No-CL Superstimulatory Protocol: Developing a New Superovulation Treatment Initiated in the Absence of Corpus Luteum (CL) and Compared with D1 and Traditional Superovulation in Cattle

Abstract

Abstract:The objective of this study was to investigate the effectiveness of superovulation under a complete absence of the Corpus luteum (CL) and compare it with D1 protocol and traditional superovulation in cattle. Animals were divided into three groups as following; 1-D1-protocol: Animals (n= 7) were leaved to get natural ovulation (D0), then received FSH for the next 4 days of the cycle. GnRH was given 12h after the last dose of FSH. 2-No-CL superovulation protocol: Animals (n=10) were synchronized and received PGF2α at D9 or D10 then classified to two subgroups (D9-sub-group and D10-sub-group). After 36 h, all follicles (≥ 5 mm) were aspirated (D0). 3-Control: Animals (n=3) were submitted to the conventional superovulation protocol. Blood samples were collected daily for 13 days. Progesterone (P 4 ) and Estradiol (E 2 ) in plasma were measured by Enzyme immune assay (EIA).The results showed that the number of growing follicles was significantly (P< 0.05) higher in both D9 and D10 subgroups in comparison to the D1 protocol (25.8 ± 4.3 and 20 ± 1.9 vs. 10.9 ± 1.9 respectively). While the number of ovulated follicle was higher in D9 sub-group than D10 sub-group, D1 protocol and control (13.8 ± 4.4 vs. 7.6 ± 3.5, 6.8 ± 1.5 and 9.7±0.9).In conclusion, the superovulation protocol with complete absent of the CL produced high number of growing follicles, decreased variability and considered as a promising superovulation protocol.