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New developments in breeding herd efficiency Dr William van Wettere

School of Animal and Veterinary Sciences Wednesday December 14 th 2011. New developments in breeding herd efficiency Dr William van Wettere. Collaborators: Prof. Paul Hughes (PPPI, SARDI),

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New developments in breeding herd efficiency Dr William van Wettere

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  1. School of Animal and Veterinary Sciences Wednesday December 14th 2011 New developments in breeding herd efficiency Dr William van Wettere Collaborators: Prof. Paul Hughes (PPPI, SARDI), Robyn Terry, Alice Weaver, Alex Whittaker, Centaine Kaisler Smith, Anthony Martyniuk, Paul Herde (University of Adelaide)

  2. Presentation Outline • General Background • Importance of reproductive performance • Regulation and control of reproduction • Towards improving breeding herd efficiency • Strategies to alleviate seasonal infertility • Feeding strategies to improve sow performance • Alternative management systems for breeding sows and litters

  3. General Background • Breeding herd productivity depends on sow reproductive performance • Three causes of sub-optimal reproductive performance are • Reduced fertility of gilts / sows mated in summer / autumn • Poor litter size, particularly in older (>4) parity sows • Extended farrowing to conception intervals

  4. General Background • Breeding herd productivity depends on sow reproductive performance • Three causes of sub-optimal reproductive performance are • Reduced fertility of gilts / sows mated in summer / autumn • Poor litter size, particularly in older (>4) parity sows • Extended farrowing to conception intervals • Together, or individually, these result in • Fewer pigs sold per sow per year • More sows required, therefore more feed • A reduction in overall herd feed conversion efficiency

  5. Control and Regulation of Reproduction • Litter size in the pig is determined primarily by • The number of oocytes shed at ovulation (ovulation rate) • The number of fertilised oocytessuccessfully implanting (embryo survival) • The number of implanted embryos that survive to birth

  6. Control and Regulation of Reproduction • Litter size in the pig is determined primarily by • The number of oocytes shed at ovulation (ovulation rate) • 95 – 100 % of oocytes are fertilised • The number of fertilised oocytessuccessfully implanting (embryo survival) • ~30 % (10 – 50%) of fertilised oocytes die by day 35 of pregnancy • The number of implanted embryos that survive to birth • ~ 5% of implanted embryo die before parturition

  7. Control and Regulation of Reproduction • Litter size in the pig is determined primarily by • The number of oocytes shed at ovulation (ovulation rate) • 95 – 100 % of oocytes are fertilised • The number of fertilised oocytessuccessfully implanting (embryo survival) • ~30 % (10 – 50%) of fertilised oocytes die by day 35 of pregnancy • The number of implanted embryos that survive to birth • ~ 5% of implanted embryo die before parturition

  8. Control and Regulation of Reproduction • The number of oocytes shed at ovulation is determined by • The maturity and number of ovarian follicles present • (at puberty / oestrus stimulation and at weaning) • The number of fertilised oocytessurviving implantation determined by • The ‘quality’ of the oocytes that are shed • The ‘quality’ of the uterine environment • (capacity to support embryo development)

  9. Control and Regulation of Reproduction • The number of oocytes shed at ovulation is determined by • The maturity and number of ovarian follicles present • (at puberty / oestrus stimulation and at weaning) • The number of fertilised oocytessurviving implantation determined by • The ‘quality’ of the oocytes that are shed • The ‘quality’ of the uterine environment • (capacity to support embryo development) Improvements in these areas are key to improving breeding herd productivity

  10. Control and Regulation of Reproduction Mating / ovulation Farrowing 1 – 21 d pre- mating 1 – 35 d post-mating

  11. Control and Regulation of Reproduction Mating / ovulation Farrowing Maximise High feed intake + Low feed intake? Litter size 1 – 21 d pre- mating 1 – 35 d post-mating

  12. Control and Regulation of Reproduction Mating / ovulation Farrowing Maximise High feed intake + Low feed intake? Litter size 1 – 21 d pre- mating 1 – 35 d post-mating Diet composition ?? Feeding level - parity specific?? Farrowing rates, Litter size + Post-natal growth

  13. Control and Regulation of Reproduction Mating / ovulation Farrowing Maximise High feed intake + Low feed intake? Litter size 1 – 21 d pre- mating 1 – 35 d post-mating Diet composition ?? Feeding level - parity specific?? Farrowing rates, Litter size + Post-natal growth Temperature + Photoperiod ?? Housing, stress and aggression

