TABLE OF CONTENTS Assisting the Ewe at Lambing Automatic Lamb Feeder Lambing Checklist Grober - Lamb Survival Prevention of Neonatal Diarrhea in Lambs Reproductive Management Systems Care of Newborn Lambs Hypothermia in Newborn Lambs Shepard's Calendar of Events Sample Lamb Mortality Record Castration and Tail Docking of Lambs Weaning Lambs Early Weaning of Lambs Timeline for a Ewe and Her Lambs
Working with an Automatic Lamb Feeder By Courtney Denard Investment in technological innovation is one means for sheep producers to help ensure the long-term sustainability of their business and contribute to the longevity of the industry. It isnâ€™t necessarily the technology itself, but rather the impact it can have on managing labour, time and financial resources as well as increasing production volume and efficiency. The Automatic Lamb Feeder is one such innovation that is making a difference for some Canadian shepherds. Producers place milk powder into the machine where it is mixed with warm water and heated to 40ËšC before it is released to hungry lambs. The machine is equipped with six nipples that provide fresh warm milk for up to 120 lambs 24/7 and can be assembled in any sheep barn in about 20 minutes. Developed 15 years ago by Foerster Technik, a German-based company, this easy-to-use technology is widely distributed in Canada by Grober Nutrition Inc., retailing at $4,995.00 plus GST. In an industry where labour is hard to come by and even harder to keep, getting all the necessary work done can be difficult on the best of days. For sheep producers, this is especially true during lambing. Multiple births, which happen more often than not, can lead to hours and hours of bottle or pail feeding lambs which were either orphaned by their mother, or are not pushy enough to get to the front of the line. The reality is the average producer is crunched for time, so two to three bottle feedings per day is about the norm. Unfortunately, this may not be enough to keep mortality rates down, or to produce consistent quality lambs. The Automatic Lamb Feeder is a production tool that can help sheep producers who are struggling with high lamb orphan rates. The benefits of this machine are plenty, making the cost of almost $5,000.00 a little bit easier to swallow. For example: Producers who have adopted the Automatic Lamb Feeder indicate their lamb mortality rates have dropped. Scours and bloat are also reduced as lambs can drink from the machine when they feel like it, instead of gorging themselves during the typical routine of two to three feedings per day. Training lambs is easier to do because of the constant supply of warm milk. Daily gains are increased as lambs can drink multiple times per day, therefore absorbing the milk in their stomachs at a slower rate. Reliance on labour becomes a non-issue as lambs can drink from the machine as often as they choose whether the producer is in our out of the barn. As well, managing the machine takes approximately one hour per day â€“ a big difference from the average five to six hours (or more) that can be spent bottle or pail feeding. The machine is built with an internal pressure tube that sends out a signal when more milk is needed to be made.
Jan Ziemerink, Automation Services Manager at Grober Nutrition Inc., has worked with the Automatic Lamb Feeder since the early 1990s. Grober recognized the value of this machine as a production tool and was instrumental in the development and launch of the machine in Canada. Over the past 17 years, Ziemerink has seen the lamb feeder do some great things on sheep farms across Canada, but as is with any technology, he has also seen the challenges. Ziemerink says that the biggest challenge goes back to proper management, which is essential to ensure producers get the longest life span out of the feeder as possible. But maintaining the technology is not onerous. “The machine has to be kept clean and drained when it is not in use, and must never be allowed to freeze during the winter months,” he says. Bill McCutcheon, an Ontario sheep producer who has owned an Automatic Lamb Feeder since 1994, agrees, but goes one step further in saying, “You also have to have rodent control. Do not keep the lines on the floor because mice will certainly chew on them.” McCutcheon faced another challenge in learning the proper way to wean the lambs. “The first time we weaned we just let the powder run out,” he says. “But the sheep just drank all the water and urinated all over the pens.” Now, McCutcheon has set up a system where weaning lambs drink the milk from long hoses, making it harder for them to consume. The sheep get tired and turn to feed instead. According to Ziemerink, one of the key success factors when adopting the Automatic Lamb Feeder is to do your homework first. “Do your research beforehand and make sure you have the right facility. The right pen set-up is important to the success of the machine,” says Ziemerink. For McCutcheon, he says that it really was a “learn as you go” type situation, however, Grober offers 24-hour technical support as well as information and videos on the website that were helpful. Through Grober’s experience with the Automatic Lamb Feeder, Ziemerink has come to see how helpful and open producers are in the Canadian sheep industry. Ziemerink says some of the best suggestions he gets about the machine are from the producers already using the technology. Traveling to farms all across Canada, as well as exhibiting at farm shows, Grober has had the opportunity to talk to many sheep producers about their experiences. “Nobody is afraid to help each other out,” Ziemerink says. “At the end of the day everyone wants to make a better product so you get a better market price.” McCutcheon’s ultimate learning experience was recognizing just how much time can be saved using the machine. “For us, the biggest thing was labour,” he says. “With this machine, you do not have to mix milk and when you have up to 65 lambs born at once, it saves a tonne of time that we can devote to other tasks on the farm – in the end making a better and more sustainable operation.” For more information on Grober or the Automatic Lamb Feeder visit Grober's website at www.grobernutrition.com or call 1-800-265-7863 x: 210.
Lambing Checklist ; In the lambing box: these items are easily accessed when going from pen to pen if they are put in an open utility tool tote that fits over a gate. Injectable Vitamin A & D, E-Sel - if needed in your area
Needles & syringes of varying sizes Notebook & pencil to keep track of mother & lamb ID numbers & other important info
Alcohol mixed with a little food colouring kept in small squeeze bottle. Use on injection sites, ear tagging or lamb navels. The colour shows you where the alcohol site is.
Elastrator rings & pliers for tail docking & castrating - to be done in the first week of life. Ear tags & pliers for your on farm ID Spray or crayon marker for quick ID of animals that need (closely) watching.
Iodine - kept in a small squeeze bottle for lamb navels.
; Lambing supplies to have on hand Lamb Kick Start -
energy boost for slow, chilled
Hair dryer & box (for warming chilled lambs) or heat lamp
Colostrum feeding tube and large syringe Scour solution Powdered Colostrum Powdered milk replacer Lamb Woolovers Lamb sling, if you’ve ever carried a cold wet
newborn lamb to its pen, you probably will want to use one of these forever after.
Prolapse retainers & harness & a big bag of white sugar - the sugar will take the swelling out of the prolapse
Nipples and bottles Towels, olds ones for drying off lambs Gloves, sleeve length and short OB gloves Lamb Pullers Lubricant
Injectable antibiotics - some work better for different infections - ask your vet
Ear tags and Pliers - you must have the new CCIA tags for when you ship animals, you may also want a different tag for on farm ID.
; Lambing supplies to consider having on hand, they might come in handy. Hand shears for trimming wooly udders Vaccinations Sheep halter or soft rope for tying up the
Scissors Adoption musk Shepherds crook, great for catching flighty
ewe that you’re going to work on Gambriel Restrainer - will keep an ewe still while you do necessary work on her.
mothers Knife - get a brightly coloured handle for when it falls in the hay (and it will) Hoof nippers (while the mothers are in the pens you might want to pare her feet)
Injectable Dextrose for hypothermic lambs
Small side cutting pliers and file. Every year we get lambs that are rejected because of sharp teeth. A simple snip of the side teeth and file down of the front teeth will usually stop the rejection, if it is not too late. Sheep raising information, books or video’s such as ‘Storeys Guide to Raising Sheep’ book or ‘Lambing Time’ video.
