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Control means for estrous cycle control in sheep

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Presented by Mourad Rekik, ICARDA, at the EIAR-DBARC-ICARDA-ILRI (LIVES)-FAO Training Workshop on Reproduction in Sheep and Goat, Debre Berhan, Ethiopia, 13-15 October 2014

Published in: Science

Control means for estrous cycle control in sheep

  1. 1. Control means for estrous cycle control in sheep Mourad Rekik EIAR-DBARC-ICARDA-ILRI (LIVES)-FAO Training on Reproduction in Sheep and Goat, Debre Berhan, Ethiopia, 13-15 October 2014
  2. 2. Control Means Introduction Synchronisation of oestrus and induction of ovulation Natural method Hormonal treatments Improvement of litter size
  3. 3. Physiological causes of reduced reproductive efficiency in sheep and goats • Long seasonal anoestrus : 2-6 mois • Pregnancy: 5 months • Postpartum anoestrus: 1-3 months • An inherent low prolificacy In most production systems, sheep and goats give birth once a year, produce single litters and the production is seasonal.
  4. 4. Improvement of fertility Control over the events of the oestrous cycle Breeding season Anoestrous season Synchronisation Induction Synchronisation
  5. 5. Mating Synchronisation Lambing Compactness The best mating time (Maximise fertility) Nutritional requirements and provision from cheap natural feed According to the market requirements and the consumer demand CHOOSE ADJUST PRODUCE
  6. 6. Natural method: The «male effect» Olfactory senses How it works hypothalamus Pituitary gland ovary Male stimuli (Pheromones) Central nervous system Reproductive tract
  7. 7. Types of Ovulatory and Estrous Cycles of Ewes in Response to Ram Introduction.
  8. 8. Variation Factors • Age : Maiden/Adults (75 % vs 95 %) • Breed : Temperate/Meridional • Season – Stage of seasonal anoestrous – Association seasonal and postpartum anoestrous • Body condition : Females in depressed BC do not respond • Male sexual aggressiveness: sex ratio and maturity
  9. 9. 8 7 6 5 4 3 2 1 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 (%) Jours Percent of mated ewes in 5 flocks (6 years, 5894 observations; anoestrous season) 67% of females Rekik, 2011
  10. 10. 16 14 12 10 8 6 4 2 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Pourcentage des femelles en oestrus (%) Jour Distribution des 1ers oestrus dans le troupeau expérimental 11 Synchronisation using the ram effect and a single injection of 20 mg of progesterone in oil
  11. 11. MALE EFFECT IN GOATS APPEARANCE OF OESTRUS 50 40 30 20 10 0 EM 1 2 3 4 5 6 7 8 9 10 11 12
  12. 12. MALE EFFECT
  13. 13. 50 40 30 20 10 0 EM EMP MALE EFFECT 1 2 3 4 5 6 7 8 9 10 11 12
  14. 14. MALE EFFECT Days 0 9 50 hours A.I. TREATMENT MALE EFFECT + P4 PROGESTAGENS PROSTAGLANDINS FEMALES 1584 600 FERTILITY 64,6% 46,8%
  15. 15. Hormonal Methods: FGA+eCG in sheep 5 1 FGA plasma levels (ng/ml) Sponges left in 12 - 14 days eCG LH Oestradiol Ovulation Corpus luteum (Progesterone) Time + 48 h + 60 h Sponges in OESTRUS Controlled mating Sponges out 2 days
  16. 16. Short protocol for synchronisation of oestrus in goats Not before 150 days postpartum 250 to 600 IU 11 days (± 1) eCG Sponges 45 mg FGA In Out Natural mating or AI 43-45 hours After withdrawal of sponges PgF2 48h prior to sponges withdrawal 98 % of goats are in oestrus between 24 and 72 hours after withdrawal of sponges
  17. 17. ALTERATIONS CAUSED BY PROGESTATIVE TREATMENTS LACK OF RESPONSE LACK OF SYNCHRONIZATION ALTERATIONS IN THE OVULATION ALTERATION IN MOBILITY AND VIABILITY OF SPERM
  18. 18. ALTERATIONS CAUSED BY PROGESTATIVE TREATMENTS 3 2,5 2 1,5 1 0,5 0 -2,5 -2 -1,5 -1 -0,5 0 Día s re sp e cto ce lo Estradiol (pg/ml) Days to oestrus
