Livestock Update, January 2001
Scott Greiner, Extension Animal Scientist, Sheep, Virginia Tech
Newborn Lamb Management
At no other time during the year is the investment of time and sound management practices more influential for a sheep producer than during lambing time. The financial success of a sheep operation is largely dependent upon maximizing pounds of lamb weaned per ewe exposed, while minimizing costs of production. Realizing pounds of lamb weaned per ewe is largely dependent on saving the lambs that are born, as the largest percentage of lamb deaths occur at or shortly after birth. Research has shown that dystocia and starvation/hypothermia are major causes of lamb mortality. Solid management practices at lambing time are essential for the economic viability of the sheep operation.
1) Visits to the lambing barn
Dystocia has been shown to be a significant cause of lamb mortality. Losses due to stillbirths and dystocia can be reduced by timely visits to the lambing barn and timely assistance of ewes. Pregnant ewes should be checked every 3-4 hours. If ewes are checked at 11 p.m. or midnight it is not necessary to check again before 5 or 6 a.m. Ewes that will lamb between these times usually show signs at the late night observation. Ewes close to lambing will be restless and may try to claim other newborn lambs. Ewes in labor will normally separate themselves, and frequently choose a corner or area along a wall or feedbunk to nest and deliver. The lambing area should be dry and well bedded, and sources of cold drafts that will chill newborn lambs should be eliminated. It is not necessary to have a heated lambing barn- a dry, draft-free area is more important. The lambing process can vary considerably between ewes. Ewes in labor should be left undisturbed. However, once the ewe begins forceful straining and the water bags are passed, delivery should normally take place within 45-60 minutes. Once the front legs are visible, lambs should be born within 30-45 minutes. After the first lamb is born, subsequent lambs are normally delivered within 30 minutes. Prolonged delivery beyond these times may indicate lambing difficulty, and the ewe should be examined and assisted if necessary. When assistance is required to deliver one lamb, the uterus should be examined for additional lambs. For lambs that are pulled, a piece of straw may inserted into the nostril to stimulate breathing. Lambs that are delivered rear legs first should be gently shaken upside-down by holding the rear legs to allow fluid to drain from the lungs.
2) Move ewes to a jug after lambing
When possible, ewes should be allowed to give birth where they initially bed down. Moving ewes to individual pens when they start lambing may prolong the birthing process and cause other complications. Additionally, allowing ewes to complete the lambing process before moving them to jugs will keep the jugs drier and help prevent injury to lambs in multiple birth situations. Lambing jugs need to be a minimum of 4 ft. x 4ft., and may be as large as 6 ft. x 6 ft. for large breeds or flocks with large numbers of multiple births. Approximately 1 lambing jug is needed for every 10 pregnant ewes. However, more may be needed during heavy lambing periods or with flocks having a large number of multiple births that require more time in the jugs. The environment of the jug is critical to newborn lamb health and survival. The jugs should be kept well bedded, dry, and free of drafts. For facilities with cement floors, a base of lime or sawdust/shavings is recommended under straw. Cement floors can be cold and damp, and therefore a source of chilling and pneumonia in newborn lambs. When feasible, lambing jugs should be cleaned between ewes.
The first 24-48 hours after birth are a critical time for the ewe and her lambs. During this time, bonding occurs and the ewe as well as her lambs learn to identify each other. The jugs also assist the shepherd keep a close eye on the ewe and lambs during this time.
Upon moving the ewe into the jug, the lambs' navels should be clipped and immersed in iodine. Many navels (less than 2 in.) will not need to be clipped. Iodine helps prevent infection and promotes drying of the navel.
Time spent in the jug will depend largely on the number of jugs available and rate at which ewes are lambing. Strong, healthy singles may be removed from the jugs in 24-36 hr. after birth, and twins 48 hr. Triplets and ewes with weak lambs may need to stay in the jug for 3 days or more. Ewes and lambs should be removed from the jug as quickly as possible, as chances of pneumonia and diarrhea are greater the longer they are kept confined to the jugs. Labor requirements are also much greater when ewes are confined to the jugs.
Upon removal from the jugs, ewes and lambs should be put into a mixing pen with 3-4 other ewes and their lambs. This will help acclimate them, and they should be closely observed to identify abandoned and rejected lambs. After a day or two, the ewes can then be put into larger groups.
Before turning out of jugs, pertinent information on the ewes and lambs should be recorded. Appropriate identification of the lambs (ear tags, paint brands, ear notches, etc.) should also be done at this time. The ability to match a ewe with her lambs can be very beneficial as a management tool. Thin, poor-doing lambs may indicate a health problem in the ewe (mastitis) or inferior milking ability.
