Reproduction in Sheep--AI techniques By Jennifer A. Hatcher DVM Rock-N-Country Veterinary Services College Grove, TN 37046 615-368-7873

About Us Three vet practice set in Williamson County Truly a mixed animal practice with clients in all of TN Have been using ultrasound for reproduction in small ruminants since 2005--now expanding to small ruminant ex lap AI in summer 2018

About Myself Started showing sheep at age 9 Began raising sheep over 20 years ago Currently raise Hampshire/Suffolk crosses Raised in a veterinary clinic and graduated from UTCVM 2005 Love working with small ruminants

Estrous cycle Anestrus--period of time in which ewe is not cycling (during the summer Estrous--the period of time in which a ewe is “cycling” and will display ESTRUS or heat consistently Estrus--the regular recurrent state of sexual excitability or “ heat” in which is accepting of a male for breeding

Basic Sheep Repro Sheep are polyestrous--have more than one cycle during a specific time of year Typical estrous cycle is 16-17 days Short day breeders--photo period is important Geographic location can effect the season Fine wool breeds/Some white faced sheep i.e Dorsets have a short anestrus than other breeds

Estrus Cycle The true HEAT or estrus time in a sheep will range from 24-30 hours ( time in which will allow to be bred) the average time is 30 hours Optimal time for breeding during this time period is 12-18 hours after onset of heat signs **Teaser ram, presence of ram or hormone induced wether for heat detection

Ewe Lambs Ewe lambs can be bred however recommended at 7-8 months of age and at least 70% of mature body weight ****Behavioral maturity Flushing Ewes--what is current BCS

Rams Do not forget that the ram is 50% of your herd Confirmation is important Genetics is important Disposition is important BSE prior to season of breeding, take care of your RAMS!!

Estrus induction on the Acyclic Ewe CIDRs, feed MGA --need Progesterone for minimum of 5 days (typical is 7 days) and CIDR most common progesterone used Need ecG when remove CIDR typical dose is 500IU There are so many different protocols, hormones (PMSG or PG 600) used--need to keep in mind that every breed is different and geographic location can effect TRIAL and ERROR

Cycling Ewes--Fall Progesterone implant needs to outlast the CL--Place CIDR for 11-14 days ***Using ecG or PMSG is not necessary during the cycling period ***This is optimum for getting ewes to cycle together for a more uniform lamb crop--not for timed AI ***Can use PGF2@ when remove CIDR but not needed 2) Estrus is typically seen 1-3 days after CIDR removal

Cycling Ewes--Fall The NON CIDR approach Give cycling ewes injection of PGF2@ day 1 Second dose of PGF2@ to be given at day 8-11 days ***Estrus is typically seen 1-3 days after second dose of PGF2@ ***Fertility may be lower than your than the progesterone (CIDR) programs

Estrous Synchronization with Vaginal Sponges, CIDR or Synchromate-B (SMB) Traditional Method Day 1 Insert CIDR for 12 days. (Use clean technique!) Day 3 Inject Prostaglandin (Lutalyse 3cc or Estrumate .6cc). Day 12 CIDR and inject PMSG (400 i.u.) or PG-600 (400 i.u. PMSG + 200 i.u. HCG). Day 13 Introduce teaser ram to better synchronize ewes and to mark ewes as they come into heat. Day 14 Inseminate ewes 51-55 hours after CIDR removal, (51 hrs for CIDR, 52 hrs for SMB or sponge) or 10-18 hrs after ewe is marked by teaser ram. Day 24 Reintroduce teaser ram and then inseminate 10-18 hrs after ewe is marked or introduce fertile ram, (1 ram to 5 ewes).

Sheep AI

AI steps Food and water should be withheal from ewe for ~12 hrs Ewes are sedated with xylazine however some are tolerable with just acepromazine, once sedate place them in cradle Cradle is raised to bring the posterior end of the to tolt at 45 degree angle Local anesthetic is injected SQ at two sites (4cm on each side of ventral midline and 6cm cranial to udder)

AI Steps 5)Place trocars and cannulae in the abdomen at each site prepped 6)Filled abdomen with Carbon Dioxide to distend abdomen 7)Place the laparoscope into the cannulae and ID the uterus 8)Place pipette with semen into the second site 9)Inject into the uterus in each horn

Pros and Cons of Lap AI Pros: Cons: The genetic potential in less time that with natural breedings Less chance of sexually transmitted diseases Can be more selective with your genetics NO RAM!!! Cons: Expense of procedure, medications Labor intensive Anesthetic risk Infection

http://ansci.wisc.edu/extension-new%20copy/sheep/publications_and_proceedings/pdf/reproduction/hormonal%20control%20of%20ewe%20reproduction.pdf

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Jennifer A. Hatcher DVM College Grove TN 37046 Rockncountryvet.com Jennifer A. Hatcher DVM College Grove TN 37046