- Sheep 201 Index
- Other web sites
Lambing should be fun.
Group housing
Pregnant
Well-developed udder
Pregnant ewe lambs
Extra feed
Consider shearing before lambing
Pregnant ewes need exercise
Crutched ewe
Image by Kelly Cole
Lambing jugs
For dipping navels
CD-T vaccine
Frozen colostrum
A healthy litter of lambs
Content mother
Getting ready for lambingLambing is the most important time of the shepherd's year. The sheep's, too. So, it is important to be prepared. Preparations include managing and feeding the sheep properly, getting the lambing facilities ready, and gathering necessary supplies.
Preparing the Ewes
Feeding and management during late gestation can determine success (or failure) of the lambing season and sheep enterprise. While random problems are not uncommon, most problems can be prevented and result from improper feeding and management, especially during the last third of pregnancy.
What's Happening During Late Gestation?
Approximately 70 percent of fetal growth occurs during the last 4 to 6 weeks of pregnancy. Most of the ewe's mammary (udder) growth is occurring during this period. In addition, her rumen capacity is decreasing. The primary result is the need for increased feed, primarily a more nutrient-dense diet.
Extra nutrition is needed to support fetal growth, especially if there are multiple fetuses involved. Extra feed is needed to support mammary development and ensure a plentiful milk supply. The quantity and quality of colostrum is affected by nutrition. Extra nutrition will prevent the occurrence of pregnancy toxemia (ketosis). It will ensure the birth of strong, healthy lambs that aren't too big and aren't too small. Birth weight is highly correlated to lamb survival. There is a quadratic relationship between birth weight and lamb survival. Small lambs have a lower rate of survival; so, do lambs that are too big.
Nutrition During Late Gestation
During late gestation, energy (TDN) is the nutrient most likely to be deficient. The level of nutrients required will depend upon the age and weight of the ewe and the number of offspring she is carrying. To meet the increased energy needs during this period, it is often necessary to feed concentrates (grain), especially if the ewe is pregnant with multiple fetuses. In addition, if forage quality is low, it may be necessary to provide a supplemental source of protein and calcium.
It is important not to under- or overfeed ewes during late gestation. There are consequences to both. Inadequate nutrition may result in pregnancy toxemia, small and weak lambs, higher lamb mortality, reduced quality and quantity of colostrum, poor milk yield, and reduced wool production (in the offspring) via fewer secondary follicles.
Fat ewes are more prone to pregnancy toxemia. They experience more dystocia (birthing difficulties). They are more likely to prolapse their vaginas. Overfeeding can result in oversized fetuses that the female cannot deliver on her own. It costs extra money to make ewes fat.
Feed Bunk Management
In addition to feeding the right ration, you must also practice good feed bunk management. All ewes should be able to eat at once. If there is inadequate feeder space, some ewes, especially the small, young, old, and timid ones, may not get enough to eat.
Pregnant ewe lambs should be fed separately from mature ewes. Their nutritional requirements are higher than mature ewes because in addition to being pregnant, they are still growing. They may also have trouble competing for feeder space. They are more submissive. Pregnant ewes should generally not be fed on the ground. This is one way that abortions are spread. An exception might be feeding on frozen ground.
Selenium and Vitamin E
Selenium and vitamin E are critical nutrients during late gestation. Low levels of selenium (Se) and/or vitamin E have been associated with poor reproductive performance and retained placentas. Selenium is passed from the placenta to the fetuses during late gestation. A selenium and/or vitamin E deficiency may cause white muscle disease (muscular dystrophy) in lambs.
Free choice mineral mixes usually provide adequate selenium to pregnant ewes. Be sure to feed mineral mixes that have been specifically formulated for sheep. It's better to add the selenium fortified mineral mix to the grain ration to ensure adequate intake by pregnant ewes. Free choice minerals do not always ensure adequate intake. When feeding free choice, be sure sheep are consuming the recommended daily dosage of the mineral mix. Loose, granulated minerals are preferred to mineral or salt blocks. Selenium may be provided via injections, but supplementation is cheaper and safer. There is a narrow range between selenium requirements and toxic levels.