GOAL: To increase the number of lambs marketed by reducing newborn lamb deaths. 1. BE PREPARED. Know the lambing due date. Record all contacts between rams and ewes – accidental and planned! Use gestation table to calculate probable lambing date called Gesta Calc, available at the Canadian Co-operative Wool Growers 1-866-488-2714, E-mail: firstname.lastname@example.org. 2. Have all of your lambing supplies on hand at least a week before the first lambs are supposed to arrive. Have an “obstetrical/delivery” bucket ready. 3. Have enough feed to supply all of your ewes through the last six weeks of pregnancy and through lactation. Have feed on hand for lamb creeps. Decide on growing and finishing rations. Changing feeds can cause production losses and health problems particularly during critical production periods (lactation, weaning, lamb grower / finisher). For information on sheep nutrition, contact the AgInfo Centre in your area. 4. Have enough claiming pens / maternity pens / small group hardening pens ready for the number of ewes you have to lamb. Set up pens and panels ahead of time. 5. WATCH YOUR EWES. Weather conditions usually determine how closely a mature ewe flock must be monitored. Ewe lambs give you less warning. It doesn’t take bitterly cold weather for wet, newborn lambs to die of hypothermia. 6. Have frozen ewe/cow colostrum on hand. Warm to body temperature in warm water – not in the microwave! Use a stomach tube on a 60cc syringe, or a “Lamb Reviver” to feed weak lambs. Have a bottle and baby lamb nipples ready for supplementing strong lambs that suck well (i.e. triplets). 7. Have barnsheets ready to record all births. If you don’t have a lambing record system, or ewe production cards from the CCWG at 1-866-488-2714, E-mail: email@example.com. 8. Tag all lambs for permanent identification. You will need Canadian Sheep Identification Program tags to ship lambs to market or move ewes from the farm. Contact the Canadian Co-operative Wool Growers Limited for information and tags. For easy management use flock tags that are easily readable and/or temporary paint brands to identify ewes and lambs belonging to each other, to colour code different groups, or to identify the corral the ewe and lambs belong in. 9. Dock all lambs at 24 to 48 hours of age. Allow lambs to nurse unhindered for the first 24 hours so as to get as much colostrum as possible. Docking procedures should be as stress-free as possible. 10. Consider castrating all ram lambs not being considered for breeding purposes, particularly those born in spring and summer. 11. Watch ewes and lambs closely – cull for mismothering. Select daughters from troublefree moms. 12. Be sure to write down all animal treatments with withdrawal period and all problem sheep! Decide who is doing the work – you or your ewes.
LAMB SURVIVAL Profitability in sheep farming is largely dependant on the number of lambs weaned per ewe each year. Typically, the lambs weaned for each ewe exposed to a ram should be at least 2 or more. Lamb survival is a result of good ewe management before and during lambing and attention to early care of lambs.
Preparation tips for successful lambing and weaning Lambing date Knowledge of lambing dates is important to ensure that ewes are managed appropriately to ensure successful lambing. Preparation of buildings and an emergency ‘nursery’ will help with the survival of small, weaker lambs and for the optimal growth of lambs from multiple births. Ewe nutrition The fittest lambs are born to ewes that have been maintained correctly from pre-mating to lambing. Weight gain usually occurs in the premating phase and is then followed by a constant weight maintenance (condition score 2.5-3) between days 50-90 of pregnancy. Ewes that are in prime condition at mating maximize egg production, show increased conception rate and egg survival. It is not desirable to have ewes on a high level of nutrition post mating as the higher rate of metabolism removes progesterone from the blood stream more quickly. Progesterone is essential for embryo survival and development. Sudden changes in diet in the first 3 weeks after mating can also affect embryo survival. Under feeding may increase the likelihood of more single births rather than multiple births. Inadequate feeding during mid pregnancy results in small birth weight lambs. Nutrition needs increase significantly in the last 4-6 weeks of pregnancy. It is important to support rapid fetal growth (70% of growth occurs in last 6 weeks) and udder development for colostrum and milk production. If the high demands are not met, pregnancy toxemia/twin lamb disease can result. Body condition score at lambing should be 3-3.5. Ewes that are fat are prone to vaginal prolapse. These factors should be considered for the next lamb crop along with light (photoperiod) management. Ewe management at lambing Lambing pens with clean, dry bedding (for each ewe) should always be available. Pens should be about 1.5m square with a corner divided off to give the lamb a safe area. Each ewe can expect to spend 1-2 days in this pen. A ‘normal’ delivery takes about 5 hours from dilation of the cervix (4 hours) and delivery (1 hour). Once the lamb is born, ensure that it starts breathing. Clean mucus away from the nose and mouth. The lamb should be encouraged to nurse as soon as possible to maximize absorption of Immunoglobulins (Ig’s) from colostrum. Weak lambs may need to be tube fed. If colostrum quantity or quality is an issue, a supplement should be considered. Observe lambs carefully to ensure they are feeding correctly, regularly and do not become chilled. This is especially important for multiple births. Management of multiple birth and orphan lambs The greatest proportion of lamb deaths is caused by a combination of chilling (hypothermia) and starvation. It can account for the death of about 30% of lambs born alive and occurs within the first 3 weeks of life. Lambs with the greatest risk of becoming hypothermic include: small and premature lambs, lambs which are weak and limp at birth, lambs from ewes in poor condition, lambs from very old or very young ewes, lambs born into a cold, wet, windy environment, twins and especially triplets The newborn lamb’s ability to produce heat is proportional to its bodyweight. Heat loss is influenced by several external factors: Body surface area: body weight ratio - a small lamb has a larger surface area in proportion to its weight and therefore will chill faster than a larger lamb. Insulation from the coat - breed differences and dryness of coat Heat loss (kcalm-1h-1) always decreases when the temperature (°C) increases irregardless of the weather conditions. This chart shows the effect of wind, environmental temperature and wetness on heat loss in newborn lambs. [From Alexander, G. (1962), Australian Journal of Agricultural Research, 13, 82-99.]
LAMB SURVIVAL Energy (fat) reserves in lambs are only 3% of BW compared to 10-15% in adults. Lambs require adequate colostrum and brown fat (type of fat born with) to help maintain body heat. A lambs brown fat reserves will be used within 3 days after birth. Starvation/ Hypothermia Risk Action Ensure lamb is provided a warm, dry, wind free environment Chilling reduces the suckling drive Select breed or cross suitable for conditions and type of operation. Low milk intake increases the lamb’s Ensure lamb is suckling and ewe is providing sufficient milk susceptibility to cold Insufficient feed/ energy intake reduces ability to generate heat
Ensure lamb is provided with and consumes adequate good quality colostrum Provide a high quality milk replacer ‘Lamb-Gro’ if lamb is orphaned or not getting sufficient milk from ewe, e.g. multiple birth lambs.
Colostrum What does it provide the newborn lamb? Nutrients (high fat%) to provide heat production and help prevent hypothermia Immunoglobulins (Ig’s) to help prevent infection. Some line the gut wall and the rest are absorbed into the bloodstream, as long as provided within the first 24 hours following birth. The most efficient IgG absorption period is in the first few hours after birth. Growth factors to promote gut growth and differentiation especially during the first 24-48 hours after birth.
How much does a lamb need? 50ml/kg body weight right at birth and every 6 hours for the first 24 hours. E.g. 4kg lamb receives 800ml (31/3 cups) The amount should be increased by 20-30% for lambs exposed to undesirable weather, this is equal to one extra feeding. Colostrum yield from ewes can be variable and low especially if the ewe has been underfed or is in poor conditions. It is ideal to use colostrum from the mother. If not possible, then use pooled ewe colostrum from same flock, then pooled ewe colostrum from another flock (same disease status), then cow colostrum (30% more via one extra feed), then artificial colostrum.
