Lambing should be fun.
Group housing
Pregnant
Well-developed udder
Pregnant ewe lambs
Extra feed
Consider shearing before lambing
Dailiy exercise
Crutched ewe
Image by Kelly Cole
Lambing jugs
For dipping navels
CD-T vaccine
Coccidiostat
A healthy litter of lambs
Getting ready for lambingLambing is the most important time of the shepherd's year. The sheep's, too. So, it's 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 of the lambing season. While random problems occur, 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?
Seventy 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 and a more nutrient-dense diet.
Extra nutrition is needed to support fetal growth, especially if there are multiple fetuses. Extra feed is needed to support mammary development and ensure a plentiful milk supply. 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.
Nutrition During Late Gestation
During late gestation, energy is the nutrient most likely to be deficient. The level of nutrients required will depend upon the age and weight of the ewe and her expected level of production, i.e. singles, twins, or triplets.
To meet the increased energy needs during this period, it is usually necessary to feed concentrates (grain). 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 underfeed or overfeed ewes during late gestation. Inadequate nutrition may result in pregnancy toxemia, small and weak lambs, higher lamb mortality, reduced colostrum quality and quantity, 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). 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, will 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.Pregnant ewes should not be fed on the ground. This is one way that abortions are spread. An exception might be 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 fetus(es) 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. 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.
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. It is recommended that you save your "best" hay 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, bonemeal, and limestone. 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.
Stress
Ewes should not be stressed during their last trimester. Handling should be minimized. Groups should be kept stable.
Vaccinations
Pregnant ewes should be vaccinated for clostridial diseases (usually clostridium perfringins type C & D and tetanus) 4 to 6 weeks prior to parturition. Vaccinated females will pass antibodies in their colostrum to their newborn lambs. Ewes that have never been vaccinated or whose vaccination status is unknown will require two vaccinations at least 2 weeks a part. Ewes should not be vaccinated within two weeks of lambing.
A pre-lambing vaccination is the only way to provide lambs with protection against clostridium perfringins type C and tetanus (if early docking and castrating is performed).
Parasite control
Pregnant and lactating ewes suffer a temporary loss in immunity (as a result of hormonal changes) around the time of lambing. This phenomenon is called the "periparturient rise" in worm eggs. It is the primary source of parasite infection for the new lamb crop.
Deworming with an effective anthelmintic will help the ewe expel the worms and reduce the exposure of newborn lambs 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 CD-T vaccinations. Valbazen® should not be given to ewes during the first trimester of pregnancy.
Due to the widespread emergence of anthelmintic-resistant worms, a better alternative to deworming the whole ewe flock might be to increase the protein content of the ration during late gestation. Higher protein rations have been shown to reduce egg counts in periparturient ewes. FAMACHA© scores can also be assessed to determine the need for anthelmintic treatment.
Feed a coccidiostat
It is a good idea to feed a coccidiostat (Bovatec®, Rumensin®, or Deccox®) to ewes during late gestation. All sheep have coccidia in their digestive systems. Feeding a coccidiostat will reduce the number of coccidia being shed into the lambing environment. You should continue feeding the coccidiostat through weaning.
There is evidence to suggest that feeding a coccidiostat 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 sp. (Enzootic/EAE) or Campylobacter sp. (vibrio). Chlorotetracycline (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. 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. They require adequate shelter.
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 problem births. Lambs can be gathered every several weeks for docking and castrating.
Supplies
The following table lists supplies you should have on hand for 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 retainor, 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 chlorohexadine For dipping navel cords Esophageal feeding tube For feeding lambs Frozen colostrum For feeding lambs Colostrum supplement To supplement colostrum Lamb milk replacer For feeding orphan lambs Lamb nipples (teats) For hand feeding 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 sutering 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
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