  14. TOPIC ONE: Towards alleviating seasonal infertility • Improving oocyte quality • Understanding timing of ovulation • Improved puberty stimulation and boar use

  15. Alleviation of Seasonal Infertility • Season of mating significantly impacts sow reproduction • During summer it is common for sow fertility to be depressed • Delayed puberty and extended weaning to oestrus intervals • Increased incidences of regular and irregular returns • Reductions in litter size • Discuss current understanding of seasonal infertility • Discuss some strategies to alleviate seasonal infertility • Dietary strategies to improve litter size • The effects of season on progesterone profiles and timing of ovulation • Strategies to improve puberty attainment

  16. Alleviation of Seasonal Infertility • Season of mating significantly impacts sow reproduction (O'Leary, Final Report to Pork CRC, 2010)

  17. Alleviation of Seasonal Infertility • Proposed mechanism of seasonal infertility ↑ day length ↓Melatonin secretion ↑ sensitivity of brain to negative feedback of oestrogen on reproductive hormones ↓ endocrine support for ovarian follicle growth

  18. Alleviation of Seasonal Infertility • Proposed mechanism of seasonal infertility ↑ day length ↓Melatonin secretion ↑ sensitivity of brain to negative feedback of oestrogen on reproductive hormones ↓ endocrine support for ovarian follicle growth ↓ follicle growth ↓ oocyte quality ↓ uterine quality ↓ ovulation rate ↓ embryo survival

  19. Alleviation of Seasonal Infertility • Proposed mechanism of seasonal infertility ↑ day length ↓Melatonin secretion ↑ sensitivity of brain to negative feedback of oestrogen on reproductive hormones ↓ endocrine support for ovarian follicle growth ↓ follicle growth ↓ oocyte quality ↓ uterine quality ↓ ovulation rate ↓ embryo survival ↑ pregnancy failure ↓ litter sizes

  20. Alleviation of Seasonal Infertility • Proposed mechanism of seasonal infertility ↑ day length ↓Melatonin secretion ↑ sensitivity of brain to negative feedback of oestrogen on reproductive hormones ↓ endocrine support for ovarian follicle growth ↓ follicle growth ↓ oocyte quality ↓ uterine quality ↑ temperature (heat stress) ↓ ovulation rate ↓ embryo survival ↑ pregnancy failure ↓ litter sizes

  21. Alleviation of Seasonal Infertility • Effect of season on oocyte development • Background • The developmental potential of the shed oocyte • Is impaired by high ambient temperatures • Is reducedduring summer in weaned sows Oocytedevelopmental competence in 5 - 8 mm follicles collected from sows in winter and summer (adapted from Bertoldo et al., 2010).

  22. Alleviation of Seasonal Infertility • Effect of season on oocyte development • How can oocyte quality be improved during summer? • Background • The developmental potential of the shed oocyte is highly sensitive to nutrition intake prior to mating • Reduced feed intake decreases oocyte quality • Manipulating dietary composition alters oocyte quality

  23. Alleviation of Seasonal Infertility • Effect of season and nutrition on oocyte development • Background • Manipulating dietary composition alters oocyte quality • High levels of dietary sugar beet pulp improve oocyte quality and embryo survival (Table 2) Oocytequality and embryo survival in standard and sugar beet pulp (SBP) fed gilts (adapted from Ferguson et al., 2007).

  24. Alleviation of Seasonal Infertility • Effect of season and nutrition on oocyte development • Oocyte quality (ability to develop as early, pre-implantation embryo) • Unaffected by feeding a wheat bran diet • Improved by feeding a lupin-fibre diet Quality of oocytes collected from standard, lupin fibre and wheat bran fed gilts (Weaver, Kind and van Wettere, unpublished) (Weaver, Kind, Hughes, van Wettere, 2011)

  25. Alleviation of Seasonal Infertility • Effect of season and nutrition on oocyte development • Feeding a lupin fibre based diet resulted in • An additional 2 embryos • A 21% increase in embryo survival • A similar response previously reported following sugar beet diets Effect of feeding a standard or lupin fibre diet during summer on reproduction (van Wettere et al., unpublished) (van Wettere, Hughes, 2011)

  26. Alleviation of Seasonal Infertility • Effect of season on early pregnancy progesterone profiles • Background • The pattern of progesterone secretion post-ovulation • Reflects ovarian function pre—ovulation • Affects the uterine environment • Stimulates the release of factors required for embryo development

  27. Alleviation of Seasonal Infertility • Effect of season on early pregnancy progesterone profiles • Background • Small scale studies suggest that • Progesterone production may be impaired during summer • Impaired progesterone production may be responsible for increased incidences of pregnancy failure during summer / early autumn • Our recent studies focussed on determining (under commercial conditions) whether progesterone profiles differ between summer and winter • How does season affect the hormone (progesterone) which regulates the uterine environment post-ovulation?

