Sheep Health

 panoramaongrass

 

Ups and Downs 

In more than 30 years of  breeding and raising Romneys we have seen our share of health problems.  We have met  relatively (thank God) uncommon problems like meningeal worm; copper toxicosis, ; enzootic abortion;  caseous lymphadenitis;  polioencephalitis; ovine progressive pneumonia; fly strike, ureteral stone.   Of course we’ve dealt all along with  endemic issues  like neonatal pneumonia;  coccidiosis and intestinal  parasites;  foot scald, weepy eye, pregnancy ketosis.    We’ve had freak accidents like lightning-strike death (just once); drowning; domestic dog attack; adjuvant-related  seromas; and, once,   a lamb who, “pronging” (doing a 90-degree up-leap) hit his head and died instantly.  These are some of  “the thousand natural shocks that flesh is heir to.”  We give this  list not to say we have solved all these problems yet or ever will, but to point out that for each we have developed preventive and curative measures that are helping.  We strive to provide ourselves and our buyers each year with sheep less likely to be harmed by these maladies and to share what we have learned about treatment and prevention with anyone who asks.

Anchorage was one of the few Romney flocks that ever got certified in the Voluntary Scrapie Eradication Program.  After a few years in that status, however, we withdrew as the program changed emphasis to focus  (so we felt) mostly on preparedness  to export ewes.  This posed requirements (like brain examination on all sheep dying at the farm) that were reasonable on the part of importing countries fearful of prion diseases but too much demanding on U.S. sheep breeders who don’t plan to export a lot of ewes.     Needless to say, we never had  any scrapie cases;  so far as I know there were no cases in Romneys in the US.  That statement is not meant to prove  resistance, but leans hard against increased susceptibility. 

I  (Stephen)  was on the Board of National Sheep Improvement Program for four years,  during which time we and two other pioneers (the Carlisles and Dee Heinrich) were the only Romney breeders.  NSIP is a very good program, but we left it because there were too few Romneys  in it in this country to make progress. 

We thank the veterinarians who have worked with us in Saugerties  at the  farm (Dr. Howard Rothstein first,   for the last 15 years Pine Plains Veterinary Associates) and Dr Cliff Shipley, University of Illinois Urbana-Champaign.  The vets at  Pipestone have been a great resource by phone.

 The statement on OPP below represents our commitment to improving health.  We thank Randy Reuter for his wise and strenuous efforts to get OPP out of our flock.

 

Lambing outcomes summaries 2014-2018

2014 lambing summary (posted in 2015)   Rams turned out late August  2013 in four breeding groups.  57 ewes exposed.  Three ewes were sold as bred in mid-October; all lambed in 2015 (two had twins, one triplets)    In late November an experienced scanner called pregnancy in all 54 ewes still at the farm.   One of these  developed a big udder but did not lamb. 

 Fifty-three ewes lambed.  Thirty-two ewes (60%) had twins; eleven (21%), singles;  ten (19%),  triplets.  105  lambs sighted.  51 females and 54 males.  Four lambs were born dead.   Chlamydia infection was diagnosed after necropsy in the second one, impelling us to treat all ewes pre-partum ewes with injectable tetracycline.  Two post neonatal deaths.  99 lambs weaned.   

 0 % ewe mortality peri-partum or post partum; one ewe died two months after giving birth.

100% of ewes exposed scanned positive or bore lambs. 

 1.98 average litter size of  53 ewes that lambed at the farm ( a measure of fertility potential)

2.0  average litter size of  56  ewes that lambed at the farm or elsewhere

1.87 average number of lambs weaned from 53 ewes that lambed 

1.83 average number of lambs weaned per ewe put to the ram (n  = 54)

 6/105 lambs (6%) born did not survive to weaning; four of these were stillborn. 

Of 101 lambs born alive, only two (2%) died before weaning.