Why is colostrum so important? The Ig’s in colostrum provide a passive protection of the newborn lamb until its own immune system is functioning. The newborn lamb does not have any antibodies at birth as they do not cross the placenta from the ewe’s bloodstream. Some primary disease causing agents of lambs include Ecolab, Rotavirus and Cryptosporidia. The newborn gut does not have the acidity or ability to help destroy these harmful bacteria. Viral agents can cause severe damage to the small intestine of young ruminants that will adversely affect their future performance. Vaccinating ewes for diseases at 5 weeks (ewe lambs) and/or 3 weeks (mature ewes) prior to lambing enables antibodies against these specific common diseases to be produced and passed to the lamb via the ewe’s colostrums, (e.g. E.coli, Tetanus, Clostridia gp). Excess colostrum can be collected from high yielding ewes and frozen for up to one year and used at a later date. Choosing lambs for artificial rearing Prolific ewes produce more lambs than their milk production can sustain, at adequate growth rates. Extra lambs are best removed entirely from the dam. It is best to remove the lamb most different in size and then gender. Lambs should be grouped according to size and then gender. Lambs should only be moved to a new group once they have achieved a target weight. This ensures that weaker, smaller lambs are provided the extra attention and smaller group size until strong enough to compete. Methods of feeding milk replacer There are many techniques for feeding milk replacer to orphan or multiple birth lambs. The choice of system depends on the number of lambs’ to be reared, individual preference, buildings etc. Lambs should ideally be raised in a room at 15-18oC. High sanitation is critical for all systems. Correct disinfection of mixing and feeding equipment will help prevent the proliferation of bloat and scour causing organisms. It is important to follow the manufacturer instructions for mixing and also feeding rate according to average size of lamb fed. Limit feeding (set amount of milk 3-4 times a day): ideal for small numbers of lambs. Milk is fed via a nipple on a bottle or nipple pail (one nipple per lamb). It is labour intensive but can allow a reduced cost of the milk feeding period with an easier transition to solid feed and easier weaning. Milk should be fed at 38-40°C (body temperature).
LAMB SURVIVAL Free choice feeding (warm or cool (4oC) but not excessively cold): Typical systems include, nipple pail units, teat bars and commercial automatic feeders (e.g. Forster). Lambs have access to milk at all times and are group fed. The milk supply must not be allowed to run out as lambs will easily over feed with new milk. Milk fed at 4oC will be consumed in smaller amounts more often. This reduces digestive upsets from overeating. In warm/hot weather, milk can be kept cold by floating a clean plastic (pop) bottle filled with frozen water in the milk replacer. Each nipple can accommodate 5-6 lambs and must be 40-45cm (16-18ins) above the stall floor. Lambs may require assistance in adapting to nipples for 1-2 days. Free choice feeding can minimize labour but disease transfer may be higher. Lambs can easily chew nipples which can result in milk replacer loss from the container. Free choice feeding results in higher feed intakes. Which encourage greater gains and therefore allows for an earlier weaning period. Commercial automatic feeders can feed 50-150 lambs per unit and so are ideal for dairy sheep operations or prolific breeds on accelerated systems. After about 10 days, larger groups can be formed and 10-25 lambs can feed off one nipple. Consult machine supplier for advice. Feeding lambs in cold conditions Ensure lamb feeding equipment is protected from extreme environmental conditions to prevent large temperature variation and freezing of milk in pipes and container. Provide lambs adequate milk to maintain positive energy balance and growth performance. Cold conditions can be a result of, or combination of, reduced air temperatures, higher humidity, wet bedding etc. When lambs reach negative energy balance, immune status can be easily compromised and the lambs become more susceptible to disease. Milk sheep Feeding a quality milk replacer to lambs from milking ewes can increase marketable milk and also may improve total milk lactation production. The regular full draw on the ewe maintains a maximal milk synthesis. If lambs are left on the ewe and do not take a full milking, then milk production declines and will not recover once lamb is removed. Weaning Lambs are usually weaned from 21-45 days of age (average 30days) and 12kg bodyweight. Lambs should be consuming a minimum of 120-150g of creep ration per day for more than 2 consecutive days and have consumed a minimum of 8-10kg of milk replacer. Typical disease pathogens for lambs: • Watery mouth – infection with E.coli precipitated by chilling, stress and/or lack of colostrum intake. This typically occurs during the first few days of life and up to six weeks of age. Young lambs salivate and become distressed with a distended abdomen. The lambs can also scour which can lead to dehydration and even death. This condition can last in lambs for up to 10 days. • Scours – inflammation of intestine from infectious disease pathogens such as E.coli, Cryptosporidia, Rotavirus and lamb dysentery (clostridia). • Pneumonia -dust, ammonia buildup, extreme weather changes (especially in humidity levels), etc. can encourage pneumonia. Pneumonia is often fatal or resulting lung damage will affect future health and productivity. • Internal Parasites- one of the biggest health problems in grazing lambs. Checklist: 1. As soon as lamb is born ensure adequate colostrum intake by suckling, bottle or stomach tube 2. Identify premature, underweight, starving, cull ewe lambs and ensure adequate milk intake and warmth. 3. Ensure good sanitation practices; maintaining barns with good ventilation, dry, no drafts, and strict cleaning of lambing premises. 4. Group lambs according to age and body weight and supply sufficient nipples. (e.g. 5-6 lambs /nipple at start and increase to 10-25 lambs/nipple dependant on machine and space etc) 5. Monitor lambs closely and regularly for signs of ill health or starvation. Treat as soon as possible. 6. Early rumen development will be accomplished by supplying a highly palatable and nutritious creep feed as soon as possible. Offer hay and clean, fresh water at all times. Grober milk replacers are manufactured to the highest standards. Grober research and on-farm testing ensures the best nutritional products available for lamb growth and development. Grober Lamb-Gro and good management provide a strong foundation for growth and production of lambs. . Kathleen Shore. MSc. (Nutritionist, Grober Nutrition) and Sally Charlton, BSc
Prevention of Neonatal Diarrhea in Lambs Written By: Allyson MacDonald, DVM MacDonald Mobile Veterinary Service (Ontario Sheep News, March 2010) This is the first of a series of articles being written for Ontario Sheep News Magazine by the Small Ruminant Veterinarians of Ontario (SRVO). It is our hope to share with the sheep industry relevant and useful information to improve your profitability. As lambing season approaches I have chosen lamb diarrhea as our opening topic. The goal of every sheep operation is to maximize the number of kilograms of meat per ewe. One way to ensure this is making sure every lamb that hits the ground has the maximum chance to grow to market weight. In a 1987 article in the Canadian Journal of Veterinary Research entitled Factors Associated with Productivity in Canadian Sheep Farms, Drs Dore, Meek and Dohoo concluded; “Prevention of scours and starvation in lambs should be given priority in order to increase productivity.” Unfortunately the list of organisms which can cause diarrhea in lambs and are prevalent in Ontario is long. It includes, but is not limited to, enterotoxigenic E. coli, Cryptosporidium parvum, Salmonella, Rotavirus, Clostridium perfringens (enterotoxemia), Coccidiosis and Giardia. Fortunately the prevention of all of these pathogens comes down to the same basic husbandry practices. COLOSTRUM The single most important factor in prevention of diarrhea is the consumption of an appropriate volume of good quality colostrum. Each lamb should consume at least 15% of its body weight in colostrum in the first 12 hours of life. In a management situation where lambs are nursing you may think there is little you can do to facilitate this but in fact many decisions you make can ensure this happens. The freshening ewe should be moved to a small individual lambing area so that the lambs are never geographically far from the milk bar. The area should be warm enough that lambs are comfortable, up and about and wandering, not huddled in a corner for warmth. An individual pen situation ensures the lamb doesn’t get discouraged from nursing by being refused by the wrong mother before bonding has occurred. No ewe has enough milk to give proper colostrum to triplets or quads. It can be time well spent to keep a colostrum bank. This involves freezing colostrum from mature ewes that only had a single lamb and can afford to spare some. It can be stored in 50 – 100 ml aliquots in Ziploc bags or in ice cube trays and fed to the weakest of the lambs. If milking sheep is not something you want to do, you can obtain cow or goat colostrum from a neighbouring farm but you need to do this on consultation with your veterinarian to ensure you do not import any disease problems. If you are unsure how well your lambs are obtaining colostrum there are inexpensive blood tests your veterinarian can run on a couple of randomly chosen lambs to see if failure to receive colostrum is an issue on your farm. To ensure the ewe has a healthy amount of good quality colostrum she needs to be in good health herself. Optimum nutrition before lambing is the key. When the ewe is moved to the lambing area be sure to wipe the udder down with a good quality disinfectant and then dry it. If the teat is dirty and the lamb nurses, the pathogens enter the gut before the colostrum and