3) Insure lambs receive adequate colostrum intake
Colostrum is the milk produced by the ewe up to 18 hours after birth. It has important nutritional value for the newborn lamb. Colostrum contains essential antibodies that provide protection for the newborn lamb, and provides energy to keep the lamb warm. Newborn lambs are susceptible to hypothermia due to their large body surface area in relation to body weight, and relatively low energy reserves.
Lamb should receive adequate intakes of colostrum within 30-60 minutes after birth. To help insure this, the ewe's teats should be stripped to remove the wax plugs that frequently obstruct the teat. In some cases, these plugs will prevent lambs from getting milk that appear to be nursing. Stripping the teats will also confirm the ewe has milk. Lambs should be monitored closely to make sure they nurse. Lambs that have nursed will have a full stomach upon palpation. Lambs that have not nursed should be assisted. Most lambs have a strong suckling reflex shortly after birth, and will nurse when presented a teat. It may be necessary to close the lamb's mouth on the teat and/or squirt milk in the lamb's mouth to initiate suckling. An effort should be made to help the lamb nurse the ewe before other methods are used to get colostrum into the lamb.
In some cases, the lamb is unable to nurse the ewe even with assistance. These lambs may be small, weak, chilled, rejected by the ewe, or injured. In these cases, tube feeding is necessary to get colostrum into the lamb. Lamb tubes that attach to syringes are available commercially, and should be on hand for all shepherds. The tube is inserted in the side of the lamb's mouth, and should follow the roof of the mouth and down the throat. Don't force the tube down; rather allow the lamb to swallow as the tube goes down the esophagus. The tube can be felt on the outside of the neck as it is inserted into the stomach, and will go in about 12 in. Although it is difficult to get the tube down the trachea (windpipe), the tube can be checked to see if air is being expelled (listen or moisten end of tube to see if bubble forms). After insertion of the tube, colostrum should be given slowly. Lambs should receive 20 cc colostrum per pound of body weight. As a reference, 30 cc equals approximately 1 oz. Therefore, a 10 lb. lamb should receive 200 cc or about 7 oz. of colostrum. After the initial tube feeding, many lambs will respond and begin to nurse on their own. If not, the lamb may need to be tube fed 2-3 hr. after the initial feeding.
Source of colostrum for these cases is another important consideration. The first choice would be from the lamb's mother. If colostrum is not available from the ewe, another ewe that has just lambed may be a source. It is a good idea to freeze colostrum for future use from ewes that lose their lambs or ewes with singles that are heavy milkers. Colostrum should be pre-measured and frozen using ice cube trays or freezer bags. Frozen colostrum should be thawed with indirect heat (water bath), and not a microwave or direct heat as antibodies will be destroyed. In an emergency, goat or cow colostrum may be used. There are also artificial colostrum substitutes available commercially.
Hypothermia and Starvation:
Hypothermia is defined as low body temperature. This condition may result from a variety of factors including exposure, weakness, trauma, and starvation. Lambs with hypothermia appear weak, gant, and hunched up. In severe cases, the lamb may be unable to hold its head up and even be unconscious. The ears and mouth may feel cold, and the lamb may lack suckling response. The normal body temperature for lambs is 102-103ƒ. Lambs with temperatures below 100ƒ are considered hypothermic. A rectal thermometer should be used to assess body temperature. Healthy lambs are adaptable to very cold temperatures, provided the environment is dry and free of cold drafts
In newborn lambs, true hypothermia may result from exposure. In these cases, it is necessary to get colostrum into the lamb immediately to bring body temperature up. Tube feeding is an effective means to administer this colostrum. It may also be necessary to move the lamb into a warmer environment to elevate body temperature. If wet, the lamb should be dried off and wrapped in a towel. A cardboard box can be used to confine the lamb, with jugs of warm water used as a heat source. This method is similar to the heating boxes that are sold commercially. Heat lamps may also be effective. However, heat lamps should not be used routinely in the lambing barn. They are expensive to operate, and do not supply enough heat to prevent hypothermia. As the lamb warms up, monitor body temperature as warming the lamb too quickly may cause shock.
For lambs that are older than 24 hr., hypothermia usually is a result of starvation. Without energy from milk lambs become hypoglycemic, then hypothermic and may die. Treatment for these situations is similar to that used for the newborn, with the exception that older lambs need not receive colostrum. Milk replacer can be fed with a bottle or tube fed. As a guideline, these older lambs should receive 6-8 oz. of warm milk.
Virginia is largely a selenium deficient state. Deficiency of Selenium and/or Vitamin E causes white muscle disease in lambs. White muscle disease is characterized my stiffness in the rear legs and an arched back in lambs a few weeks of age. For prevention of white muscle disease, lambs should receive 0.25 mg of injectable selenium per 10 pounds of bodyweight before being turned out of the jug. A selenium-fortified trace mineral salt should be offered to the flock year-round as an additional preventative measure.