Breeding Time
Hampshire ewes will start coming into oestrus in early January and continue cycling every 16 days until May if they are not bred. Breeding activity is greatest during March/April and the larger number of multiple births result from mating at this time. Some ewes are not as restricted in their breeding season and will start coming in oestrus in late October. Ewes born during the spring will come into oestrus at 9 to 12 months of age. Ram lambs are usually fertile at 7 to 9 months of age and could be mated to 15 to 25 ewes. Yearling and older rams can successfully breed 30 to 60 ewes in a season. Rams fitted with a marking harness, have a suitable oil base dye applied to their brisket or in front of their sheaths will indicate breeding activity by leaving a mark on the rump of the ewes in heat. Rams vary in aggressiveness and jump marks should be distinguished from marks made when breeding actually occured. By using a ram marking Procedure at breeding time lambing date (146 – 147 days after breeding), infertility problems and embryo death losses (25 to 40 days after breeding) can be predicted.
Ram and ewes should be healthy and reproductively sound for breeding.
Certain management practices are influenced by season of year. Variations in temperature, forage growth, facilities and market opportunities should be considered before breeding season. Selection for fertile and prolific breeding sheep must be continuous, although some management practices are useful in helping to attain or restrict the maximum genetic potential for lamb production. The following management practices are known to influence lambing rate.
Moving
Temporary sterility can occur in rams four to six weeks after being transported. Exact distance of the haul which results in temporary sterility has not been determined. This condition will usually be corrected without any special treatment in four to six weeks. Ram movement should be scheduled so interruption of the breeding season doesn't occur. Movement of ewes to a strange place just before breeding season will result in a smaller number of lambs being born. This reduction in lambing rate (about 15 to 25%) is often noticed after one breeder takes his ewes to the place where a partnership ram will be for the breeding season.
Shearing
Removal of the fleece 2 weeks before breeding season is beneficial for ewes located in a hot and humid environment. Shear rams every 4 to 6 months to keep them cool. Shearing just prior to breeding is not recommended when the weather is cold or when insects such as flies and mosquitoes are present in sufficient number to continually annoy the sheep. One inch of wool cover seems to be adequate to protect a sheep from cold and certain types of heat stress.
Increasing feed intake, usually grain, 2 weeks before breeding results in more multiple births. Use of protein supplements for flushing does not give the same beneficial results as grain when breeding during hot weather. Shearing can be useful in flushing for fleece removal stimulates appetite. Thus if sufficient pasture is available, fresh shone sheep will consume more, gain weight and produce more multiple births just as if they were flushed with grain. The pastures should not contain clover varieties or lucerne which are known to produce excessive amounts of estrogen. Most emphasis is on flushing ewes, but rams should be on a good feeding program and conditioned before breeding.
Drenching for internal parasites plus Vitamin A just before the breeding season will aid in the flushing process.
Association with Ram
The introduction of a teaser ram into the ewe flock will stimulate the ewes, by his physical presence and odour to come into heat. Some ewes might be on heat at the time the ram is put with them, but most breeding activity will start 11 to 14 days later. This condition occurs most frequently during the January/February breeding season.
Breeding at night
An increase in lambing rate can be realised when the ram is placed with the ewes at night and removed during the day. Rams easily adjust to being removed each morning, fed and returned to the breeding flock at night. This practice enables a ram, especially ram lambs, to be mated to a larger number of ewes during a breeding season.
Lambing Time
Traditionally preparation for lambing becomes serious 4 to 6 weeks before the first ewe is expected to lamb, but it must be remembered that lambing starts at mating. Ewes gaining in body weight at mating ovulate better which result in more twinning.
Maintain ewes after breeding in good health at a nutrition level which does not encourage noticeable body weight increases until 4 to 6 weeks before lambing. During the last third of gestation, body weight increase should reflect fetal growth and not increased fat deposits on the ewe. Excessive nutrient intake during rapid fetal development results in larger lambs, which is associated with more difficulties at birth. Twin lamb disease or ketosis can occur if energy intake in insufficient during the last 4 to 6 weeks of gestation. If a ewe has developed “domsiekte” or “twin pregnancy” a good method of saving her is by using 2 teaspoons full of glycerine every 2 hours for the first day and less thereafter, until she has recovered completely. She must also have access to clean water and appertising food.