infections become established. Which antibodies are present in the colostrum can be affected by vaccination of the ewe. You should discuss with your veterinarian which vaccines would be the most appropriate for your farm. Clostridium perfringens is widespread in Ontario and this vaccine is commonly recommended. The vaccine will only be effective if a proper vaccine protocol for your farm is established. THE FIRST 48 HOURS The lamb requires a warm clean area to spend the first few days of its life. The levels of clinical diarrhea are highest in accelerated lambing programs. Although these programs make sense from a management point of view they also put extreme pressure on the lambing area. Be sure to plan for sufficient space for the lambs and ewe to have a couple of days to bond and to improve the lamb’s resistance to disease. These pens should be cleaned out and disinfected between uses. If space allows it, it is ideal to be able to leave a pen empty and dry for 24 hours between residents to eliminate pathogens. The type of disinfectant you need may vary from farm to farm based on your previous pathogen history, but formalin, Virkon or a quaternary ammonia product might be recommended. Lime is effective against some, but not all, organisms. Cryptosporidia is one of the leading causes of lamb diarrhea and is not killed by lime. Common but essential husbandry practices include dipping the navel with an iodine disinfectant, at least 2% but can go up to 7%. An empty film canister works for dipping (if you can still find one). Be sure the dip container is stored in a cool dark place and thoroughly clean at regular intervals so it does not become a source of infection. Also inject each lamb with vitamin E / selenium. Be sure to accurately weigh and dose animals with these products. Over dosing is common and the toxic effects can be more fatal than not dosing at all. STRESS This is an often thrown around term in management circles. Almost every article you read states the animal should have a stress free environment, why? When an animal is under stress their body releases cortisol, a hormone inside the body that has a variety of effects. In this discussion the most important effect is the suppression of the immune system. We need the immune system of both the ewe and the lamb to be at a maximum. Healthy ewes don’t get mastitis, which results in poor nutrition to the lambs, and they don’t get pneumonia, which results in the ewes spreading organisms to the lambs. Healthy lambs run around more, nurse more often and start eating earlier. Stress can take one of two forms, physical and mental. The most obvious physical stresses include; overcrowding, damp bedding and poor ventilation. To evaluate these factors you need to get down to sheep level. The environment at 6 feet may not reflect that at 2 feet where the sheep are breathing. While down on your knees breathing, see if you can feel dampness seeping through your pant leg. It may look dry but if moisture is seeping through, the animals are sleeping in a wet environment. Mental stress may be harder to evaluate but just as important. Sit back and watch the herd. On paper there may be enough bunk space but if it is all in one area the dominant sheep may not allow submissive sheep to eat until they have eaten all the best feeds. If there is only one water bowl submissive sheep may only seldom get to drink and you can’t produce milk if you are thirsty. Sheep hate changes in routine and loud noises. If your weekend help comes in and turns on loud rock music and handles animals differently than you do this will really upset the flock.
IN THE FACE OF A DIARRHEA OUTBREAK Sometimes, in spite of our best efforts at prevention, we will get cases of diarrhea. It is a problem if cases of diarrhea exceed 2% of the lambs. The single most important factor in stopping an outbreak of diarrhea is to establish the cause. Your veterinarian can be very helpful in getting a diagnosis. You may choose to have a farm visit or talk to your veterinarian about what type of samples they need to establish a diagnosis. Some tests can be done on feces right in the clinic while other must be done at an outside laboratory. The Animal Health Laboratory in Guelph processes food animal cases at a discounted rate and a proper diagnosis early on can prevent a lot of wasted time and medication treating the wrong disease. While waiting for a diagnosis there are a few simple steps that can be taken no matter what the cause. Immediately move your lambing area. Infectious organisms build up in the environment. Use gates or temporary walls but start in a fresh area. Keep affected lambs hydrated. Keep them with their mothers so they will nurse but supplement them with an oral electrolyte solution at a level of 10% of their body weight over 24 hours. This would mean that a 6.5 pound (3 kg) lamb wound require 150 ml of electrolytes twice per day. Lambs are very susceptible to low blood sugar so with small ruminants we always suggest a high-energy electrolyte source. This is usually mixed up 2 litres at a time. Be sure to keep the remaining solution in the fridge so that organisms don’t start to grow in it, we don’t want it to become a source of further problems. Warm just the amount you need to feed at each meal. If you are supplementing fluids you must be very vigilant that all equipment for mixing and feeding is well sterilized. If an animal is weakened fighting one organism you don’t want to introduce another. Once you have established a diagnosis you and your veterinarian can come up with an organized and effective treatment protocol. I hope this article has been helpful to you. Good luck with the upcoming arrivals.
Allyson MacDonald Bibliography Allyson graduated from the Ontario Veterinary College in 1988. Entering mixed practice with a speciality in dairy medicine, she gradually took on more small ruminant work. Over the last decade her specialty has been sheep and goat dairy medicine. Her primary concern is to maximize response to treatment based on a proper diagnosis and species appropriate therapy.
Reproductive Management Systems Adapted from ‘Evaluating Farm Resources and Sheep Production Systems’ By Bill McCutcheon, Former OMAFRA Sheep Specialist The type of reproductive management system you choose should compliment your farm resources (land base, facilities, labour etc). The table below gives a brief outline of the advantages and disadvantages for the most common types of management systems. Once per year Lambing: System Potential Advantages Grass • Lower feed costs: Peak nutritional needs Lambing during lactation and lamb growth are met by (April-May) grazing • Lower lamb mortality: Warmer weather during lambing and outdoor housing means fewer lambs lost to hypothermia and illnesses such as pneumonia • More ewes/person: Management is relatively simple during the year and less labour is required at lambing • Reduced housing: A warm barn for lambing is not needed • Less reproductive management: Breeding occurs in the late fall when sheep are naturally most fertile. Breeding at other times of the year will restrict you to specific breeds of sheep and/or intensive management of the reproductive cycle. Winter • Improved market potential: Lambing at Lambing this time of the year will allow producers to (Jan-Feb) take advantage of the large Easter market for new crop lambs and market larger lambs before the large lamb supplies in fall. • Lower worm loads: Control of feeding sites should reduce the level of worm infestation, improving nutritional efficiency and lamb growth, while decreasing de-worming costs. • Moderate reproductive management: For winter lambing, ewes must be bred in the late summer or early fall. A number of breeds with long reproductive seasons will naturally begin cycling by this time of the year.
• • •
Potential Disadvantages Deworming costs increase: Anytime manure is in close contact with feed (i.e. feeding on the ground and grazing) there is an increased likelihood of worm infestation. Worms must be controlled, particularly in young animals, as heavy infestations will rapidly decrease profitability. Decrease in selling price: As this is the least labour intensive type of production system, the majority of producers in Ontario lamb at this time of the year. Therefore there is a large increase in number of lambs marketed in the late summer and fall. As economic laws dictate, price generally decreases when supply increases.
High lamb mortality: Even with good management and facilities, death losses can be as high as 15% of the lamb crop. Increased housing costs: A snug barn is essential. Higher feed costs: Ewes must be fed highenergy rations to maintain lactation and lambs not sold for Easter must be fed for growth (not on pasture). More health problems: Even with excellent management, disease losses in animals housed indoors are generally heavier, as the close contact between animals facilitates the spread of diseases. If ventilation, sanitation, and stocking levels are substandard, very high losses may occur. Fewer ewes per person: Management and labour are higher relative to spring lambing (feeding, keeping animals clean, and closely monitoring lambing).