If feed supplementation is not able to raise selenium levels sufficiently, some shepherds may find it necessary to give Se/Vitamin E injections to newborn lambs. A veterinary prescription is required for Bo-Se®. Blood and tissues levels of selenium and vitamin E can be checked to see if there is a problem.
Calcium
Calcium (Ca) intake is important during late gestation. The ewe's requirements for calcium virtually double during late gestation. Milk fever is caused by a low blood calcium level, which can be the result of inadequate intake of calcium or failure to immobilize calcium reserves. Excessive intake of calcium can also be a problem. To prevent this from this situation, it is recommended that you save pure legume hays for lactation and feed a mixed (legume-grass) hay during late gestation.Grains, such as corn, barley, and oats, are poor sources of calcium. Forages are generally higher in calcium, especially legumes (alfalfa, clovers, lespedeza). Supplemental calcium can be provided through complete grain mixes or mineral supplements such as dicalcium phosphate, bone meal, or limestone. Kelp is also a good source of calcium. If low quality forage is fed, calcium should be supplemented through the grain ration. Free choice minerals do not always ensure adequate intake.
Exercise
Daily exercise is recommended for ewes throughout their pregnancy. "Fit" ewes have fewer lambing problems. Separating feed, water, and minerals encourages exercise.
Stress
Ewes should not be stressed during their last trimester. Even if a dog does not harm a pregnant ewe, it can stress the ewe, causing pregnancy complications. Handling should be minimized during late gestation. Groups should be kept stable. If new animals are introduced into a group, they will be a period during which ewes will have to re-establish social hierarchy.
Vaccinations
Pregnant ewes should be vaccinated for clostridial diseases (usually either CDT or Covexin®-8) four to six weeks prior to parturition. Vaccinated females will pass antibodies in their colostrum to their newborn lambs via the colostrum. Ewes that have never been vaccinated or whose vaccination status is unknown require two vaccinations during late gestation, approximately 4 weeks apart. Ewes should not be vaccinated within two weeks of lambing, as this is not enough time to get antibodies in the colostrum.
A pre-lambing vaccination is the best way to provide lambs with passive protection against clostridial diseases, especially clostridium perfringins type C and tetanus. If the dam was not recently vaccinated for tetanus, the tetanus antitoxin can be given at the time of docking and castration. The tetanus antitoxin provides immediate passive immunity to tetanus lasting for about 7 to 14 days.
Parasite control
Pregnant and lactating ewes suffer a temporary loss in immunity to gastro-intestinal parasites as a result of the hormonal changes that are occurring around the time of lambing. Fetal demand for glucose and protein also lessens the ewe's ability to resist parasites. This phenomenon is called the "periparturient rise." The primary result is increased egg shedding by periparturient ewes, which is usually the primary source of parasite infection for the new lamb crop whose immune systems are still naive.
Deworming with effective anthelmintics will help the ewe expel the worms and reduce the exposure of the offspring to infective worm larvae. It will reduce the worm burden when the ewes are turned out to pasture in the spring. Deworming can be done at the same time as CDT vaccinations. Valbazen® should not be given to ewes during the first trimester of pregnancy.
Due to the widespread emergence of anthelmintic-resistant worms, there are better alternatives to deworming all periparturient ewes. Increasing the protein content has been shown to reduce fecal egg counts in periparturient ewes, resulting in better ewe and lamb performance. FAMACHA© and body condition scores can also be used to assess the need for anthelmintic treatment. Young ewes, ewes carrying or raising three or more lambs, and high-producing dairy ewes can be targeted for treatment or preferential feeding.Keeping ewes and lambs in confinement or dry lot during the periparturient period is another strategy. The periparturient egg rise is less of a concern in winter lambing programs. If lambs are never put to pasture, there is less impact of the periparturient egg rise, in which case only ewes with clinical signs of parasitism would need to be dewormed.
Feed a coccidiostat
It is a good idea to feed a coccidiostat to ewes during late gestation. All sheep have coccidia in their GI tracts. Similar to worms, there is an increase in oocytes during the periparturient period. Coccidiostats disrupt the life cycle of coccidia; therefore, feeding a coccidiostat will reduce the number of coccidia oocytes being shed into the lambing environment. Coccidiostats should not be fed year-round, as drug resistance could develop.
