Breeding Ewe Lambs By: Dr. J.D. Bobb

Breeding your ewe lambs is a vital part of every sheep operation.  They should be your best genetics and the future of your flock.  Many purebred producers are reluctant to breed ewe lambs because they do not feel that they will mature to as large a female. Commercial producers know that they can not afford to feed a ewe for two years before they get a return on their investment.

A set of pregnant ewe lambs require more attention, better quality of feed, current vaccinations and their own lot.  You can not treat these lambs like they are part of the mature flock.  First and foremost they need their own lot with plenty of bunk space.  They should never be mixed with larger older ewes.  Ewe lambs in late pregnancy have physical limitations on how much feed they can consume and are easy pushed out of bunk space by larger stronger ewes.  It is much harder to keep ewe lambs in the proper condition, we see many groups that are over fat or under conditioned.  Over fat ewe lambs have a tendency to have increased incidence of vaginal and rectal prolapse and lambing problems related to large lambs.  Under fed ewe lambs have weak lambs, poor milk production and struggle to breed back with the ewe flock the next year because they never recover their proper body condition.

Ewe lambs need to receive a booster to their Chlamydia, Vibrio, and scour shots that the mature flock does not require.  The population of ewe lambs has not been exposed to the diseases that exist in the mature ewe flock.  Their immune system is not as stable or capable to handle a disease challenge as your mature ewes.  You will need to time the vaccinations to booster their immunity and get their immune system ready for a disease outbreak.  The booster of abortion vaccinations should be timed at mid gestation which is 60 to 80 days.  We frequently see increased abortions in ewe lambs because they have not been exposed to organisms such as toxoplasmosis.  Once they have become exposed they will mount their own immune response and develop long term immunity.  The only control for toxoplasmosis is feeding Deccox or Rumensin in their feed.  The use of tetracycline the last six weeks of gestation is highly recommended, to aid in abortion control.  We have had the best results by pulse feeding higher levels of crumbles rather than a constant lower level.  I would recommend pulsing the crumbles at six weeks and three weeks prior to the start of lambing at ½ gram per head per day for three days each time.

It is very wise to carefully consider the ram that you will breed your ewe lambs to.  Do not breed them to the old thick made stud ram.  Consider using a ram that should produce easier lambing.  The commercial producer should use a finn cross, rambouillet, targee, or there are many other choices that will produce an easy lambing cross.  Usually after one season of using a ram that produces large lambs a producer will be more cautious.

Ewe lambs tend to have fewer lambs than the mature flock.  In some cases they will have over a two hundred percent lamb crop, but ewe lambs that are nursing multiple births need special feeding to prevent them from becoming a disappointment as a yearling.  I would be happy with a set of ewe lambs that had a 130-160% lamb crop.    A first time lambing ewe will have less antibodies is her colostrum, and her lambs will be challenged by scours and pneumonia more than a mature ewe.  They produce less milk on the average and will often wean lighter lambs.  There are exceptions, but you will need to feed and care for ewe lambs more intensely than the older flock.

Do not become complacent with your observations when you are doing chores.  Always spend a little extra time examining the ewe lambs.  Take note of their condition; make sure they have plenty of room when they are eating.  My biggest concern with ewe lambs is when they are fed free choice round bales.  You are going to fix prolapse vaginas and rectums if they are in late pregnancy with unlimited access to round bales of hay.  To make the situation worse they often stand with their front legs elevated reaching for fresh hay.

If you have a lot of multiple births in your ewe lambs, watch them closely for lambing paresis (pregnancy disease) and ketosis.  You need to keep the energy up with out them getting fat.

Parasite Management By: Guest Author Richard Ehrhardt Ph.D.

I have been working in the area of parasite management in the North Central Midwest for the past 5 yrs and as a producer/academic in upstate New York before that.   I agree that parasite management is fairly simple if you do not graze lactating ewes and lambs.  Large flocks (500-2500) that I work with in the North who have abandoned grazing ewes and lambs and changed their production system to graze only dry ewes have far fewer problems with parasite infection.  This is because dry ewes have strong immunity to parasites whereas lactating ewes and especially lambs do not.   This is a profitable mode of production for some of these producers but not all.  We also have flocks in this region that are profitable but have an entirely different mode of production that minimize input costs (buildings, labor, equipment) and keep lambs and ewes on pasture as a back bone of their production system..  What we have learned is that both modes of production can be profitable if carefully managed and like anything, unprofitable if poorly managed.