Multiple lambings per year System Potential Advantages Accelerated • Year round supply of lambs: There is great Lambing potential to supply lamb during the winter (individual ewes months and for the Christmas and Easter lamb 3 times markets. every two years • Price stability: With an increase in the OR five times in number of marketing dates and the potential 3 years-Cornell to supply diverse markets, there is less risk ‘Star’ Program) of being dramatically affected by price fluctuations. • Lower lamb mortality: With two warm weather lambing seasons and one cold weather season, overall lamb mortality is decreased relative to once/year winter lambing • More lambs marketed/ ewe/year: Greater returns are possible per ewe. • Reduced lambing space: Relative to once/year winter lambing, less barn space is needed as 1/3 to 1/2 of the flock is lambing at a given time.
Potential Disadvantages Intensive management: Year round lambing requires year-round attention to management. Higher feed cost/ewe/year: Although more lambs are produced per ewe, the cost of keeping the ewes productive is also greater. Ewes must be fed at a high level of nutrition for longer periods of the year, and cannot be allowed to lose condition between lambings. Housing costs: Although only a percentage of the flock will be lambing at a given time, there still must be insulated barn space for winter lambing. Ewe longevity and health: There may be more udder and health problems with ewes on accelerated lambing programs.
Hypothermia in Newborn Lambs Dr. S. John Martin Introduction Many newborn lambs die, not from disease, but from hypothermia (chilling). This is especially true in Ontario, where many ewes produce in the coldest months of the year to have lambs ready for the Easter market. Even a newborn lamb at grass in May can be vulnerable (Figure 1). By careful shepherding of the ewe from conception to delivery, and the perinatal care of the new born lamb, many deaths can be avoided.
To maintain its body temperature, the newborn lamb must produce as much heat as it is losing to the environment. If the lamb cannot do this, its body temperature will start to fall, and, if not remedied, lead to death. The rate of heat loss is influenced by several external factors.
Figure 1: Bales used to form a windbreak for lambs
1. Body surface area:body weight ratio. A small lamb has a larger surface area in proportion to its weight (Figure 2). Therefore, it will chill faster than a larger lamb. This risk is greater for lambs born as triplets or quads. 2. Insulation from the coat. Some lambs are born with a thicker coat than others; compare a newborn North Country Cheviot lamb to a Charollais. Once the lamb is dry, the heavier coat will give more insulation, thus the lamb will lose less heat. 3. How quickly after birth the ewe licks the lamb dry. Lambs from maiden ewes, or the later lambs from a multiple birth are the most vulnerable in this regard. 4. Drafts. Lambs born in a drafty pen or outside with no shelter from the wind will have an accelerated heat loss. 5. FIGURE 2. The effect of wind, environmental temperature and wetness on heat loss in newborn lambs. [From Alexander, G. (1962), Australian Journal of Agricultural Research, 13, 82-99.]
Environmental temperature. A lamb loses body heat faster, the lower the surrounding temperature.
The heat production mechanism uses the fat reserves, mainly brown fat, laid down during pregnancy and oxygen to produce energy and heat. The starter for these processes is a component of the colostrum. The lamb must nurse the ewe within a few minutes of birth. The producer can influence many of these factors by: • • •
selecting a breed or cross which is suited to the operation, e.g., inside lambing against May lambing at grass winter lambing in a draft free but well-ventilated building being there during lambing to watch the ewes and ensure that all lambs are dried and start to nurse as soon after birth as possible.
This may mean using some form of oestrus synchronization at the breeding season to concentrate lambings into a short time period and to reduce the labour requirements. Lamb birth weight is influenced by placental size early in pregnancy. By ensuring correct nutrition in the early stages of pregnancy, good placental development can be assured.
Heat Production To maintain body heat after birth, the lamb must use its' own energy reserves to generate heat. This energy reserve is mainly brown fat stores laid down in pregnancy. With oxygen these are converted to energy plus heat. The trigger to start this process is a component of the ewe's colostrum. The fat reserves are limited, and must be complimented by a steady supply of milk from the ewe; the lamb must be suckling regularly in the critical first days after birth to maintain its energy reserves. Adequate fat reserves at birth for the lamb are derived from the ewe via the placenta during the last half of pregnancy. Ewe nutrition in this period is critical. Not only are the reserves being laid down, but the lamb is rapidly developing. Poor nutrition will result in a small, weak lamb at birth with little internal body fat. This lamb is already at risk, but being weak it will not nurse quickly and may be slow to start breathing. Being oxygen deficient and lacking the "kick start" from colostrum, heat and energy production will be low; the lamb will rapidly become hypothermic. This occurs within the first five hours after birth. Twelve hours or more into life, a lamb is again vulnerable. Soon after birth the heat mechanism was working but now the energy reserves are used up. The lamb is not able to replace these reserves from the ewe; heat production slows and again the lamb becomes hypothermic. This time the cause is starvation; inadequate milk from a ewe that is feeding another lamb, has chronic mastitis with little milk, or was inadequately fed during late pregnancy.
Recognizing Hypothermia The only accurate way to recognize hypothermia is by taking the lambs rectal temperature (Table 1). Use a thermometer that measures subnormal body temperatures (many clinical thermometers do not go low enough). Many of the electronic thermometers do and are more robust for the barn than the traditional mercury/glass versions. The lower the rectal temperature, the more severe the hypothermia. The rectal temperature of a dull weak lamb, that seems unable or unwilling to suckle, should be checked immediately. The sooner remedial action can be taken, the better are the lamb's chances of survival. The normal rectal temperature for a new born lamb is between 39°C and 40°C.
Treatment The basis of treatment of the hypothermic lamb is to warm it up and provide a source of energy to start heat production again. Treatment varies with the degree of hypothermia as indicated by the rectal temperature (Figure 9).
Mild Hypothermia The lamb's rectal temperature is between 37°C and 39°C. The lamb is weak but may be able to stand. It should be moved into shelter, dried off if wet, and fed colostrum by stomach tube. TABLE 1. The appearance and behaviour of hypothermic newborn lambs. [After F.A. Eales, 1983, "Hypothermia in Newborn Lambs", in Diseases of Sheep, edited by W.B. Martin] Age Cause (hours)
Appearance and Behaviour 35°C
Long delivery Immature lamb
Weak but can stand
Low heat production
Recumbent Coma and death
20°C Deep coma
Using a stomach tube is comparatively simple. The operator sits with the lamb restrained on the lap. The tube is passed into the side of the mouth in the space between the front and side teeth (Figure 3). Using gentle pressure, the tube is slid into the oesophagus and down to the stomach (Figure 4). The tube will move easily, any resistance or coughing indicates that the tube has entered the windpipe. It should be removed immediately. The accidental passing of colostrum into the lungs will result in the death of the lamb with an aspiration pneumonia.
FIGURE 3. Using the stomach tube.
FIGURE 5. Stomach tube in place before attaching syringe with colostrum.
FIGURE 4. Lamb with stomach tube into stomach.
Small lambs, under 1.5 kg (3 lbs) at birth, may not have sufficient fat reserves to initiate heat production, even with colostrum. These can be fed an equivalent amount of 20% dextrose solution by stomach tube as an energy source (Figure 5). The lamb can stay with the ewe provided she is in a sheltered area. The lamb should be watched to ensure that it is suckling. Once the rectal temperature has returned to normal, it and the ewe can be returned to the flock.
How to make up 20% dextrose solution Calculate total amount needed and multiply this by 0.4 to determine how much 50% solution to use. Example: 5 kg x 10 mL/kg = 50 mL of 20% solution needed. 50 mL x 0.4 = 20 mL of 50% solution. Draw this amount into syringe. Then draw up the difference as boiling water. This solution will be close to body temperature.
Severe Hypothermia Once the rectal temperature falls below 37째C more radical treatment is required. There are two parts to this treatment: 1. reverse the hypoglycaemia 2. warm the lamb. The lamb should not be given colostrum until it has been revived; the rectal temperature must be above 37째C. 1. Reversing The Hypoglycaemia The blood glucose of this lamb will be low. A 20% dextrose solution at a dose rate of 10 mL/kg body weight is injected into the abdominal cavity (intra peritoneally). The site for the injection is about 2 cm (1 in.) below the navel and 2 cm (1 in.) lateral to the midline (Figure 6). Use a large (60 cc) syringe and a 20 or smaller gauge 1 inch needle, inserted at 90째 to the body wall. This is the injection site. Ask your veterinarian to show you how to do it. The internal organs will be pushed away by the needle and not damaged. Both the conscious and comatose lamb can be injected in this manner. Only the lamb able to swallow should be fed by stomach tube.
