Managing the Sheep Flock During Lambing Season
by Rodney Kott, MSU Extension Sheep Specialist
Lambing season is the critical time when the sheep producer's skill, effort, and concern determine the success of the entire operation. Dozens of problems occur. Many, however, can be traced back to poor management, inadequate equipment or an indifferent attitude. Of the three, attitude is the most important followed by management. Poor equipment is often blamed for most problems, but good management and a good attitude can make even poor equipment work.
Perhaps one of the most important and least stressed management tools available to sheep producers is observation. A complete knowledge of sheep production is useless if producers do not have the ability, or more appropriately stated, do not take the time to recognize problems as they arise. A part of a producer's daily routine should include close observation of all ewes and lambs. You would be surprised at the amount of things you would see by spending just thirty minutes per day looking at your sheep. After a few weeks you would know your sheep very well. You would know how they normally act, move, play, eat, etc. You will be able to tell when they are not feeling well. This will give you a head start on identifying problems during lambing.
A new lamb is a 10-to-14 pound sopping wet baby that has left a warm, well nourished environment for a harsher life outside. Now it must initiate breathing and maintain body temperature. If you can't provide the lamb with a suitable environment you may want to choose to lamb later when weather is warmer.
The facility components of a shed lambing system include: 1) an area for ewes about 1 to 3 weeks prior to lambing, 2) a drop pen for ewes within a week of lambing, 3) lambing jugs for newly born lambs until they are 24 to 72 hours old, 4) nursery pens for a few ewes and their lambs 24 hours to 3 days after lambing, and 5) mixing pens for ewes with lambs for ewes with lambs 3 to 30 days of age.
The need to lamb 100 ewes in a facility large enough for only 50 ewes is a common problem. However of 100 ewes, no more than about 35 will lamb per week. Also, after the newborn lamb has dried off, has been fed, and has had the opportunity to adjust to a harsher environment, it can be moved to cooler and presumably less costly quarters.
This should be a large outside lot that ewes can be kept in prior to lambing. This lot usually contains the ewes that are several weeks from lambing. Ewes closer to lambing are usually kept in a drop area close to the lambing shed. This lot should have access to a sheep working facility and the lambing shed.
A lambing barn does not have to be fancy nor does it require a new building. In most cases existing facilities can easily be converted into workable lambing barns.
The most common facilities used are unheated lambing barns. They protect the animal from rain, wind and snow and provide temperatures just higher than outside temperatures. In certain areas heated lambing facilities may be beneficial, with temperatures maintained at 35 to 45 degrees F. However, when heated barns are utilized proper ventilation is more critical. If ammonia can be smelled in the barn ventilation is inadequate.
Workroom: Optional, but comes in handy for lamber to stay in, store equipment and take care of chilled lambs. This room should be heated and provide access to electricity and hot water.
Drop Area: A space to house ewes that are within a week of lambing during adverse weather will come in handy. This space usually only needs to be large enough to house about 35 to 50 % of the ewe flock. This area should be large enough to allow 12 to 14 square feet per ewe. As lambing progresses less ewes will be in this group. The size of this area can be reduced accordingly making room for mixing pens. Also by dividing the drop band into small groups of ewes (10 to 20 ewes per pen) it may be possible to avoid having a night lamber. If you are unable to house the drop band inside, a lamber should be on duty at all times during cold weather as the lambs must be brought inside immediately after lambing.
Lambing Jugs: One lambing jug for every 7 to 10 ewes in the flock should be adequate. They should be at least 4 by 4 feet and preferably 5 by 5 feet. Ewes will usually remain in these jugs from 12 to 24 hours.
Nursery Pens: The first set of nursery or mixing pens that the ewes are placed in should be large enough (16 to 20 sq. feet per ewe and lambs) to hold about 5 to 7 ewes with their lambs. Ewes should remain in these pens another 24 to 48 hours, therefore, approximately two or three of these pens for every 100 ewes in the flock will be needed.
These are larger pens where ewes and lambs are combined into larger more manageable groups as they come out of the lambing shed. They are usually designed to hold about 20 ewes and their lambs but in certain instances may hold as many as 100 ewes and their lambs. Lambs are still relatively young when they are placed in these pens and therefore some type of shelter should be available. This shelter, however, need not be very elaborate (it can be as little as plastic stretched over a wooden frame and against a wind break).
It is desirable to shear ewes about two weeks prior to lambing. This will enable you to house more ewes in the same shed space. Also it is easier for the lambs to start suckling and encourages the ewes to seek shelter from cold and to take their newborn lambs with them.
In the northern United States a large percentage of the internal parasites undergo arrested development (hypobiosis) during the winter months. Most anthelmintic are only marginally effective against these arrested larva. However around lambing something occurs to stimulate maturation of these larva to adults. The result is a periparturient rise in worm egg counts and the beginning of an internal parasite problem. Just before lambing is an ideal time to worm the ewes. However, make sure that the drug you are using is safe for pregnant ewes.
Lambs are born about 145 days after the rams are turned in with the ewes. Make sure you have purchased supplies and set up the lambing facilities well before lambing begins. Once lambing begins your time will be better spent looking after the sheep. Also, spend some time looking for booby traps. I can assure you that if you do not find them, the lambs will.
If you are to have a successful lambing season you will avoid the following:
Trying to find some boards to build a needed jug panel under three feet of snow at
3 AM in the morning.
Repairing a hole in the lambing shed or a broken window when a sudden blizzard arrives.
Going to town to try and find lambing supplies the day 20 new lambs arrive.