I also agree that parasite management programs need to be specifically tailored to individual farms and should involve a DVM to be successful and properly and legally executed.  Each farm has a unique resource base, feeding system (grazing or otherwise), management system, etc. so a one-size-fits-all approach is obviously not going to work.   There are however some basic guiding principles and facts to understand in developing these programs.

1. Drug resistance in gastrointestinal nematode  populations infecting sheep is extremely common and widespread in the Northern USA as is in other parts of the country and World.   We have documented resistance to every chemical class in large flocks in Michigan and reports from large flocks in Ontario are the same (northern regions but perhaps more humid than the western Midwest region).  To be more specific ivermectin has the same efficacy as does treating with water in many flocks in the North.  Each farm has a unique pattern of resistance so ivermectin resistance although common, is not an absolute for all just as for the rest of the products within chemical classes.   This work has involved careful and meticulous use of validated methods of measuring resistance.
2. It is widely accepted concept that failure to maintain a refugia population is a major factor in the acceleration of drug resistance.  This concept is nearly uniformly accepted is by DVMs, veterinary parasitologists  and animal management experts from throughout the world.  There is however considerable debate on the best and most feasible way to do this. Frequent treatment  and treating all animals when there is no untreated parasite  population in sheep OR pasture is clearly accepted as a major means by which resistance accelerates.   FAMACHA is one way to maintain refugia and may be appropriate for some systems.  I agree that it is not a solution for all farms because of feasibility issues and challenges in early detection in lactating ewes and lambs.  However it is a valid system for some and should not be summarily discarded.  All flocks need a refugia maintenance plan regardless of production system and these should be developed by DVMs and health and management experts on a farm by farm basis.  Refugia maintenance is a principle embraced by progressive crop farmers as well to combat herbicide resistance so this approach is not unique to livestock industries.

Hopefully, I have persuaded you that education and research in this area is very important and that this work needs to involve successful practitioners like Dr. Kennedy who have undeniable experience in sheep production medicine. Without this connection, any potential impact will be compromised.

Sincerely,

Richard

Richard Ehrhardt  Ph.D.
Small Ruminant Specialist
Michigan State University Extension

Dried Distillers Grains and Ram Fertility Research J.D. Bobb

 

Research done by M.L. Van Emon may give us some insight to ram fertility issues we have been seeing over the last several years.  Antidotal stories of questionable rams associated with diets high in feed byproducts finally might have some research to back their stories.

Data was collected on 120 ram lambs that were substituted DDGS for corn at 0, 15 or 30% of the diet.  The ram lambs were 90 days of age at the beginning of the trial and fed for 116 days.

1. No significant change in final body weight across the treatments.
2. No significant change of days on feed was noted.
3. Increasing the percentage of DDGS increased the dry matter intake and Average Daily Gain.
4. No significant changes in Carcass characteristics were noted.
5. No significant difference in scrotal circumference was noted.
6. No significant changes in testosterone levels were noted.
7. Spermatozoa concentration decreased linearly as DDGS increased in the diet.
8. No significant difference in semen motility was noted.

DDGS are known for having high and variable amounts of sulfur content.  They have proven to be a valuable feed byproduct to the industry, but until more is learned about their possible side effects on semen production care should be taken to avoid feeding DDGS to the ram pen.  The author speculates that the sulfur content may alter the selenium and copper utilization and absorption.   

 

Zactran — Some Hope for Foot Rot in Sheep JD Bobb

Foot Rot has been one of the most frustrating and stubborn diseases in the sheep industry.  Many good flocks of sheep and producers have gone by the wayside in attempts to clean up their flocks.  We had a good vaccine until about 5 years ago and have not been able to reestablish that product in the market.  Producers overseas in Europe and other countries have had very good success with the drug Gamithromycin.  It has not been available in the United States until about a year ago.  The drug is sold under the name of Zactran and is not approved for use in sheep.