FIGURE 6. The site of intra peritoneal injection of glucose solution as indicated by the syringe
2. Warming The lamb also needs to be slowly warmed to restore body temperature. The best method is to use a "warming box" where the lamb is placed in a container heated by warm (37°C-40°C) moving air (Figure 7). Always use a warm air heater rather than the more severe heat lamp at this stage. The rectal temperature should be checked every 30 minutes to avoid overheating above the normal rectal temperature (hyperthermia). Once the lamb's rectal temperature has reached 37°C, it should be removed from the warmer, given a feed of colostrum by stomach tube, then returned to the ewe, or, if it is still weak, placed in an "aftercare" unit (Figure 8). Do not return the lamb to the ewe unless it is strong enough to nurse unaided. The aftercare unit has individual compartments for each lamb, with a heat lamp overhead.
Figure 7 – Warming box Figure 8 – Aftercare unit Colostrum Once the lamb's rectal temperature has reached 37°C, its heat production system should be restarted with colostrum. Give colostrum by stomach tube at 50 mL/kg body weight. Usually there is little problem with the ewe refusing the lamb after treatment. Ewe's colostrum is obviously the best, but cow colostrum can be used. Collect and freeze the colostrum in 500 mL batches. Thaw it in a water bath at 35°C, never in a microwave as this will denature the complex proteins in the colostrum. As in all conditions, prevention is the best cure for hypothermia. Good nutrition during gestation, good lambing quarters, observation of the ewe and lamb at lambing and assisting where necessary, will go a long way to preventing lamb losses from hypothermia.
Shepherd’s Calendar of Events The following summary provides an overall picture of when different management practices will occur throughout a reproductive cycle. Although it does provide the basics, it will not fit every operation and should be expanded or modified to accommodate the management priorities of each sheep farm. Before Breeding Season Ewes • • • • •
• • •
Check udders for evidence of previous mastitis and/or Maedi-Visna (hard lumps etc.), and that both teats look functional Check mouths for missing teeth or other problems Check ewe production and age records Cull ewes that are not sound or have lower productivity than desirable, and replace with ewe lambs Flush ewes: - 1 pound grain/day or move to lush pasture 2-3 weeks before breeding (increases plane of nutrition increases fertility and ovulation rate) - If ewes are overconditioned, the effect of flushing will be lessened. If necessary, vaccinate ewes for vibriosis and enzootic abortion (EAE) 2-3 weeks before breeding May wish to deworm at this time as well Replace any lost tags
Rams • • • • •
Evaluate sire production records. Cull and replace any rams with lower than desired productivity. Check for general health and condition. Check scrotal area (testis and epididymis) for any unusual lumps (Brucellosis) May wish to tested for sperm quality (not commonly done) Rams will spend a decreased amount of time resting and feeding at the beginning of the breeding season, therefore, for approximately 1-2 months before breeding season ensure rams are provided a good maintenance or flushing ration depending on their body condition. The plane of nutrition before breeding season will also have an effect on fertility, as sperm development takes ~50 days in rams. Replace any lost tags
Breeding • The ovulation rates in ewes tend to be lower at the first part of the breeding season. Running vasectomized or teaser ram with ewes for a few weeks early in the season tends to increase fertility and synchronize their estrous cycles (more condensed lambing). • Allow at least 1 mature ram or 2 ram lambs per 50 ewes. • Use a ram marking harness or painted brisket to monitor breeding. Changed colours (from lighter to darker shades every 17 days). • Typical breeding seasons span ~2-3 estrous (34 to 51 days). You may wish to allow ewe lambs an extra cycle longer than normal (68 days). Remove rams at the end of the season.
Early Pregnancy (First 15 Weeks) • Feed according to body condition (put thin ewes into a separate pen and provide extra feed) • Mature ewes do not need a very high plane of nutrition at this point of pregnancy. Feed a maintenance diet of clean, but lower quality hay. • Ewe lambs are still growing and should receive good quality roughages and grain (about 20 percent of the ration) during this period. • If you vaccinate for abortion diseases, ewe lambs and new ewes in the flock should receive their second shot during mid-gestation. Six Weeks Before Lambing • Increase energy in diet gradually to prevent pregnancy toxemia. An example of a feeding schedule is: o ~6 weeks before lambing, feed 1/4 to 3/4 pound grain/ewe/day o ~2 weeks before lambing 1 pound per ewe per day • Shear or crutch ewes before lambing. Control ticks and lice immediately after shearing. • May wish to treat for internal parasites and trim feet at this time as well. • Vaccinate ewes for Clostridial diseases (including tetanus). • If white muscle is a problem in your area, feed selenium-vitamin E OR use an injectable solution • Check facilities and equipment to be sure everything is ready for lambing, this includes making provisions for additional help for doing night checks etc.
Lambing • Although average gestation is 148 days, the first lambs generally appear 142 days after turning the rams in with the ewes. • Most lambs are lost just after birth and extra effort at lambing pays off with more lambs at weaning time. Be prepared to do checks through the night as well as during the day. • Put ewe and lambs in lambing pen after lambing (not before). • Grain feeding the ewes during the first three days after lambing is not necessary • Most ewes will lamb without incident. It is best to monitor their progress, but not to handle them or get too close unless it looks like she may be having problems. Learn the signs of a ewe in trouble (typical time for each stage of labour etc.) and know the basics of how to assist if necessary. • Disinfect lamb's navel with iodine as soon as possible after birth. • Be sure both teats are functioning and that the lambs nurse and are looking ‘happy’ • Some ewes may be able to nurse more than 2 lambs successfully; however, you may want to remove extra lambs. These lambs may be bottle fed or fostered to ewes with single lambs. • Castrate and tail dock lambs before 1 week of age. Vaccine with sore mouth vaccine if it has been a problem in the past. Ear tag or otherwise identify the lamb(s). If the ewes were NOT given Se:E supplement during pregnancy, inject lambs soon after birth. • If all is well, turn ewe and lambs out of the lambing pen after ~3 days • House ewes with single and multiple lamb separately and feed according to requirements (ewes with multiple lambs require more energy to maintain lactation) • Deworm ewes to prevent postpartum rise in worms
Lambing to Weaning • Feed ewes according to number of lambs. • Provide creep feed for lambs (especially those born during the winter and early spring). • Vaccinate lambs for overeating disease (Type D Clostridia) at five weeks and seven weeks of age. Weaning • Lambs should be weaned between 50 and 60 days of age or when they weigh at least 40 pounds and are eating creep and drinking water. (remove ewes from sight and sound of the lamb pens if possible, if lambs not eating creep may consider using a ‘teacher’ animal (older lamb or yearling replacement animal) • Vaccinate for Type D clostridia again, 2 weeks before putting lambs on finishing ration • Decrease ewes’ energy intake ~1 week prior to and for ~2 weeks after weaning (feed low quality forage and remove grain). This helps decrease milk production and lessens the chance of mastitis. • Handle the ewes as little as possible for about 10 days following weaning, to protect their udders until milk production has decreased. Weaning to Pre-Breeding • If ewes go to pasture, treat for internal parasites. • Feed a maintenance ration to the ewes. • Don't over condition ewes prior to breeding.
Lamb Mortality Record Animal ID
Date of death
Age of lamb
Prior signs of illness (e.g. respiratory distress, offfeed, wasting, etc.)
Cause confirmed? (e.g. post mortem finding)
Castration and Tail Docking of Lambs Adapted from â€˜Tail Docking and Castration of Lambsâ€™ By. Manus Graham (Moredun Foundation, Scotland) (Also Refer to the Recommended Codes of Practice).
