Management and nutritional strategies to improve ... Management and nutritional strategies to improve

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  • Management and nutritional

    strategies to improve the postnatal

    performance of light weight pigs

    By

    Sadie Louise Douglas

    BSc (Hons) Bioveterinary Science

    MSc (Hons) Control of infectious disease in animals

    A thesis submitted for the degree of Doctor of Philosophy

    (PhD)

    School of Agriculture, Food and Rural Development

    Newcastle University

    Submitted February 2014

  • i

    ABSTRACT

    During the production period from birth to slaughter there are some pigs that grow

    markedly slower, despite conditions that seem to support the rapid growth of their

    contemporaries. This reduction in growth inevitably leads to weight variation within a

    group and results in system inefficiencies. The aim of this thesis was to identify risk

    factors involved in poor growth and to develop management and nutritional treatments

    to enable light pigs to maximise their growth at different stages of production.

    Risk factor analysis for a large dataset showed that, in particular, low birth and weaning

    weight result in poor growth to finishing. Some light pigs do, however, have the

    capacity to compensate for low weight at earlier stages of production. Preweaning

    intervention demonstrated that low birth weight pigs cross fostered into litters with

    similar weight littermates had a significantly higher weaning weight than those in mixed

    litters with heavier pigs; however the provision of supplementary milk to such litters

    had no further beneficial effect. A post weaning feeding regime formulated for low birth

    weight pigs, with a higher nutrient specification diet based on more digestible

    ingredients, not only showed improved performance to 10 weeks of age, but also

    enabled low birth weight pigs to meet the BW of heavier birth weight pigs. In contrast,

    a high specification diet (higher in amino acid: energy content) had no effect on the

    growth of low birth weight pigs when offered from 9 weeks of age, suggesting a critical

    window for intervention.

    Overall, the crucial stages of postnatal growth for light pigs have been identified, and

    preweaning and early post weaning treatments have been developed. These not only

    improve the performance of low birth weight pigs but also allow them to catch up with

    heavier birth weight pigs.

  • ii

    Declaration

    This thesis has been composed by myself and has not been submitted as part of any

    previous application for a degree. All sources of information have been specifically

    acknowledged by means of referencing.

    Sadie Louise Douglas

  • iii

    Acknowledgements

    Firstly I would like to thank the British Pig Executive for sponsoring my PhD and the

    support and guidance they have provided throughout.

    A huge thank you goes to my supervisors Professor Ilias Kyriazakis and Professor

    Sandra Edwards for the encouragement and guidance they have provided over the

    course of my PhD. I feel incredibly lucky to have had two supervisors with such

    expertise, who despite their busy schedules, always found time to give me support when

    it was needed.

    Completing my experimental work would not have been possible without the help of all

    the staff at Cockle Park Farm, who always accommodated me despite my sometimes

    difficult requests. In particular, Darren, Mark and Jim who not only provided invaluable

    knowledge and assistance but also kept me entertained during the weekends and

    holidays, making my time on farm so enjoyable. Also to Paul Lamothe for his

    invaluable help with my behavioural data analysis during his stay in Newcastle. I would

    also like to thank all the staff at Newcastle University who has provided assistance at

    various points during my PhD, in particular Peter Avery for his statistical expertise,

    Steve Hall for his never ending IT support and Debra Patterson for her impressive

    organisational skills.

    A special thank you goes to Ian Wellock and Primary Diets for their invaluable help in

    diet formulation and for their advice and expertise. I would also like to thank ACMC

    and Genus for kindly providing data.

    I cannot thank my parents enough for their encouragement and support throughout my

    PhD as well as the rest of my education, they have provided me with so many

    opportunities that would have not been possible without them. And finally to Mathew,

    for his understanding of my absence at times, unwavering support of my goals and for

    his continued support.

  • iv

    Whilst I have not been able to thank everyone personally, I now realise how much work

    and assistance is required to complete a PhD, and I am extremely grateful to anyone

    who has helped me at any point during the completion of this thesis.

  • v

    Publications and conference abstracts

    Peer-reviewed publications

    Douglas, S. L., S. A. Edwards, E. Sutcliffe, P. W. Knap, and I. Kyriazakis. 2013.

    Identification of risk factors associated with poor lifetime growth performance in pigs.

    Journal of Animal Science. 91: 4123-4132.

    Douglas, S. L., S. A. Edwards and I. Kyriazakis. 2014. Management strategies to

    improve the performance of low birth weight pigs to weaning and their long term

    consequences. Journal of Animal Science. 92: 2280-2288.

    Douglas, S. L., S. A. Edwards, I.J. Wellock and I. Kyriazakis. Under review. High

    specification starter diets improve the performance of low birth weight pigs to 10 weeks

    of age. Journal of Animal Science.

    Conference and abstracts

    Douglas, S.L., S. A. Edwards, and I. Kyriazakis. (2013). Can low birth weight exhibit

    catch up growth post weaning if fed according to size? Proceedings for the British

    Society of Animal Science, 16-17 th

    April 2013. Theatre Presentation.

    Douglas, S.L., S. A. Edwards, and I. Kyriazakis. (2013). Can low birth weight pigs

    exhibit catch up growth post weaning if fed according to size? European Symposium of

    Porcine Health Management, Edinburgh, 22-24 th

    May 2013. Poster presentation.

    Douglas, S.L., S. A. Edwards, and I. Kyriazakis. (2012). Identification of risk factors

    associated with poor growth performance in pig. Proceedings for the British Society of

    Animal Science, 24-25 th

    April 2012. Theatre Presentation.

  • vi

    List of abbreviations

    ADG Daily live weight gain

    ADFI Average daily feed intake

    ADMI Average daily milk intake

    BiW Birth weight

    BW Body weight

    CP Crude Protein

    CRL Crown rump length

    CV Coefficient of variation

    d Day

    DE Digestible Energy

    FW Final weight

    H Hour

    FCE Feed conversion efficiency

    FI Feed intake

    IW Intermediate body weight

    kg Kilogram

    LBiW Low birth weight

    m Metre

    mo Month

    NBiW Normal birth weight

    NE Net energy

    OR Odds ratio

    PI Ponderal index

    SD Standard deviation

    SDG Scaled ADG

    SFI Scaled FI

  • vii

    wk Week

    WW Weaning weight

  • viii

    Contents

    Chapter 1. Introduction ..................................................................................................... 1

    1.1 What are light pigs? ................................................................................................ 1

    1.2 Problems associated with light pigs ........................................................................ 2

    1.3 How has the industry attempted to deal with light pigs? ........................................ 3

    1.4 Thesis aims .............................................................................................................. 5

    Chapter 2. The risk factors associated with poor growth performance in pigs ................. 6

    2.1 Animal characteristics ............................................................................................. 6

    2.2 The prenatal environment ....................................................................................... 7

    2.2.1 Intrauterine growth restriction.......................................................................... 8

    2.2.2 Birth weight ...................................................................................................... 9

    2.3 The postnatal environment .................................................................................... 10

    2.3.1 Lactation ......................................................................................................... 10

    2.3.2 Weaning ......................................................................................................... 12

    2.3.3 Post weaning .................................................................................................. 13

    2.4 Conclusions ........................................................................................................... 15

    Chapter 3: Identification of risk factors associated with poor li