Udder development becomes noticeable 4 to 6 weeks before lambing. Ewes carrying multiple fetuses tend to show udder development sooner than ewes with single fetus when breeding dates are similar. Yearling ewes do not usually show udder development as readily as older ewes, and poor-milking ewes are even later developing. Pregnancy can be accurately determined by a skilled operator by use of ultrasonic devices or the specially designed rectal probe. Tagging, removal of wool from around udder, flanks, vulva and dock, should be performed 3 to 4 weeks before lambing on ewes that have excessive wool length (3 – 5cm). Removal of this small amount of wool will enable the operator to watch udder development and the lambs to find the teats for nursing. Heavy ewes should be sorted from the main flock. A roomy, dry shelter is necessary for the heavy ewes and the bedding must not be deep so as to restrict movement of newborn lambs.
Within 24 hours of lambing, most ewes will have milk present in the udder, but should not be milked at this time. A hollowing or dropping below the loin and around dock will occur a few hours before lambing. Ewes seek a remote area in the barn or pasture as their time to lamb approaches. Digging in the bedding with either front leg is indicative of bed preparation for lambing and the ewe is not in labour. Providing the ewe has selected an appropriate place to lamb, she should not be moved, because such action will delay the birth process.
A whitish or clear gelatinous-appearing mucus is expelled from the vulva, which indicates that the cervix is relaxing. At this stage in the birth process, the tip of the nose and front feet of the lamb can be felt. Labour continues and the fetus is passed along the vagina until the toes and nose are visible at the vulva. Once the top of the head pases beyond the vulva the remainder of the birth process is anticlimactic. The ewe gets up and start s cleaning, by licking, the nose and then the remainder of the head. If the ewe is to have twins, interest in the firstborn will cease after the head is clean. Back to labour she goes, and soon another lamb arrives. The first lamb is attempting to stand and nose about for a warm meal. Then the lamb gets properly connected with the milk supply, its tail will shake vigorously.
Abnormal presentations most commonly observed are: one leg back, both legs back, head back and one or both forward, or breech. Often in abnormal presentation ewes stand longer, stretch and twist, with labour being interupted often. A ewe with a breech presentation will often stand, arch her back and straddle her legs as if to eliminate urine. Often a “water-bag” is not presented when the birth position is breech.
Physical examination of the ewe can occur at various stages of the birth process, but following the appearance of the “water-bag” usually results in less stress to the ewe. If you explore with the right hand, the ewe should be resting on the right side, and left if you are left handed. Wash arm in clean water and generously apply a mild soap, either from a bar or a liquid. Quickly determine the abnormality in presentation. Often the head will turn back when an attempt is made to pull legs and head into the birth canal. Normally there is sufficient room to grasp the head and pull it into the birth canal. When assisting birth, a cord (3mm in diameter) measuring a meter in length with small plastic ring attached near the middle of the cord by a single knot or loop of the cord is helpful. One end of the cord is run through the ring and a knot is tied at the end of this portion of cord. The loop now formed can be expanded over the fingers on the hand you are exploring the uterus with. A similar but more rigidly constructed lamb puller is available from sheep supple houses.
Do not panic; carefully work the cord over the ear, using your index finger mostly, then the other ear. Finally get the cord below the lower jaw and hold down on the cord while pulling on the knotted end of the cord until the plastic ring passes under the chin. The head is safely secured, the other cord (2m length) is fixed with a small slip loop on each end. With the head resting in the uterus, gently pull one leg forward, place the slip loop above the ankle on the underside of the leg and place a half on the pastern joint. Push this leg back and pull the other forward and affix the leg as described previously. Both legs can be pushed back into the uterus. Gently pull the head into the birth canal and when it pops into place, start bringing one leg forward. With the cord on the underside, the foot is lifted upward and forward. After both legs are in the birth canal, gently pull on the cords and work the lamb out. After you commit the delivery of the lamb, complete the process as quickly as possible. Twins must be sorted so the head and legs on the same lamb are worked with. Once the lamb becomes detained or lodged in the birth canal, the head and tongue begin to swell. With such swelling it often becomes impossible to push the head back into the vagina.