There is very strong research done overseas that supports the effectiveness and safety of using this product in sheep for eradicating Foot Rot from flocks.  I would suggest you work closely with your Veterinarian due to the unapproved  label for sheep use.  One Danish study showed that in 44 out of 48 flocks that the treatment was effective.  The German’s have used a protocol were every animal was treated and 23 days later any animal showing any signs was retreated and have demonstrated that the flock is Foot Rot free using PCR testing.

The program should include foot trimming, a clean dry environment (concrete is best), removal of chronic animals from the flock.

Dosage, 2cc ewe lambs, 4cc ewes, 5cc rams, slaughter withdrawal 35 days in cattle.

Worming Sheep

Worms, worms, perhaps all the FHAMACA and parasite resistance isn’t working. About every second question we get now is about worms and bottle jaw. Lets talk about bottle jaw, this condition is caused by fluid collecting  evenly in the intramadibular  area. This develops as the result of anemia. Anemia is the result of blood sucking stomach worms. Other chronic diseases and chronic disease conditions may cause severe anemia, Johne’s being one of those disease. Localized infections can be confusing as well.

In  response to my critics that promote parasite resistance and FHAMACA programs good  luck and I question the animal welfare aspects of their procedures. Would you tolerate worms in your child as long as they didn’t  kill him. We get criticized in the pig business for our confinement methods but we have no mange and very seldom worms. How can you allow an animal become parasitized to the point that it compromises health and production and becomes a source of infection for the balance of the flock before you take action.  My position as a veterinarian is to do my best to see that animals are treated humanely and given a chance to survive. No animal should be left behind.

In my camp I am going to recommend the use of wormers and pasture rotation. Along with this recommendation I am going to suggest that if you are located in a warm or humid area the lambs should not go to pasture. If ewes and lambs are held in dry lot and weaned at 8 to 10 weeks of age and fed to market you expect lambs to go to market in 120 to 150 days of age and a feed conversion of 4:1 or less. Run them on grass, wean at weights at not much higher than the 8 to 10 week weight, stand the death loss and if lucky get an 8:1 feed conversion. Worms and coccidiosis are no longer a problem and much easier to control worms in the ewes. If you have to much grass, run more ewes. that is an expansion program that works and the Pipestone Lamb and Wool Program is on going proof that the system works.

Wormers I like: as long as we stay away from copper wire and organic junk they all work if programed to each individual production situation. I ignore the tape worms as eventually animals develop resistance and they are expelled. Tape worm segments are often observed in fecal material and thy may indicate the presence of stomach worms if animals haven’t been wormed. That takes Valbazen off the list unless dealing with liver flukes. Cydectin and Ivomectin products work but I prefer Dectomax as an injectable or Prohibit as a drench. Dectomax is the most effective on undeveloped migrating larvae and Prohibit is effective against adults only and said to be the most effective against resistant worms. Makes sense to me to use Dectomax in the fall when coming off pasture and drenching with Prohibit prior to going to grass in the spring.

In my flock I use Dectomax spring and fall. I don’t worm lambs until they are pulled off self feeder and retained for breeding stock. I have done this successfully with several breeds over the years and with other wormers as well.

Johne’s disease, Paratuberculosis

This is a wide spread disease infecting many animals but not humans. It is a chronic disease transmitted through fecal material and colostrum milk. Animals are most likely infected young in life and don’t show symptoms until later in life, two years and older in cattle. There is very little transmission adult to adult.

There is no known treatment for the disease and vaccines are not approved in this country. There are various tests for the disease but the most meaningful is post mortem analysis. The various tests have value but are sometimes difficult to interpolate and in sheep I would not advise.

Apparently the sheep strains are different from cattle strains but this is not true in goats. Cattle always exhibit diarrhea in the final stages along with emaciation but appetite may remain normal. Water intake may increase. Sheep and Goats may or may not develop diarrhea but become emaciated and loss of wool or hair may occur.

When using cow colostrum for goats it should be pasteurized or gone thru a drying process before use. This isn’t as essential in sheep. Avoid fecal contamination of teats. Testing and herd interpretation may be necessary in Cattle and goats. Eradication in sheep can be resolved by early culling when symptoms of wasting develop. Elimination of off spring from culled animals is also helpful.

Hot Weather Thoughts By: Dr.G.F. Kennedy

Flies are always a problem

Premise spray and bait can be effective.