Castration To castrate or not to castrate â€“ that is a question that must be answered by the individual producer. There are many conflicting opinions on this topic. The purpose of this section is to provide producers with all the options. If you do decide that it is necessary to castrate, it is critical that you are certain of your ability to successfully perform this procedure by using proper technique and equipment. Also, anyone performing this technique should take all precautions to avoid unnecessary pain or distress to the animal during the surgery and recovery period. Castration should be done as early as management procedures will allow (after the lamb has received colostrum and before 7 days of age). Castration of rams after the age of 3 months should be done by a veterinarian using appropriate analgesics and anesthetics. Reasons to Castrate The primary reason to castrate is to prevent indiscriminate breeding and subsequent pregnancies in young sheep. Some producers feel that any attempt to run large numbers of intact males on a property, along with females of the same species is difficult. In the sheep industry, it is quite common to run both females and males together, and therefore, a percentage of the industry feel that it is necessary to castrate. In addition, there is thought to be a higher incidence of male fighting, which can cause injury and loss of productivity. It has also been suggested that if done at a young age, it may enhance pelt removal and meat quality. Reasons not to Castrate It is felt by some that castration is unnecessary if lambs are to be marketed for slaughter prior to puberty, which generally occurs between 3 and 5 months of age. Increased male fighting, change in flavour of the meat, and indiscriminate breeding are not seen in animals that are less than 4 months. In addition, studies have shown entire (un-castrated) male lambs show better growth rate, efficiency of feed utilization and carcass yield than castrated lambs. Some markets, particularly ethnic markets, prefer intact ram lambs. Castration Methods If the decision is to castrate, there are a number of methods that can be used. The following is a list of methods with their advantages and disadvantages. 1. Rubber Ring - Basically the rubber ring is designed to constrict blood flow to and from the testes and scrotum, thus causing them to slough off after approximately 3 to 6 weeks, leaving a sealed scar behind. It is important to ensure that both testes are present and there is no scrotal hernia (intestines extending into the scrotum due to a hole in the gut wall). The ring should be placed below the rudimentary teats while ensuring that both testes are trapped in the scrotum. Only when everything is correct should the ring be gently released off the elastrator. Avoid placing the ring directly on the teats or the testes as this may increase discomfort. If the ring is placed too high (i.e. between the teats and the body wall, the urethra may become trapped, thus preventing the bladder from emptying. This will not only cause great discomfort but will prevent urine from being passed, which will lead to the death of the lamb. Advantages: Cheap, quick, no blood loss, effective with care, modest level of skill required for safe use. Less irritation by flies then with an open wound.
Disadvantages: painful, infection may occur around ring, risk of trapping urethra, in very small lambs the testes are so small that they can actually pass back from the scrotum through the central hole in the ring after the ring has been correctly applied. May be an increased risk of tetanus. 2. Surgical (Open) castration This is the complete removal of testes via surgery. This procedure requires good hygiene if infection and delayed healing are to be avoided. With this procedure an open wound is left. As assistant is required to catch and restrain the lamb thus leaving the operator’s hands free and clean. Only a very sharp knife or scalpel designated for the purpose should be used for castration. Check to be sure there is no scrotal hernia and that both testes are present. The scrotum should be cleaned and swabbed with dilute Pevidine or Hibitane. The bottom of the scrotum is drawn downwards (leaving the testes behind) and cut off with one smooth stroke of the scalpel. The open scrotum is then pushed up towards the abdomen causing the testes to appear. The testes are grasped one at a time and drawn steadily downwards until the cord breaks. The remaining part of the cord recoils into the inguinal canal and the blood vessels in it contract and thus are much less likely to bleed than were they to be cut. However, some testicular arteries fail to seal despite this traction and severe haemorrhage can result causing a serious setback or death. Although, by leaving an open wound there is less chance of abscessing to occur because the wound is draining, there is a chance of infection. Furthermore, should any loops of bowel travel down either of the inguinal canals there is nothing to prevent them prolapsing and becoming damaged with usually fatal consequences. Advantages: Can be used in lambs up to 3 months of age; cheap; effective; quick; modest level of skill required. Disadvantages: Risk of severe haemorrhage; risk of potentially serious infection; risk of prolapse of intestinal loops; two people required to maintain good surgical asepsis; not suitable during fly season; painful. 3. Bloodless castrators (emasculators) The purpose of these instruments is to damage irreversibly the blood vessels to each testis by crushing the spermatic cords without cutting the skin of the scrotum. Thus deprived of their blood supply, the testes shrivel within the scrotum, and the scrotum itself is retained. This is the crux of the method and it’s main advantage – there is no open wound by which infection could gain access. It is essential that the scrotum is not crushed across its full width. Were this to happen then it too would be likely to atrophy (due to all the small blood vessels in the skin of the scrotum being crushed) and fall off leaving a gaping wound, which would be unlikely to heal over. Such a wound would cause considerable suffering and could allow infection to gain access into the abdominal cavity via the inguinal canals resulting in peritonitis and death. For many years the Burdizzo emasculator has been available. It is important to use the small version for lambs as the larger cattle model would crush too much of the scrotum. Lugs or “cordstoppers” on the ends of the lower jaw help prevent failures (see below). It can be difficult to manoeuvre the cord, apply the instrument and restrain the lamb at the same time (often the lamb will struggle vigorously when the crush is applied, if not before) so ideally a handler and an operator are required to do the job safely and effectively. More recently a new lamb emasculator, the Little Nipper, has become available which is designed to be easier to use with one hand. Both of these instruments are precision
made and must not be used for other purposes. They should be stored carefully, oiled and with the jaws open. Each testis gives off a spermatic cord (containing an artery, a vein, a nerve and a vas deferens which is the tube that carries sperm from the testis to the penis), which can be felt running in the neck of the scrotum from the top of the testis towards the inguinal canal in the abdominal wall. Doing one side at a time, the spermatic cord is manoeuvred to the outer edge of the neck of the scrotum (in order to minimise the amount of scrotal skin that will be bruised by the jaws of the instrument) before being crushed. It is vital that the skin in the middle of the scrotum is not damaged but essential that the cord is crushed. When the second cord is being crushed the instrument should be applied slightly lower so that the left and right crushes are not directly opposite one another but staggered in order that a greater width of skin in the middle of the scrotum is undamaged. This undamaged area of skin will contain sufficient small blood vessels to keep the scrotum viable (alive). Care must be taken to ensure that the cord does not slip from between the jaws as they are closed. The lugs help to prevent this but were it to happen then the blood supply to that testis would be undamaged and the testis would develop in the normal way. This is arguably the major drawback with this method as such failures will not be apparent for some weeks. Skill and care are therefore required. Traditionally two crushes are applied to each cord for good measure, the second on e below the first as this area should by then be numb. However, a single crush on each cord maintained for 6 to 10 seconds may be as effective with some instruments. The instrument should be applied below the teats (to avoid the urethra as in the rubber ring method) but away from the testis to avoid unnecessary pain. Ensure there is no scrotal hernia present before applying the instrument. Crushing a loop of bowel would usually result in leakage of gut contents and death. When the cord is crushed, the main nerve to the testis is also destroyed and so the testis quickly becomes insensitive. So although the crush itself is painful there is not the build-up of the type of pain one gets with the rubber ring. However, there is usually some subsequent swelling and stiffness of
gait. The method relies on the instrument being in good working order and the operator being possessed of a considerable level of skill in its use. The high number of failures (i.e. lambs not effectively castrated) sometimes encountered with this method is its main criticism. Hence, application (missing the cord) and hasty removal (failure to apply the crush for 6 to 10 seconds) are the major contributing factors. Another factor is the instrument itself. If the hinges or the jaws of the instrument are worn then it may not exert enough pressure to crush the cord effectively. Furthermore, if the jaws of the instrument have become roughened by rust or abuse (being used as a pliers, etc) then they will cut the skin of the scrotum in places and serious infection may follow. Variability in the pressure exerted by different instruments has been studied and prototypes of powered instruments which always exert the same pressure have been developed. Advantages: no open wound or focus for infection or flies; no blood loss; can be used on lambs up to 3 months of age; cheap once instrument purchased; scientific evidence suggests it is not as painful as other methods at least in the first few hours after castration. Disadvantages: Comparatively high level of skill and care required; failure rate can be considerable; failures not easily detected at the time; ideally an assistant is required to hold the lamb; risk of damaging urethra; comparatively slow; effectiveness of instruments varies with manufacture; wear and abuse; cost of instrument.
