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Estrous synchronization & ovulation induction. ชัยวัฒน์ จรัสแสง ภาควิชาศัลยศาสตร์และวิทยาการสืบพันธุ์. References. Hafez, E.S.E. and Hafez, B. Reproduction in farm animals seven edition Gasser, C.L. and Day, M. L. Current and Future Estrous Synchronization Systems .
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Estrous synchronization& ovulation induction ชัยวัฒน์ จรัสแสง ภาควิชาศัลยศาสตร์และวิทยาการสืบพันธุ์
References • Hafez, E.S.E. and Hafez, B. Reproduction in farm animals seven edition • Gasser, C.L. and Day, M. L. Current and Future Estrous Synchronization Systems. • WAAESDHandbook of estrous synchronization
Estrous synchronization • Estrous cycle21 days (17-24 days) • Synchronize or induce • Normal estrous cycle
Synchronization in Farm animals • Days to first breeding (DFB) • voluntary waiting period (VWP) • TAI or Fixed Time AI
Synchronization • Shortening the luteal phase • Luteolysis • PGF2 • Estrogen • Extending the luteal phase • Long term of progestogen 14-21 days • Negative feedback on LH
Advantages of synchronized ovulation • Can synchronize large group to ovulate at same time • Shorten calving season • Reduce labor required for AI breeding • Reduces overall management problems with AI • Market uniform calf crop (same age) • Improves management practices (cattle grouped-closer observation, better feeding practices, etc.)
Disadvantages of synchronized ovulation • Low conception rates • Cost • Concentrated labor required during breeding and calving season • Cows all calving at once (especially bad if have many calving problems)
Compounds used in ovulation synchronization • Progestogens or progestagens 1. Progesterone • Neutralizes the corpus luteum and its natural production of progesterone to rearrange cycle • Used in cattle • CIDR, PRID
Progestogens 2. Synthetic progestogens - Norgestomet Crestar® (implant) - Medroxyacetate progesterone (MAP) Inject - Melengestrol acetate (MGA) (oral)
Prostaglandins • Prostaglandins - Ceases function of the corpus luteum - Must have functional corpus luteum - No effect on developing CL before 5 days of age - No effect on waning CL after about 16 days of age
PGF2 • Natural PGF2 • Dinoprost tromethamine (Lutalyse®) • Synthetic analogue • Cloprostenol sodium Estrumate® • Luprostinal Prosolvin® • Etiproston tromethamine Prostavet®
PGF2 • Prostaglandin analogue a. Very similar to prostaglandin compounds b. Can separate the effects of the prostaglandins (e.g. analogues produce less sweating in mares than prostaglandins)
PGF2 • Intramuscular injection requires higher dosage than intrauterine injection because of the short half-life of the substance a. Metabolizes quickly once in circulation b. Half-life about 2-3 minutes; approximately 90% deactivated in single passage through body Used in cows, ewes, sows and mares IVSM (intravulvosubmucosal) Warning::::::::>>> Causes of abortion
GnRH agonists • Hypothalamus hormone • Release of FSH, LH • Buselerin (Cystorelin®, Factrel®, Fertagyl®, OvaCyst®)
Estrogens • Estradiol conjugates • Estradiol valerate • Estradiol bazoate • Estradiol cypionate
Gonadotropins • eCG or PMSG (equine chorionic gonadotropin or pregnant mare serum gonadotropin) • FSH ( follicle stimulating hormone) • hCG(human chorionic gonadotropin)
Swine synchronization 1. Progestogen (Altrenogest) (Regumate®) • Fed 14-18 days • Normal estrus begins on 4-5 days after withdrawal • Estrus 2-4 days • Fixed-time 6-7 days after progestogen withdrawal Side effects in swine - Development of cystic follicles - Lowered fertility
Swine synchronization 2. Inject 500-1000 IU of hCG • On days 12 • Then Inject PGF2about 3 weeks later
Horses synchronization • Altrenogest (Regumate®) • Fed 15 days • Estrus 3 days after withdrawal • PGF2 • Diestrous • Single injection estrous 3-5 days • hCG and PGF2 PGF2 hCG PGF2 hCG estrus 1 7-8 15 21-22 2-4 days
Sheep and Goats Synchronization • Ewes estrus (16 days) Does estrus (21 days) • Progestogen (implant or pessary) • Implant 12-14 days sheep • Implant 18-21 days goats • Inject eCG 400-800 IU at withdrawal • TAI ewe at 48-60 hrs and does 30- 48 hrs after progestogen withdrawal
Sheep and Goats Synchronization • PGF2 • Ewes 2 injection 9 days apart double AI at 2-3 days • Does 2 injection 11-12 days apart AI or natural mating at 2-3 days
Cattle synchronization • PGF2 • Two PGF2 11-14 days apart • Estrus 72-96 hrs
Cattle synchronization • Progestogen and PGF2 • Vaginal pessary CIDR or PRID 7 days • PGF2inject at 6 days • AI at Estrus (48-72 hrs)
Cattle synchronization • MGA and PGF2
Cattle synchronization • Progestogen and estrogen • 3 mg Norgestomet implant • 5 mg estradiol valerate inject • removal implant 9 days • AI when esturs or TAI 54 hrs after removal
GnRH and PGF2 • Novel protocols • GnRH agonist + • PGF2 • CIDR • MGA
Heat-Synch ECP at 48hrs
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