Biological aspects of genetic differences in piglet survival

J. Leenhouwers

Research output: Thesisinternal PhD, WU

Abstract

The objective of this thesis was to gain insight in the biological background of differences in the direct genetic (piglet) component of piglet survival. Estimations of the direct genetic component of piglet survival were obtained by calculation of estimated breeding values for piglet survival (EBVps), which predict survival from onset of farrowing until weaning. The results in this thesis show that differences in survival as a consequence of differences in EBVps are already apparent in the perinatal period (i.e. in the period around birth). Both farrowing survival and survival during the first days after birth significantly increase with increasing EBVps of the litter. Differences in the course of farrowing (i.e. duration of farrowing and birth intervals) do not account for EBVps-related differences in farrowing survival and postnatal survival. Increased postnatal survival with increasing EBVps is not due to differences in early piglet behavior, such as the time from birth until first colostrum uptake. Explanations for increasing farrowing survival and postnatal survival with increasing EBVps are more likely to be found in a higher degree of fetal development or maturity during late gestation. This is substantiated by increased relative organ weights (liver, adrenals, and small intestine), increased serum cortisol levels, increased glycogen reserves in liver and muscle, and an increased carcass fat percentage in litters with high EBVps. The strong positive relationship between fetal cortisol and EBVps possibly caused the majority of the observed differences in fetal development and maturity. Knowing that cortisol plays a major role in the preparation for the transition from intrauterine to extrauterine life, piglets with a higher genetic merit for piglet survival may have an improved ability to cope with hazards during birth and within the first days of life.</p><p>The results in this thesis contribute to our understanding of the practical consequences of selection for increased piglet survival.</p>
Original languageEnglish
QualificationDoctor of Philosophy
Awarding Institution
  • Wageningen University
Supervisors/Advisors
  • Brascamp, E.W., Promotor, External person
  • van der Lende, T., Promotor, External person
Award date4 Dec 2001
Place of PublicationS.l.
Print ISBNs9789058085177
Publication statusPublished - 2001

Keywords

  • pigs
  • piglets
  • animal breeding

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