Last update: August 12, 2011 02:50:13 PM E-mail Print




P.R. King.,  P.J. Griessel. & A.P. Pretorius

Grootfontein Agricultural Development Institute, Middelburg, Cape 5900

D.M. Barry

Dept of Human & Animal Physiology, University of Stellenbosch, Stellenbosch 7600


It is unknown whether the stage of oestrous cycle at which an ewe is treated with progestagen effects the ovulation response following superovulation treatment. A preliminary study was undertaken to determine whether progesterone treatment at the beginning or towards the end of the cycle influences ovulation and embryo recovery rate. Fifty one Boer Goat ewes were divided into two groups (A and B) on a stratified mass basis. Initially both

groups were treated with sponges containing O.332g progesterone (EAZI- BREED CIDR's) during spring. Twelve days following sponge removal all ewes were intramuscularly injected with 5mg PGF2a (Lutelyze). Group A and B were then respectively sponged with CIDR's on day three and day 15 following PGF2a treatment. Superovulation treatment was begun ten days after the second progesterone treatment and the CIDR's were removed four days later. All ewes were handmated at oestrus and were flushed five days later. The mean body weight following flushing of Group A and B was 51 kg and 53.6 kg respectively (p>0.05). Eight ewes in Group A did not respond to the superovulation treatment compared to one in Group B. The total number of corpora lutea recorded and embryos/ova recovered was respectively 63.7% and 33.1% higher in Group B than Group A Furthermore Group B yielded 48% more freezable embryos than Group A. From these preliminary results it would appear that, in Boer Goats, progesterone status prior to synchronization with progestagen does influence superovulation results.



Proceedings 34th SASAS congress