Practical Lambing and Lamb Care – A Veterinary Guide

Practical Lambing and Lamb Care – A Veterinary Guide

Fourth Edition

Neil Sargison, BA, VetMB, PhD, DSHP, DipECSRHM, FRCVSUniversity of EdinburghRoyal (Dick) School of Veterinary StudiesEaster Bush Veterinary CentreScotland;President of the European College of Small Ruminant Health Management

James Patrick Crilly, MA, VetMB, CertAVP, DipECSRHM, MRCVS Larkmead Veterinary GroupUK

Andrew Hopker, BVM&S, CertAVP, MRCVSRoyal (Dick) School of Veterinary StudiesEaster Bush Veterinary CentreScotland

This edition first published 2018© 2018 John Wiley & Sons Ltd

Edition HistoryLongman Group Limited (1st edition, 1986)Longman Group Limited (2nd edition, 1995)John Wiley & Sons (3rd edition, 2004)

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Library of Congress Cataloging‐in‐Publication Data

Names: Sargison, Neil, author. | Eales, F. A., 1948– Practical lambing and lamb care.Title: Practical lambing and lamb care / Neil Sargison, University of Edinburgh, Royal (Dick) School of Veterinary

Studies, Easter Bush Veterinary Centre, Roslin, Midlothian, James Patrick Crilly, Larkmead Veterinary Group, Ilges Lane, Cholsey, Oxfordshire, Andrew Hopker, Royal (Dick) School of Veterinary Studies, Easter Bush Veterinary Centre, Roslin, Midlothian.

Description: Fourth edition. | Hoboken, NJ : Wiley, 2018. | Revised edition of: Practical lambing and lamb care : a veterinary guide / Andrew Eales and John Small ; with drawings by David Pollock. 3rd ed. 2004. | Includes bibliographical references and index. |

Identifiers: LCCN 2017054875 (print) | LCCN 2017055986 (ebook) | ISBN 9781119133650 (pdf) | ISBN 9781119140672 (epub) | ISBN 9781119140665 (paper)

Subjects: LCSH: Lambs. | Sheep–Parturition. | Veterinary obstetrics. | Lambs–Diseases. | Ewes–Diseases. | Sheep–Diseases.

Classification: LCC SF376.5 (ebook) | LCC SF376.5 .E25 2018 (print) | DDC 636.3/089–dc23LC record available at https://lccn.loc.gov/2017054875

Cover Design: WileyCover Images: (Top left and bottom images) Courtesy of James Patrick Crilly; (Top right image) Courtesy of Neil Sargison

Set in 10/12pt Warnock by SPi Global, Pondicherry, India

10 9 8 7 6 5 4 3 2 1

v

Preface to the Fourth Edition vii

1 General Lambing Management 1

2 Specific Causes of Lamb and Kid Mortality 37

3 Husbandry and Health Planning to Prepare for Lambing or Kidding: Ensuring Pregnancy in Ewes and Does 61

4 Husbandry and Health Planning to Prepare for Lambing: Nutritional Management of Pregnant Ewes and Does 87

5 Husbandry and Health Planning to Prepare for Lambing: Health Management of Pregnant Ewes and Does 101

6 Identifying Unwell Ewes and Lambs, Does and Kids 129

7 Legislation 139

Index 155

Contents

vii

It has now been fourteen years since the publication of the third edition of Practical Lambing and Lamb Care, and 32 years since the first edition. It has been our privilege to update this important globally relevant resource through the preparation of the fourth edition. In doing so, we wish to acknowledge the excellence of the previous editions and the expertise of their Moredun Research Institute‐based authors, Colin Macaldowie, John Small, and the sadly missed Andy Eales.

In this new edition, we have attempted to maintain the impressive scope of the previous editions, while focusing on practical husbandry and animal health. We have attempted to extend the scope of the book by including goat kidding man-agement. For clarity, many of the principles referred to under the headings of lambing, ewes and lambs are equally relevant to kidding, goats and kids. The principles of goat management are only described separately where they differ.