It is most desirable to have all pregnant ewes in the immediate drop band. However, in most instances this is not possible. In these cases it is necessary to sort off the "closeup" ewes and place them in an areas where they can be given the most attention. About one week before the first lamb is expected, sort out 25 to 30 percent of the ewes that you think will lamb first. Ewes closest to lambing normally have considerable udder development, their vulvas are enlarged and slightly dilated and the ewes appear heavy through the middle. However, none of these sign is a perfect indicator. Ewes not in the closeup group must therefore be rechecked several times each day as you will likely have some lambs born in this group. Check ewes not in the "closeup" drop band every 5 or 6 days and place any ewes showing signs of being close to lambing in the closeup band. Do everything possible to avoid having lambs born out in the snow.
The lamber's role is to assist delivery when necessary and to see that the lambs survive. Shortly after lambing the lambs should be picked up and the ewe, along with her lambs, placed in a lambing jug. A high percentage of mismothering can occur in the drop and therefore it is essential that the lamber be very attentive. If the drop is only being checked periodically it is beneficial that ewes in the drop be divided into small groups.
Once the ewes and lambs have been brought in, the naval cord of the lambs should be clipped to a length of 2" and dipped in 7% tincture of iodine. Do not use a spray application of iodine; instead use a wide mouth jar and immerse the navel in iodine. This practice is considered "essential" for preventing losses from navel ill.
When the ewe and lambs are placed in the jug, a stream of colostrum should be milked from each teat in order to remove the wax-like plug in the teat canal. By doing this the lamb will be able to suckle with less difficulty.
This is a good time to access the ewes milk production and make grafts if necessary. Shortly after the lamb is able to stand it should be assisted in suckling if it cannot do so itself. The value of colostrum within the first 2 hours of birth cannot be overemphasized. Antibodies developed by the ewe against infectious organism are transmitted through the colostrum to the lamb. These antibodies provide disease protection to the lamb for several weeks following birth. Without early absorption of these colostral antibodies, the lamb is susceptible to disease. The production of and the ability of the lamb to utilize colostral antibodies decreases dramatically shortly after birth.
If the lamb is weak, the best way to save its life is to stomach tube the lamb 2 - 4 oz of colostrum. To keep a source of colostrum on hand "steal" some from other ewes (cow colostrum from cows 1st milking is next best). A lamb needs about 6 ounces of colostrum to receive adequate antibody protection. Most good milking ewes will produce four times that amount. Freeze this spare colostrum in ice cube trays or in small plastic bags and thaw out as needed. Warm colostrum gently (usually in a water bath). Do not thaw or heat in a microwave. The antibodies in colostrum are proteins and can be destroyed if cooked.
Problems and any treatment administered should be noted so that the family can be properly cared for while in the lambing barn.
At this point we should be aware of one of the primary deficiencies in newborn lambs -- the lambs thermoregulatory system (internal thermostat) is only partially functional. It does not become completely functional until the lamb is about 3 days old. The lambs body temperature will fluctuate with changes in environmental temperatures.
During the first days of life the lamb will need to nurse at least 3 times a day. If the lamb becomes too chilled to nurse, it will soon die of starvation. The stress of chilling also reduces the lambs resistance to diseases such as scours and pneumonia. Providing shelter for ewes with newborn lambs is intended to minimize losses in lambs due to environmental exposure. The period in the lambing pen is important in forming a strong bond between the ewe and her lambs which will be important in preventing losses due to abandonment in later life.
Lambs and ewes must be watched for signs of problems such as starvation, scours, pneumonia. etc. Early diagnosis is essential to effective treatment. To facilitate early diagnosis, ewes and lambs in the lambing jugs should be observed twice each day. Get all ewes and lambs up. Healthy lambs will usually stretch and try to nurse when chased up. Observe lambs for general appearance and attitude, i.e. droopy ears, hunched up, sunk in sides, etc. If the lamb doesn't look "right" try to determine the source of the problem, i.e. hypothermia, starvation, scours, dehydration, pneumonia, physical injury, ewe with mastitis, ewe not letting lamb nurse, etc.
If all is going well the ewe and her new family should be ready to move to the nursery pens by 12 to 24 hours. If there are no nursery pens available, it is recommended to keep the ewes in the jugs another day or two. Upon leaving the jug the lambs and ewe should be identified with ear tags, paint brands, etc. so that if problems arise after they are turned loose they can be brought back together.
Nursery pens should contain 5 to 7 ewes and their lambs. These families are still usually less than 3 days old and still getting used to each other. Lambs are still extremely susceptible to hypothermia and starvation. Ewes and lambs should be carefully checked at least twice a day. Check the rear end of lambs for scours. If the lamb appears gaunt or hungry check the number and find the ewe. Does the ewe have adequate milk production? Does the ewe have mastitis? Has the ewe disowned the lamb? If problems exist a lamb may need to be bummed or grafted or, in some instances, the young family should be returned to the jugs for a couple days. If all is well the lambs can be moved to the mixing pens after the lambs are about 3 days of age.
After a suitable time in the nursery pens ewes and their lambs can be combined into larger groups. These groups usually consist of about 20 ewes and their lambs. These pens usually contain significantly less shelter than the young family has previously become accustomed to and therefore they should be watched fairly closely for the next couple of days.
By a couple days the new family should be fairly well adjusted to the new environment and well on their way. However, they will still need to nurse several times each day. If they do not receive enough milk they may quickly deplete their body energy reserves and become susceptible to hypothermia. Generally lambs in the mixing pens need be checked daily. Make sure ewes and lambs do not loose each other. Check for bummers or lambs in the wrong pen. Check ewes for mastitis.