 Average birth weight for singletons 15.1 lbs; for twins 11.9; for triplets 10.8

 Comments: unprecedented (for us) 100% conception rate, unprecedented  fertility potential  1.98  and unprecedented number of lambs weaned from ewes put to the ram (1.83).  This was due in part to a program Graeme had started here to combat vibrio and chlamydia infection with vaccination and oral TC, respectively.  The second had to be complemented by late stage injections.  An usually high number of triplets boosted the average litter size; this may go back to our efforts a few years ago to boost production by encouraging triplets, yet the Wishart trait and the Pinoak lines we had brought in were not in the lineage of all the triplet mothers.  We only had this high a proportion of triplets once before, following a breeding season in which all the ewes had been cycled for AI.

 The 1.83 ratio was  so far  above our long-stated yearly objective of 1.6 that we can hardly expect a repeat in the near future but it’s nice to know it can be done.

 Note:  I wrote most of this in April 2014 meaning to post it and forgot to.  It is thus going up at the same time as the 2015 summary in pretty much the same format.

 

 

 

2015 lambing summary (posted June 25 2015)

 Rams turned out late August  2014 in four breeding groups.  52 ewes exposed.  Three ewes were sold as bred in mid-October; all lambed in 2015.    In late November an experienced scanner called pregnancy in all 49 ewes still at the farm.   Two did not develop udders and did not lamb.  We suspect “missed abortion.”

 Forty-seven ewes lambed.  First lamb Jan 28, last on March 2.  Twenty four ewes (51%) had twins; nineteen (40%) , singles;  four (9%), triplets.  79 lambs sighted.  49 females and 30 males.  Three lambs were born dead, a triplet coming breech and one twin in each of two pairs. None of these looked like a case of placental failure due to infection.   One pre-weaning death at 2 days, one at one week post-natal.  Seventy- four lambs weaned.

 0 % ewe mortality peri-partum or post partum

100% of ewes exposed scanned positive or bore lambs. 

 1.68 average litter size of 47 ewes that lambed ( a measure of fertility potential)

1.57 average number of lambs weaned from 47 ewes that lambed 

1.51 average number of lambs weaned per ewe put to the ram, below our objective of 1.6.  This year the average litter size was much lower than in hard-to-match 2014 when it was 1.98.  It’s hard to explain the variations year to year.  We may have flushed a little more lightly.  Weather is always an imponderable.

 5/79 lambs (6%) born did not survive to weaning; three of these never took a breath. 

Of 76 lambs born alive, only two (2.6%) died before weaning.

 Average birth weight for singletons 14.6 lbs; for twins 11.8; for triplets 10.6

Comments: unsurpassable conception rate for second year in a row and good ewe outcomes.  Good lamb survival, good shepherding all around  by Graeme. 

 Our program of treating against vibrio and chlamydia during pregnancy had its first full  season in 2014-2015.  It seems to have helped prevent late abortions and stillbirths due to infection, which were a big problem before the 2014 lambing.  We also give every newborn  lamb a shot of biomycin to  prevent  Pasteurella  pneumonia.

 

 

2016 lambing summary (posted 7 Oct 2016)

 Rams turned out late August  2015   52 ewes exposed.  Three ewes were sold as bred in mid-October; all lambed in 2016.    In late November an experienced scanner called pregnancy in  48/49 ewes still at the  farm.   One of the 48  did not develop an udder and did not lamb.  We suspect “missed abortion.”  Two ewes died very suddenly in late pregnancy with no signs if illness.

 Forty-five  ewes lambed.  First lamb Jan 22, last on March 7.  Twenty eight  ewes (62 %) twinned; thirteen (29%) had singletons; four(9% ) had triplets.

81  lambs sighted, 43 females and 38 males.  Four  lambs were born dead.  All 77 liveborns survived to weaning.

 0 % ewe mortality intra-partum or post partum but 4% counting two deaths in late pregnancy before labor.

96% of ewes exposed carried to near term or term.. 

 1.8 average litter size of 45 ewes that lambed ( a measure of fertility potential)

1.71 average number of lambs weaned from 45 ewes that lambed 

1.57 average number of lambs weaned per ewe put to the ram, just below our objective of 1.6.  

 4/81  lambs (5%) born did not survive to weaning; none of these never took a breath as far as we can tell.

 Average birth weight for singletons 13.5 lbs (range 12.19) ; for twins 12.2; for triplets 12.2 (10, 14.5)

Comments: good conception rate for third year in a row.  Good lamb survival, good shepherding all around  by Graeme. 