We have structured this fourth edition to begin with chapters describing gen-eral practical lambing and kidding management, and care of newborn lambs and kids. These chapters describe preparation for lambing or kidding, obstetrical procedures and health management of newborn lambs or kids. Lambing and kidding are part of a management continuum, the outcomes of which are deter-mined by interventions occurring throughout the year. Thus, the foundations for a successful outcome are laid long beforehand. We have dedicated three chapters to animal husbandry and health, describing planned reproductive, nutritional and disease management, with reference to preparation for a successful lambing or kidding. This is followed by a chapter describing a practical approach to ensure that individual sick or unwell animals can be identified and treated promptly. Finally, we have included a chapter describing and explaining animal welfare and disease control legislation.

We are grateful to all of those veterinary colleagues and farmers who have helped us to gain the experience and expertise required in the writing of this book, and to our publisher, Wiley, for their support and patience in this venture.

Neil SargisonJames Patrick CrillyAndrew Hopker

Preface to the Fourth Edition

September 2018University of EdinburghRoyal (Dick) School of Veterinary Studies

1

Practical Lambing and Lamb Care – A Veterinary Guide, Fourth Edition. Neil Sargison, James Patrick Crilly and Andrew Hopker. © 2018 John Wiley & Sons Ltd. Published 2018 by John Wiley & Sons Ltd.

1

It is should be emphasised that most sheep and goats give birth to their lambs and kids naturally and unassisted, as nature intended. When problems do arise, timely intervention is required to prevent losses. However, inappropriate inter-vention too soon can also cause harm to both ewe and lamb, can compromise animal welfare and may result in economic loss.

The normal hormonal processes involved in giving birth occur most effectively when the dam feels safe and is undisturbed. While good observation is essential, disturbance of the lambing ewes should be minimised and shepherds should move among the flock in a calm and quiet manner. The role of a good shepherd in the delivery of lambs at lambing time should be to provide the right amount of assistance at the right time, and no more. The keys to achieving this are good preparation and adequate supervision of lambing ewes to spot problems in a timely manner.

Most assisted deliveries can be undertaken satisfactorily, using a gentle hygienic technique to give a viable, humane and profitable outcome. The general princi-ples and practice of delivering goat kids are the same as those for lambing ewes. In this chapter, specific reference to goats is only made where the important principles differ.

Preparation for Lambing

Around the world, the economics of small ruminant farming have necessitated a shift of focus away from the care of individual animals and towards whole flock or herd approaches. Careful preparation for lambing or kidding is now, therefore, of paramount importance to protect of the welfare of pregnant and lambing ewes or does, and their newborn lambs or kids. Lambing should be seen as the critical time when the benefits of general preparation, nutrition and animal health man-agement throughout the year are realised.

Careful shepherding and the design and selection of the lambing environment – be it in lambing paddocks, or lambing sheds – is required to minimise distur-bance of lambing ewes, thus enabling the establishment of a good ewe‐lamb bond and enhancing the survival of newborn lambs. Whenever possible, steep

General Lambing Management

Practical Lambing and Lamb Care2

and exposed fields should be avoided. Lambing fields should not be too large and water sources not too far apart (Figure 1.1).

When potentially less suitable lambing paddocks must be used, they should, if possible, be reserved for single‐bearing adult ewes. Buildings should be well ven-tilated and drained. Pens should be small enough to allow animals to be grouped according to their nutritional and animal health needs, and should be designed in a manner such that lambing and lambed ewes can be isolated and removed without undue disturbance of the whole group. Consideration should be given to the housed ewe space requirements of about 1.1 m2 per ewe, the need for con-stant access to forage, and concentrate feed trough space requirements of about 0.5 m per ewe (Figure 1.2). These requirements vary with breed and litter size.

Sufficient individual pens should be available, based on a figure of about 10% for the flock. These should be large enough to allow the ewe and lamb to lie safely apart from each other, and need to be clean and well drained. All pens should be well lit and easily accessible. Food and water must be available at all times.

