ADSC 2010 Lecture 28 Outline of Last Lecture I Reproduction Post Partum Estrus A Cattle B Ewe C Sow D Mare II Management of the Reproductive Tract III Estrus in the Female IV Estrus Detection Outline of Current Lecture I Estrus Synchronization A Benefits B Disadvantages C Methods a Cows b Ewes c Sows d Mares II Artificial Insemination A Benefits Current Lecture I Estrus Synchronization A Benefits 1 Decreased time and labor involved in Heat detection necessary for shorter time period Breeding concentrate into a 2 5 day period Parturition 2 Increased conception rate Ovulation time would be known and Time AI could be used 3 Increase use of AI Allows greater use of superior genetics 4 More efficient use of facilities Breeding parturition weaning and marketing could be better planned 5 Important in ET Embryo Transfer B Disadvantages 1 Success rate can be low 2 Requires more intensive management 3 Amy be cost prohibitive GnRH cystorelin factrel and Fertagyl 6 50 dose PGF2 lutalyse estrumate and prostamate 2 50 dose Progesterone CIDR 8 dose Progesterone melengestrol acetate MGA C Methods a Cows 1 Progesterone or progesterone type compounds Administration oral injectable and vaginal insert Inhibits follicular development and ovulation allows CL to regress at cow s normal time and prevents new CL from forming After removal follicle develops and ovulation occurs 2 4 days later Can be used in conjunction with prostaglandin CIDR intravaginal progesterone releasing device o Day O insert CIDR o Day 6 IM injection of prostaglandin lutalyse etc o Day 7 Remove Insert o Day 8 12 Estrus detection and AI 12 hr post estrus o Introduce clean up bull 2 Prostaglandin PGF2 Administration IM injection Causes CL to regress any time after day five of cycle Approximately 1 3 of cow herd will not respond to single injection Can be used in conjunction with progesterone Lutalyse estrumate prostamate o Day 0 Inject IM o Day 0 7 Heat detect and AI 12hr post estrus o Day 14 Inject IM to non responders o Day 14 21 Heat detect and AI 12hr post estrus or Timed AI 76 80 hr post injection 3 Gonadotropin Releasing Hormone GnRH Administration injection Causes release of LH followed by ovulation and CL development Also initiates development of a new dominant follicle 2 3 days later Used in combination with PGF2 Cystorelin factrel or Fertagyl and lutalyse estrumate or prostamate o Day 0 Inject GnRH IM o Day 7 Inject PGF2 IM o Day 6 12 Heat detect and AI 12hr post estrus OR o Day 6 10 Heat detect and AI 12hr post estrus o Day 10 Inject GnRH IM and Timed AI 72 hr 4 Combination of Progesterone GnRH PGF2 Administration Progesterone Oral GnRH PGF2 Injections MGA cystorelin etc and lutalyse etc o Day 1 14 Feed MGA 5 mg head day o Day 15 Remove MGA from feed o Day 26 Inject GnRH IM o Day 33 Inject PGF2 IM o Day 33 40 heat detect AI o Day 41 Introduce clean up bull b Ewes Not used to a great degree If used mainly vaginal progesterone sponges and PGF2 IM injection c Sows PGF2 not effective until after day 14 of cattle not very useful Some progesterone compounds used o Oral for 18 days remove and estrus will occur 4 6 days later d Mares II No real programs not enough research done Artificial Insemination A Benefits 1 Allows use of genetically superior sires 2 Helps control diseases particularly venereal disease 3 Eliminates excess males on the farm Safety issued with handling Reduces costs feed facilities etc 4 Allows for accurate record keeping AI is an essential component of an estrus synchronization program
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