 Our program of treating against vibrio and chlamydia during pregnancy had its second  season in 2015-2016.  It seems to have helped prevent late abortions and stillbirths due to infection, which were a big problem before the 2014 lambing.  We also give every newborn  lamb a shot of biomycin to  prevent  Pasteurella  pneumonia.

 2017 lambing summary (posted June 5 2017 )   52 ewes were exposed, of which twelve left the farm exposed and forty stayed home.  DNL = did not lamb

     Stayed 40                              Moved 12                                    Total   52

DNL 5       Lambed 35           DNL  2            Lambed 10      DNL  7         Lambed 45

                 # lambs 66                                      # lambs 16                            # lambs 82

 

Among 45 ewes who lambed,  14 (31%) had a single, 22 (49%)  twins and 9 (20%) triplets

At home, 64 lambs were weaned; one of 66 was born dead fully formed and one died at age 1 month.  No maternal mortality. 

 

M:F ratio in lambs born at home 37/29 = 1.27 proportion M = 37/66 = 0.56

Prolificacy  of  ewes that conceived and stayed home 66/35 =1.89

Prolificacy  of  ewes that moved away bred 16/10  = 1.6

Prolificacy  of  all ewes that conceived   82/45  = 1.82

Lambs weaned at home/ewes that lambed at home 64/35 = 1.83

Lambs weaned at home/ewes exposed that stayed here = 1.6.  This is the bottom line of production efficiency. 

Comment : good prolificacy, good lamb survival and  good maternal survival.  The bottom line was pulled down by five ewes that did not lamb but met  our yearly objective for this statistic (see home page objectives).   We could not distinguish between failure to conceive and unrecognized abortion. We did not scan 2016. but probably will in 2017.  Where failure to conceive occurred, we can’t now sort out ram from ewe factor.

 

2018 lambing summary (posted Aug 3 2018 )   45 ewes were exposed starting in mid-August, of which three  left the farm exposed and forty-two stayed home.  DNL = did not lamb

     Stayed 42                              Moved 3                                    Total   45

DNL 1       Lambed 41           DNL  0            Lambed 3      DNL  1         Lambed 44

                 # lambs 71                                      # lambs 5                            # lambs 76

 Reporting on births at our farm among 41 ewes who lambed,  14 (34%) had a single, 23 (59%)  twins and 3 (7%) triplets

At home, 68/71 lambs  were weaned; of  the three losses before weaning, two were at   six days  of age; no maternal mortality.   The denominator includes five lambs that went as bottle babies before 60 days of age.

M:F  proportion M = 32/71 = 0.45

Prolificacy  of  ewes that conceived and stayed home 71/40 =1.78

Prolificacy  of  ewes that moved away bred 5/3 – 1.67 (note I have to check this figure drawn from memory)

Prolificacy  of  all ewes that conceived   76/44  = 1.73

Lambs weaned at home/ewes that lambed at home 68/41 = 1.66    Comment:  not quite as high as last year. 

Lambs weaned at home/ewes exposed that stayed here = 1.62   This figure  is the bottom line of production efficiency.  Comment:  1.62 is a little better than any of the preceding three years, which were all slightly below our stated objective of 1.6.

Since we breed for “white” and for “extension dominant colored” and  for  “recessively colored,”  here are relevant facts about color types.

Matings of white ram Chqapin 145 (Awt A_ ) with white ewes thought not to be “color carriers” and thus  denoted as Awt A_ produced 30 white lambs.  The same ram used on “extension dominant” natural-colored ewes that we conservatively call A_ A_ Ed E_ produced 8 natural-colored lambs and 7 whites.  The proposed allelotype for the natural-colored lambs would be A_A_Ed E_. For the white lambs it would be Awt A_ E+ E+.  In past years we have always used an extension dominant ram on ewes thought to have their color from extension; this year we did not have such a ram. having concentrated on recessive rams. 