Tail Docking It is quite common to tail dock lambs with the purpose of reducing future accumulations of faeces around the tail and breech area, which favour the occurrence of Blow Fly Myiasis (â€œStrikeâ€?). The blowfly (Lucilia sericata) is attracted to the damp warm conditions of a soiled breech and tail to lay its eggs. The larvae which hatch out burrow into the flesh to feed, leading to tissue damage, distress, loss of condition and even death depending on the severity of the infestation. Docking tails helps to address food safety concerns, as there is generally a decrease in tag (manure build up) on a docked animal, helping to avoid contact of the meat with bacteria during butchering. Other reasons given for docking include ease of management at mating and lambing and altering the appearance of certain breeds for traditional reasons. Whereas the former may be the case, the latter is not a sound reason for docking. There is a belief that long tails may reduce breeding efficiency in ewes but the evidence does not support this. However, available evidence does indicate that docking is beneficial to lambs on farms where blowfly strike is a problem, one study revealing an incidence of strike five times greater in undocked lambs compared with docked lambs. In this regard length of tail remaining after docking is important. Very short tails increase susceptibility to strike whereas long docked tails give the lowest incidence of strike. The tail affords a degree of protection against the elements to the sensitive anus and vulva and perhaps the udder also. Therefore, it is in each farmerâ€™s interest to consider carefully the necessity for docking lambs rather than doing so out of routine. Clearly if scouring is controlled by an adequate pasture management and working program the need to dock should be reduced. (Note: Some breeds, such as the Icelandic sheep, are naturally tailless.)
Tail Docking Methods The following is a list of methods available for tail docking. 1. Rubber Ring This is the most widely used method. Using an elastrator, a constricting latex ring is applied to the tail below the level of the anus in males and the vulva in females. This cuts off the blood supply to the tail beyond the ring resulting in death of those tissues and the sloughing (shedding) of that part of the tail. The actual separation usually occurs at the joint immediately above the ring. This takes about 3 to 4 weeks. Some operators attempt to place the ring on a joint in the belief that this is less painful or more effective. At present, there is no hard evidence to support this although a minority of lambs do seem to react less than others for some reason. Advantages: effective; cheap; quick; can be performed by single operator; relatively unskilled; relatively safe for operator and lamb.
Lamb being tail docked using a rubber ring
Disadvantages: infection can occur over the prolonged sloughing period as the ring cuts into the tissues. This can allow bacteria to gain access via the tail resulting in abscesses or, more seriously, Clostridial diseases such as tetanus. Pus formation around the ring is common and may attract flies. Rubber rings may not be used by Law if the lamb is more than 7 days old, timing incompatible with common hill farming practice. Despite its clean appearance, there is a good deal of scientific evidence that this method involves considerable pain in the majority of lambs. 2. Knife A small majority of farmers use this method. Severing at a joint is easier and therefore swifter. A scalpel or very sharp knife which is not used for any other purpose (other than castration) must be employed. It should be placed in an antiseptic liquid such as povidone-iodine (“Pevidine”) or chlorhexidine gluconate (“Hibitane”) after use on each lamb. Good hygiene is essential. Soiled tails should be cleaned and swabbed with a dilute Pevidine or Hibitane solution before docking and the operator’s hands should be washed and dried frequently. An assistant should catch and restrain the lambs thereby allowing the operator to keep his/her hands free from contaminants. Applying a wound powder or spray (eg. Terramycin aerosol) to the stump may help prevent infection. Advantages: effective; cheap. Disadvantages: risk of serious haemorrhage (bleeding), particularly in older lambs, which causes a major set-back or at worst is fatal; leaves an open wound which can allow entry of bacteria, not suitable in fly season; there is scientific evidence that it is the most painful method; two people required if hygiene to be maintained. 3. Burdizzo
A Burdizzo or similar bloodless castration instrument is used to crush the tail, preferably on a joint. It is held in place for 5 or 6 seconds and then usually a knife is introduced below the jaws of the instrument and the tail severed just below the crush. Advantages: Less likely to bleed severely compared with the knife method; can be used in older lambs. Disadvantages: slow; some consider this method cruel as it may involve crushing bone; may damage the Burdizzo jaws; effectively leaves an open wound; awkward to perform single-handed; good hygiene requires a handler and an operator. 4. Docking Iron These instruments (a number of different designs are available e.g. Alfred Cox, Ritchey Tagg) use a blade heated by an integral gas burner to sever and cauterize (sear) the tail in one swift action. The lamb is held by an assistant or a specially designed cradle. Advantages: As well as severing the tail easily, the heated blade cauterizes the tissues and blood vessels thus minimising or preventing haemorrhage; the heat sterilises the blade; scientific evidence suggests this is the least painful method, as the nerve endings are destroyed by the intense heat; one design can be operated single-handedly and the flame and blade have a guard over them; can be used in older lambs. Disadvantages: some designs involve the use of two operators with a risk of burns being suffered; fire risk; some scientific evidence suggests that cauterized tails take slightly longer to heal; a different method must be used for castration. Long term side-effects of tail docking Various studies have been conducted to see if the different methods of tail docking adversely affect subsequent growth and productivity. No such effects were found overall. Nevertheless, individual lambs which suffer severe haemorrhage or infection are detrimentally affected. There is evidence that if tail are docked too short there may be damage to the rectal and/or vaginal nerves, which leads to a higher incidence of rectal and vaginal prolapse. Summary • • • • • • •
Only castrate or dock if necessary. Avoid castrating or docking lambs less than 24 hours old and older than a week of age. Only castrate or dock healthy lambs. Ensure lambs to be castrated or docked are protected against the Clostridial diseases. Avoid castrating or docking in bad weather or in soiled, muddy surroundings or during the fly season. Before castrating check that there is no scrotal hernia and that both testes are present in the scrotum. Check afterwards, especially last thing at night, for signs of ill effects such as haemorrhage or excessive discomfort. Ensure all operators are trained and competent.
Weaning lambs Properly weaning ewes from their lambs can have a significant impact on current and future lamb crops. In operations, where lambs are weaned young and reared on concentrates, weaning usually takes place at six to ten weeks of age. Providing a pelleted creep feed to lambs from early in life, may help reduce the stress of the transition and decrease the drop in condition. In a pasture system, lambs are weaned at the end of the summer when the availability of pasture limits the growth of the lambs, and when ewes need to be dried off for rebreeding. At least 7 days before weaning, protein and energy levels in lactation diets should be reduced as this has been shown to reduce the discomfort felt by ewes on weaning. This also encourages consumption of dry feed by the lamb. Low quality feedstuffs, such as cornstalks and straw, make excellent lactation rations for the week prior to weaning. The change in diet will initiate the drying-up process prior to weaning. Ewes should be maintained on low quality diets for at least 7 days post weaning. The weaning strategy should be such that it minimizes the stress to both the ewe and the lamb. The ewes should be quietly removed to quarters where they are out of sight and hearing of the lambs. Lambs should be kept in familiar surroundings. The weaning strategy should also minimize the incidence of mastitis infections and ensure adequate milk production for the following lactation (decrease energy in ewe diet one week before and for two weeks after weaning). Ewes that are severely infected with mastitis or have chronic mastitis problems should be culled from the ewe flock. Once weaning is complete, the lambs should be observed carefully for early signs of illness, and to ensure they are getting enough feed and water. Prior to weaning, the lambs should be consuming sufficient amounts of feed and water to meet their requirements, and should be familiar with feeders and waterers. Early weaned lambs (less than 8 weeks of age) should have access to high quality lamb creep feed.