Manure removal is critical, old manure packs create heat as well as fly breeding grounds. Fans and shade, particularly rams.

Sheep temperatures normally may be 103 degrees or higher and still be normal so they are can tolerate hot weather better than some species.

Cool clean source of water.

Keep it simple.

 

Meningeal Worm

by Dr. J.L. Goelz

The Meningeal worm of whitetail deer (Parelaphostrongylus tenuis) has an interesting life cycle.  The intermediate host is a snail.  Deer consume the snail when grazing and the larva migrate through the tissues to the spinal cord and ultimately the brain.  Deer are a well adapted host and develop little or no problems with worms migrating through their brain.  However, if the snail is consumed by a sheep, goat llama, elk or moose, the migration causes a severe inflammatory response.  This usually occurs when the parasite enters into neurological tissues such as the spinal canal.  The intense inflammation results in paresis (neurologic lamness) or paralysis of the hind legs.  Severity of signs varies from knuckling on their fetlock or dragging a toe, all the way to complete paralysis and the entire spectrum in between.

Diagnosis of P. tenuis is suspected in areas where both white-tail deer and the intermediate host snail are present.  This usually means within 200 miles of the Great Lakes although cases have been suspected in other areas.  Confirmation of P. tenuis is difficult as there is no live animal test and necropsy is difficult as the larva are microscopic.  Treatment of affected animals is aimed at killing the larva with an avermectin such as Ivomec, ivermectin (generic) or Dectomax at normal label dose.  I prefer to use the injectable products as they reach higher blood concentrations more quickly.  Some veterinarians include Safe-guard (fenbendazole) daily for 5 days in addition to ivermectin.  Decreasing the immune response is another component to treatment, usually with dexamethasone daily for three days or Predef if the ewe is pregnant.  Lifting the ewe and re-positioning a down ewe on deep bedding is important to minimize muscle damage.  Anti-oxidants such as Vitamin E should also be considered.  Affected animals should be re-evaluated for improvement daily.  If the ewe cannot stand, and no  improvement is made after five days, humane euthanasia should be considered.  If improvement in mobility occurs with treatment the sheep may have a full and complete recovery or may have permanent, neurological problems for the rest of its life.

If P. tenius is suspected treatment of the entire flock with an avermectin is warranted.  If one sheep ingested snails with larva it is a good bet that other sheep are also infected with larva but it just has not made it to the spinal canal.  In endemic areas treatment every three weeks should be considered in the prime infection season (late summer and fall).  Restricting grazing of low lying areas during fall will also help reduce risk.

Sheep Keds

by: Dr. G.F. Kennedy

Sheep keds are the most widely distributed and most common external parasite of sheep. They are a wingless fly that spends their entire life time on the sheep and if they fall off don’t survive. When an egg is laid, they pupate for 22 days before emerging. The adults suck blood and cause irritation that results in wool damage and when severely infested can debilitate the sheep.

Treatment requires shearing and pour-on of an insecticide that has residual activity. Permethrin 1% Pour-on is the most effective product available and may be repeated in 21 days in severe infestations. Injectable and pour-on ivermectin products are not very effective.

They are not a tick but a wingless fly.

Navel Ill

Every year I get questions about stiff lambs with one or more swollen joints, these lambs are not doing well and they hurt when they move. Joints may show no swelling early. Navel ill needs to be distinguished from white muscle disease where the entire lamb moves with difficulty and the muscles may appear swollen. Lambs affected with navel ill tend to be the poorer lambs of the group.

Bacteria enter via the navel cord shortly after birth from contaminated surroundings and perhaps some times the vaginal channel during birth or assisted birth. My solution to prevent navel ill is simple, include one cc of penicillin along with one cc of CDT mixed in the same syringe when applying bands before the lambs leave the jug.

The long standing perceived method is to apply iodine shortly after birth. To do this adequately on a timely basis is almost impossible. Most of the time, all you achieve is stains of the fingers. A cc of pen at processing is much more effective and provides some tetanus protection as well.

Treatment resolves around sustained use of antibiotics, and I prefer penicillin. 1cc per 10# body wt daily subcutaneous. I like to start with two cc of dexamethasone once and Banamine can be used to control pain. Results will be determined by the amount of joint damage and early diagnosis is important.