a theory: I lab-tested the livers of three of these lambs, and they were in the normal or high-normal range. But I don’t know whether possibly damage had already been done, and the body had cleared some of the concentrations by the time the lambs had died. I am going to discuss with my vet more, but my inclination is to continue to give Se at birth, but maybe cut the dose in half, and maybe also give it orally, rather than via injection. Twins

Coccidia: one of the classics. Ironically, even though I don’t have “feed lot” lambs, I am still plagued with coccidia in late summer, after weaning. My vet theorizes it’s likely because our grass is so wet, even in summer, in the evenings/nights. I’ve heard many friends say this was a terrible year for coccidia, due to last winter not having enough deep-freeze nights to kill of the population in the soil. One friend of mine lost a third of her lamb crop in a short time period to this cause. So I don’t feel so bad about three, and these three also appeared to have other things going on simultaneously, so may have just been weak individuals. Nonetheless, I’m still thinking about prevention. I was a little late in treating this year, due to travel schedules and whatnot. I like to be home when I treat for it. I use Corid, which can cause vitamin B deficiency; so I want to watch the lambs closely during treatment. I’m considering adding a coccidiastat to my mineral mix, at least during summer. More thoughts to come on that topic.

Fetal Death: three ain’t bad, but I’m still annoyed by this. I feel all I can do is maintain vigilance in handling during pregnancy. Handle as little as possible, as little with dogs as possible, and prevent things like mad escapes where they all run over a slippery bridge and do dramatic banana-peel slips/falls (which just happened yesterday, <sigh>). I’m especially eyebrow-raising about the abort that happened right after vaccinating. Right after! Another case where you try to do something to prevent deaths, only to appear to cause one… I will continue to evaluate my pregnancy vaccination protocol, to see if there is a place to drop something. Which leads to…. SpringDay

Clostridium type D: curse this bacteria! This year, I vaccinated the ewes during pregnancy, which should confer maternal immunity for about 60 days. Then I vaccinated the lambs at 60 and 90 days. And still, two losses, at two and seven weeks of age. These were super clear cases: big, vigorous lambs, sudden death with no symptoms, angry purple intestines; and kidneys pale, amorphous and mush like Jell-O. My vet confirmed one with me upon necropsy- so clear, it wasn’t even worth lab-testing. The most maddening thing about this manifestation, “overeating disease” is that it kills the biggest and best lambs.

What gives? Some say it doesn’t happen on nursing lambs. I guess they haven’t seen lambs nursing off of high maternal milk  (MWWT) ewes on PNW grass. Dr. Kennedy vaccinates for CDT at birth, using a half-dose vaccine, along with 1cc of Penicillin. Many controversies could be stirred over this approach: that using a half-dose of vaccine is risky; that maternal immunity, if present, may nullify the vaccine; that a lamb’s immune system isn’t ready for coping with vaccines at birth.

But, if I do have some ewes which are not managing to confer immunity via milk, then I might catch those lambs if I vaccinate them early. So, I think I’m going to vaccinate for CDT at birth this year, then consider dropping it somewhere else, maybe on the ewes. One friend pointed out, it would be much better to give it when the lambs were at least several days old, and their immune systems are more mature. But as days go by, I have a harder time catching lambs. So I’ll ponder this: maybe I can keep a list and try to do them at two days old or something, in rolling fashion after each day’s births. While I can still nab them!

Happy New Year to you and yours, may your 2017 lamb crops be plentiful and thrifty!

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