In table format, there are eight possible unions between two allelotypes of ram that we used in 2017 and four allelotypes of ewes.  The distribution of unions is shown schematically in table 1

Ewe allotype shorthand Ram Aw A_ Ram Ax Ay
       
Awt A_ E+ E+ “white” A E
A_A_Ed E_ “ext dom color” B F
Awt Ax E+  E+ “white color carrier” C G
Ax Ay E+ E+ “recessive color” D H

The number of unions in each letter-coded cell is shown in table 2 below  with the distribution of lamb allelotypes resulting from each type of union,

Union  number no. lambs   no. lambs   no. lambs  no. lambs  total  no.
type of type Awt A_ E+ E+ A_ A_ Ed E+ Awt Ax E+  E+ Axt Ay E+  E+ lambs
    “white” “ext dom[inant] “white color “recessive  
      color” carrier” color”  
             
A 18 30 0 0 0 30
B 9 7 8 0 0 15
C 0         0
D 0         0
E 2 0 0 4 0 4
F 0         0
G 7     9 5 14
H 5 0 0 0 8 8
tot 41 37 8 13 13 71

As is my wont, more precise definitions and explanations for the COGNOSAG terminology are below for those with a taste for such.

“Allelotype” refers in this  context only to the alleles at the agouti locus (for example Awt , Ax where Ax means any non-wt allele at agouti such as light blue)  and at the extension locus where only two alleles are known, Ed the dominant and E+ that does not confer color.

All allelotypes listed are educated guesses, are not based on DNA.

We believe that a high proportion (>95%)  of our white ewes that have no known recessive color in their ancestry are Awt Awt, but denote them anyway as Awt A_ because if one allele is Awt that makes  all other alleles at agouti either imperceptible or every subtle.  We think we can now recognize Awt Aa through recent experience and pencil that sheep thus.

Since Ed obscures the expression of all alleles at agouti we have taken to calling sheep that got color at extension A_A_ Ed E_  even when we know that several generations of the “white” side have been white.  It would be safe I think to write Awt A_ Ed E_ or even Awt A_ Ed E+ but were prefer to be conservative.

We are certain that we no longer have any sheep that are double dominant at extension Ed Ed; nonetheless to spread caution to others   we write Ed E_ because there is no way by looking to tell an Ed sheep from an Ed Ed one.

The outcomes above indicate that we are moving stepwise to emphasize recessive color without abandoning extension dominant.  This is frankly risky as a marketing gambit; we think  it is good for the Romney breed.  The recessive  sheep (ask Graeme) have distinctive  strengths of  hardiness, temperament, good mothering, muscling,   fleece weight  and variations in fleece hue that can compensate  for the main charge against them: not big enough to show in he big time.   Whether the compensation  is  enough depends on one’s wish to flourish  in that arena.a

 

2019 lambing summary posted July 31 2019

42 ewes put to ram.  All stayed here.   Full term  births sighted in 41.  Graeme suspected one ewe  had  aborted early on.

83 lambs from 42 ewes put to ram  = 1.98  Some call this “lambing percentage,” but we don’t

83  from 41 ewes  that surely conceived  = 2.02 . Some call this  “lambing percentage;” we don’t.

It could be called average litter size from ewes with term births.

The statistic that we choose is number lambs weaned /number ewes put to ram.  We  get there like this:

4/83 lambs born dead (3 were triplets, two being from one set on 1398) leaves 79 born alive.  Two of the 79 were likely born alive but  were  found  dead several hours later  hidden behind,  a feeder untouched by first- time dam

77/83 lived  past 24 hours.  Two died after that before weaning.  Total weaned  = 75/83 (67 here and 8 (all triplets)   who had gone as bottle babies to a family in Tivoli NY)

75 lambs weaned/42 ewes put to ram = 1.79.  This is the second-best ratio we have ever had, the best having been 1.83 in 2014.  The last four years 2015-2018 were 1.51, 1.57,1.6 and 1.62 in series.  Note, however, that this ratio is higher always than it might be if we counted only lambs weaned from dams, not bottle babies.  The most rigorous numerator would exclude bottle babies.

No maternal mortality.

Of the 83 lambs males were 46, females 37.

