Effects of different estrus synchronization and superovulation treatments on ovarian response and embryo collection in the South African Boer goat

Mpoyo, Robert Kabyla (2004-03)

Thesis (MSc)--Stellenbosch University, 2004.

Thesis

ENGLISH ABSTRACT: Different synchronization and superovulation treatments were evaluated in the South African Boer goat (n = 367). Two progestagen implants, Synchro-Mate-B (SMB)/Crestar™ and Controlled Internal Drug Releases (CIDR), containing 3mg norgestomet and 0.33gm of natural progesterone, respectively, were used in the synchronization treatments. A luteolytic agent, Estrumate (Cloprostenol) 125)lg, was administered 12h before progestagen withdrawal. Synchronization treatment groups were: 1) 5MB x 1 (n = 123), one dose of 5MB for 13 to 17 days; 2) 5MB x 2 (n = 32), two doses of 5MB implanted for 10then 17 days; 3) CIDR x 1 (n = 187), one dose of CIDR; 4) CIDR x 2 (n = 25), two doses of CIDR, inserted for 9 to 17 days. On day 1 of the treatment, 0.5mg of estradiol cypionate (ECP) was administered to a group of randomly chosen goats (n = 112). Superovulation treatments consisted of Ovagen ™ or Embryo-STM. An additional single dose (300 UI) of Pregnant Mare Serum Gonadotropin (PMSG) was administered to a group of randomly chosen does. Superovulation treatment groups were: 1) OV alone (n = 147), Ovagen 9 mg every 12h, 8 times starting 72h prior to progestagen removal; 2) OV + PMSG (n = 164), same treatment as 1 plus 300 ru ofPMSG once 48h prior to progestagen removal; 3) E-S alone (n=16), Embryo-S 25 units twice a day, 8 times starting 72h before progestagen removal; 4) E-S + PMSG (n=40), same treatment as 3 plus 300 ru of PMSG once 48h prior to progestagen removal. Most does were naturally bred to bucks. Embryos were collected using the surgicallaparascopic procedure on day 6 and corpora lutea counted. Data were not normally distributed and therefore analyzed using a nonparametrie test (Wilcoxon, 1945 and Kruskal- Wallis, 1952) with outcome variable using the Mixed Procedure of SAS and the Tukey test. Differences were considered significant at p<0.05. Slightly more CL were on the left (52%) than on the right (48%) ovary. Superovulation treatment was significantly associated (p<O.OOl) while synchronization treatment was only marginally associated (p=0.06) with ovulation rate. Ovagen alone and Ovagen + PMSG were significantly more effective (p<0.05) than Embryo-S alone or Embryo-S + PMSG in influencing ovulation. Only synchronization treatment with 2 doses of CIDR was significantly more (p=0.04) effective in producing a high ovulation rate. Superovulation treatment was significantly (p=0.02) associated with the number of transferable embryos while synchronization treatment was not. Ovagen + PMSG was significantly (p=0.02) effective in producing more transferable embryos than Embryo-S + PMSG. Both superovulation and synchronization treatments were significantly (p<0.05) associated with producing unfertilized oocytes. Effectiveness of addition of ECP was shown in its association (p=0.05) with better quality embryos in univaraete analysis, though it did not have significant effect in the multivariate model. Though there was apparent advantage of CIDR over 5MB, no significant difference in ovulation rate or embryo quality was associated with synchronization treatments. Effectiveness of Ovagen over Embryo-S was demonstrated and addition ofPMSG improved embryo quality.