Despite long‐term planning, the need for careful skilled assistance for some lambing ewes is inevitable. A clear plan is required to avoid suffering in ewes which cannot be lambed. This should include guidelines about when and how to seek assistance and provision for the immediate humane destruction of dis-tressed animals. Lambing equipment should be prepared in advance (see Table 1.1). Provision should be made for the management of those diseases which occur annually in most flocks around lambing, and there should also be clear guidelines about when to seek assistance, and to ensure prompt and humane destruction to prevent further suffering when treatment is unsuccessful or une-conomical. Preparation for lambing must also be aimed at prevention and man-agement of disease in newborn lambs. Despite careful preventive management, the occurrence of disease in newborn lambs is inevitable, so provision should be made for the treatment of the common problems and specific diseases that occur in the flock.

Figure 1.1 Lambing fields should ideally be small and flat with easy access to food and water.

Figure 1.2 Lambing sheds need to be carefully organised to ensure ease of observation, precision nutritional management and minimal disturbance of lambing ewes.

Table 1.1 Equipment list for lambing sheep.

Suitable antiseptic solutionObstetric lubricantArm length disposable glovesLambing ropes, snares or other aidsClean needles and syringesAntibiotics for treatment of mastitis or metritisInjectable anti‐inflammatory drugsPlastic retainers or harnesses, local anaesthetic, clean obstetric tape and needles for the management of vaginal prolapseCalcium borogluconate injection for the treatment of hypocalcaemiaPropylene glycol, or other concentrated energy supplements for the treatment of pregnancy toxaemiaStrong iodine tincture for navels and a dip cup or spray to applyStomach tubes, colostrum, a warming box, glucose injection, syringes and needles for the treatment of starvation and hypothermiaKettle for hot waterRehydration drench or formula for lambsClips or small syringes and needles for subconjunctival injections to correct entropionOral antibiotics for watery mouth prevention if neededInjectable antibiotics for the treatment of neonatal bacteraemias if neededElastrator rubber rings for lambs if neededMarker paintSpare hurdles for making addition pensDisinfectant for pens and floorsSufficient clean buckets for food and water

Practical Lambing and Lamb Care4

Normal Lambing

The normal ewe gestation period is 143–147 days. Impending lambing (parturi-tion) is signalled by udder development, accumulation of colostrum, slackening of the sacro‐iliac ligaments between the tail head and the vulva and visible drop-ping of the abdominal contents, giving an appearance of hollowness of the sub‐lumbar spaces on both sides of the ewe. The birth process is described as having three consecutive stages.

First stage labour is represented by cervical dilation, which takes 2–6 hours, being fastest in ewes bearing multiple lambs (multiparous ewes). Behavioural changes are often the first sign of impending lambing. The ewe will frequently separate herself from the flock or not come forward for feeding. If she does come to the trough, she may leave early. Sheep may paw at the ground and then sniff the area, while frequently lying down and then standing (Figure 1.3).

Ewes lambing outdoors often separate themselves from the flock at this stage, so it is important that corners, ditches, bushes and other such areas are checked regularly. Abdominal contractions (straining) will start, initially lasting 15–30 seconds and occurring at about 15 minute intervals. Straining becomes more frequent, until it is happening every two to three minutes, and a string of mucus may be seen at the vulva. The appearance of the water bag at the vulva indicates that the ewe is ready to give birth, although the bag may burst and go unno-ticed. This process usually occurs faster in older animals which have previously given birth, and tends to be slower in ewe lambs and gimmers. Disturbance of the sheep during this process may also delay progress.

Second stage labour is represented by the passage of the lamb through the birth canal, and typically takes about one hour. The breaking of the water bag (rupture of allanto‐chorion) is indicated by a rush of fluid, following which part of the

Figure 1.3 Ewes in first stage labour initially separate themselves from the main group in a preferred lambing site before abdominal contractions begin.