Birth types were in 41 litters: 10 (24%) singletons, 20 (49%)  twins and 11 (27%) triplets

Distribution  of lambs by birth type and color (white vs not-white) 2019

 

   

 unions

single

twins

trip

total

 wh

not-wh

expected

 
                 

not-white

 

1

wh by  wh

15

4

14

12

30

28

2

0

*

2

xD by xD

8

2

6

9

17

0

17

13

**

3

rec by rec

10

3

10

6

19

0

19

19

 

4

rec by WCC

7

1

8

6

15

8

7

7.5

 

5

rec by wh

1

0

2

0

2

2

0

0

 

6

col. total

41

10

40

33

83

38

45

   
                     

 

Legend  wh means phenotypically white no indication of color genes in registration number

Awt A_ E+ E+

xD extension dominant A_A_Ed E_

rec colored sheep with two color alleles at agouti Ax Ay E+ E+

WCC white color carrier looks white known by parentage or offspring  to have one color allele at agouti locus  Awt Ax E+ E+

Distribution by allelotype

White             Awt A_ E+ E+           26

WCC               Awt Ax E+ E+           12

Recessive        Ax Ay E+ E+              28

Xdom              A_A_ E+ E_               17

Total                                                    83

 

Comments two “white by white” unions left a surprise recessive lamb.  Certain of paternity, we concluded that all four sheep were unrecognized color carriers. There was consanguinity  in both unions.  We had a  good idea of where the color gene might have come from for 3  of the sheep  going back to Culver lines.   In the fourth one (145) no clue and the pedigree only went back 4 gen.

 We re-registered as bw all progeny of 145 sold to other farms or kept here, but we did not re-register 145 himself.  He was culled for  reasons besides  being bw: always seemed thin and had an unhealing sore on his brisket.  He was a nice ram and did well for us all years we had him.

 These surprises remind us that unrecognized color carriers are not a rarity.  I have guesstimated in the past that in America the prevalence is 5 – 10% but that was based on the unrealistic assumption of no consanguinity.  The estimate would be lower if all unions that leave a surprise were non-consanguineous.  I’m assuming that many such  are in fact consanguineous.

In flocks that discriminate against recessive color an agouti color allele can be passed down the line for generations un-noticed.  The only way to spot it is to put a ram where it’s under consideration to  five or six known color carriers.  If  none  of the resulting eight or ten  lambs is colored,  it’s pretty likely the ram is not a color carrier but not ruled out completely.   No  flock that discriminates against recessive color, however,  is apt to have a bunch of white color carrier ewes; so, this is not a practical test.  Editorializing, it is vital that when a previously unrecognized white color carrier is identified the breeder make a big effort to notify everyone he or she knows who might have that  line and to re-register the particular sheep as bw even if the pedigree shows no b as far back as it goes.

It is likely that ram 1486 is Ed  Ed ,  as the probability of 17 colored lambs in a row from a union of two sheep Ed E+ is 0.75 E+17 = 0.007.  This observation contradicts what I wrote  in 2018,  that we are sure we don’t have any double dominant Ed Ed rams.

We recorded birth weights and weaning weights as always but did not calculate average daily gains because there were too many variables to adjust for (litter size, time of birth, age of dam, rearing type and agouti alleleotype) and too few sheep to enable adjustment factors.  Generally, weaning weights were lower this year than in past.  We  think this is due to the higher prevalence of recessive lambs in this year’s cohort.

 

Comment: we need to look at allelotypes of ewes born 2018 who will be bred in fall 2019.  Much as we all enjoy the recessives we need a good  mix of “pure white.”  We want want to acquire at least one white yearling in 2019 from outside.

 

Sex ratio sidebar on a whim: In about half of years we lament “too many rams.”  Here’s a 22 year table that shows proportion male among lambs born at term alive or dead at our place.  Overall, the proportion of males is 49%, close to what  one expects from a coin toss.   The 2018 results (45% male)  give for 23 consecutive years total a proportion male of 0.49.