  28. Alleviation of Seasonal Infertility • Effect of season on early pregnancy progesterone profiles • Results: during summer • Progesterone was higher on d3 and 7, but lower on d 19 and 23 (van Wettere, Hughes et al., 2011) Different superscripts, within time point, indicate significant difference

  29. Alleviation of Seasonal Infertility • Optimal timing of ovulation • From 24 hours before to 4 hours after ovulation (Nissen et al., 1997) • Within the 16 hour period prior to ovulation (Bortolozzo et al., 2005) • Within the 12 hour period prior to ovulation(Waberski et al., 1994)

  30. Alleviation of Seasonal Infertility • Use of boars to alleviate seasonal infertility

  31. Alleviation of Seasonal Infertility • All gilts received PG600 (intervet at 23 weeks of age) • Age at puberty (with boar contact) = 167 days of age • Age at second oestrus = 190 days of age (Bartlett, Hughes, van Wettere, 2006)

  32. Alleviation of Seasonal Infertility • Use of boars to alleviate seasonal infertility (van Wettere et al., Report to Pork CRC, 2008)

  33. Alleviation of Seasonal Infertility • Use of boars to alleviate seasonal infertility More appropriate use of boars (d18 – 23) to pick up regular returns More accurate use of ultrasound to detect pregnancy losses (i.e d25 – 30 post-first AI) (van Wettere et al., Report to Pork CRC, 2008)

  34. Alleviation of Seasonal Infertility • Summary • It is evident that oocyte quality is impaired during summer, probably due to • Photoperiod induced reduction in endocrine support • Heat induced suppression of maternal intake • Including fibre (whole lupins/hulls) in pre-mating diets increases embryo survival • Maximise metabolic status of the lactating sow, and gilt prior to mating • Timing of ovulation appears to be altered relative to oestrus during summer • Optimise duration of boar contact (15 – 20 minutes) • Consider increasing frequency to twice daily • Inseminate at first detection of oestrus • If puberty attainment an issue consider using PG600 and boar exposure • Adding betaine to summer diets can be beneficial • Alleviates heat induced reductions in ovulation rate (fed pre-mating) • Increases litter size when added to gestation diets • If included in pre-mating diets SHOULD be added to gestation diets

  35. TOPIC TWO: Feeding strategies to improve sow performance • Gestation feeding • Lactation feeding

  36. Gestation feeding to improve sow performance • Primary aim of gestation feeding is to • Maximise embryo survival and reduce incidences of pregnancy failure Litter size and farrowing rates maximise Farrowing High feed intake + Low feed intake? Mating / ovulation 1 – 21 d pre- mating 1 – 35 d post-mating

  37. Gestation feeding to improve sow performance • Primary aim of gestation feeding is to • Maximise embryo survival and reduce incidences of pregnancy failure Litter size and farrowing rates maximise Farrowing High feed intake + Low feed intake? Mating / ovulation 1 – 21 d pre- mating 1 – 35 d post-mating Litter size and farrowing rates Diet composition affects

  38. Gestation feeding to improve sow performance • Embryonic loss appears to the primary limitation to litter size in older sows • Increasing evidence in other species that ‘micro-nutrients ‘play a vital role in embryonic development • Formulating vitamin and mineral content of diets based on minimum requirements may not be appropriate at key stages in the reproductive cycle • In particular, there is strong evidence to support a beneficial effect of B-Vitamin supplementation (Folates, Vitamin B12) on embryo development and survival • In sheep, humans and mice • In sows, metabolic demand for B-Vitamins (Folate and Vitamin B12) increases dramatically during the first 30 – 60 day of pregnancy,

  39. Gestation feeding to improve sow performance • Suggested that: • Maternal intake of B-Vitamins may limit litter size in modern, highly prolific sows • Growing pigs: B-vitamin requirements to optimise G:F are 270 – 470% > NRC recommendations (Stahly et al., 2007) • In pregnant sheep: B-vitamin requirements are higher in highly prolific breed (Girard et al., 1996) • In pigs: Folate increases embryo survival when ovulation rate is high(Matte et al., 2006) • Folateis essential for • Cell proliferation and normal embryonic function • Conversion of homocysteine to methionine • ElevatedHomocysteine • Results in abnormal embryo development and increased pre-natal mortality • Associated with early pregnancy failure in sows • Vitamin B12 • Enzymatic co-factor for conversion of homocyteine to methionine • Inadequate Vitamin B12 may limit actions of folate