AFRIKAANSE OPSOMMING: Verskillende sinkronisasie en multi-ovulasie behandelings is ge-evalueer in die Suid-Afrikaans Boerbok (n= 367). Twee progestagene, Synchro-Mate-B (SMB)/Crestar™ en Controlled Internal Drug Releases (CIDR), bevattende 3mg norgestomet en 0.33gm natuurlike progesteroon, respektiewelik, is gebruik tydens die sinkronisasiebehandelings. 'n Luteolitiese middel, Estrumate (Cloprostenol) 125J.lg, is toegedien 12 h voor progestageen verwydering. Sinkronisasie behandelings groepe was: 1) 5MB x 1 (n = 123), een dosis 5MB vir 13 tot 17 dae; 2) 5MB x 2 (n = 32), twee dosisse 5MB implante vir 10 tot 17 dae; 3) CIDR x 1 (n = 187), een CIDR vir die hele periode; 4) CIDR x 2 (n = 25), twee CIDRs, vir 9 tot 17 dae. Op dag 1 van die behandeling is 0.5mg estradiol cypionate (ECP) aan 'n willekeurige groep bokooie toegedien (n = 112). Multi-ovulasie behandelings het bestaan uit Ovagen™ of Embryo-S™. 'n Bykomstige dosis (300 UI) Dragtige Merrie Serum Gonadotrofien (PMSG) is toegedien aan 'n willekeurige groep ooie. Multi-ovulasie behandelingsgroepe was: 1) OV alleen (n = 147), Ovagen 9 mg elke 12h, 8 keer beginende 72 h voor progestageen verwydering; 2) OV + PMSG (n = 164), selfde behandeling as in (1) plus 300 IV PMSG eenmalig 48h voor progestageen verwydering; 3) E-S alleen (n=16), Embryo-S 25 eenhede tweemaal per dag, ag inspuitings beginende 72h voor progestageen verwydering; 4) E-S + PMSG (n=40), selfde behandeling as in (3) plus 300 IV PMSG eenmalig 48h voor progestageen verwydering. Die meerderheid ooie is natuurlik deur ramme gedek. Embrio's is gekollekteer deur gebruik te maak van die chirurgieslaparoskopiese metode op dag 6 en die aantal corpora lutea getel en aangeteken. Aangesien die data nie 'n eweredige verspreiding gehad het nie, is dit geanaliseer deur gebruik te maak van 'n nie-parametriese toets (Wilcoxon, 1945 en Kruskal-Wallis, 1952) met variërende uitkomste deur die Gemengde Prosedure Toets van SAS en die Tukey toets. Verskille is as beduidend aanvaar met 'n P-waarde van <0.05. Onbeduidend meer CLs is op die linker (52%) as op die regter (48%) ovarium opgemerk. Multi-ovuasie behandelings was beduidend geassosieer (p<0.001) met ovulasietempo, terwyl sinkronisasie behandelings net marginaal geassosieer was (p=0.06) met ovulasietempo. Ovagen alleen en Ovagen + PMSG was beduidend meer effektief (p<0.05) as Embryo-S alleen of Embryo-S + PMSG om ovulasie te beïnvloed. Slegs die sinkronisasie behandeling met 2 dosisse CIDR was beduidend meer (p=0.04) effektief om 'n hoër ovulasietempo te veroorsaak. Multi-ovulasie behandeling was beduidend geassosieer met die aantal oordraagbare embrio's, terwyl sinkronisasie nie dieselfde tendens gewys het nie. Ovagen + PMSG het beduidend meer (p=0.02) oordraagbare embrio's opgelewer as Embryo-S + PMSG. Beide multi-ovulasie en sinkronisasie behandelings was beduidend geassosieer (p<0.05) met onbevrugte oosiete. Die rol van die byvoeging van ECP is getoon in die assosiasie daarvan (p=0.05) met beter kwaliteit embrio's in 'n eenvariante analiese, alhoewel dit nie 'n beduidende effek op die multi-variante model gehad het nie. Alhoewel dit blyk dat CIDR 'n beter reaksie as 5MB gee, kon geen beduidende verskil in die ovulasietempo of embriokwaliteit opgewys word nie. Die groter effektiwiteit van Ovagen oor Embryo-S is gedemonstreer, terwyl die byvoeging van PMSG embriokwaliteit verbeter het.

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