 

                                   Table 1.  Proportion male at birth by year  1996-2017

                                                               

                      Number male              Number female                     Total lambs        Proportion male

 

1996                       33                                           49                           82                           .4                                           

1997                       32                                           36                           68                           .47

1998                       37                                           38                           75                           .49

1999                       39                                           43                           82                           .48

2000                       19                                           18                           37                           .51

2001                       48                                           47                           95                           .51

2002                       39                                           28                           67                           .58

2003                       42                                           39                           81                           .52

2004                       42                                           37                           79                           .53

2005                       30                                           39                           69                           .43

2006                       44                                           49                           93                           .47

2007                       39                                           51                           90                           .43

2008                       29                                           36                           65                           .45

2009                       43                                           42                           85                           .51

2010                       51                                           37                           88                           .58

2011                       35                                           34                           69                           .51

2012                       34                                                                           76                           .45

2013                       44                                                                           76                           .58

2014                       54                                                                           103                         .52

2015                       30                                                                           79                           .38*

2016                       38                                                                           81                           .47

2017                       37                                                                           66                           .56  

2018                       32                                                                          71                           .45

All years               871                                                                        1777                       .49

 

* This proportion  of 0.38 is “statistically significant at the 5% level”   when compared to the proportion of .49 seen in all the other years combined.  Significance level is meaningless since this is a comparison suggested by the data.

 

 Statement on Ovine Progressive Pneumonia dated February 15, 2007 (still holds 2017)

Between 1994 and 1998 four sheep born at Anchorage Farm tested positive for OPP at their buyers’ place. We did not know about this until 1998. In that year we began a multi-cycle test and cull series to eradicate OPP from our flock, using the AGID test.

By January 2000 the mothers of every one of our year-2000 lambs were negative. In August 2000 all the brood ewes for year 2001 lambs were negative. In Jan 2001 all brood ewes were again negative. All breeding rams tested negative all three times. A sample (n = 8) of year-2000 lambs were all negative in March 2001.

The Anchorage Farm flock was closed to American ewes from 1998-2005, when we brought in 8 mature ewes from Pin Oak Farms, Aurora OR. All had tested negative for OPP in 2005. (New Zealand has no reported cases of “Maida-visna,” as they call it. We have imports tested anyway before sendoff.). We introduced an American ram in 2000. He tested negative in May 2000 and Jan 2001. A second American ram, also from a flock we have known well for years, came in 2003. In August 2004 we tested every sheep on the farm older than one year (n = 61). All were negative.

We do not say that we are “OPP free.” This is not a recognized term, and you should be suspicious about such claims. Nor do we adhere to the consecutive year annual testing guidelines recommended by the OPP Concerned Sheep Breeders Society (of which we are members) that would let us say “OPP tested according to OPPCSBS guidelines ” (see The Banner April 2004 p 111-114). Repeat: we do not say “tested according.” Given our closed flock and the negative surveys mentioned above 2000-2004, we do say that our sheep are at very low risk (our term) to have got infected here. We therefore say this about serotesting:

If your vet draws blood for OPP testing by AGID from a sheep you bought from Anchorage Farm and the test is positive less than 90 days after the sheep leaves Anchorage Farm we will pay you the test cost (vet call plus lab). We will also offer you a choice of cash refund for the purchase price or replacement of the animal with one of the same quality that is sero-negative.

If you are considering buying from us and want the sheep (one or more) and their sires and dams (any still with us) to be tested at your expense before purchase we will be happy to arrange that with due notice. We think this action, being earlier in the sheep’s life than the post-purchase test, is less useful to you, but it is your call.

CONDITIONS FOR REMEDY OF A POST-PURCHASE POSITIVE TEST:

  1. The sample must be drawn less than ninety (90) days after the sheep leaves Anchorage Farm
  2. The sheep must be bought directly by you from Anchorage Farm, not bought by you from an intermediary buyer
  3. You must prove you own the sheep (e.g. transfer papers or bill of sale)
  4. Written proof of the positive test signed by the vet who drew the blood
  5. You must notify us within a year of purchase
  6. Any seropositive sheep shall be shipped and the sale-barn purchase payment to you made over to Anchorage Farm.

We don’t take a stand on whether you should OPP-test your flock or individuals in it. If you are concerned about OPP in your flock, and not all breeders are, we recommend you talk to anyone from whom you might buy about that person’s test results and management. We do urge that if you choose to test newcomers to your flock, you do the first test soon after arrival at your place.