Feel around the lamb to determine if one or both legs are back, and if there is room to manoeuvre the legs into position. There may be room for the lamb to be delivered by just pulling. As a last resort to save the ewe, it may become necessary to remove the lamb's head and then correct the other posture problem. Extreme caution should be exercised when pulling a lamb with one leg back, for it is very possible that the ribs will be broken. If the toes point downward, the presentation is breech and seldom is there sufficient room to turn the lamb around. If just a tail is present, the hocks of the lamb are against the ewe's pelvis and no progress can be made. Pressure exerted by the ewe just forces more fluid into the lungs. Broken ribs are possible when delivery is breech and assistance must be with care.
Assist the new lamb by cleaning the mucus from around the nose and face with a piece of cloth. Position the lambs so the ewe can lick and become acquainted with her offspring. Ewes should stand soon after lambing and assistance might be necessary if delivery was difficult. After gaining strength, the ewe and lambs could be moved to a lambing pen (1.5m X 1.5m) or claiming area where other ewes and young lambs are present.
Place your hands under the lambs chest and raise it about one foot above the ground. Walk in front of the ewe, allowing her to see, smell, lick and bleat for her lambs. Do not hold the lamb high of out of sight, for the ewe will not usually follow. An initiation lamb bleat might stimulate the ewe to follow more closely. Should the ewe turn as if she wishes to return to where the lamb was born, quickly but carefully place the lamb on the ground and step several paces away from them. Once in the lambing pen, dip the lambs navel in a disinfectant (7% iodine or a similar tissue-drying ointment). Check the udder for any firm or hard spots and carefully milk out the teat plug. Treat the ewe with a recommended antibiotic if you placed your hand in her reproductive tract. Never grab the newborn lamb immediately behind the ears, for he will pull back vigorously. Hold under the chest with one hand and guide the mouth towards the teat. It may be necessary to lay the lamb down, hold is mouth near the teat and squirt some colostrum on the tongue. The strong lamb is then usually more willing to seek out the source of food. Once the lamb stands and finds the milk, he is on his way.
While assisting the lamb with his first meal the ewe may wish to keep the lamb at her head. Use a small cord or your belt to secure the ewe's head to the fence and let the lamb nurse, turn her around and let the other lamb nurse. At first, lambs tend to select a side and not nurse the other half.
Enlarge teats, low slung udders and the presence of non-functional nipples create special problems. Hopefully the lambs are very active and hungry when their mother has enlarged teats. At first, milk the colostrum into a warm bottle equipped with a lamb nipple (enlarge the opening) and feed the lamb and then get him to nurse the teat. In all three cases the lambs must be encouraged to look lower for food than is customary. You can hear the hungry, unceasing bleats of lambs before entering the barn. Their cry is similar to that of a lamb lost from his mother. While the lamb is standing, place your hand under the stomach and gently lift upward. For a few days newborn well-fed lambs are lazy. When disturbed from their warm resting spot, the healthy lamb will arch his back and stretch. The sick lamb will stand hunched up. Watch for symptoms of pneumonia, thumping when breathing, head down and listless, in young lambs. Young lambs consuming large quantities of milk may appear to have an exotic disease. Seeming they are unable to stand on their front legs with most of the weight on the rear legs. Any movements are to the rear, with the front legs being dragged back.
A tablespoon or two of mineral oil or other laxative will stimulate movement of fecal material. Lambs can show none of these symptoms by accumulate large quantities of fecal material around the tail. This is called pinning and requires extra labour to correct situation.
In emergencies, frozen cow's colostrum and milk from a ewe that recently lambed is beneficial in getting the newborn lamb started, and a supply of synthetic ewe's milk is useful in raising orphans or assisting lambs on short rations.
If chilled, the lamb can be placed in a bucket of water, making sure the head does not go under water. After removing from the water, rub the lamb dry and place him under a heat lamp. Make sure the lamp is not in a position to start a fire or burn the wool on the ewe. Use heat lamps sparingly.
Fostering lambs can be completed successfully by confining the ewe's head in a stanchion-type structure. The slotted arrangement is placed across one corner of a lambing pen. Lambs can move freely about the head of the ewe, allowing both to get acquainted. Seldom more than 4 – 5 days are required to graft a lamb on another ewe. Grafting can occur shortly after birth, provided the ewe has not smelled her lamb.