There is evidence to suggest that feeding a coccidiostat, especially Rumensin®, during late gestation will aid in the prevention of abortions caused by Toxoplasma gondii, which is a coccidia organism harbored by domestic cats. Coccidiostats, especially Rumensin®, can be fatal to equines.
Antibiotics
The use of antibiotics may aid in the prevention of abortions caused by Chlamydia spp. (Enzootic/EAE) or Campylobacter spp. (vibrio). Chlortetracycline (aureomycin®) has been approved by the FDA to feed to pregnant ewes at a rate of 80 mg per head per day to help prevent abortions. A Veterinary Feed Directive (VFD) just be obtained from a veterinarian in order to include an antibiotic in the feed. Alternatively, injections of antibiotics (e.g. LA-200) every 2 weeks during late gestation may help to prevent abortions.
Shearing or crutching
It is a good idea to shear wooled ewes about a month or so before lambing. An alternative to shearing is crutching. Crutching is when you remove the wool from around the udder and vulva. There are numerous advantages to shearing prior to lambing. Shorn ewes put less moisture into the air. Shearing results in a cleaner, drier environment for newborn lambs. The last thing you want is for a newborn lamb to latch onto a tag or lock or wool, instead of a teat.
Shorn ewes are less likely to lay on their lambs. They are more likely to seek shelter in inclement weather. Shorn ewes take up less space in the barn and around feeders. Shearing before lambing results in much cleaner fleeces. At the same time, shorn ewes will require more feed to compensate for heat loss due to shearing, especially during cold weather. Proper shelter should be provided to shorn ewes.
Facilities
Getting the lambing facility ready is as important as having the sheep ready for lambing. The lambing barn or area should be clean. Ideally, the barn should be cleaned and limed. Fresh bedding should be spread before turning the ewes in. Drafts in the lambing barn should be eliminated. A drop area should provide 12 to 14 square feet per ewe.
Lambing pens (jugs) should be set up before the first ewe lambs. The general rule of thumb is that you should have enough pens to house 10 percent of the flock at a given time. If lambing is more concentrated, additional pens will be needed. 4 ft. x 4 ft. pens are adequate for small ewes, but 4 ft. x 6 ft. or 5 ft. x 5 ft. pens are needed for larger ewes and ewes with multiple births. Lambing pens can have solid or open sides. It is a good idea to have at least one grafting pen. A grafting pen has a hand stanchion built into it.
Less facilities are required for pasture lambing. Lambing should occur in a clean, well-rested pasture. There should be access to shelter. It may be necessary to jug ewes with problem births. Lambs can be gathered every several weeks for marketing (ear-tagging, docking, and castrating).
Lambing supplies
The following table lists supplies you might want to have on hand during lambing.
Rubber gloves, protective sleeves or latex gloves For assisting with difficult births and handling newborns OB lubrication For assisting with difficult births Nylon rope, snare, or leg puller For assisting with difficult births Disinfectant For assisting with difficult births Bearing retainer, ewe spoon, or prolapse harness For holding vaginal prolapse in Heat lamp or warming box For warming chilled lambs Various antibiotics To give to ewes whose births you assist Needles and syringes For giving shots Thermometer For diagnosing problems Gentle iodine, betadine, or chlorhexadine For dipping navel cords Esophageal feeding tube For feeding lambs Frozen colostrum For feeding lambs Colostrum replacement For feeding lambs Lamb milk replacer For feeding orphan lambs Lamb nipples (teats) For hand feeding orphan lambs Lamb bar For feeding several orphan lambs Propylene glycol For treating pregnancy toxemia Calcium borogluconate For treating milk fever 50% dextrose For weak lambs Oral dosing syringe For giving oral medications OB S-curved needle For suturering Ear tags and an applicator For identifying lambs Docking and castrating equipment For docking and castrating Hanging scale For weighing feed and lambs Weigh sling To weigh newborn lambs Pocket record keeping book For recording lambing data Head stanchion For grafting lambs and getting ewe to accept her own lambs
Getting ready for lambing
<== SHEEP 201 INDEX
Copyright© 2021. Sheep 101 and 201.