General Lambing Management 5

placenta (the amnion) and foetus are presented into the birth canal. Powerful reflex and voluntary contractions of abdominal muscles will occur every couple of minutes. Parts of the lamb may be seen protruding from the vulva (Figure 1.4).

Once the lamb has appeared at the vulva it is normally delivered soon after-wards (Figure 1.5). Again, disturbance of the ewe may delay this process.

Once the lamb is born, the ewe should immediately lick and clean the lamb. This process is important for stimulating the lamb and establishing the bond between mother and young, as well as drying the lamb. Ewes bearing multiple lambs may start to deliver the next within minutes, or a gap of an hour may occur. Delays greater than one hour should be considered abnormal, and the ewe should be examined.

Figure 1.4 The appearance of the placenta and foetus in the birth canal indicates second stage labour.

Figure 1.5 Normal unassisted delivery of a lamb in anterior presentation.

Practical Lambing and Lamb Care6

Third stage labour is completed by expulsion of foetal membranes (placenta), which usually occurs within 2–3 hours of the end of second stage labour. The placenta may be passed at the time of lambing, or shortly afterwards (Figure 1.6). If the placenta has not been passed within three hours, the ewe should be inves-tigated, as this could result in potentially serious infection.

The process of preparing to give birth, including dilation of the cervix and delivery of the lamb(s), takes longer in ewes lambing for the first time (primipa-rous), compared with animals which have given birth previously. These animals should be given sufficient undisturbed time in a quiet environment to allow the hormonal mechanisms of birth to take place. Careful, unobtrusive observation should be undertaken, to allow early detection of potential problems.

When to Intervene

Every sheep and every delivery is different, so there are no hard and fast rules for when to intervene. Intervention with lambing should only be considered when failure to do so might compromise the health of the ewe or unborn lamb. Intuitive, common sense assessment of the ewe usually gives an indication of prolonged birth stress. If the ewe lies on her side (lateral recumbency), with fre-quent abdominal straining and vocalisation, it may indicate that the lamb is engaged in the birth canal. Tooth grinding and, heavy breathing, involving con-traction of abdominal muscles and panting, may indicate more serious concerns. Table 1.2 gives some guidelines as to when intervention and assistance should be considered.

Difficult, painful and extended lambings have serious consequences for the health and welfare of both the ewe and her lambs. The consequences of the birth of weak lambs as a result of an obstructed labour (dystocia) include an increased mortality rate, a higher incidence of neonatal infections, slower weight gain,

Figure 1.6 The placenta should be passed within about 3 hours of lambing.

General Lambing Management 7

higher medication costs and greater time spent on their care. The consequences of trauma on the ewe include reduced colostrum and milk let‐down or produc-tion, poor mothering behaviour, higher medication costs, time spent on care and potentially reduced future fertility (Figure 1.7).

Table 1.2 Indications of the need to assist lambing.

The ewe has been trying to lamb for one hour without a lamb being delivered.The interval between the water‐bag breaking and expulsion of a foetus exceeds 30 minutes.No further progress has been made 20 minutes after some of the lamb has been visible at the vulva.Frequent powerful contractions have persisted, but no progress made in the delivery of a lamb.The ewe appears to have started to lamb, then stopped.The lamb’s head is visible, but no forelimbs have been seen at the vulva.Two forelimbs, but no head is seen visible at the vulva.A foetal head and only one forelimb is seen at the vulva.Only a tail is seen at the vulva.A large and obviously stuck lamb is seen, sometimes with a swollen head or tongue.Parts of two lambs are seen at the same time at the vulva.Thirty minutes have elapsed after the birth of the first lamb, but twins or triplets are expected.An unpleasant brown or smelly vulval discharge is noted, indicating the presence of decomposing foetuses.Other problems, such as vaginal prolapse, have been identified.

Figure 1.7 Protracted lambing or unskilled intervention can seriously compromise the health, welfare and productivity of both the ewe and her lambs.