  40. Gestation feeding to improve sow performance • Supplementing summer gestation diets with betaine (7.6 – 9.0 g / day) increased litter size in older (parity 3 +) sows (van Wettere and Hughes, 2009)

  41. Gestation feeding to improve sow performance • Incidences of early pregnancy failure were • Reduced by Folic Acid (20 mg/kg)+ Vitamin B12 (150 µg/kg) supplementation • Unaffected by betaine (3g / kg) supplementation (van Wettere, Smits and Hughes, 2011)

  42. Gestation feeding to improve sow performance • Parity 4 plus sows gave birth to fewer piglets compared to parity 2&3 sows • Total born: 11.2 ± 0.1 versus 12.0 ± 0.2 • Born Alive: 10.3 ± 0.1 versus 11.2 ± 0.2 • Betaine supplementation (3g/kg) increased litter size in parity 4 plus sows only • Total born: 11.6 ± 0.2 versus 11.1± 0.2 • Born Alive: 10.6 ± 0.2 versus 10.1 ± 0.2 • Folic Acid (20 mg/kg) and Vitamin B12 (150 µg/kg) supplementation increased litter size in parity 2&3 sows: • Total born: 12.3 ± 0.3 versus 11.7± 0.3 (van Wettere, Smits and Hughes, 2011)

  43. Gestation feeding to improve sow performance • Gestation feeding levels during summer / autumn • Sows housed • In groups of 100 • On straw • With electronic sow feeders (ESFs) • Different feeding levels from d2 – 30 post-insemination • Low (1.9 kg / sow / day) • Medium (2.3 kg / sow / day) • High (2.8 kg / sow / day) (van Wettere, Kennett and Hughes, 2011)

  44. Gestation feeding to improve sow performance • Gestation feeding levels during summer / autumn • Daily feed intake recorded and sows / gilts divided into 2 categories based on feed intake • Poor eaters - failed to eat entire ration during first 4 days post-insemination • 12 – 14% of sows / feed allocation = poor eaters • 29 – 33% of gilts / feed allocation = poor eaters • Good eaters - consumed entire ration during first 4 days post-insemination (van Wettere, Kennett and Hughes, 2011)

  45. Lactation feeding to improve sow performance • Lactation is metabolically very demanding for the sow • Metabolic requirements for milk production often exceed voluntary feed intake, resulting in • Mobilisation of body reserves • Decreased, or cessation of, reproductive function post-weaning • In older parity sows, expression of oestrus may not be affected, but embryo survival is (poor litter size of older parity sows) • Achieving a sufficient increase in lactation feed intake to improve reproduction may not be possible • Therefore, one option is to include ‘micro-nutrients’ with the potential to improve reproductive performance

  46. Lactation feeding to improve sow performance • Betaine supplementation (2 g / kg) during lactation • Increases piglet weaning weights (~ 580 g / piglet) • Reduced WOI and increase subsequent litter size • Increased betaine content of sow’s milk (289 vs 198 g / kg; P < 0.05) (Ramis et al., 2010)

  47. Lactation feeding to improve sow performance • Adding 3 g / kg fish oil (omega-3 PUFA) to lactation diets (MP sows) • Increased subsequent litter size by 1 piglet total born (Smits et al., 2011)

  48. Feeding strategies to improve sow performance • Summary • Supplementary folic acid and vitamin B12 • reduce incidences of early pregnancy failure • Increases litter size in early parity sows • Adding betaine to gestation diets increased litter size of older parity sows • Adding betaine or fish oil to lactation diets can increase litter size

  49. TOPIC THREE: alternative management strategies for breeding sows and litters

  50. Alternative / Future management strategies • Reality, consumer and retailer focus on production animal welfare is increasing rapidly • Coles is refusing to sell pork produced from sows housed in gestation stalls • APL approved a voluntary ban on dry sow stalls by 2017 • Concern is, that farrowing crates and current weaning methods may be next target • Raises a number of management concerns / issues • How to reduce aggression in group housing situations? • How to modify weaning methods and lactation housing to improve public perception whilst maintaining productivity?

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