  19. 19. 34 33 32 31 30 29 28 27 26 Panel A 0 1 2 3 4 5 Interval sponge withdrawal-oestrus (h) Number of treatments 80 70 60 50 40 30 20 10 0 20 40 60 80 Fertility (%) Interval sponge withdrawal-oestrus (h) No oestrus Panel B Alterations caused by eCG: Relationship between the interval withdrawal of sponges-oestrus and the number of eCG treatments (Panel A) and between the same interval and fertility of the does (Panel B) (Redrawn from Chemineau et al., 1999).
  20. 20. 180 160 140 120 100 80 60 40 20 Conception rate Prolificacy 0 200 300 400 % conception rate or prolificacy Dose of eCG (IU) The effect of increasing doses of eCG on conception rate and prolificacy at the induced oestrus of local Tunisian female goats (N. Lassoued and M. Rekik, 2010, unpublished results)
  21. 21. MELATONIN
  22. 22. Utilisation Protocol Implant insertion 7 d. 42 to 49d. (6 to 7 weeks) Isolation of rams Mating Ram Introduction 150 d +/- 5 d After ram introduction 3 implants ram 1 implant Ewe/ewe lamb Lambing
  23. 23.  Awassi breed- Syria 84 12 84 16 Mélovine (CEVA®) 92 28 84 40 100 90 80 70 60 50 40 30 20 10 0 Mélovine Control Fertility % Implant in : 26 March 9 April 23 April 7 May Mating : May End May June mid June mid July end June July
  24. 24. Maiden ewes during anoestrus Breed Treatment Females lambing (% fertility) Lambs born(% prolificacy) Noire de Thibar Mélovine: 70 49 (70%) 52 (106%) + 22% Control: 70 34 (48%) 34 (100%) Sicilo- Sarde Mélovine: 60 30 (50%) 30 (100%) + 12% Control: 60 23 (38%) 23 (100%) Rekik, 2010
  25. 25. Estrus synchronisation with Prostaglandin (PGF2α) I: intramuscular injection of 125 mg of Cloprosterol (Estrumate®) • Cycling ewes • does not interfere with subsequent cyclicity of sheep in 90% of cases : "natural“estrus 1st I 2nd I Estrus 10- 14 days 36 to 48 h after the second injection
  26. 26. Estrus synchronisation with Ovsynch Protocol G P G 7 days 48 h 16-24 h GnRH (Receptal /Fertagyl 2.5 ml) PGF2α (Estrumate 2 ml) GnRH (Receptal /Fertagyl 2.5 ml) Fixed time AI Ovulate the dominant follicle Intiate the new follicular wave Induce luteolysis Induce ovulation of new dominant follicle Synchronisation of estrus Synchronisation of ovulation
  27. 27. Improvement of prolificacy
  28. 28. Selection • Possible but difficult h2 <0,1 • Low genetic progress: low heritability of the trait • Indrect selection on prolificacy: ovulation rate, Embryo mortality • Several generations: 20 • Tunisia: W strain of th Barbarine breed: 160% vs 120% for ordinary Barbarine
  29. 29. Crossbreeding with prolific breeds Fast way to improve litter size Heterosis: 3% for prolificacy QFO D ’Man X QFO Nb. 36 31 LW (Kg) 45,7+5,7 40,5+5,9 Fertility(%) 77,7 90,3 Prolificacy(%) 1,14+0,35 + 20% 1,43+0,50
  30. 30. Nutritional method: Flushing Short feeding supplementation Distribution of concentrates (60% above maintenance) Mating 2 weeks prior 2 weeks after Ovulation rate Embryo losses Between 20 and 40 % in terms of lambs born
  31. 31. Hormonal methods : eCG • Synchronisation of ovulations and oestrus • Variable effect according to a. doses (High doses litter size) b. breed Response of Noire de Thibar ewes in terms of ovulation rate to increasing doses of eCG eCG dose (IU) Ovulation rate 0 1.41 400 1.47 600 1.76 800 1.63 1000 1.76
  32. 32. Hormonal method : Immunisation against androstenedione (during breeding season) Active 1st immunisation 3 weeks 2nd immunisation AD-HSA AD-HSA 3 weeks Mating Passive Injection immune serum Mating Antibodies
  33. 33. Immunisation against androstenedione Expected results • Increase of ovulation rate from 0,37 to 1,17 (active immunisation, Land et al., 1982) • Less variability in response • Most increase is represented by twins • Effective on non prolific breeds • No adverse effects on immunised dams • Reduced labor
  34. 34. Conclusions • Several methods There is no best method • Options are dependent upon: • Physiological stage • Potential of the production system • Objectives, know how and financial asset of farmers • Products availability and effectiveness
  35. 35. Thank you

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